Articles de revues : « Young tea cultivars »

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Jin, Jing, Yi-Qing Lv, Wei-Zhong He, Da Li, Ying Ye, Zai-Fa Shu, Jing-Na Shao et al. « Screening the Key Region of Sunlight Regulating the Flavonoid Profiles of Young Shoots in Tea Plants (Camellia sinensis L.) Based on a Field Experiment ». Molecules 26, n^o 23 (26 novembre 2021) : 7158. http://dx.doi.org/10.3390/molecules26237158.

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Both UV and blue light have been reported to regulate the biosynthesis of flavonoids in tea plants; however, the respective contributions of the corresponding regions of sunlight are unclear. Additionally, different tea cultivars may respond differently to altered light conditions. We investigated the responses of different cultivars (‘Longjing 43’, ‘Zhongming 192’, ‘Wanghai 1’, ‘Jingning 1’ and ‘Zhonghuang 2’) to the shade treatments (black and colored nets) regarding the biosynthesis of flavonoids. For all cultivars, flavonol glycosides showed higher sensitivity to light conditions compared with catechins. The levels of total flavonol glycosides in the young shoots of different tea cultivars decreased with the shade percentages of polyethylene nets increasing from 70% to 95%. Myricetin glycosides and quercetin glycosides were more sensitive to light conditions than kaempferol glycosides. The principal component analysis (PCA) result indicated that shade treatment greatly impacted the profiles of flavonoids in different tea samples based on the cultivar characteristics. UV is the crucial region of sunlight enhancing flavonol glycoside biosynthesis in tea shoots, which is also slight impacted by light quality according to the results of the weighted correlation network analysis (WGCNA). This study clarified the contributions of different wavelength regions of sunlight in a field experiment, providing a potential direction for slightly bitter and astringent tea cultivar breeding and instructive guidance for practical field production of premium teas based on light regimes.

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Shin, Young-Hwan, Rui Yang, Yun-Long Shi, Xu-Min Li, Qiu-Yue Fu, Jian-Liang Lu, Jian-Hui Ye et al. « Light-sensitive Albino Tea Plants and Their Characterization ». HortScience 53, n^o 2 (février 2018) : 144–47. http://dx.doi.org/10.21273/hortsci12633-17.

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Albino tea plants are mutants that grow albino young leaves owing to lack of chlorophylls under certain environmental conditions. There are two types of albino tea plants grown in production, i.e., light- and temperature-sensitive albino tea cultivars. The former grows albino leaves in yellow color under intensive sunlight conditions and the later grows albino leaves with white mesophyll and greenish vein as the environmental temperature is below 20 °C. Both albino teas attract great attention because of their high levels of amino acids and the “umami” taste. There have been many studies focusing on the temperature-sensitive albino tea plants, whereas little attention has been given to the light-sensitive albino tea cultivars. The characteristics of the albino tea cultivars and the mechanism underlying them were reviewed in the present article based on the published literatures, including chemical compositions, morphological characteristics, and molecular genetic mechanism.

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Gao, Chenxi, Yue Sun, Jing Li, Zhe Zhou, Xuming Deng, Zhihui Wang, Shaoling Wu et al. « High Light Intensity Triggered Abscisic Acid Biosynthesis Mediates Anthocyanin Accumulation in Young Leaves of Tea Plant (Camellia sinensis) ». Antioxidants 12, n^o 2 (6 février 2023) : 392. http://dx.doi.org/10.3390/antiox12020392.

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There is increasing interest in the production and consumption of tea (Camellia sinensis L.) processed from purple–leaved cultivar due to their high anthocyanin content and health benefits. However, how and why seasonal changes affect anthocyanin accumulation in young tea leaves still remains obscured. In this study, anthocyanin and abscisic acid (ABA) contents in young leaves of Zifuxing 1 (ZFX1), a cultivar with new shoots turning to purple in Wuyi Mountain, a key tea production region in China, were monitored over four seasons. Young leaves produced in September were highly purplish, which was accompanied with higher anthocyanin and ABA contents. Among the environmental factors, the light intensity in particular was closely correlated with anthocyanin and ABA contents. A shade experiment also indicated that anthocyanin content significantly decreased after 168 h growth under 75% shade, but ABA treatment under the shade conditions sustained anthocyanin content. To confirm the involvement of ABA in the modulation of anthocyanin accumulation, anthocyanin, carotenoids, chlorophyll, ABA, jasmonic acid (JA), and salicylic acid (SA) in the young leaves of four cultivars, including ZFX1, Zijuan (ZJ), wherein leaves are completely purple, Rougui (RG) and Fudingdabaicha (FDDB) wherein leaves are green, were analyzed, and antioxidant activities of the leaf extracts were tested. Results showed that ABA, not other tested hormones, was significantly correlated with anthocyanin accumulation in the purple–leaved cultivars. Cultivars with higher anthocyanin contents exhibited higher antioxidant activities. Subsequently, ZFX1 plants were grown under full sun and treated with ABA and fluridone (Flu), an ABA inhibitor. ABA treatment elevated anthocyanin level but decreased chlorophyll contents. The reverse was true to those treated with Flu. To pursue a better understanding of ABA involvement in anthocyanin accumulation, RNA–Seq was used to analyze transcript differences among ABA– or Flu–treated and untreated ZFX1 plants. Results indicated that the differentially expressed genes in ABA or Flu treatment were mainly ABA signal sensing and metabolism–related genes, anthocyanin accumulation-related genes, light–responsive genes, and key regulatory MYB transcription factors. Taking all the results into account, a model for anthocyanin accumulation in ZFX1 cultivar was proposed: high light intensity caused reactive oxygen stress, which triggered the biosynthesis of ABA; ABA interactions with transcription factors, such as MYB-enhanced anthocyanin biosynthesis limited chlorophyll and carotenoid accumulation; and transport of anthocyanin to vacuoles resulting in the young leaves of ZFX1 with purplish coloration. Further research is warranted to test this model.

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Cai, Wen-He, Xin-Qiang Zheng et Yue-Rong Liang. « High-Light-Induced Degradation of Photosystem II Subunits’ Involvement in the Albino Phenotype in Tea Plants ». International Journal of Molecular Sciences 23, n^o 15 (31 juillet 2022) : 8522. http://dx.doi.org/10.3390/ijms23158522.

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The light-sensitive (LS) albino tea plant grows albinic shoots lacking chlorophylls (Chls) under high-light (HL) conditions, and the albinic shoots re-green under low light (LL) conditions. The albinic shoots contain a high level of amino acids and are preferential materials for processing quality green tea. The young plants of the albino tea cultivars are difficult to be cultivated owing to lacking Chls. The mechanisms of the tea leaf bleaching and re-greening are unknown. We detected the activity and composition of photosystem II (PSII) subunits in LS albino tea cultivar “Huangjinya” (HJY), with a normal green-leaf cultivar “Jinxuan” (JX) as control so as to find the relationship of PSII impairment to the albino phenotype in tea. The PSII of HJY is more vulnerable to HL-stress than JX. HL-induced degradation of PSII subunits CP43, CP47, PsbP, PsbR. and light-harvest chlorophyll–protein complexes led to the exposure and degradation of D1 and D2, in which partial fragments of the degraded subunits were crosslinked to form larger aggregates. Two copies of subunits PsbO, psbN, and Lhcb1 were expressed in response to HL stress. The cDNA sequencing of CP43 shows that there is no difference in sequences of PsbC cDNA and putative amino acids of CP43 between HJY and JX. The de novo synthesis and/or repair of PSII subunits is considered to be involved in the impairment of PSII complexes, and the latter played a predominant role in the albino phenotype in the LS albino tea plant.

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Feng, Lin, Ming-Jun Gao, Ru-Yan Hou, Xiao-Yi Hu, Liang Zhang, Xiao-Chun Wan et Shu Wei. « Determination of quality constituents in the young leaves of albino tea cultivars ». Food Chemistry 155 (juillet 2014) : 98–104. http://dx.doi.org/10.1016/j.foodchem.2014.01.044.

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KC, Santosh, Lizhi Long, Qunfeng Zhang, Kang Ni, Lifeng Ma et Jianyun Ruan. « Effect of Interactions between Phosphorus and Light Intensity on Metabolite Compositions in Tea Cultivar Longjing43 ». International Journal of Molecular Sciences 23, n^o 23 (2 décembre 2022) : 15194. http://dx.doi.org/10.3390/ijms232315194.

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Light intensity influences energy production by increasing photosynthetic carbon, while phosphorus plays an important role in forming the complex nucleic acid structure for the regulation of protein synthesis. These two factors contribute to gene expression, metabolism, and plant growth regulation. In particular, shading is an effective agronomic practice and is widely used to improve the quality of green tea. Genotypic differences between tea cultivars have been observed as a metabolic response to phosphorus deficiency. However, little is known about how the phosphorus supply mediates the effect of shading on metabolites and how plant cultivar gene expression affects green tea quality. We elucidated the responses of the green tea cultivar Longjing43 under three light intensity levels and two levels of phosphorus supply based on a metabolomic analysis by GC×GC-TOF/MS (Two-dimensional Gas Chromatography coupled to Time-of-Flight Mass Spectrometry) and UPLC-Q-TOF/MS (Ultra-Performance Liquid Chromatography-Quadrupole-Time of Flight Mass Spectrometry), a targeted analysis by HPLC (High Performance Liquid Chromatography), and a gene expression analysis by qRT-PCR. In young shoots, the phosphorus concentration increased in line with the phosphate supply, and elevated light intensities were positively correlated with catechins, especially with epigallocatechin of Longjing43. Moreover, when the phosphorus concentration was sufficient, total amino acids in young shoots were enhanced by moderate shading which did not occur under phosphorus deprivation. By metabolomic analysis, phenylalanine, tyrosine, and tryptophan biosynthesis (PTT) were enriched due to light and phosphorus effects. Under shaded conditions, SPX2 (Pi transport, stress, sensing, and signaling), SWEET3 (bidirectional sugar transporter), AAP (amino acid permeases), and GSTb (glutathione S-transferase b) shared the same analogous correlations with primary and secondary metabolite pathways. Taken together, phosphorus status is a crucial factor when shading is applied to increase green tea quality.

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Zubova, Mariya Yur'yevna, Tat'yana Nikolayevna Nikolaeva, Tat'yana Leonidovna Nechaeva, Lyudmila Stepanovna Malyukova et Natal'ya Viktorovna Zagoskina. « ABOUT THE CONTENT OF PIGMENTS, PHENOLIC COMPOUNDS AND ANTIRADICAL ACTIVITY OF YOUNG TEA SHOOTS (CAMELLIA SINENSIS L.) ». chemistry of plant raw material, n^o 4 (27 décembre 2019) : 249–57. http://dx.doi.org/10.14258/jcprm.2020016065.

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The data on the morphophysiological characteristics of young three-leaf shoots (flashes, the first collection wave) of Camellia sinensis L. cultivars Kolhida and Kimyn, cultivated in the conditions of Russia subtropics (Krasnodar region, Sochi), the accumulation of photosynthetic pigments (chlorophylls a and b), phenolic compounds, including flavanes, and antiradical activity of extracts obtained from them are presented. It has been shown that the Kolhida cultivar is characterized by the formation of larger leaves compared to those of the Kimyn cultivar, as well as a high accumulation of photosynthetic pigments in them. At the same time, in the leaves of both tea representatives, the total content of chlorophylls a and b was higher compared with the stems. A similar tendency is characteristic for the accumulation of the phenolic compounds sum and flavanes, whereas the number of proanthocyanidins (soluble and insoluble) in the stems exceeded that in the leaves by 2–3 times. Both cultures had the same ability to form all forms of phenolic compounds, which is consistent with the data on the activity of L- phenylalanine ammonia-lyase – the key enzyme of their metabolism. It was established that the antiradical activity of extracts obtained from tea leaves was, on average, 30–40% higher than that of the stems and correlated with the content of phenolic compounds in them.

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Dong, Fang, Lanting Zeng, Zhenming Yu, Jianlong Li, Jinchi Tang, Xinguo Su et Ziyin Yang. « Differential Accumulation of Aroma Compounds in Normal Green and Albino-Induced Yellow Tea (Camellia sinensis) Leaves ». Molecules 23, n^o 10 (18 octobre 2018) : 2677. http://dx.doi.org/10.3390/molecules23102677.

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Tea (Camellia sinensis) cultivars with green leaves are the most widely used for making tea. Recently, tea mutants with white or yellow young shoots have attracted increasing interest as raw materials for making “high-quality” tea products. Albino teas are generallycharacterized as having metabolites of relatively high amino acid content and lower catechin content. However, little is known about aroma compounds in albino tea leaves. Herein, we compared original normal leaves (green) and light-sensitive albino leaves (yellow) of cv. Yinghong No. 9. GC-MS was employed to analyze endogenous tea aroma compounds and related precursors. Quantitative real time PCR was used to measure expression levels of genes involved in biosyntheses of tea aromas.The total contents of most endogenous free tea aromas, including aroma fatty acid derivatives, aroma terpenes, and aroma phenylpropanoids/benzenoids, and their glycosidically bound aroma compounds, were lower in yellow leaves than in green leaves. The content of the key precursor geranyl diphosphate (GDP) and expression levels of key synthetic genes involved in the formation of linalool, a major aroma compound in cv. Yinghong No. 9, were investigated. Linalool content was lower in albino-induced yellow leaves, which was due to the lower GDP content compared with normal green leaves.

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KC, Santosh, Meiya Liu, Qunfeng Zhang, Kai Fan, Yuanzhi Shi et Jianyun Ruan. « Metabolic Changes of Amino Acids and Flavonoids in Tea Plants in Response to Inorganic Phosphate Limitation ». International Journal of Molecular Sciences 19, n^o 11 (21 novembre 2018) : 3683. http://dx.doi.org/10.3390/ijms19113683.

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The qualities of tea (Camellia sinensis) are not clearly understood in terms of integrated leading molecular regulatory network mechanisms behind inorganic phosphate (Pi) limitation. Thus, the present work aims to elucidate transcription factor-dependent responses of quality-related metabolites and the expression of genes to phosphate (P) starvation. The tea plant organs were subjected to metabolomics analysis by GC×GC-TOF/MS and UPLC-Q-TOF/MS along with transcription factors and 13 metabolic genes by qRT-PCR. We found P starvation upregulated SPX2 and the change response of Pi is highly dependent on young shoots. This led to increased change in abundance of carbohydrates (fructose and glucose), amino acids in leaves (threonine and methionine), and root (phenylalanine, alanine, tryptophan, and tyrosine). Flavonoids and their glycosides accumulated in leaves and root exposed to P limitation was consistent with the upregulated expression of anthocyanidin reductase (EC 1.3.1.77), leucoanthocyanidin dioxygenase (EC 1.4.11.19) and glycosyltransferases (UGT78D1, UGT78D2 and UGT57L12). Despite the similar kinetics and high correlation response of Pi and SPX2 in young shoots, predominating theanine and other amino acids (serine, threonine, glutamate, valine, methionine, phenylalanine) and catechin (EGC, EGCG and CG) content displayed opposite changes in response to Pi limitation between Fengqing and Longjing-43 tea cultivars.

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Bai, Peixian, Kang Wei, Liyuan Wang, Fen Zhang, Li Ruan, Hailin Li, Liyun Wu et Hao Cheng. « Identification of a Novel Gene Encoding the Specialized Alanine Decarboxylase in Tea (Camellia sinensis) Plants ». Molecules 24, n^o 3 (1 février 2019) : 540. http://dx.doi.org/10.3390/molecules24030540.

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Theanine, a unique amino acid in Camellia sinensis, accounts for more than 50% of total free amino acids in tea and has a significant contribution to the quality of green tea. Previous research indicated that theanine is synthesized from glutamic acid (Glu) and ethylamine mainly in roots, and that theanine accumulation depends on the availability of ethylamine which is derived from alanine (Ala) decarboxylation catalyzed by alanine decarboxylase (AlaDC). However, the specific gene encoding AlaDC protein remains to be discovered in tea plants or in other species. To explore the gene of AlaDC in tea plants, the differences in theanine contents and gene expressions between pretreatment and posttreatment of long-time nitrogen starvation were analyzed in young roots of two tea cultivars. A novel gene annotated as serine decarboxylase (SDC) was noted for its expression levels, which showed high consistency with theanine content, and the expression was remarkably high in young roots under sufficient nitrogen condition. To verify its function, full-length complementary DNA (cDNA) of this candidate gene was cloned from young roots of tea seedlings, and the target protein was expressed and purified from Escherichia coli (E. coli). The enzymatic activity of the protein for Ala and Ser was measured in vitro using ultra-performance liquid chromatography coupled with mass spectrometry (UPLC-MS). The results illustrated that the target protein could catalyze the decarboxylation of Ala despite of its high similarity with SDC from other species. Therefore, this novel gene was identified as AlaDC and named CsAlaDC. Furthermore, the gene expression levels of CsAlaDC in different tissues of tea plants were also quantified with quantitative real-time PCR (qRT-PCR). The results suggest that transcription levels of CsAlaDC in root tissues are significantly higher than those in leaf tissues. That may explain why theanine biosynthesis preferentially occurs in the roots of tea plants. The expression of the gene was upregulated when nitrogen was present, suggesting that theanine biosynthesis is regulated by nitrogen supply and closely related to nitrogen metabolism for C. sinensis. The results of this study are significant supplements to the theanine biosynthetic pathway and provide evidence for the differential accumulation of theanine between C. sinensis and other species.

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Muoki, R. C., P. N. Kamau, S. M. Kamunya, O. Kiplagat et C. Kawira. « Evaluation of Morphological Attributes in Tea Progenies Arising from Gamma-Treated Seeds ». International Journal of Tea Science 15, n^o 01 (30 septembre 2020) : 06–15. http://dx.doi.org/10.20425/ijts1512.

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A key step in characterization of germplasm is the identification of phenotypic variation present in a given population. A study was carried out to determine the effect of different dosages of gamma rays (50 and 100Gy) on phenotypic variation using 21 standardized morphological descriptors of the UPOV Tea Test Guidelines. The trial comprised of open-pollinated seed stocks from six commercial tea cultivars namely TRFCA SFS150, TRFK 303/1199, EPK C12, GW Ejulu-L, TRFK 301/1 and TRFK 301/4 along with untreated controls. Data was collected for three seasons (dry, warm wet and cold wet) using five randomly selected plants from each treatment. Principle Component Analysis using 17 informative descriptors showed the first eight principal components accounted for 78% of the total variance, with 15 being highly informative. Cluster analysis further identified characters such as young shoot anthocyanin colouration at base of the petiole, leaf blade shape/color/length, shoot color/length, density of pubescence, plant vigour and density of branches as most discriminating descriptors resulting in four phenotypically well-defined groups. Most traits showed significant correlation, an indication that the traits could be used for indirect selection. The study provides a basis for rapid and early screening of base populations for identification of elite cultivars.

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Dutta, J., S. Gupta, D. Thakur et P. J. Handique. « First Report of Nigrospora Leaf Blight on Tea Caused by Nigrospora sphaerica in India ». Plant Disease 99, n^o 3 (mars 2015) : 417. http://dx.doi.org/10.1094/pdis-05-14-0545-pdn.

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Tea [Camellia sinensis (L.) O. Kuntze] is an economically important non-alcoholic caffeine-containing beverage crop widely cultivated for leaves in India, especially in the Darjeeling district of West Bengal. In May 2012, distinct blight symptoms were observed on leaves of popular tea cultivars AV-2, Tukdah 78, Rungli Rungliot 17/144, and Bannockburn 157 in commercial tea estates of the Darjeeling district. This disease reduces yield and quality of the leaves. The initial symptoms were frequently observed on the young leaf margins and apices. Foliar symptoms are characterized by grayish to brown, semicircular or irregular shaped lesions, often surrounded by pale yellow zones up to 9 mm in diameter. The lesions later expand and the affected leaves turn grayish to dark brown and eventually the dried tissue falls, leading to complete defoliation of the plant. The disease causes damage to leaves of all ages and is severe in young leaves. A portion of the symptomatic leaf tissues were surface sterilized in 70% ethanol for 30 s, then in 2% NaClO for 3 min, rinsed three times in sterile distilled water, and plated onto potato dextrose agar (PDA). The fungal colonies were initially white and then became grayish to brown with sporulation. Conidia were spherical to sub spherical, single-celled, black, 19 to 21 μm in diameter, and were borne on a hyaline vesicle at the tip of each conidiophore. Morphological characteristics of the isolates were concurring to those of Nigrospora sphaerica (1). Moreover, the internal transcribed spacer (ITS) region of the ribosomal RNA was amplified by using primers ITS1 and ITS4 and sequenced (GenBank Accession No. KJ767520). The sequence was compared to the GenBank database through nucleotide BLAST search and the isolate showed 100% similarity to N. sphaerica (KC519729.1). On the basis of morphological characteristics and nucleotide homology, the isolate was identified as N. sphaerica. Koch's postulates were fulfilled in the laboratory on tea leaves inoculated with N. sphaerica conidial suspension (106 conidia ml−1) collected from a 7-day-old culture on PDA. Six inoculated 8-month-old seedlings of tea cultivars AV-2 and S.3/3 were incubated in a controlled environment chamber at 25°C and 80 to 85% humidity with a 12-h photoperiod. In addition, three plants of each cultivar were sprayed with sterile distilled water to serve as controls. Twelve to 14 days after inoculation, inoculated leaves developed blight symptoms similar to those observed on naturally infected tea leaves in the field. No symptoms were observed on the control leaves. The pathogen was re-isolated from lesions and its identity was confirmed by morphological characteristics. It was reported that N. sphaerica is frequently encountered as a secondary invader or as a saprophyte on many plant species and also as a causative organism of foliar disease on several hosts worldwide (2,3). To our knowledge, this is first report of N. sphaerica as a foliar pathogen of Camellia sinensis in Darjeeling, West Bengal, India, or worldwide. References: (1) M. B. Ellis. Dematiaceous Hyphomycetes. CMI, Kew, Surrey, UK, 1971. (2) D. F. Farr and A. Y. Rossman. Fungal Databases, Syst. Mycol. Microbiol. Lab., ARS, USDA. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ July 01, 2013. (3) E. R. Wright et al. Plant Dis. 92:171, 2008.

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Aktar, Shirin, Peixian Bai, Liubin Wang, Hanshuo Xun, Rui Zhang, Liyun Wu, Mengdi He, Hao Cheng, Liyuan Wang et Kang Wei. « Identification of a BAHD Acyltransferase Gene Involved in Plant Growth and Secondary Metabolism in Tea Plants ». Plants 11, n^o 19 (22 septembre 2022) : 2483. http://dx.doi.org/10.3390/plants11192483.

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Plant acyl-CoA dominated acyltransferases (named BAHD) comprise a large appointed protein superfamily and play varied roles in plant secondary metabolism like synthesis of modified anthocyanins, flavonoids, volatile esters, etc. Tea (Camellia sinensis) is an important non-alcoholic medicinal and fragrancy plant synthesizing different secondary metabolites, including flavonoids. In the tea (C.A sinensis) cultivar Longjing 43 (LJ43), eight samples were performed into three groups for transcriptome analysis under three biological replications. Among the BAHD acyltransferase genes in tea cultivars, the expression of TEA031065 was highest in buds and young leaves following the RNA sequencing data, which was coincident with the tissue rich in catechins and other flavonoids. We then transformed this gene into wild-type Arabidopsis as an over-expression (OX) line 1 and line 2 in ½ MS media to verify its function. In the wild types (WT), the primary root length, number of secondary roots, and total root weight were significantly higher at 24%, 15%, and 53.92%, respectively, compared to the transgenic lines (OX1 and OX2). By contrast, the leaves displayed larger rosettes (21.58%), with higher total leaf weight (32.64%) in the transgenic lines than in the wild type (WT). This result is consistent with DCR mutant At5g23940 gene in Arabidopsis thaliana. Here, anthocyanin content in transgenic lines was also increased (21.65%) as compared to WT. According to the RNA sequencing data, a total of 22 growth regulatory genes and 31 structural genes with TFs (transcription factors) that are correlative with plant growth and anthocyanin accumulation were identified to be differentially expressed in the transgenic lines. It was found that some key genes involved in IAA (Auxin) and GA (Gibberellin) biosynthesis were downregulated in the transgenic lines, which might be correlated with the phenotype changes in roots. Moreover, the upregulation of plant growth regulation genes, such as UGT73C4 (zeatin), ARR15, GH3.5, ETR2, ERS2, APH4, and SAG113 might be responsible for massive leaf growth. In addition, transgenic lines shown high anthocyanin accumulation due to the upregulation of the (1) 3AT1 and (3) GSTF, particularly, GSTF12 genes in the flavonoid biosynthesis pathway. However, the TFs such as, CCoAMT, bHLH, WRKY, CYP, and other MYBs were also significantly upregulated in transgenic lines, which increased the content of anthocyanins in A. thaliana seedlings. In conclusion, a BAHD acyltransferase (TEA031065) was identified, which might play a vital role in tea growth and secondary metabolites regulation. This study increases our knowledge concerning the combined functionality of the tea BAHD acyltransferase gene (TEA031065).

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Xu, Cunbin, Jinling Li, Hualei Wang, Huijuan Liu, Zhihai Yu et Zhi Zhao. « Whole-Transcriptome Sequencing Reveals a ceRNA Regulatory Network Associated with the Process of Periodic Albinism under Low Temperature in Baiye No. 1 (Camellia sinensis) ». International Journal of Molecular Sciences 24, n^o 8 (12 avril 2023) : 7162. http://dx.doi.org/10.3390/ijms24087162.

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The young shoots of the tea plant Baiye No. 1 display an albino phenotype in the early spring under low environmental temperatures, and the leaves re-green like those of common tea cultivars during the warm season. Periodic albinism is precisely regulated by a complex gene network that leads to metabolic differences and enhances the nutritional value of tea leaves. Here, we identified messenger RNAs (mRNAs), long noncoding RNAs (lncRNAs), circular RNAs (circRNAs), and microRNAs (miRNAs) to construct competing endogenous RNA (ceRNA) regulatory networks. We performed whole-transcriptome sequencing of 12 samples from four periods (Bud, leaves not expanded; Alb, albino leaves; Med, re-greening leaves; and Gre, green leaves) and identified a total of 6325 differentially expressed mRNAs (DEmRNAs), 667 differentially expressed miRNAs (DEmiRNAs), 1702 differentially expressed lncRNAs (DElncRNAs), and 122 differentially expressed circRNAs (DEcircRNAs). Furthermore, we constructed ceRNA networks on the basis of co-differential expression analyses which comprised 112, 35, 38, and 15 DEmRNAs, DEmiRNAs, DElncRNAs, and DEcircRNAs, respectively. Based on the regulatory networks, we identified important genes and their interactions with lncRNAs, circRNAs, and miRNAs during periodic albinism, including the ceRNA regulatory network centered on miR5021x, the GAMYB-miR159-lncRNA regulatory network, and the NAC035-miR319x-circRNA regulatory network. These regulatory networks might be involved in the response to cold stress, photosynthesis, chlorophyll synthesis, amino acid synthesis, and flavonoid accumulation. Our findings provide novel insights into ceRNA regulatory mechanisms involved in Baiye No. 1 during periodic albinism and will aid future studies of the molecular mechanisms underlying albinism mutants.

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Ngoc, Hoang Thi Huyen, Tran Thi Thuy Van, Nguyen Manh Ha, Nguyen Quoc Binh et Mai Thanh Tan. « Bioclimatic assessments for tea cultivation in Western Nghe An ». VIETNAM JOURNAL OF EARTH SCIENCES 41, n^o 1 (8 janvier 2019) : 81–94. http://dx.doi.org/10.15625/0866-7187/41/1/13586.

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Bioclimatology is applied for growing tea in the West of Nghe An province, where the tea is considered as a high economic efficient plant to be priorly cultivated for reducing poverty and getting rich. Based on the bioclimatic characteristics of tea plant and regional climatic data from 1980 to 2014, the bioclimatic diagrams are built and the tea cultivability is mapped in term of annual average temperature and total precipitation, for this region with regarding its district of Con Cuong as an analytical key. The climate, including both temperature and precipitation, in Con Cuong is relatively suitable for the tea plantation. The Western Nghe An, a land of approx. 1.4 million ha, could be classified in five areas with different suitability for tea plant. The unfavorable area occupies only 1% of total region and the four favorable rests account for 99% of total, in which, the most favorable area is largest with about 746,355 ha, i.e. over 50% of whole region. The three other areas are cultivable but they are less favorable in terms of either temperature or precipitation. Growing tea in Western Nghe An, even in favorable areas, it should be taken into account of the weather disadvantages in certain moments of the year such as extreme dry, cold, hot and rainy events.ReferencesAhmed S., 2014. Tea and the taste of climate change, www.herbalgram.org, issue, 103, 44–51.Ahmed S., Stepp J.R., Orians C., Griffin T., Matyas C., 2014. Effects of extreme climate events on tea (Camellia sinensis) functional quality validate indigenous farmer knowledge and sensory preferences in tropical China. PloS one, 9(10), e109126.Bhagat R.M., Deb Baruah R., Safique S., 2010. climate and tea [camellia sinensis (l.) o. kuntze] Production with Special Reference to North Eastern India: A Review. Journal of Environmental Research And Development, 4(4), 1017–1028.Carr M., 1972. The Climatic Requirements of the Tea Plant: A Review. Experimental Agriculture, 8(01), 1–14. https://doi.org/10.1017/S0014479700023449.Carr M.K.V., Stephen W., 1992. Climate, weather and the yield of tea. In: Tea Cultivation to consumtpion. K.C. Wilson and M.N. Clifford (Eds). Chapman and Hall, 87–135.Daleen Lotter, David le Maitre, 2014. Modeling the distribution of Aspalathus linearis (Rooibos tea): implications of climate change for livelihoods dependent on both cultivation and harvesting from the wild. Ecology and Evolution, 4(8), 1209–1221.Ducan J.M.A., Saikia S.D., Gupta N., Biggs E.M., 2016. Observing climate impacts on tea yield in Assam, India. Applied Geogr., 77, 64–71.Institute of Geography, 2016. Department of Climatically Geography. The precipitation and temperature data at meteorological measuring stations in the West of Nghe An Province between 1984 and 2014. Data stored at Department of Climatically Geography, Institute of Geography, Ha Noi, 46p.Gaussen H., 1954. 8 ème Congrès international de Botanique. Section 7 et 3. Paris.Hadfield W., 1976. The effect of high temperature on some aspects of the physiology and cultivation of tea bush (Camellia sinensis) in North East India. In: Light as an Ecological factor. G.C. Evans, R. Bainbridge and O. Rackham (Eds.) Blackwel Sci. Publ., London, 477–495.Hoang Luu Thu Thuy, 2012. The comprehensive assessment of natural, socio-economic and environmental conditions for environmental protection planning in Nghe An Province. Doctoral Thesis. Institude of Geography, Hanoi, 150p.Huang Shoubo, 1989. Meteorology of tea plants in China: a review. Agri. Forest Meteorol., 47, 19–30.Huang Shoubo, 1991. A study on the ecological climates of some famous tea growing areas in high mountainous regions of China. Chinese Geographical Science, 1(2), 121–128.International Center for Tropical Agriculture, 2017. Identification of suitable tea growing areas in Malawi under climate change scenarios. Ciat report, Cali, Colombia, 39p.Kabir S.E., 2001. A study on Ecophysiology of Tea (Camellia sinensis) with special reference to the influence of climatic factors on physiology of a few selected Tea clones of Darjeering. International Journal of Tea Science, 1(4), 1–9.Kandiah S., Thevadasan T., 1980. Quantification of weather parameters to predict tea yields. Tea Q., Srilanka, 49(1), 25–33.Kaye L., 2014. Climate change threatens Sri Lanka’s tea industry. Triple Pundit: People, Planet, Profit. Available at: www.triplepundit.com/2014/06/climate-changethreatens-sri-lanka-tea-industry. Accessed July 25, 2014.Nakayama A., Harada S., 1962. Studies on the effect on the growth of tea plant. IV. The effect of temperature on the growth of young plants in summer. Bull. Tea Res. Station, Japan, 1, 28–40.Nguyen Bao Ve, 2005. The syllabus of industrial trees. Hanoi Argricultural Publishing House, 224p.Nguyen Dai Khanh, 2003. The assessment of agricultural climatic conditions for tea’s growth in major tea regions of Vietnam. Doctoral Thesis. Institute of Meteorology and Hydrology, 149p.Nguyen Khanh Van, Nguyen Thi Hien, Phan Ke Loc, Nguyen Tien Hiep, 2000. The bioclimatic diagrams of Vietnam. Vietnam National University Publishing House, Ha Noi, 126p.Nguyen Van Hong, 2017. Analyzing, assessing landscape for agriculture, forestry development and biodiversity conservation in the southwestern border districts in Nghe An province. Doctoral thesis. Vietnam National University, Hanoi, 150p.Nguyen Van Tao (ed.), 2004. Completing the asexual propagation process of LDP1 and LDP2 cultivars by cuttings in order to transfer to production. State Project of production pilot, coded KC.06.DA.09.NN. Institute of Tea Research, Phu Tho, 50p.Nkomwa E.C., Joshua M.K., Ngongondo C., Monjerezi M., Chipungu F., 2014. Assessing indigenous knowledge systems and climate change adaptation strategies in agriculture: A case study of Chagaka Village, Chikhwawa, Southern Malawi. Physics and Chemistry of the Earth, Parts A/B/C, 67–69, 164–172.Pham Hoang Ho, 2003. An Illustrated Flora of Vietnam, 2, 430–434. Youth Publishing House, 952p.Rebecca Boehm, Sean B. Cash, Bruce T. Anderson, Selena Ahmed, Timothy S. Grifﬁn, Albert Robbat Jr., John Richard Stepp, Wenyan Han, Matt Hazel and Colin M. Orians, 2016. Association between Empirically Estimated Monsoon Dynamics and Other Weather Factors and Historical Tea Yields in China: Results from a Yield Response Model. Climate, 4, 20; doi:10.3390/cli4020020. www.mdpi.com/journal/climate.Schepp K., 2014. Strategy to adapt to climate change for Michimikuru tea farmers in Kenya. Adap CC Report. 2008. Available at: www.adapcc.org/en/kenya.htm. Accessed July 25, 2014.Sen A.R., Biswas A.K., Sanyal D.K., 1966. The Influence of Climatic Factors on the Yield of Tea in the Assam Valley, J. App. Meteo., 5(6), 789–800.Statistics Office of Nghe An Province, 2016. The annual abstracts of statistics 2015. Nghe An Publishing House, Nghe An, 453p.Tanton T.W., 1982. Environmental factors affecting yield of tea (camellia sinensis). Effect of air temperature. Expl. Agri., 18, 47–52.The People’s Committee of Nghe An Province, 2013. The Decision No. 448/QĐ-UBND dated 31/01/2013 to approve the hi-tech agriculture planning on the production of tea in Nghe An Province.The People’s Committee of Nghe An Province, 2013. The Decision No. 6290/QĐ-UBND dated 24/12/2013 to approve the adjustments and supplements for the development of Nghe An tea Industrial zone planning in 2013–2020.Walter H, Lieth, 1967. Klimadiagram - Weltatlas. Veb Gustav Fischer Verlag Jena.Wijeratne M.A., 1996. Vulnerability of Sri Lanka tea production to global climate change. Water, Air and Soil Pollution, 92(1-2), 87–94.Wijeratne M.A., Anandacoomaraswamy A., Amarathunga M., Ratnasiri J., 2007. Assessment of impact of climate change on productivity of tea (Camellia sinensis L.) plantations in Sri Lanka, 119–126.http://nghean.gov.vn, 05/06/2015. Many crops are withered in Con Cuong.http://baonghean.vn, 25/03/2013. Drought threaten rice and tea in Con Cuong. http://baonghean.vn/con-cuong-han-han-de-doa-lua-che-44581.html.

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Wu, Y. F., A. S. Cheng, C. H. Lin et C. Y. Chen. « First Report of Bacterial Wilt Caused by Ralstonia solanacearum on Roselle in Taiwan ». Plant Disease 97, n^o 10 (octobre 2013) : 1375. http://dx.doi.org/10.1094/pdis-02-13-0186-pdn.

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Roselle (Hibiscus sabdariffa L.) is a herbaceous plant belonging to the Malvaceae family. Its calyxes are rich in vitamin C and anthocyanins and are used to make roselle drink and hibiscus tea. Roselles are grown in counties of Taitung, Pingtung, and Chiayi in Taiwan. In addition to a few local cultivars, the major cultivar currently grown in Taiwan is Roselle cv. Victor. In April of 2012, a wilt disease appeared on seedlings of a cultivar, Chiada 1, at the Chungpu Township of Chiayi County. Mature plants were free from this disease. Leaves appeared weak and drooping when they were still green, followed by collapse of the whole plant a few days later. Browning of vascular and pith tissues was evident, especially at the base of the stem. A whitish mass of bacteria oozed from the cut end of diseased stems, suggesting that bacteria might be the cause of this disease. A total of 15 bacterial strains were collected. Colonies on tetrazolium chloride medium (3) were round to oval and fluidal, each with a pink or red center after incubation at 30°C for 48 h. When tobacco leaves were infiltrated with these strains, a hypersensitive reaction (HR) typical of phytopathogenic bacteria was induced. All strains produced the expected amplicon (282 bp) after PCR with the Ralstonia solanacearum-specific primer pair, AU759f and AU760r (4). Three hexose alcohols (mannitol, sorbitol, and dulcitol), rather than three disaccharides (lactose, maltose, and cellobiose), were utilized, which suggests R. solanacearum biovar 4 (2). R. solanacearum phylotype I was determined by phylotype-specific multiplex PCR (1). Pathogenicity of the strains was tested on roselle, tomato, pepper, and eggplant. Young plants of the various species were inoculated at the four- to six-leaf stage by soil drenching with 30 ml of bacterial suspension (about 108 CFU/ml). Control plants were inoculated with sterile water. Each treatment comprised eight plants with a single plant in each pot. Plants were incubated in a greenhouse at 25 to 31°C and 56 to 93% humidity. Wilting was observed 4 to 6 days after inoculation, while the control did not wilt. To find the correlation between plant growth stage and resistance to the pathogen, 2-, 3-, 4-, and 5-week-old roselle plants cv. Chiada 1 were transplanted into artificially infested soil. Eight plants in each treatment were planted with a single plant in each pot. The disease incidences for plants of different ages were 75%, 62.5%, 50%, and 12.5%, respectively. This study showed that resistance increases with plant age. Hence, if older seedlings are transplanted, the risk of bacterial wilt of roselle can be reduced. To our knowledge, this is the first report of R. solanacearum on roselle in Taiwan. References: (1) M. Fegan and P. Prior. Bacterial Wilt Disease and the Ralstonia solanacearum Species Complex, page 449. C. Allen et al., eds. The American Phytopathological Society. St. Paul, MN, 2005. (2) A. C. Hayward. J. Appl. Bacteriol. 27:265, 1964. (3) A. Kelman. Phytopathology 44:693, 1954. (4) N. Opina et al. Asia Pac. J. Mol. Biol. Biotechnol. 5:19, 1997.

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Wu, Mu-Chen, Bo-Kang Liou, Yuh-Shuen Chen, Shih-Chieh Lee, Jia-Jin Xie, Yih-Mon Jaw et Shih-Lun Liu. « Understanding Young Taiwanese Consumers’ Acceptance, Sensory Profile, and Drivers of Liking for GABA Oolong Tea Beverages with Cold Infusions ». Foods 11, n^o 19 (26 septembre 2022) : 2989. http://dx.doi.org/10.3390/foods11192989.

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The sensory qualities of Taiwanese teas are evaluated by the experts from the Tea Research and Extension Station (TRES) at tea competitions held annually. The prices of Taiwanese teas are also influenced by the results of these tea competitions. However, a tea winning an award and having a high sensory quality and price does not mean that it is liked by Taiwanese consumers. The check all that apply method (CATA) is a scientific method of sensory evaluation. It is able to evaluate the sensory characteristics with consumers and is cheap and time-saving. Twelve samples of γ-aminobutyric acid (GABA) Oolong tea made by the Taiwan Tea No. 12 cultivar were selected from the first Taiwanese GABA tea competition in 2020. The aim of this research was to study young Taiwanese consumers’ acceptability for GABA Oolong tea infusions, and their opinions towards the sensory qualities of teas through questionnaires composed of CATA questions and hedonic scales. Based on the results, the CATA method identified 21 important descriptive terms for GABA tea that were selected by over 20% of consumers. It was found that the consumers like GABA Oolong teas with 13 specific sensory characteristics, but dislike the ones with another 6 specific sensory characteristics. We conjecture that the different process of tea production will affect consumers’ preference for GABA Oolong tea. Overall, GABA Oolong tea has the same delightful sensory characteristics as traditional Taiwanese specialty Oolong teas, and is liked by the young Taiwanese consumers.

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Li, Xiaojiang, Yang Xu, Yilin Mao, Shuangshuang Wang, Litao Sun, Jiazhi Shen, Xiuxiu Xu, Yu Wang et Zhaotang Ding. « The Effects of Soybean–Tea Intercropping on the Photosynthesis Activity of Tea Seedlings Based on Canopy Spectral, Transcriptome and Metabolome Analyses ». Agronomy 14, n^o 4 (18 avril 2024) : 850. http://dx.doi.org/10.3390/agronomy14040850.

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Intercropping soybean in tea plantations is a sustainable cultivation system that can improve the growing environment of tea plants compared to monoculture tea. However, the effects of this system on the photosynthesis activity of tea seedlings have yet to be reported. Therefore, we used tea cultivar ‘Zhongcha108’ as experimental materials to investigate the effects of intercropping soybean on the canopy spectral parameters and photosynthesis activity of tea seedlings. Canopy spectral reflectance data showed that soybean–tea intercropping (STS) improved the reflectance of 720, 750 and 840 nm bands in tea seedlings’ canopy. The vegetation indexes (VIs) value related to photosynthetic pigments in STS was obviously higher than monoculture tea (T). In addition, the Fv/Fm and SPAD value in STS were also clearly higher. Transcriptome analysis data indicated that STS induced the expression of light-harvesting complex (LHC) genes, photosystem subunit (Psbs and Psas) genes and dark reaction biological process genes (FBP1, RPE, Calvin cycle protein CP12-1 and transketolase). These results indicate that STS enhanced the photosynthesis activity. The metabolome analysis showed that STS promoted the accumulation of carbohydrate metabolites, which further provided evidence for the enhancement of photosynthesis in the leaves of tea seedlings. This study enhanced our understanding of how intercropping soybeans in a young tea plantation improves the photosynthesis activity to promote tea seedlings’ growth and development.

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Wei, Xiao-Juan, Xiao-Jing Liang, Jin-Lin Ma, Kai-Xiang Li et Haiying Liang. « Biological Characteristics and Vegetative Propagation of a New Camellia Cultivar Maozi ». HortScience 51, n^o 12 (décembre 2016) : 1581–85. http://dx.doi.org/10.21273/hortsci11031-16.

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Camellia flowers are highly prized for their beauty worldwide and are strongly symbolic in many cultures. A new interspecific hybrid cultivar, Camellia ‘Maozi’, generated by crossing Camellia pubipetala with C. japonica ‘Dahong Mudan’, exhibits strong hybrid vigor and has small flowers with a rare light tone of purple. In southwest China with a subtropical monsoon climate, young Camellia ‘Maozi’ trees flush shoots three times in spring, summer, and autumn, with an average annual growth of 12.9 cm. Adult trees flush once a year. Floral bud formation occurs in late April and early May. Camellia ‘Maozi’ flowers are sterile with no fruits and seeds produced. While an individual flower wilts 4–8 days after opening, the blossom can last 1–3 months. Frost damage can be found in young leaves when temperature drops to 4–7 °C. Under direct sunlight with temperatures of 37–39 °C lasting for more than 2 days, young leaves can turn yellow on their edges. Its primary diseases include sooty mold, shoot tip blight, and peony leaf tip blight. Its primary insect pests are tea green leafhopper (Jacobiasca formosana) and tea aphid (Toxoptera aurantii). Rooting of stem cuttings occurs directly from stems, mostly without callus development. Two hours of treatment with 500 mg·L−1 indole-3-butyric acid and rooting in a mix of latosolic red soil and vermiculite (2:1 v/v) resulted in high rooting rate and quality of aboveground growth. Grafting can be carried out from May to September, while survival rate and new shoot length are highest in July. The most compatible rootstock is C. oleifera, followed by C. polyodonta. The results of this study are of value for understanding the reproductive biology of Camellia ‘Maozi’ and further disseminating it as a new cultivar for camellia collection.

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Rom, Curt R., et Renae E. Moran. « RELATIONSHIPS OF LEAF AREA AND TRUNK DIAMETER OF APPLE TREES AFFECTED BY ROOTSTOCK AN D CULTIVAR ». HortScience 27, n^o 11 (novembre 1992) : 1169c—1169. http://dx.doi.org/10.21273/hortsci.27.11.1169c.

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Trunk cross-sectional area (TCA) has been used to estimate leaf area (LA) and yield efficiency but variation in LA and TCA relationships have been unexplored. LA and TCA of 10-yr-old 'Starkspur Supreme Delicious' on 9 rootstocks (STKs) were measured in 1989. LA and TCA of 2-yr-old trees of 3 cultivars (CVs) on 5 STKs were measured in 1991. Regression of LA and TCA was performed for each CV, STK and each CV/STK. On mature trees, LA varied significantly with STK. The number and LA of shoot leaves (LVS) and spur LVS varied with STK but the % of total was not significantly different (approx. 52% spur LVS). The relationships of LA and TCA were linear for mature (r2=.94) and young (r2=.44) trees. On young trees, TCA varied with CV, but LA did not. Both LA and TCA were significantly different among STKs. The linear relationships of LA and TCA had unique intercepts with each CV, STK and CV/STK combination but slopes were not significantly different. Leaf area of Jonagold' and 'Gala' tended to increase more with increasing TCA than 'Empire'.

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Li, Qin, Jianan Huang, Shuoqian Liu, Juan Li, Xinhe Yang, Yisong Liu et Zhonghua Liu. « Proteomic analysis of young leaves at three developmental stages in an albino tea cultivar ». Proteome Science 9, n^o 1 (2011) : 44. http://dx.doi.org/10.1186/1477-5956-9-44.

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Santos, Silvia Correa, Carlos Ruggiero, Cristina Lacerda Soares Petrarolha Silva et Eliana Gertrudes Macedo Lemos. « A microsatellite library for Carica papaya L. cv. Sunrise solo ». Revista Brasileira de Fruticultura 25, n^o 2 (août 2003) : 263–67. http://dx.doi.org/10.1590/s0100-29452003000200020.

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In experimental areas of the Education and Researches Ilha Solteira and Jaboticabal UNESP/Campus farms were selected and tagged 20 hermaphrodite plants and 20 feminine of cultivar Sunrise Solo, Improved Sunrise Solo cv.72/12 and Baixinho of Santa Amália.The seeds origined of the selected fruits were cropped to be analysed the self-pollination efficiency and frequency of the sex in the progenies. After that, samples of the young leaf of the matrix plants were colected for the extration of the DNA. It was built five library enriched of microsatellite sequencies, using probes (TCA)10, (TC)13, (GATA)4, (CAC)10 e (TGAG)8.It was possible the development of the primers only in the library that has utilized the probe (TCA)10. This probe allowed the design of 32 primer pairs. From these, 31 presented pattern of unique band in agarose Metaphor and in acrilamide. For primer S36 were observed 2 bands, but with no polymorphism to differentiation in the sexual form at papaya tree culture. However, these primers can be tested, in the futures, in the investigation of the others features in segregated populations of this specie and the related species, germoplasm analysis, cultivars identification, parent evolution and molecular markers for the assisted plant breeding programs.

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KWACH, BOWA O., P. OKINDA OWUOR, DAVID M. KAMAU, SOLOMON W. MSOMBA et MARY A. UWIMANA. « VARIATIONS IN THE PRECURSORS OF PLAIN BLACK TEA QUALITY PARAMETERS DUE TO LOCATION OF PRODUCTION AND NITROGEN FERTILIZER RATES IN EASTERN AFRICAN CLONAL TEA LEAVES ». Experimental Agriculture 52, n^o 2 (20 mai 2015) : 266–78. http://dx.doi.org/10.1017/s0014479715000083.

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SUMMARYTheaflavins contribute to astringency and brightness while thearubigins contribute to colour and mouth feel of black tea. Green leaf flavan-3-ols influence levels and distribution of theaflavins and thearubigins in black tea and are black tea quality precursor compounds. Caffeine also contributes to tea quality. Although location of production and nitrogenous fertilizer rates influence black tea quality, it is not known if the variations arise from the levels and distribution of the precursor compounds in green leaf or other factors. The variations and distribution of the flavan-3-ols and caffeine in young green leaves of clone TRFK 6/8 due to nitrogen fertiliser rates in seven locations within Eastern Africa were evaluated. Green leaf comprising two leaves and a bud were harvested from each plot, and subjected to HPLC analysis for caffeine, total polyphenol, dihydroxyflavan-3-ols, trihydroxyflavan-3-ols, ratios of trihydroxyflavan-3-ols to dihydroxyflavan-3-ols and total catechins levels. Results were subjected to statistical analysis using split plot design, with locations as main treatments and nitrogen rates as the sub-treatment. Caffeine and flavan-3-ols levels changed (p ≤ 0.05) with location of production, demonstrating that even with use of same cultivar and similar agronomic management quality of tea from one location cannot be replicated in another location. Caffeine levels increased (p ≤ 0.05) with rise in nitrogen fertilizer rate in all locations, but the extent depended on location. Total polyphenols and individual flavan-3-ols showed an inverse quadratic response, except EGCG that linearly decreased (p ≤ 0.05) in some locations, due to increasing rates of nitrogen fertilizer. Similar responses in the black tea quality parameters had been observed in previous studies. The black tea quality results were therefore directly influenced by the green leaf precursor compound patterns. Region specific nitrogenous fertilizer rates need development to ensure high tea quality.

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Uthai, Narissara. « Effects of temperature, steeping time and particle size used in infusion brewing on total phenolic content and antioxidant activity of tea produced from young upland rice leaves ». African Journal of Food, Agriculture, Nutrition and Development 21, n^o 02 (24 mars 2021) : 17477–91. http://dx.doi.org/10.18697/ajfand.97.20150.

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Tea was brewed from young leaves of 4 weeks old Thai upland black waxy rice plants of the cultivar ‘Damgatondam’, which has a noticeable fragrant smell from both seeds and leaves. The plants were harvested about 1 cm above soil level, washed, and cut into pieces, about 1 cm long. These pieces were then steamed for 1 min in a steamer rack, withering for 5min by spreading them out in a thin layer, pan-roasted at 70°C for 30 min, and finally dried at 70°C for 90 min. They were either kept as pieces of leaves or ground into a powder, and both were used for brewing tea by infusion in water at 4oC, room temperature (about 25oC), for 1, 3, 5, 7, 9, 11, or 15 h and brewing at 70oC or 98oC for 1, 3, 5, 7, 9, 11 or 15 min. Directly after brewing, the tea was stored at -25oC awaiting analysis. Each sample was analyzed for total phenolic content (TPC) and for antioxidant activity, by ferric reducing antioxidant power (FRAP), 2,2 diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazo line-6-sulphonic acid) (ABTS) assays. Results showed that tea brewed from ground leaves had higher antioxidant activity than tea brewed from ungrounded leaves. The highest level of extraction was at 98oC for 15 min, where the TPC was 62.79 mg GAE/100g, antioxidant activity was 278.04 for DPPH, 195.38 for ABTS and 1150.13 mg TE/100g for FRAP. Samples extracted at 4oC or room temperature also had high levels of TPC and antioxidant activity with the maximum extraction at room temperature for 15 h; where TPC was 46.76 mg GAE/100g, and antioxidant activities were 152.72 for DPPH, 140.42 for ABTS and 950.32 mg TE/100 g for FRAP. Therefore, the level of extraction for tea brewed in all four conditions depended on both temperature and brewing time. Also, extraction of high levels of bioactive compounds depended on large surface areas of the leaves being in contact with water.

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Li, Wei, Liqiang Tan, Yao Zou, Xiaoqin Tan, Jiacheng Huang, Wei Chen et Qian Tang. « The Effects of Ultraviolet A/B Treatments on Anthocyanin Accumulation and Gene Expression in Dark-Purple Tea Cultivar ‘Ziyan’ (Camellia sinensis) ». Molecules 25, n^o 2 (15 janvier 2020) : 354. http://dx.doi.org/10.3390/molecules25020354.

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‘Ziyan’ is a novel anthocyanin-rich tea cultivar with dark purple young shoots. However, how its anthocyanin accumulation is affected by environmental factors, such as ultraviolet (UV), remains unclear. In this study, we observed that UV light treatments stimulated anthocyanin accumulation in ‘Ziyan’ leaves, and we further analyzed the underlying mechanisms at gene expression and enzyme activity levels. In addition, the catechins and chlorophyll contents of young shoots under different light treatments were also changed. The results showed that the contents of total anthocyanins and three major anthocyanin molecules, i.e., delphinidin, cyanidin, and pelargonidin, were significantly higher in leaves under UV-A, UV-B, and UV-AB treatments than those under white light treatment alone. However, the total catechins and chlorophyll contents in these purple tea plant leaves displayed the opposite trends. The anthocyanin content was the highest under UV-A treatment, which was higher by about 66% than control. Compared with the white light treatment alone, the enzyme activities of chalcone synthase (CHS), flavonoid 3′,5′-hydroxylase (F3′5′H), and anthocyanidin synthase (ANS) under UV treatments increased significantly, whereas the leucoanthocyanidin reductase (LAR) and anthocyanidin reductase (ANR) activities reduced. There was no significant difference in dihydroflavonol 4-reductase (DFR) activity under all treatments. Comparative transcriptome analyses unveiled that there were 565 differentially expressed genes (DEGs) of 29,648 genes in three pair-wise comparisons (white light versus UV-A, W vs. UV-A; white light versus UV-B, W vs. UV-A; white light versus UV-AB, W vs. UV-AB). The structural genes in anthocyanin pathway such as flavanone 3-hydroxylase (F3H), F3′5′H, DFR, and ANS, and regulatory gene TT8 were upregulated under UV-A treatment; F3′5′H, DFR, ANS, and UFGT and regulatory genes EGL1 and TT2 were upregulated under UV-AB treatment. However, most structural genes involved in phenylpropanoid and flavonoid pathways were downregulated under UV-B treatment compared with control. The expression of LAR and ANR were repressed in all UV treatments. Our results indicated that UV-A and UV-B radiations can induce anthocyanin accumulation in tea plant ‘Ziyan’ by upregulating the structural and regulatory genes involved in anthocyanin biosynthesis. In addition, UV radiation repressed the expression levels of LAR, ANR, and FLS, resulting in reduced ANR activity and a metabolic flux shift toward anthocyanin biosynthesis.

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Uthai, Narissara, P. Thamakorn, S. Kerdpiboon et R. Nokkoul. « Process optimization, antioxidant activity and sensory characteristics of green tea made from young fragrant rice leaves cultivar damgatondam ». African Journal of Food Agriculture Nutrition and Development 19, n^o 04 (28 novembre 2019) : 14950–70. http://dx.doi.org/10.18697/ajfand.87.18120.

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Guan, Yuanyuan, Zhiyuan Wei, Luyi Zhou, Kaige Wang, Meng Zhang, Puwen Song, Ping Hu, Haiyan Hu et Chengwei Li. « Tae-miR397 Negatively Regulates Wheat Resistance to Blumeria graminis ». Plants 12, n^o 17 (29 août 2023) : 3096. http://dx.doi.org/10.3390/plants12173096.

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MicroRNA (miRNA) plays a crucial role in the interactions between plants and pathogens, and identifying disease-related miRNAs could help us understand the mechanisms underlying plant disease pathogenesis and breed resistant varieties. However, the role of miRNA in wheat defense responses remains largely unexplored. The miR397 family is highly conserved in plants and involved in plant development and defense response. Therefore, the purpose of this study was to investigate the function of tae-miR397 in wheat resistance to powdery mildew. The expression pattern analysis revealed that tae-miR397 expression was higher in young leaves than in other tissues and was significantly decreased in wheat Bainong207 leaves after Blumeria graminis (Bgt) infection and chitin treatment. Additionally, the expression of tae-miR397 was significantly down-regulated by salicylic acid and induced under jasmonate treatment. The overexpression of tae-miR397 in common wheat Bainong207 enhanced the wheat’s susceptibility to powdery mildew in the seedling and adult stages. The rate of Bgt spore germination and mycelial growth in transgenic wheat plants overexpressing tae-miR397 was faster than in the untransformed wild-type plants. The target gene of tae-miR397 was predicted to be a wound-induced protein (Tae-WIP), and the function was investigated. We demonstrated that silencing of Tae-WIP via barley-stripe-mosaic-virus-induced gene silencing enhanced wheat’s susceptibility to powdery mildew. qRT-PCR indicated that tae-miR397 regulated wheat immunity by controlling pathogenesis-related gene expressions. Moreover, the transgenic plants overexpressing tae-miR397 exhibited more tillers than the wild-type plants. This work suggests that tae-miR397 is a negative regulator of resistance against powdery mildew and has great potential for breeding disease-resistant cultivars.

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Burgess, P. J., et M. K. V. Carr. « Responses of Young Tea (Camellia sinensis) Clones to Drought and Temperature. II. Dry Matter Production and Partitioning ». Experimental Agriculture 32, n^o 4 (octobre 1996) : 377–94. http://dx.doi.org/10.1017/s0014479700001472.

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SUMMARYThe physiological basis for differences in yields from well-watered and draughted plants of four contrasting clones of tea was studied in terms of light interception, dry matter production and partitioning at a high altitude site in Southern Tanzania where there are marked seasonal variations in rainfall and temperature. The plant dry weights, including roots, were measured eight months after field planting and subsequently at intervals of three to four months, corresponding to the different seasons, during the following two years. Fully irrigated plants of one clone (S15/10) were also harvested after four years in the field. Clones differed in the rates of canopy spread and hence in their capacity to intercept solar radiation. The ‘radiation use efficiency’ (the net total dry matter production per unit of intercepted short-wave radiation) was similar for the four well-watered clones and ranged from 0.40 to 0.66 g MJ−1, which corresponds closely to values reported for other woody tropical plants. A 16-week drought treatment imposed two years after planting reduced the mean light interception of the four clones by about 25% and the mean radiation use efficiency by 78% to 0.09 g MJ−1. Clone S15/10, a cultivar from Kenya which produces large yields, partitioned a greater proportion of dry matter to leaves and harvested shoots than the other clones, and correspondingly less to large structural roots. This resulted in a maximum harvest index of 24%, substantially greater than other values reported in the literature. There were seasonal differences in partitioning, with more dry matter being diverted to roots and less to shoots during the cool season. Although the drought treatments had no significant effect on root growth, the amount of dry matter partitioned to leaves, stems and harvested shoots declined by 80–95%. The roots of all four clones extended in depth at similar rates (about 2 mm d−1), those of Clone S15/10 reaching 2.8m after four years. The results are discussed in terms of appropriate field cultural practices and possible selection criteria for high yielding clones.

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Burgess, P. J., et M. K. V. Carr. « Responses of Young Tea (Camellia sinensis) Clones to Drought and Temperature. II. Dry Matter Production and Partitioning ». Experimental Agriculture 32, n^o 4 (octobre 1996) : 377–94. http://dx.doi.org/10.1017/s0014479700003756.

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SUMMARYThe physiological basis for differences in yields from well-watered and draughted plants of four contrasting clones of tea was studied in terms of light interception, dry matter production and partitioning at a high altitude site in Southern Tanzania where there are marked seasonal variations in rainfall and temperature. The plant dry weights, including roots, were measured eight months after field planting and subsequently at intervals of three to four months, corresponding to the different seasons, during the following two years. Fully irrigated plants of one clone (S15/10) were also harvested after four years in the field. Clones differed in the rates of canopy spread and hence in their capacity to intercept solar radiation. The ‘radiation use efficiency’ (the net total dry matter production per unit of intercepted short-wave radiation) was similar for the four well-watered clones and ranged from 0.40 to 0.66 g MJ−1, which corresponds closely to values reported for other woody tropical plants. A 16-week drought treatment imposed two years after planting reduced the mean light interception of the four clones by about 25% and the mean radiation use efficiency by 78% to 0.09 g MJ−1. Clone S15/10, a cultivar from Kenya which produces large yields, partitioned a greater proportion of dry matter to leaves and harvested shoots than the other clones, and correspondingly less to large structural roots. This resulted in a maximum harvest index of 24%, substantially greater than other values reported in the literature. There were seasonal differences in partitioning, with more dry matter being diverted to roots and less to shoots during the cool season. Although the drought treatments had no significant effect on root growth, the amount of dry matter partitioned to leaves, stems and harvested shoots declined by 80–95%. The roots of all four clones extended in depth at similar rates (about 2 mm d−1), those of Clone S15/10 reaching 2.8m after four years. The results are discussed in terms of appropriate field cultural practices and possible selection criteria for high yielding clones.

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Li, Jiao, He, Sun, Xu, Zhang, Jiang, Li et Niu. « Gene Expression Profiles and microRNA Regulation Networks in Tiller Primordia, Stem Tips, and Young Spikes of Wheat Guomai 301 ». Genes 10, n^o 9 (6 septembre 2019) : 686. http://dx.doi.org/10.3390/genes10090686.

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Tillering and spike differentiation are two key events for wheat (Triticum aestivum L.). A study on the transcriptomes and microRNA group profiles of wheat at the two key developmental stages will bring insight into the molecular regulation mechanisms. Guomai 301 is a representative excellent new high yield wheat cultivar in the Henan province in China. The transcriptomes and microRNA (miRNA) groups of tiller primordia (TPs), stem tips (STs), and young spikes (YSs) in Guomai 301 were compared to each other. A total of 1741 tillering specifically expressed and 281 early spikes differentiating specifically expressed differentially expressed genes (DEGs) were identified. Six major expression profile clusters of tissue-specific DEGs for the three tissues were classified by gene co-expression analysis using K-means cluster. The ribosome (ko03010), photosynthesis-antenna proteins (ko00196), and plant hormone signal transduction (ko04075) were the main metabolic pathways in TPs, STs, and YSs, respectively. Similarly, 67 TP specifically expressed and 19 YS specifically expressed differentially expressed miRNAs were identified, 65 of them were novel. The roles of 3 well known miRNAs, tae-miR156, tae-miR164, and tae-miR167a, in post-transcriptional regulation were similar to that of other researches. There were 651 significant negative miRNA–mRNA interaction pairs in TPs and YSs, involving 63 differentially expressed miRNAs (fold change > 4) and 416 differentially expressed mRNAs. Among them 12 key known miRNAs and 16 novel miRNAs were further analyzed, and miRNA–mRNA regulatory networks during tillering and early spike differentiating were established.

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Dávila-Aviña, Jorge, Bernardo Gallegos-Ruiz, Santos García et Norma Heredia. « Comparison of total polyphenol content, antioxidant activity, and antimicrobial potential among nine cactus pear (Opuntia spp.) cultivars and their by-products ». Journal of the Professional Association for Cactus Development 20 (14 septembre 2018) : 113–27. http://dx.doi.org/10.56890/jpacd.v20i.32.

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Nopal cacti (Opuntia spp.) are important natural resources in semi-arid zones throughout theworld, where their fruits and stems are used as forage or human food depending on the varietyand ripeness of the cladode. Members of the genus Opuntia show variable phytochemicalcomposition as well as a high capacity for adaptation to extreme environmental conditions. Onepart of the process to prepare and use of “nopalitos” for human consumption includes removalof modified leaves or thorns, which is approximately 20% of the fresh weight of cladodes isconsidered as a by-product (production residue). The objective of this study was to evaluatethe phytochemical composition, antioxidant capacity, and antibacterial potential of cladodesand cladode by-products from nine nopal cultivars. Young cladodes (<1 month, nopalitos) andtheir corresponding by-products were washed, dried, and macerated in ethanol. Ethanolextracts were isolated by evaporation and resuspended in water. Total phenols and flavonoidswere quantified, and antioxidant capacity was assessed by spectroscopic assays [troloxequivalent antioxidant capacity (TEAC) and percent inhibition of diphenylpicrylhydrazyl (DPPH)radicals]. Antimicrobial activities of the extracts against Vibrio cholerae and Clostridiumperfringens were determined by the well diffusion method and calculation of minimalbactericidal concentration (MBC) by agar plate assay. All extracts tested showed antioxidantand antibacterial activities. Extracts of cladodes and their corresponding by-products showedsimilar MBCs for C. perfringens (around 15 mg ml-1) and V. cholerae (4.0 mg ml-1). However,extracts of cladode by-products showed higher antioxidant capacity than those of cladodesaccording to both DPPH and TEAC assays. Higher concentrations of phenols and flavonoidswere also found in the extracts of by-products (ranging from 91.23 to 853.78 mg gallic acidequivalents per gram dry weight and from 17.10 to 39.42 mg quercetin equivalents per gramdry weight, respectively). This study demonstrates that nopal cactus species exhibit higherantioxidant activity and contents of both phenols and flavonoids in cladode by-products thanthat in their corresponding cladodes. Our data indicate that discarded cladode by-products maybe are a potentially valuable resource for nutraceutical and drug development.

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Liu, Yang, Yifan Zhang, Yang Liu, Ling Lin, Xingyao Xiong, Donglin Zhang, Sha Li, Xiaoying Yu et Yanlin Li. « Genome-Wide Identification and Characterization of WRKY Transcription Factors and Their Expression Profile in Loropetalum chinense var. rubrum ». Plants 12, n^o 11 (27 mai 2023) : 2131. http://dx.doi.org/10.3390/plants12112131.

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The WRKY gene family plays important roles in plant growth and development, as well as in the responses to biotic and abiotic stresses. Loropetalum chinense var. rubrum has high ornamental and medicinal value. However, few WRKY genes have been reported in this plant, and their functions remain unknown. To explore the roles that the WRKY genes play in L. chinense var. rubrum, we identified and characterized 79 LcWRKYs through BLAST homology analysis and renamed them (as LcWRKY1–79) based on their distribution on the chromosomes of L. chinense var. rubrum. In this way, according to their structural characteristics and phylogenetic analysis, they were divided into three groups containing 16 (Group I), 52 (Group II), and 11 (Group III) WRKYs, respectively. LcWRKYs in the same group have similar motifs and gene structures; for instance, Motifs 1, 2, 3, 4, and 10 constitute the WRKY domain and zinc-finger structure. The LcWRKY promoter region contains light response elements (ACE, G-box), stress response elements (TC-rich repeats), hormone response elements (TATC-box, TCA-element), and MYB binding sites (MBS, MBSI). Synteny analysis of LcWRKYs allowed us to establish orthologous relationships among the WRKY gene families of Arabidopsis thaliana, Oryza sativa, Solanum lycopersicum L., Vitis vinifera L., Oryza sativa L., and Zea mays L.; furthermore, analysis of the transcriptomes of mature leaves and flowers from different cultivars demonstrated the cultivar-specific LcWRKY gene expression. The expression levels of certain LcWRKY genes also presented responsive changes from young to mature leaves, based on an analysis of the transcriptome in leaves at different developmental stages. White light treatment led to a significant decrease in the expression of LcWRKY6, 18, 24, 34, 36, 44, 48, 61, 62, and 77 and a significant increase in the expression of LcWRKY41, blue light treatment led to a significant decrease in the expression of LcWRKY18, 34, 50, and 77 and a significant increase in the expression of LcWRKY36 and 48. These results enable a better understanding of LcWRKYs, facilitating the further exploration of their genetic functions and the molecular breeding of L. chinense var. rubrum.

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Guo, M., Y. M. Pan, Y. L. Dai et Z. M. Gao. « First Report of Brown Blight Disease Caused by Colletotrichum gloeosporioides on Camellia sinensis in Anhui Province, China ». Plant Disease 98, n^o 2 (février 2014) : 284. http://dx.doi.org/10.1094/pdis-08-13-0896-pdn.

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Yellow Mountain fuzz tip, a cultivar of Camellia sinensis (L.) Kuntze, is commonly grown in the Yellow Mountain region in Anhui Province of China. During 2011 to 2012, leaf and twig blight on tea plants occurred from July to September in growing regions. Symptoms of blight on leaves of infected plants were detected in 30 to 60% of the fields visited and up to 500 ha were affected each year. Symptoms began as small, water-soaked lesions on young leaves and twigs and later became larger, dark brown, necrotic lesions, 1 to 3 mm in diameter on leaves and 2 to 5 mm long on twigs. To determine the causal agent, symptomatic leaf tissue was collected from plants in Gantang and Tangkou townships in September 2012. Small pieces of diseased tea leaves and twigs were surface-disinfested in 2% NaClO for 3 min, rinsed twice in distilled water, plated on potato dextrose agar, and incubated at 28°C for 5 days. Eleven isolates were recovered and all cultures produced white-to-gray fluffy aerial hyphae and were dark on the reverse of the plate. The hyphae were hyaline, branching, and septate. Setae were 2- to 3-septate, dark brown, acicular, and 78.0 to 115.0 μm. Conidiogenous cells were hyaline, short, branchless, cylindrical, and 11.3 to 21.5 × 4.2 to 5.3 μm. Conidia were hyaline, aseptate, guttulate, cylindrical, and 12.5 to 17.3 × 3.9 to 5.8 μm. Appresoria were ovate to obovate, dark brown, and 8.4 to 15.2 × 7.8 to 12.9 μm. DNA was amplified using the rDNA-ITS primer pair ITS4/ITS5 (3), glyceraldehyde-3-phosphate dehydrogenase gene (GAPDH) primer pair GDF/GDR (2) and beta-tubulin 2 gene (Tub2) primer pair Btub2Fd/Btub4Rd (4). Sequences (GenBank Accession Nos. KC913203, KC913204, and KC913205) of the 11 isolates were identical and revealed 100% similarity to the ITS sequence of strain P042 of Colletotrichum gloeosporioides (EF423527), 100% identity to the GAPDH of isolate C07009 of C. gloeosporioides (GU935860), and 99% similarity to Tub2 of isolate 85 of C. gloeosporioides (AJ409292), respectively. Based on the above data, the 11 isolates were identified as C. gloeosporioides (Penz.) Penz. & Sacc. To confirm pathogenicity, Koch's postulate was performed and 4 ml of conidial suspension (1 × 105 conidia/ml) of each of the 11 isolates was sprayed on five leaves and five twigs per plant on four 12-month-old Yellow Mountain fuzz tip plants. Control plants were sprayed with distilled water. The inoculated plants were maintained at 28°C in a greenhouse with constant relative humidity of 90% and a 12-h photoperiod of fluorescent light. Brown necrotic lesions appeared on leaves and twigs after 7 days, while the control plants remained healthy. The experiments were conducted three times and the fungus was recovered and identified as C. gloeosporioides by both morphology and molecular characteristics. Tea plant blight caused by C. gloeosporioides was identified in Brazil (1), but to our knowledge, this is the first report of C. gloeosporioides causing tea leaf and twig blight on Yellow Mountain fuzz tip plants in Anhui Province of China. References: (1) M. A. S. Mendes et al. Page 555 in: Embrapa-SPI/Embrapa-Cenargen, Brasilia, 1998. (2) M. D. Templeton et al. Gene 122:225, 1992. (3) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990. (4) J. H. C. Woudenberg et al. Persoonia 22:56, 2009.

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Spychała, Julia, Agnieszka Tomkowiak, Aleksandra Noweiska, Roksana Bobrowska, Jan Bocianowski, Michał Książkiewicz, Aleksandra Sobiech et Michał Tomasz Kwiatek. « Expression Profiling of the Slow Rusting Resistance Genes Lr34/Yr18 and Lr67/Yr46 in Common Wheat (Triticum aestivum L.) and Associated miRNAs Patterns ». Genes 14, n^o 7 (29 juin 2023) : 1376. http://dx.doi.org/10.3390/genes14071376.

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The main efforts in common wheat (Triticum aestivum L.) breeding focus on yield, grain quality, and resistance to biotic and abiotic stresses. One of the major threats affecting global wheat cultivation and causing significant crop production losses are rust diseases, including leaf rust caused by a biotrophic fungus Puccinia triticina Eriks. Genetically determined resistance to leaf rust has been characterized in young plants (seedling resistance) as well as in plants at the adult plant stage. At the seedling stage, resistance is controlled vertically by major R genes, conferring a race-specific response that is highly effective but usually short-lived due to the rapid evolution of potentially virulent fungi. In mature plants, horizontal adult plant resistance (APR) was described, which provides long-term protection against multiple races of pathogens. A better understanding of molecular mechanisms underlying the function of APR genes would enable the development of new strategies for resistance breeding in wheat. Therefore, in the present study we focused on early transcriptomic responses of two major wheat APR genes, Lr34 and Lr67, and three complementary miRNAs, tae-miR9653b, tae-miR9773 and tae-miR9677b, to inoculation with P. triticina. Plant material consisted of five wheat reference varieties, Artigas, NP846, Glenlea, Lerma Rojo and TX89D6435, containing the Lr34/Yr18 and Lr67/Yr46 resistance genes. Biotic stress was induced by inoculation with fungal spores under controlled conditions in a phytotron. Plant material consisted of leaf tissue sampled before inoculation as well as 6, 12, 24 and 48 h postinoculation (hpi). The APR gene expression was quantified using real-time PCR with two reference genes, whereas miRNA was quantified using droplet digital PCR. This paper describes the resistance response of APR genes to inoculation with races of leaf rust-causing fungi that occur in central Europe. The study revealed high variability of expression profiles between varieties and time-points, with the prevalence of downregulation for APR genes and upregulation for miRNAs during the development of an early defense response. Nevertheless, despite the downregulation initially observed, the expression of Lr34 and Lr67 genes in studied cultivars was significantly higher than in a control line carrying wild (susceptible) alleles.

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Toft, Benjamin D., Mobashwer M. Alam, John D. Wilkie et Bruce L. Topp. « Phenotypic Association of Multi-scale Architectural Traits with Canopy Volume and Yield : Moving Toward High-density Systems for Macadamia ». HortScience 54, n^o 4 (avril 2019) : 596–602. http://dx.doi.org/10.21273/hortsci13293-18.

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The vigorous growth and large canopy size of commercial macadamia (Macadamia integrifolia, M. tetraphylla, and hybrids) cultivars generally restricts macadamia orchards to low-density planting. Little is known of the detailed interactions between plant architecture and yield components specific to macadamia. This chapter examines how dependent traits such as canopy size and yield might be determined by direct and indirect interactions between traits at different scales within the canopy. Fifteen genotypes (n = 3) were phenotyped in two growing seasons for architectural and reproductive traits, around the age of their transition from juvenility to maturity. Genotypes varied in canopy volume, cumulative yield, and canopy efficiency, and particular genotypes with low canopy volume and high yield were considered potentially useful for future high-density orchard systems. There was high variability in architectural, floral, and yield traits at multiple scales. Direct and indirect effects of architectural traits on the variability of yield and tree size were quantified using path coefficient analysis. Canopy volume was subject to positive direct effects from trunk cross-sectional area (TCA; 0.72), lateral branching (0.24), and branch unit (BU) length (0.24). Other traits showed significant indirect effects with canopy volume via TCA, such as branch cross-sectional area (BCA; 0.43), BU length (0.40), lateral branching (0.35), and internode length (0.32). Branch angle had a significant indirect negative effect on canopy volume via BU length (−0.11). Nut number had the strongest direct effect on yield (0.97), and this relationship was significantly indirectly influenced by raceme number (0.47), raceme length (0.50), nut number per raceme (0.33), canopy volume (0.37), and branch angle (0.35). In these relatively young trees, early yield was directly and positively influenced by canopy volume (0.12), presumably due to increased early light interception, which suggests that early canopy vigor contributes to early yield. This study suggests that yield and canopy size are determined by complex phenotypic interactions between architectural traits at different scales. Therefore, preplanting (i.e., scion and rootstock selections) and postplanting (i.e., pruning and training) manipulations that specifically manage architectural traits such as shoot length, branching, branch angle, raceme length, and nuts per raceme may result in the creation of efficient macadamia canopies.

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Luo, Xueyin, Mengxian Zhang, Pei Xu, Guofeng Liu et Shu Wei. « The Intron Retention Variant CsClpP3m Is Involved in Leaf Chlorosis in Some Tea Cultivars ». Frontiers in Plant Science 12 (28 janvier 2022). http://dx.doi.org/10.3389/fpls.2021.804428.

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Tea products made from chlorotic or albino leaves are very popular for their unique flavor. Probing into the molecular mechanisms underlying the chlorotic leaf phenotype is required to better understand the formation of these tea cultivars and aid in future practical breeding. In this study, transcriptional alterations of multiple subunit genes of the caseinolytic protease complex (Clp) in the chlorotic tea cultivar ‘Yu-Jin-Xiang’ (YJX) were found. Cultivar YJX possessed the intron retention variant of ClpP3, named as CsClpP3m, in addition to the non-mutated ClpP3. The mutated variant results in a truncated protein containing only 166 amino acid residues and lacks the catalytic triad S182-H206-D255. Quantitative analysis of two CsClpP3 variants in different leaves with varying degrees of chlorosis in YJX and analyses of different chlorotic tea cultivars revealed that the transcript ratios of CsClpP3m over CsClpP3 were negatively correlated with leaf chlorophyll contents. The chlorotic young leaf phenotype was also generated in the transgenic tobacco by suppressing ClpP3 using the RNAi method; complementation with non-mutated CsClpP3 rescued the wild-type phenotype, whereas CsClpP3m failed to complement. Taken together, CsClpP3m is involved in leaf chlorosis in YJX and some other tea cultivars in a dose-dependent manner, likely resulting from the failure of Clp complex assembly due to the truncated sequence of CsClpP3m. Our data shed light on the mechanisms controlling leaf chlorosis in tea plants.

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Thu Yen, Hoang Thi, Nguyen Thuy Linh, Huynh Thi Thu Hue et Nguyen Hai Dang. « Evaluating Expression of Gene Encoding Flavonol Synthase in Green TrungDu and Purple TrungDu by Real time PCR and HPLC Technique ». VNU Journal of Science : Natural Sciences and Technology 36, n^o 2 (24 juin 2020). http://dx.doi.org/10.25073/2588-1140/vnunst.4909.

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In plants, flavonol synthase (FLS) is a multifunctional enzyme that converts dihydroflavonol into flavonols and naringenin into dihydrokaempferol. FLS from tea has been shown to metabolize dihydroquercetin to quercetin. In this study, we conducted studying on the relationship between quercetin content and the expression level of FLS in two traditional tea cultivars of Vietnam, TrungDuxanh and TrungDutim tea grown in tea garden of Thai Nguyen University of Agriculture and Forestry. Tea shoots with one apical bud and two to three young leaves using as research materials which collected in September 2017. The using of HPLC technique did not detect the quercetin content from the these tea samples. The preliminary results of quantification of FLS gene expression by real time PCR showed the expression level of FLS in green Trung Du tea is higher than purple Trung Du, although the difference is not great. Thus, at the time of collecting, the expression of FLS in green Trung Du and purple Trung Du can not synthesize quercetin but synthesize other flavonols.

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Lu, Jing, Jinke Du, Liying Tian, Mengshuang Li, Xianchen Zhang, Shihua Zhang, Xiaochun Wan et Qi Chen. « Divergent Response Strategies of CsABF Facing Abiotic Stress in Tea Plant : Perspectives From Drought-Tolerance Studies ». Frontiers in Plant Science 12 (17 novembre 2021). http://dx.doi.org/10.3389/fpls.2021.763843.

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In plants, the bZIP family plays vital roles in various biological processes, including seed maturation, flower development, light signal transduction, pathogen defense, and various stress responses. Tea, as a popular beverage, is widely cultivated and has withstood a degree of environmental adversity. Currently, knowledge of the bZIP gene family in tea plants remains very limited. In this study, a total of 76 CsbZIP genes in tea plant were identified for the whole genome. Phylogenetic analysis with Arabidopsis counterparts revealed that CsbZIP proteins clustered into 13 subgroups, among which 13 ABFs related to the ABA signaling transduction pathway were further identified by conserved motif alignment and named CsABF1-13, these belonged to the A and S subgroups of CsbZIP and had close evolutionary relationships, possessing uniform or similar motif compositions. Transcriptome analysis revealed the expression profiles of CsABF genes in different tissues (bud, young leaf, mature leaf, old leaf, stem, root, flower, and fruit) and under diverse environmental stresses (drought, salt, chilling, and MeJA). Several CsABF genes with relatively low tissue expression, including CsABF1, CsABF5, CsABF9, and CsABF10, showed strong expression induction in stress response. Thirteen CsABF genes, were examined by qRT-PCR in two tea plant cultivars, drought-tolerant “Taicha 12” and drought-sensitive “Fuyun 6”, under exogenous ABA and drought stress. Furthermore, CsABF2, CsABF8, and CsABF11, were screened out as key transcription factors regulating drought tolerance of tea cultivars. Subsequently, some potential target genes regulated by CsABFs were screened by co-expression network and enrichment analysis. This study update CsbZIP gene family and provides a global survey of the ABF gene family in tea plant. The resolution of the molecular mechanism of drought resistance in different varieties could be helpful for improving stress resistance in tea plant via genetic engineering.

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KC, Santosh, Lizhi Long, Meiya Liu, Qunfeng Zhang et Jianyun Ruan. « Light Intensity Modulates the Effect of Phosphate Limitation on Carbohydrates, Amino Acids, and Catechins in Tea Plants (Camellia sinensis L.) ». Frontiers in Plant Science 12 (8 octobre 2021). http://dx.doi.org/10.3389/fpls.2021.743781.

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Metabolites are major contributors to the quality of tea that are regulated by various abiotic stresses. Light intensity and phosphorus (P) supply affect the metabolism of tea plants. However, how these two factors interact and mediate the metabolite levels in tea plants are not fully understood. The present study investigated the consequences of different light intensity and P regimes on the metabolism of carbohydrates, amino acids, and flavonoids in the Fengqing tea cultivar. The leaves and young shoots were subjected to untargeted metabolomics analysis by two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC–TOF/MS), ultra-performance liquid chromatography-quadrupole-TOF/MS (UPLC–Q–TOF/MS), and targeted analysis by high-performance liquid chromatography (HPLC) along with quantification of gene expression by quantitative real time-PCR (qRT–PCR). The results from young shoots showed that amino acids, pentose phosphate, and flavonol glycosides pathways were enhanced in response to decreasing light intensities and P deficiency. The expression of the genes hexokinase 1, ribose 5-phosphate isomerase A (RPIA), glutamate synthetase 1 (GS1), prolyl 4-hydroxylase (P4H), and arginase was induced by P limitation, thereafter affecting carbohydrates and amino acids metabolism, where shading modulated the responses of transcripts and corresponding metabolites caused by P deficiency. P deprivation repressed the expression of Pi transport, stress, sensing, and signaling (SPX2) and induced bidirectional sugar transporter (SWEET3) and amino acid permeases (AAP) which ultimately caused an increase in the amino acids: glutamate (Glu), proline (Pro), and arginine (Arg) under shading but decreased catechins [epicatechingallate (ECG) and Gallic acid, GA] content in young shoots.

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Zhang, Kexin, Xia Feng, Ying Liu, Yajun Yang, Xinyuan Hao, Dongliang Li, Xinchao Wang et Lu Wang. « Integrative transcriptome and whole‐genome bisulfite sequencing analyses of a temperature‐sensitive albino tea plant cultivar ». Physiologia Plantarum 175, n^o 6 (novembre 2023). http://dx.doi.org/10.1111/ppl.14064.

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AbstractGreen tea made from albino buds and leaves has a strong umami taste and aroma. The cultivar ‘Zhonghuang 2’ (ZH2, Camellia sinensis) is a natural mutant with young shoots that are yellow in spring and green or yellow‐green in summer. However, the mechanism of leaf color change remains unclear. Here, we found that young shoots of ZH2 were yellow at low temperature (LT) and green at high temperature (HT), indicating that ZH2 is a temperature‐sensitive cultivar. Transmission electron microscopy analysis showed that the grana in the chloroplasts of young shoots grown at LT were poorly stacked, which caused a lack of photoreactions and chlorophyll. RNA‐seq results showed 1279 genes differentially expressed in the young shoots grown at LT compared with those at HT, including genes related to cytochrome synthesis, chloroplast development, photosynthesis, and DNA methylation. A whole‐genome bisulfite sequencing assay revealed that the dynamics of DNA methylation levels in the CG, CHG, and CHH contexts decreased under LT, and the change was most obvious in the CHH context. Furthermore, 72 genes showed significant changes in both expression and DNA methylation levels, and most of them were related to cytochrome synthesis, chloroplast development, photosynthesis, transcription factors, and signaling pathways. These results demonstrate that DNA methylation is involved in the LT‐regulated albino processes of ZH2. Changes in DNA methylation levels were associated with changes in gene expression levels, affecting the structure and function of chloroplasts, which may have a phenotypic impact on shoot and leaf color.

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Zhou, Hanchen, Shijie Wang, Hao-Fen Xie, Guofeng Liu, Lubobi Ferdinand Shamala, Jingyi Pang, Zhengzhu Zhang, Tie-Jun Ling et Shu Wei. « Cytosolic Nudix Hydrolase 1 Is Involved in Geranyl β-Primeveroside Production in Tea ». Frontiers in Plant Science 13 (11 mai 2022). http://dx.doi.org/10.3389/fpls.2022.833682.

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Geraniol is a potent tea odorant and exists mainly as geranyl glycoside in Camellia sinensis. Understanding the mechanisms of geraniol biosynthesis at molecular levels in tea plants is of great importance for practical improvement of tea aroma. In this study, geraniol and its glycosides from tea plants were examined using liquid chromatography coupled with mass spectrometry. Two candidate geraniol synthase (GES) genes (CsTPS) and two Nudix hydrolase genes (CsNUDX1-cyto and CsNUDX1-chlo) from the tea genome were functionally investigated through gene transcription manipulation and gene chemical product analyses. Our data showed that in tea leaves, levels of geranyl β-primeveroside were dramatically higher than those of geranyl β-glucoside, while free geraniol was undetectable in this study. A tempo-spatial variation of geranyl β-primeveroside abundance in tea plants existed, with high levels in young and green tissues and low levels in mature or non-green tissues. Cytosolic CsNUDX1-cyto showed higher hydrolysis activity of geranyl-pyrophosphate to geranyl-monophosphate (GP) in vitro than did chloroplastidial CsNUDX1-chlo. A transgenic study revealed that expression of CsNUDX1-cyto resulted in significantly more geranyl β-primeveroside in transgenic Nicotiana benthamiana compared with non-transgenic wild-type, whereas expression of CsNUDX1-chlo had no effect. An antisense oligo-deoxynucleotide study confirmed that suppression of CsNUDX1-cyto transcription in tea shoots led to a significant decrease in geranyl β-primeveroside abundance. Additionally, CsNUDX1-cyto transcript levels and geranyl β-primeveroside abundances shared the same tempo-spatial patterns in different organs in the tea cultivar “Shucha Zao,” indicating that CsNUDX1-cyto is important for geranyl β-primeveroside formation in tea plants. Results also suggested that neither of the two candidate GES genes in tea plants did not function as GES in transgenic N. benthamiana. All our data indicated that CsNUDX1-cyto is involved in geranyl β-primeveroside production in tea plants. Our speculation about possible conversion from the chemical product of CsNUDX1-cyto to geranyl β-primeveroside in plants was also discussed.

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