Academic literature on the topic 'BERRY RIPENING, MASTER REGULATORS'

<p style="text-align: justify;"><strong>Aims</strong>: The objective was to better understand the mechanisms involved in grape ripening that brings about important changes in the physiology and chemistry of the fruit. So we focused on the involvement of two growth regulators: abscisic acid (ABA) and indol-acetic acid (IAA) in controlling grape berry ripening process.</p><p style="text-align: justify;"><strong>Methods and results</strong>: We described the evolution of the two plant growth regulators during the development of cv. Merlot grapes (Vitis vinifera L.). In order to better understand the role of ABA and IAA in the ripening control, these two growth regulators were applied on the grapes at the onset of veraison. The hormonal profile was established on treated berries and different physiological parameters were assayed to evaluate the effects of both applications. The partitioning of both plant growth regulators in nontreated berries showed that ABA and IAA accumulated at the onset of ripening. Moreover, it appeared that endogenous ABA decreased progressively in the flesh while accumulated in the skin from the beginning of the colour change to maturity. The hormonal treatments modified the hormonal profile and several physiological parameters: sugar, acidity, colour, and Botrytis sensibility.</p><p style="text-align: justify;"><strong>Conclusion</strong>: These findings suggest that both treatments have modified the ripening process. Exogenous ABA has induced advancement in grape ripening, while IAA application has delayed this process. These observations support the view that the grape ripening process may be influenced by the hormonal status.</p><p style="text-align: justify;"><strong>Significance and impact of study</strong>: This study gives new information about the ripening control of the non-climacteric fruits. In grape berries, it provides evidence of a possible co-involvement of ABA and IAA in controlling ripening process.</p>

Experiments were conducted during 1999 and 2000 at Griffin, Ga., with rabbiteye blueberries (Vaccinium ashei Reade) to determine how the growth regulator CPPU affected fruit set, berry size, and yield. CPPU (applied at two different timings) was used alone, and in conjunction with GA3 on mature, field-grown `Tifblue' plants. A control treatment without either growth regulator was also included. The CPPU concentration used was 10 mg·L-1 (a single application per treatment), and the GA3 concentration used was 200 mg·L-1 (two applications per treatment). Results from both years showed a positive benefit of CPPU with respect to fruit set and berry size, especially in the absence of GA3. Depending on timing, berry number per plant was increased by more than 200% in 1999 using CPPU. Berry size increases of more than 30% occurred in 2000 when CPPU alone was applied at 17 d after flowering (DAF). CPPU did not increase berry size of GA3-treated plants in either year. Total yield per plant during 2000 was 5.0, 7.1, and 8.3 kg for control, CPPU applied 7 DAF, and CPPU applied 17 DAF treatments, respectively, without GA3. While CPPU did substantially increase fruit set, berry size, and yield of `Tifblue', there was a notable delay in fruit ripening. These results suggest that CPPU may be useful for increasing yield of rabbiteye blueberries under conditions of inadequate fruit set (such as occurs in much of the Southeast), but a delay in ripening will likely result. Chemical names used: N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU); gibberellic acid (GA3).

The effects of 2,3,5-triiodobenzoic acid (TIBA) and naphthaleneacetic acid (NAA) on berry maturation and photoassimilates partitioning were investigated. Five-year-old potted `Kyoho' grape grown under a non-heating glasshouse were used. TIBA (200 mg/L) and NAA (200 mg/L) were applied to clusters at the beginning of veraison (45 days after full bloom). TIBA application increased not only soluble solids concentration in the juice but also anthocyanin content of peel, compared with those of control. On the other hand, the application of NAA reduced berry growth and delayed the berry maturation with harder flesh, lower soluble solids, higher acidity and poor coloration. In order to examine the effect of both plant growth regulators on photoassimilates partitioning in plant tissues, the whole plants were fed with 13CO2 at 10 days and 20 days after application of TIBA and NAA. The 13C distribution of pericarp and peel in NAA application was found on the lowest among the treatments. However, there were no significant differences in the 13C distribution and 13C absorption rate of pericarps between TIBA and control. These results indicate that NAA weakened the sink activity in grape berries, resulted in smaller berry size and the delay of maturation, whereas the berry ripening induced by TIBA application could not be explained by the distribution of photoassimilates in grape berries.

Grapevine (Vitis vinifera L.) fruit ripening is a complex biological process involving a phase transition from immature to mature. Understanding the molecular mechanism of fruit ripening is critical for grapevine fruit storage and quality improvement. However, the regulatory mechanism for the critical phase transition of fruit ripening from immature to mature in grapevine remains poorly understood. In this work, to identify the key molecular events controlling the critical phase transition of grapevine fruit ripening, we performed an integrated dynamic network analysis on time-series transcriptomic data of grapevine berry development and ripening. As a result, we identified the third time point as a critical transition point in grapevine fruit ripening, which is consistent with the onset of veraison reported in previous studies. In addition, we detected 68 genes as being key regulators involved in controlling fruit ripening. The GO (Gene Ontology) analysis showed that some of these genes participate in fruit development and seed development. This study provided dynamic network biomarkers for marking the initial transcriptional events that characterizes the transition process of fruit ripening, as well as new insights into fruit development and ripening.

Currently, viticulture is using plant growth regulators as an alternative to increasing grape and must quality for vinification. This work aimed to evaluate the effect of different doses of abscisic acid and ethephon on the quality of Merlot grapes. The plant growth regulators were applied isolated and combined, on the stages of veraison and 15 days before harvest (DBH). The parameters of mass and berry diameter, soluble solids content, titratable acidity, must pH, phenolic compounds, and total anthocyanin contents. The results showed that the application of ethephon at the dose of 200 mg∙L-1 on veraison caused an earlier bunch threshing, an increased berry peel sensibility, and rupture ripening grapes, in both productive cycles. The use of abscisic acid at the dose of 600 mg∙L-1 helped increase the soluble solids content of the grapes, however, a strong influence of the climatic conditions was observed on the effect of the plant growth regulations on Merlot grapes.

Abstract Intensive agriculture poses new challenges for science and practice that go far beyond increasing the gross yield. They include the prevention of lodging of cereals when high agricultural background, the synchronization of fruit ripening, which is necessary for their machine harvesting, an increase in the proportion of early harvesting with its unchanged value. The competent use of plant growth regulators will allow solving such problems. In most cases, they are not used to increase the yield of dry matter per unit area. This task is successfully solved by such traditional means as fertilizers. Physiologically active compounds are widely used in vegetable and berry crops, in crops of grain and legumes. These crops, due to their biological characteristics, require management of growth and development during the period of crop formation, especially in conditions of the Non-Black Earth Zone. All common pea varieties are characterized by uneven ripening, cracking of beans, being close to the soil and significant lodging of stems. All these things force researchers to search for physiologically active compounds that can shorten the stem, activate photosynthetic activity, accelerate maturation, facilitate harvesting and increase productivity. Undoubtedly, as the understanding of the mechanisms of hormonal regulation of plant growth and development is expanded and deepened, more and more possibilities will appear for managing these processes to increase productivity or reduce labor costs.

The abscisic acid (ABA) increase and auxin decline are both indicators of ripening initiation in grape berry, and norisoprenoid accumulation also starts at around the onset of ripening. However, the relationship between ABA, auxin, and norisoprenoids remains largely unknown, especially at the transcriptome level. To investigate the transcriptional and posttranscriptional regulation of the ABA and synthetic auxin 1-naphthaleneacetic acid (NAA) on norisoprenoid production, we performed time-series GC-MS and RNA-seq analyses on Vitis vinifera L. cv. Cabernet Sauvignon grape berries from pre-veraison to ripening. Higher levels of free norisoprenoids were found in ABA-treated mature berries in two consecutive seasons, and both free and total norisoprenoids were significantly increased by NAA in one season. The expression pattern of known norisoprenoid-associated genes in all samples and the up-regulation of specific alternative splicing isoforms of VviDXS and VviCRTISO in NAA-treated berries were predicted to contribute to the norisoprenoid accumulation in ABA and NAA-treated berries. Combined weighted gene co-expression network analysis (WGCNA) and DNA affinity purification sequencing (DAP-seq) analysis suggested that VviGATA26, and the previously identified switch genes of myb RADIALIS (VIT_207s0005g02730) and MAD-box (VIT_213s0158g00100) could be potential regulators of norisoprenoid accumulation. The positive effects of ABA on free norisoprenoids and NAA on total norisoprenoid accumulation were revealed in the commercially ripening berries. Since the endogenous ABA and auxin are sensitive to environmental factors, this finding provides new insights to develop viticultural practices for managing norisoprenoids in vineyards in response to changing climates.

This report presents an efficient protocol of the stable genetic transformation of coffee plants expressing the Cry10Aa protein of Bacillus thuringiensis. Embryogenic cell lines with a high potential of propagation, somatic embryo maturation, and germination were used. Gene expression analysis of cytokinin signaling, homedomains, auxin responsive factor, and the master regulators of somatic embryogenesis genes involved in somatic embryo maturation were evaluated. Plasmid pMDC85 containing the cry10Aa gene was introduced into a Typica cultivar of C. arabica L. by biobalistic transformation. Transformation efficiency of 16.7% was achieved, according to the number of embryogenic aggregates and transgenic lines developed. Stable transformation was proven by hygromycin-resistant embryogenic lines, green fluorescent protein (GFP) expression, quantitative analyses of Cry10Aa by mass spectrometry, Western blot, ELISA, and Southern blot analyses. Cry10Aa showed variable expression levels in somatic embryos and the leaf tissue of transgenic plants, ranging from 76% to 90% of coverage of the protein by mass spectrometry and from 3.25 to 13.88 μg/g fresh tissue, with ELISA. qPCR-based 2−ΔΔCt trials revealed high transcription levels of cry10Aa in somatic embryos and leaf tissue. This is the first report about the stable transformation and expression of the Cry10Aa protein in coffee plants with the potential for controlling the coffee berry borer.

The article presents data on determining the effectiveness of the use of the growth regulator Organostim on grapes of the Arcadia variety in the conditions of the Orenburg region. The studies were carried out on the basis of the Orenburg branch of the Federal Research Center of Horticulture from 2019 to 2021. Vineyard was established in 2012. Objects of research were the introduced grape variety Arcadia, growth regulator Organostim, VR (15 g/l dihydroquercetin + 30 g/l triethanolammonium salt of orthoresoxyacetic acid). Getting a stable harvest occupies one of the main places in the viticulture industry of the Orenburg region. In modern agriculture, plant growth regulators are used, which improve plant root nutrition, increase resistance to stress factors, stimulate plant growth, the formation of ovaries and berries, accelerate ripening times, and improve product quality. As a result of the studies, data were obtained that showed that when using the Organostim option (2.0 l / ha), the maximum number of bunches was noted (12 pcs.), average berry weight (7.4 g), number of berries per bunch (105 pcs.). There is an increase in the mass of the bunch and productivity at a rate of consumption of an agrochemical of 2.0 l / ha by 22 % and 111 %, respectively, relative to the control variant. It was revealed that the average yield per hectare when using Organostim (2.0 l/ha) was 11.4 t/ha, and the increase was 6.0 tons. As a result of the studies, the effectiveness of the use of the plant growth regulator Organostim on the Arcadia grape variety was established.

Grapevine is one of the most important and cultivated fruit crops in the world. Its economic importance is especially related to winemaking and the production of high-quality grape is one of the major concerns of the viticulturists. In the last years, continuous temperatures increasing have caused an anticipation of the onset of berry ripening, called veraison, modifying the physiological characteristics of grape, its final quality and consequently wine quality. To prevent these negative effects, the interpretation of the molecular mechanisms controlling this process could provide allow the development of more specific and targeted intervention strategies. To this aim, many molecular studies have been performed. One of the most important is represented by the generation of the grapevine gene expression atlas; this study showed a transcriptomic reprogramming during the vegetative-to-mature transition, suggesting the existence of key regulator genes. Further studies showed that this phase transition seem to be regulated by specific genes, defined switch genes; they are mainly transcription factors and the identification of the functions of these genes could provide important details about the molecular mechanism controlling the maturation process in grapevine. Among these transcription factors, five of them, VviNAC33, VviNAC60, VviAGL15, VviWRKY19 and VvibHLH75, have been selected for functional characterization. Their functional analysis in grapevine has been performed using stable genetic transformation and transient gene expression approaches. The application, improvement and development of these approaches has supported the functional characterization of the five selected genes. Regarding the stable transformation, to identify a standard method, 3 different protocols in 3 different cultivars, using GFP as reporter gene, have been tested. The results showed that the regeneration of transgenic somatic embryos and plants occurred only in Shiraz and Garganega cultivars using embryogenic calli as transformation material, indicating that this complex process is cultivar-dependent. Stable genetic transformation was used for the functional analysis of both VviNAC33 and VviNAC60. In a previous work, both NAC genes have been overexpressed in grapevine plants; the overexpression of VviNAC33 has altered the chlorophyll metabolism, while the overexpression of VviNAC60 has caused stunted growth and anthocyanins leaf accumulation, indicating that both genes are involved in the regulation of vegetative-to-mature transition. In this PhD project, both NAC gene have been fused with EAR motif, the strongest transcriptional repression domain in plants, and stably expressed in Garganega and Shiraz plants. The results showed that some putative target genes of both NAC transcription factors are less expressed than WT plants, indicating that EAR motif represents a good approach to study the function of a transcription factor. Regarding transient gene expression, this method was used for the functional analysis of VviAGL15, VviWRKY19 and VvibHLH75. Leaf agroinfiltration was optimized using YFP as reporter gene and tested in different cultivars by a vacuum system. The analysis of YFP transient expression showed that the fluorescence signal is especially localized in the first and second leaf from apex. VviAGL15, VviWRKY19 and VvibHLH75 have been functionally characterized using the improved leaf agroinfiltration protocol. Each transcription factor was co-expressed with YFP gene: the visualization of its expression has allowed to select only agroinfiltrated leaves. Next microarray analysis of overexpressing leaves showed that many upregulated genes are involved in processes associate with ripening, and an exhaustive molecular interpretation of these preliminary results seem to indicate that VviAGL15, VviWRKY19 and VvibHLH75 are master regulators of the onset of berry ripening, controlling many aspects of the maturation programs.

La vite (Vitis vinifera L.), una delle più coltivate piante da frutto, riveste notevole importanza economica in tutto il mondo. Poichè negli ultimi decenni la viticoltura sta subendo gli effetti del riscaldamento globale (Webb et al., 2007), è necessario mantenere una produzione di uva e vino di elevata qualità. Una delle maggiori sfide consiste nell’identificazione dei principali geni regolatori dello sviluppo della pianta di vite durante il ciclo vegetale annuale e, in particolare, della transizione dalla fase vegetativa a quella matura (detta véraison), durante la quale avvengono profonde modificazioni biochimiche, fisiologiche e trascrizionali. Grazie ad un'analisi di network di co-espressione sull’atlante del trascrittoma della vite e ad un dataset di dati trascrizionali di bacche (Massonnet, 2015; Palumbo et al., 2014; Fasoli et al., 2012), è stata identificata una nuova categoria di geni chiamata 'switch’; tali geni sono significativamente up-regolati durante la transizione di fase ed inversamente correlati a molti geni soppressi durante la fase matura. Tra questi, i fattori di trascrizione NAM/ATAF/CUC (NAC) rappresentano un’interessante famiglia genica dato il ruolo chiave in processi biologici come sviluppo e risposte allo stress in pianta (Jensen et al., 2014). Per la caratterizzazione funzionale cinque geni NAC sono stati selezionati come putativi principali regolatori della riprogrammazione del trascrittoma durante la maturazione della vite. VvNAC11, VvNAC13, VvNAC33 e VvNAC60 sono stati identificati come geni 'switch' dalla sopra citata analisi, mentre VvNAC03 come gene omologo a NOR (non-ripening) di pomodoro, uno dei principali regolatori della maturazione di tale frutto (Giovannoni, 2004; Giovannoni et al., 1995). I cinque NAC sono stati sovra-espressi transientemente in Vitis vinifera per ottenere una panoramica dei loro effetti primari sul trascrittoma. Sono poi state ottenute e caratterizzate dal punto di vista molecolare e fenotipico piante di vite stabilmente trasformate con VvNAC33 e VvNAC60. VvNAC33 sembra essere coinvolto nella regolazione negativa della fotosintesi poiché le foglie sovra-esprimenti tale gene contengono una minor quantità di clorofilla, mentre VvNAC60 provoca una ridotta crescita della pianta e una prematura lignificazione dello stelo rispetto ad una pianta controllo della stessa età. Questi risultati riflettono comportamenti tipici di piante in fase di maturazione e senescenza, sostenendo l’ipotesi di un ruolo fondamentale dei NAC nella transizione di fase in vite. Al fine di identificare i target che agiscono a valle dei NAC, sono state eseguite analisi microarray sulle foglie delle piante trasformate in modo transiente e stabile. In entrambe le over-espressioni è stata influenzata l’espressione di un'ampia gamma di processi cellulari tra cui, tra le categorie funzionali più rappresentate, vi sono trasporto, metabolismo secondario e attività dei fattori di trascrizione. L'identificazione di VvMYBA1, un noto regolatore della biosintesi degli anotciani in vite (Kobayashi et al., 2002), come target di VvNAC60 suggerisce un ruolo di tale NAC in processi tipici dell’inizio della maturazione. Un altro approccio utilizzato in questo lavoro è stato la complementazione funzionale del mutante nor di pomodoro con i NAC selezionati. Risultati preliminari hanno rivelato che VvNAC03 e VvNAC60 sembrano avere una funzione simile a NOR poichè riescono a maturare almeno esternamente. In conclusione, i risultati ottenuti in questo lavoro suggeriscono la capacità dei VvNAC selezionati di influenzare l'espressione di geni coinvolti nella regolazione che controlla lo sviluppo dalla fase vegeativa alla fase matura in vite. Questo lavoro ha inizato a far luce sul ruolo dei NAC nello sviluppo della vite, ma dovranno essere effettuate ulteriori analisi per ottenere una piena compresione del macchinario molecolare che regola questo complesso sistema di regolazione.
Grapevine is the most widely cultivated and economically important fruit crop in the world. Viticulture has been affected by the global warming currently under way over the past few decades (Webb et al., 2007). Improving the genetics of key grapevine functions is needed to keep producing high quality grapes and wine. In this context, a challenging task is to identify master regulators that program the development of grapevine organs and control transition from vegetative-to-mature growth featured by grape berries during the annual plant cycle. This transition, called véraison, is marked by profound biochemical, physiological and transcriptomic modifications that allow vegetative green berries to enter the ripening process. Thanks to an integrated network analysis performed on the grapevine global gene expression atlas and from a large berry transcriptomic data set (Massonnet, 2015; Palumbo et al., 2014; Fasoli et al., 2012) a new category of genes, called ‘switch’ genes, was identified; they were significantly up-regulated during the developmental shift and inversely correlated with many genes suppressed during the mature growth phase. Among them, plant-specific NAM/ATAF/CUC (NAC) transcription factors represent an interesting gene family due to their key role in the biological processes in plant development and stress responses (Jensen et al., 2014). Five NAC genes were selected for functional characterization as key factor candidates of the major transcriptome reprogramming during grapevine development. VvNAC11, VvNAC13, VvNAC33 and VvNAC60 were identified as ‘switch’ genes in the above-mentioned analysis whereas VvNAC03 was selected because it is a close homologue of tomato NOR (non-ripening), known for its crucial role in tomato fruit ripening regulation (Giovannoni, 2004; Giovannoni et al., 1995). Firstly, the five transcription factors were transiently over-expressed in Vitis vinifera to get an overview of their primary effects on native species. Secondly, we obtained grapevine plants that were stably transformed with VvNAC33 and VvNAC60 and subjected to molecular/phenotypic characterizations. VvNAC33 seemed to be involved in negative regulation of photosynthesis since over-expressing leaves revealed a chlorophyll breakdown, while VvNAC60 affected regular plant development, showing a slight growth and earlier stem lignification in comparison to a same-age plant control. These results reflected typical behaviors of plants undergoing ripening and senescence, thus supporting our working hypothesis proposing a crucial role of NACs in the transition from vegetative to mature development in grapevine. In order to identify downstream targets of the NAC transcription factors analyzed in this work, we performed microarray analysis on leaves of transient and stable ectopic expressing plants. We noted that both over-expressions affected a wide range of cellular processes and among the most represented functional categories we found transport, secondary metabolism and transcription factor activity. The identification of VvMYBA1, a known grapevine regulator of the anthocyanin biosynthetic pathway (Kobayashi et al., 2002), as VvNAC60 target suggests a VvNAC60 role in processes like anthocyanin biosynthesis featured by grape berries at the onset of ripening. Another approach used to clarify NACs roles was to check the ability of VvNACs to fulfil the tomato NOR function. Preliminary results revealed that VvNAC03 and VvNAC60 could partially complement the nor mutation in tomato, establishing a partial ripening phenotype in fruits. Taken together, these findings suggest the ability of the selected VvNACs to affect the expression of genes involved in the regulatory network that controls the developmental shift to a mature phase in grapevine. This work has shed some light on the roles of these NACs in grapevine development, but further analysis must be conducted to fully elucidate the molecular machinery in this complex regulation system.

Objectives: The objectives of the proposal were to study how potassium (K) enters the berry and in what tissues it accumulates, to determine what is the sensitive phenological stage that is responsive to K, to study the influence of K on sugar translocation, to determine if K has effects on expression of genes in source and sink organs and to study applied aspects of the responses to K at the vineyard level. During the research it was realized that K acts externally so a major part of the original objectives had to be deserted and new ones, i.e. the role of K in enhancing water loss from the berry, had to be developed. In addition, the US partners developed practical objectives of understanding the interaction of K application and water deficit as well as application of growth regulators. Background: In our preliminary data we showed that application of K at mid-ripening enhanced sugar accumulation of table grapes. This finding is of major implications to both early and late harvested grapes and it was essential to understand the mode of action of this treatment. Our major hypothesis was that K enters the berry and by that increases sugar translocation into the berry. In addition it was important to cover practical issues of the application which may influence its efficacy and its reproducibility. Conclusions: The major conclusion from the research was that our initial hypothesis was wrong. Mineral analysis of pulp tissue indicated that upon application of K there was a significant increase in most of the major minerals. Subsequently, we developed a new hypothesis that K acts by increasing the water loss from the berry. In vitro studies of K-treated berries corroborated this hypothesis showing greater weight-loss of treated berries. This was not necessarily expressed in the vineyard as in some experiments berry weight remained unchanged, suggesting that the vine compensated for the enhanced water loss. Importantly, we also discovered that the efficacy of different K salts was strongly correlated to the pH of the salt solution: basic K salts had better efficacy than neutral or acidic salts and modifying the pH of the same salt changed its efficacy. It was therefore suggested that K changes the properties of the cuticle making it more susceptible to water loss. Of the practical aspects it was found that application of K to the clusters was sufficient to trigger its affect and that dual application of K had a stronger effect than single application. With regard to timing, it was realized that application of K after veraison was affective and the berries responded also when ripe. While the effect of K application was significant at harvest, it was mostly insignificant one week after application, suggesting that prolonged exposure to K was required. Implications: The scientific implications of the study are that the external mineral composition of the berry may have a significant role in sugar accumulation and that water loss may have an important role in sugar accumulation in grapes. It is not entirely clear how K modulates the cuticle but according to the literature its incorporation into the cuticle may increase its polarity and facilitate generation of "water bridges" between the flesh and the environment. The practical implications of this study are very significant because realizing the mode of action of K can facilitate a much more efficient application strategy. For example, it can be understood that sprays must be directed to the clusters rather than the whole vines and it can be predicted that the length of exposure is important. Also, by increasing the pH of simple K salts, the efficacy of the treatment can be enhanced, saving in the costs of the treatment. Finally, the ability of grape growers to apply K in a safe and knowledgeable way can have significant impact on the length of the season of early grape cultivars and improve the flavor of high grape yields which may otherwise have compromised sugar levels.