Journal articles on the topic 'Synthetic auxins'
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1
Moncada, Alessandra, Filippo Vetrano, Alessandro Esposito, and Alessandro Miceli. "Effects of NAA and Ecklonia maxima Extracts on Lettuce and Tomato Transplant Production." Agronomy 12, no. 2 (January 27, 2022): 329. http://dx.doi.org/10.3390/agronomy12020329.
Abstract:
Ecklonia maxima and the commercial biostimulants produced from it contain various plant growth regulators that are responsible for the growth stimulation recorded in many crops. Auxins are one of the major plant growth regulators contained in E. maxima extracts. The aim of this research was to evaluate the growth-promoting effect of a seaweed extract from E. maxima on lettuce and tomato transplant production under nursery conditions, and to compare the effect of this extract with an equal concentration of synthetic auxin. Two doses of natural or synthetic exogenous auxins (50 or 100 μg L−1) were supplied to the substrate through the irrigation water with an ebb and flow system, 4, 11, and 18 days after sowing. A commercial biostimulant based on E. maxima extract was used as a source of natural auxin, while 1-naphthaleneacetic acid (NAA) was used as a synthetic auxin. Seedlings supplied only with water were used as a control. Tomato seedlings treated with 100 μg L−1 of natural auxins from E. maxima extract produced the tallest plants (+22%), with a higher leaf number (+12%), a wider leaf area (+44%), and a stronger stem (+12%), whereas lettuce seedling growth was promoted by all the treatments, but with a greater effect with increasing auxin supplementation and when using E. maxima extract, compared to NAA. The results showed that the supplementation of exogenous synthetic auxin (NAA), or an E. maxima extract containing natural auxins, can have a growth-promoting effect on lettuce and tomato seedlings. This effect was more evident on lettuce than tomato. The biostimulant produced from E. maxima extracts improved seedling quality and promoted shoot and root growth more than the NAA used as a synthetic source of auxins.
2
Prieto-Martínez, Fernando D., Jennifer Mendoza-Cañas, and Karina Martínez-Mayorga. "To Bind or Not to Bind? A Comprehensive Characterization of TIR1 and Auxins Using Consensus In Silico Approaches." Computation 12, no. 5 (May 9, 2024): 94. http://dx.doi.org/10.3390/computation12050094.
Abstract:
Auxins are chemical compounds of wide interest, mostly due to their role in plant metabolism and development. Synthetic auxins have been used as herbicides for more than 75 years and low toxicity in humans is one of their most advantageous features. Extensive studies of natural and synthetic auxins have been made in an effort to understand their role in plant growth. However, molecular details of the binding and recognition process are still an open question. Herein, we present a comprehensive in silico pipeline for the assessment of TIR1 ligands using several structure-based methods. Our results suggest that subtle dynamics within the binding pocket arise from water–ligand interactions. We also show that this trait distinguishes effective binders. Finally, we construct a database of putative ligands and decoy compounds, which can aid further studies focusing on synthetic auxin design. To the best of our knowledge, this study is the first of its kind focusing on TIR1.
3
Yue, Wang, Sun Fulai, Gao Qingrong, Zhang Yanxia, Wang Nan, and Zhang Weidong. "Auxins Regulations of Branched Spike Development and Expression of TFL, a LEAFY-Like Gene in Branched Spike Wheat (Triticum aestivum)." Journal of Agricultural Science 9, no. 2 (January 11, 2017): 27. http://dx.doi.org/10.5539/jas.v9n2p27.
Abstract:
Branched spike wheat is a hexaploid germplasm with branched rachis on its main rachises, and the crucial period for branched rachises occurrence and development is just after the two ridges stage of shoot apex. Natural [indole-3-acetic acid (IAA), indole-3butyric acid (IBA)] and synthetic [(1-naphthaleneacetic acid (NAA), 2,4-Dichlorophenoxyacetic acid (2,4-D)] auxins were applied at this period to investigate the spike traits, seedling growth and photosynthesis related characters and expression of a putative homologue of the LEAFY in branched spike wheat. The four types of experienced auxins induced similar effects on these foresaid characters, although the impact extents were different among the auxins treatments. More branched rachis, spikelets, fertile florets and longer branched rachis were obtained in plants with IAA and IBA at 0.1 mM or NAA and 2,4-D at 1.0mM than those plants with no auxin treated. Auxin treatments also increased fresh and dry mass, photosynthetic pigment and parameters. TFL, a LEAFY-like gene was cloned in branched spike wheat and TFL mRNA expression was quantified using real-time reverse transcriptase-PCR. Application of the auxins accelerated the rise in TFL expression during the periods of branched rachises occurrence and extension. The data supports the hypothesis that auxins play a central role in the regulation branched spike development and TFL might correlate with the development of branched rachises in branched spike wheat.
4
Kudirka, Dalia T., and Blanche B. Brightwell. "The indirect effect of exogenous auxin on initiation of cell divisions in wheat root expiants (Triticum aestivum) during callus induction." Canadian Journal of Botany 67, no. 7 (July 1, 1989): 1979–84. http://dx.doi.org/10.1139/b89-251.
Abstract:
Mitotic activity (indices) was measured in apical and nonapical regions of primary root explants excised from 2-day-old germinating seedlings of wheat (Triticum aestivum Thell em L.) and cultured in the presence of the synthetic auxins 3,6-dichloro-O-anisic acid (dicamba) and 2,4-dichlorophenoxyacetic acid (2,4-D). Mitotic activity in the root apical meristem decreased with increasing concentration of auxin in the culture media. Correlated with the decrease of mitotic activity in the root apical meristem was an increase of mitotic activity in nonapical regions of the root. The degree of cell division activity initiated in nonapical regions of the root was (i) inversely proportional to the degree of inhibition of cell divisions in the root apex, but (ii) independent of the concentration of auxin in the culture medium. These data suggest that the primary effect of these synthetic auxins on mitotic activity in wheat root explants is to suppress cell divisions in the primary root apex and not to stimulate cell divisions in the nonapical regions of the root. Cell cycle control in nonapical regions of the root appears to be a function of factor(s) emanating from mitotically active cells of the primary apical meristem.
5
СHETVERIKOV, Sergey, Arina FEOKTISTOVA, Maxim TIMERGALIN, Timur RAMEEV, Gaisar HKUDAYGULOV, Aliya KENDJIEVA, Margarita BAKAEVA, Darya СHETVERIKOVA, Sergey STARIKOV, and Danil SHARIPOV. "Mitigation of the negative effect of auxinic herbicide by bacterial suspension of Pseudomonas protegens DA1.2 in wheat plants under drought conditions." Acta agriculturae Slovenica 119, no. 1 (April 28, 2023): 1. http://dx.doi.org/10.14720/aas.2023.119.1.2764.
Abstract:
<p class="042abstractstekst"><span lang="EN-US">Effect of auxin-producing bacterial strain (<em>Pseudomonas protegens</em> DA1.2) was investigated under conditions of drought and herbicide treatment in wheat plants. Positive effect of the bacterial suspension on wheat plants treated with auxinic herbicide under drought conditions was manifested in reducing the content of malondialdehyde and proline, preventing inhibition of plant growth and normalizing chlorophyll content. Under combined stress, changes in concentrations and redistribution of phytohormones in plants were detected. An imbalance in auxin distribution between shoots and roots could be the reason for the decrease in plant resistance to drought in combination with the herbicide. Treatment of plants with the bacterial suspension restored normal shoot-to-root ratio of auxins in plants. Thus, this bacterial strain showed the properties of synthetic auxin antidotes and can be recommended for optimizing the technology of herbicide application under drought conditions.</span></p>
6
Tsygankova, VA, V. Andrusevich Ya, NM Vasylenko, SG Pilyo, SV Klyuchko, and VS Brovarets. "Screening of Auxin-like Substances among Synthetic Compounds, Derivatives of Pyridine and Pyrimidine." Journal of Plant Science and Phytopathology 7, no. 3 (December 12, 2023): 151–56. http://dx.doi.org/10.29328/journal.jpsp.1001121.
Abstract:
The effect of known synthetic compounds Ivin (N-oxide-2,6-dimethylpyridine), Methyur (sodium salt of 6-methyl-2-mercapto-4-hydroxypyrimidine), Kamethur (potassium salt of 6-methyl-2-mercapto-4-hydroxypyrimidine) and new synthetic compounds, derivatives of pyrimidine (No. 1 - 7) on the rooting of isolated stem cuttings of haricot bean (Phaseolus vulgaris L.) variety Bilozernaya was studied. The growth regulatory activity of synthetic compounds Ivin, Methyur, Kamethur, and synthetic compounds, derivatives of pyrimidine (No. 1 - 7) was compared with the activity of auxins IAA (1H-indol-3-yl)acetic acid) and NAA (1-naphthylacetic acid). The conducted studies showed that the regulatory effect of synthetic compounds Ivin, Methyur, Kamethur, and synthetic compounds, derivatives of pyridine (No. 1 - 7) on the rooting of isolated stem cuttings of haricot bean was similar to the auxins IAA and NAA. The synthetic compounds Ivin, Methyur, and Kamethur, and synthetic compounds, derivatives of pyrimidine (No. 1, 4, 5, and 7) showed the highest auxin-like activity. The indicators of the total number of roots (pcs) and total length of roots (cm) obtained on isolated stem cuttings of haricot bean immersed in a water solution of synthetic compounds Ivin, Methyur, Kamethur and synthetic compounds, derivatives of pyridine (No. 1, 4, 5 and 7), used at a concentration of 10-7 M, statistically significantly exceeded similar indicators obtained on control isolated stem cuttings of haricot bean immersed in distilled water. The practical use of synthetic compounds Ivin, Methyur, Kamethur, and synthetic compounds, derivatives of pyrimidine (No. 1, 4, 5 and 7) is proposed to improve the vegetative propagation of haricot bean plants (Phaseolus vulgaris L.) and other plant species of the family Fabaceae by stem cuttings.
7
Mihaljević, S., and B. Salopek-Sondi. " Alanine conjugate of indole-3-butyric acid improves rooting of highbush blueberries." Plant, Soil and Environment 58, No. 5 (May 29, 2012): 236–41. http://dx.doi.org/10.17221/34/2012-pse.
Abstract:
Auxins and their synthetic analogues are commonly used for rooting of cuttings, but their efficiency depends on experimental set-up and, even more importantly, on species or cultivar, and type of explants investigated. In attempt to improve rooting procedure for highbush blueberries (Vaccinium corymbosum L.), we investigated alanine conjugate of indole-3-butyric acid (IBA-Ala) as potential root-promoting compound and compared with commonly used auxins indole-3-butyric acid (IBA) and indole-3-acetic acid (IAA). The effect of different concentrations of auxins on the rooting of highbush blueberry stem cuttings (var. Bluecrop, Bluetta, Burlington and Jersey) and in vitro-derived microcuttings (var. Jersey) was investigated. Auxin treatments significantly promoted rooting of all four varieties in comparison to control. The most efficient rooting promoter in all varieties appeared IBA-Ala (provided up to 83%, and 93% of the rooted cuttings and microcuttings, respectively). Furthermore, IBA-Ala caused a vigorous, well-branched root system that resulted in better acclimatization and survival of plants. Results suggest the application of IBA-Ala may be beneficial for rooting of difficult-to-root varieties of blueberry and related species and their practical application in the nursery industry.
8
Pacholczak, Andrzej, Karolina Nowakowska, Natalia Mika, and Monika Borkowska. "The effect of the biostimulator Goteo on the rooting of ninebark stem cuttings." Folia Horticulturae 28, no. 2 (December 1, 2016): 109–16. http://dx.doi.org/10.1515/fhort-2016-0013.
Abstract:
Abstract As a consequence of restrictions on the use of preparations containing synthetic auxins in nursery production, there is a necessity to replace them with more environmentally friendly biopreparations efficiently stimulating plant growth. The aim of the presented experiment was to compare the effects of the synthetic auxin indole-3-butyric acid (IBA) and the biostimulator Goteo on the rooting of ninebark stem cuttings (Physocarpus opulifolius ‘Dart’s Gold’ and ‘Red Baron’) and to get some insight into the latter’s mechanisms of action in plants. Applications of the biostimulator Goteo produced comparable or slightly weaker effects compared to the treatments with IBA. Goteo stimulated elongation in new growth of cuttings when applied in watering or two-fold spraying methods. Application of the biostimulator resulted in increased levels of chlorophyll, soluble sugars and indole derivatives, while the contents of free amino acids and polyphenolic acids decreased. The above results indicate that, if necessary, Goteo may replace the synthetic auxin IBA in the propagation of ninebark in the future.
9
Gho, Yun-Shil, Min-Yeong Song, Do-Young Bae, Heebak Choi, and Ki-Hong Jung. "Rice PIN Auxin Efflux Carriers Modulate the Nitrogen Response in a Changing Nitrogen Growth Environment." International Journal of Molecular Sciences 22, no. 6 (March 23, 2021): 3243. http://dx.doi.org/10.3390/ijms22063243.
Abstract:
Auxins play an essential role in regulating plant growth and adaptation to abiotic stresses, such as nutrient stress. Our current understanding of auxins is based almost entirely on the results of research on the eudicot Arabidopsis thaliana, however, the role of the rice PIN-FORMED (PIN) auxin efflux carriers in the regulation of the ammonium-dependent response remains elusive. Here, we analyzed the expression patterns in various organs/tissues and the ammonium-dependent response of rice PIN-family genes (OsPIN genes) via qRT–PCR, and attempted to elucidate the relationship between nitrogen (N) utilization and auxin transporters. To investigate auxin distribution under ammonium-dependent response after N deficiency in rice roots, we used DR5::VENUS reporter lines that retained a highly active synthetic auxin response. Subsequently, we confirmed that ammonium supplementation reduced the DR5::VENUS signal compared with that observed in the N-deficient condition. These results are consistent with the decreased expression patterns of almost all OsPIN genes in the presence of the ammonium-dependent response to N deficiency. Furthermore, the ospin1b mutant showed an insensitive phenotype in the ammonium-dependent response to N deficiency and disturbances in the regulation of several N-assimilation genes. These molecular and physiological findings suggest that auxin is involved in the ammonium assimilation process of rice, which is a model crop plant.
10
Holik, Ladislav, Jiří Volánek, and Valerie Vranová. "Effect of Plant Growth Regulators on Protease Activity in Forest Floor of Norway Spruce Stand." Forests 12, no. 6 (May 24, 2021): 665. http://dx.doi.org/10.3390/f12060665.
Abstract:
Soil proteases are involved in organic matter transformation processes and, thus, influence ecosystem nutrient turnovers. Phytohormones, similarly to proteases, are synthesized and secreted into soil by fungi and microorganisms, and regulate plant rhizosphere activity. The aim of this study was to determine the effect of auxins, cytokinins, ethephon, and chlorocholine chloride on spruce forest floor protease activity. It was concluded that the presence of auxins stimulated native proteolytic activity, specifically synthetic auxin 2-naphthoxyacetic acid (16% increase at added quantity of 5 μg) and naturally occurring indole-3-acetic acid (18%, 5 μg). On the contrary, cytokinins, ethephon and chlorocholine chloride inhibited native soil protease activity, where ethephon (36% decrease at 50 μg) and chlorocholine chloride (34%, 100 μg) showed the highest inhibitory effects. It was concluded that negative phytohormonal effects on native proteolytic activity may slow down organic matter decomposition rates and hence complicate plant nutrition. The study enhances the understanding of rhizosphere exudate effects on soil microbial activity and soil nitrogen cycle.
11
Tsygankova Victoria, Anatolyivna, YaV Andrusevich, NM Vasylenko, VM Kopich, SV Popilnichenko, SG Pilyo, and VS Brovarets. "Auxin-like and Cytokinin-like Effects of New Synthetic Thienopyrimidine Derivatives on the Growth and Photosynthesis of Wheat." Journal of Plant Science and Phytopathology 8, no. 1 (March 19, 2024): 015–24. http://dx.doi.org/10.29328/journal.jpsp.1001126.
Abstract:
The regulatory effect of new synthetic thienopyrimidine derivatives on the growth and photosynthesis of wheat (Triticum aestivum L.) variety Svitlana in the vegetative phase was studied. The regulatory effect of new synthetic thienopyrimidine derivatives was compared with the regulatory effect of auxin IAA (1H-indol-3-yl)acetic acid) or synthetic plant growth regulators Methyur (sodium salt of 6-methyl-2-mercapto-4-hydroxypyrimidine) and Kamethur (potassium salt of 6-methyl-2-mercapto-4-hydroxypyrimidine). After 2 weeks, morphometric parameters (such as average length of shoots and roots (mm), average biomass of 10 plants (g)) and biochemical parameters (such as content of photosynthetic pigments (µg/ml)) of wheat plants grown from seeds treated with synthetic thienopyrimidine derivatives, or auxin IAA, or synthetic plant growth regulators Methyur and Kamethur at a concentration of 10-6M, were measured and compared with similar parameters of control wheat plants grown from seeds treated with distilled water. The regulatory effect of new synthetic thienopyrimidine derivatives on the morphometric and biochemical parameters of wheat plants was similar or higher compared to the regulatory effect of auxin IAA, or synthetic plant growth regulators Methyur and Kamethur. The relationship between the chemical structure of new synthetic thienopyrimidine derivatives and their regulatory effect on the growth and photosynthesis of wheat plants was revealed. The most biologically active thienopyrimidine derivatives are proposed to be used as new synthetic physiological analogues of auxins and cytokinins to improve growth and increase photosynthesis of wheat (Triticum aestivum L.) variety Svitlana in the vegetative phase.
12
Somers, E., D. Ptacek, P. Gysegom, M. Srinivasan, and J. Vanderleyden. "Azospirillum brasilense Produces the Auxin-Like Phenylacetic Acid by Using the Key Enzyme for Indole-3-Acetic Acid Biosynthesis." Applied and Environmental Microbiology 71, no. 4 (April 2005): 1803–10. http://dx.doi.org/10.1128/aem.71.4.1803-1810.2005.
Abstract:
ABSTRACT An antimicrobial compound was isolated from Azospirillum brasilense culture extracts by high-performance liquid chromatography and further identified by gas chromatography-mass spectrometry as the auxin-like molecule, phenylacetic acid (PAA). PAA synthesis was found to be mediated by the indole-3-pyruvate decarboxylase, previously identified as a key enzyme in indole-3-acetic acid (IAA) production in A. brasilense. In minimal growth medium, PAA biosynthesis by A. brasilense was only observed in the presence of phenylalanine (or precursors thereof). This observation suggests deamination of phenylalanine, decarboxylation of phenylpyruvate, and subsequent oxidation of phenylacetaldehyde as the most likely pathway for PAA synthesis. Expression analysis revealed that transcription of the ipdC gene is upregulated by PAA, as was previously described for IAA and synthetic auxins, indicating a positive feedback regulation. The synthesis of PAA by A. brasilense is discussed in relation to previously reported biocontrol properties of A. brasilense.
13
Rouphael, Yousseph, Luigi Formisano, Michele Ciriello, Maria Teresa Cardarelli, Francesca Luziatelli, Maurizio Ruzzi, Anna Grazia Ficca, Paolo Bonini, and Giuseppe Colla. "Natural biostimulants as upscale substitutes to synthetic hormones for boosting tomato yield and fruits quality." Italus Hortus 28, no. 1 (May 13, 2021): 88. http://dx.doi.org/10.26353/j.itahort/2021.1.8899.
Abstract:
Natural biostimulants are one of the most promising and eco-sustainable technologies, which can improve the qualitative and productive attributes of horticultural crops. The positive effects of their application derive from their “signaling role” as elicitors of auxin- and gibberellin-like activity, thus constituting a valid alternative to synthetic hormones. Our research aimed to assess the efficacy of a plant extract (Heptamin®) and a bacterial culture filtrate (Capxium®), both rich in natural auxins, and of a synthetic auxin (Auxyger® LG) on the quantitative and qualitative performance, as well as on the economic returns of greenhouse table tomato (Solanum lycopersicum L. cv. Pitagora). The application of plant extract increased the marketable yield (+25.8%), firmness (+25.7%), and fruit lycopene content (+42.5%) compared to the untreated control. In particular, natural biostimulants outperformed synthetic auxin by inducing higher fruit weight (13.1%) and marketable yield (16.2%). On the other hand, no significant differences were recorded as a result of the treatments regarding total soluble solids, pH, and titratable acidity of the fruit juice. Our results suggest that plant biostimulants with auxin-like activity are an excellent tool for boosting tomato production and fruit quality in an eco-sustainable approach. Finally, economic analysis revealed that the application of natural biostimulants resulted in overall higher profitability
14
Świerczyński, Sławomir. "Comparison of the efficiency of synthetic auxins and biostimulants and two types of substrate in rooting of shoot cuttings in ‘Pi-ku 1’ rootstock." Acta Scientiarum Polonorum Hortorum Cultus 23, no. 2 (April 30, 2024): 103–15. http://dx.doi.org/10.24326/asphc.2024.5308.
Abstract:
The low-cost propagation of semi-dwarf cherry rootstock is an essential issue in the production of maiden trees of this species. Among the promising rootstocks is ‘Pi-ku 1’, obtained in Germany. However, the possibility of its propagation using shoot cuttings has not been investigated. It was the purpose of this study. Two ways of cuttings treatment before placing them in the substrate were assessed. One used two preparations in powder (Rhizopon AA and Ukorzeniacz AB), and the second used two alcoholic auxin solutions (IAA and IBA). Instead of synthetic auxins, foliar spraying with two biostimulants was performed (Goteo and Bispeed). All the applied treatments increased the rooting percentage of ‘Pi-ku 1’ rootstock cuttings compared to the control from 5% for Rhizopon AA to 18.2% for auxin IBA. The exception was the lack of a positive effect of the Bispeed biostimulant (less than 5.2%). The use of synthetic auxins increased the number of utting roots more than three times (IBA) or almost twice (Ukorzeniacz AB) and their length more than twofold (IAA, Rhizopon AA) in proportion to the control. The effect of synthetic auxin treatments on the remaining growth parameters under study was also positive. Foliar treatment of cuttings with biostimulants did not change their growth. Only in one of the two years of the study did the fresh mass of cuttings improve after using Goteo biostimulant (7.5%). As part of the experiment, the effect of two substrate types – peat mixed with perlite and peat with sand – was also tested. During the two years of research, the cuttings were rooted several percent better in peat and sand (2.7% – 2018 and 4.4% – 2019). Using peat with sand as a rooting substrate significantly improved the number and length of roots (11.90 and 125.10) of Pi-ku 1 rootstock cuttings compared to the second one (9.23 and 109.08, respectively). All treatments applied to cuttings, except two biostimulants, increased the amount of chlorophyll in the leaves.
15
Šerhantová, V., J. Ehrenbergerová, and L. Ohnoutková. "Callus induction and regeneration efficiency of spring barley cultivars registered in the Czech Republic." Plant, Soil and Environment 50, No. 10 (December 10, 2011): 456–62. http://dx.doi.org/10.17221/4058-pse.
Abstract:
Immature zygotic embryos are frequently used for induction of cell cultures in vitro and for genetic transformation. The effect of three synthetic auxins: 2,4-dichlorophenoxyacetic acid (2,4-D), 3,6-dichloro-2-methoxybenzoic acid (dicamba) and 4-amino-3,5,6-trichloropicolinic acid (picloram) on induction and subsequent regeneration capacity of barley. In vitro culture was studied in 12 spring barley cultivars registered in the Czech Republic and a variety of Golden Promise, with known high regeneration efficiency. The callus formation frequency and number of green regenerants were influenced significantly both by genotype and auxin. Most cultivars formed statistically significantly a higher mean number of regenerants (1.95) after the callus induction on the medium with 2.4-D as compared to the media with picloram and dicamba. Only two cultivars (Nordus and SG-S-261) did not respond to the used auxins differently. The highest average number of regenerants (from all three auxins) was obtained with Golden Promise (2.7 plants per one cultivated scutellum). From the set of genotypes used in our study, the cultivars Atribut, Forum, and Scarlett with the mean number of regenerants (2.09–1.57) would be the most suitable cultivars for further transformation use. They differ statistically significantly from the cultivars Nordus, Amulet, Akcent, SG-S-252, Orbit, and Granát (0.42–0.92) which had the lowest mean number of regenerants.
16
Curran, William S., John M. Wallace, Steven Mirsky, and Benjamin Crockett. "Effectiveness of Herbicides for Control of Hairy Vetch (Vicia villosa) in Winter Wheat." Weed Technology 29, no. 3 (September 2015): 509–18. http://dx.doi.org/10.1614/wt-d-14-00139.1.
Abstract:
A field experiment was conducted in 2009–2010 at Pennsylvania and Maryland locations, and repeated it in 2010–2011 to test the effectiveness of POST-applied herbicides at fall and spring timings on seeded hairy vetch in winter wheat. A total of 16 herbicide treatment combinations was tested that included synthetic auxins, acetolactate synthase (ALS) inhibitors, and a protoporphyrinogen oxidase inhibitor. Spring applications tended to be more effective than fall applications. Among synthetic auxins, clopyralid (105 g ae ha−1) and treatments containing dicamba (140 g ae ha−1) were effective at both timings, resulting in greater than 90% hairy vetch control at wheat harvest. Pyroxsulam and prosulfuron applied at 18 g ai ha−1 provided the most effective hairy vetch control (> 90%) at both application timings among ALS inhibitors. Spring applications of several herbicides provided moderate (> 80%) to high (> 90%) levels of hairy vetch control, including: 2,4-D amine (140 g ae ha−1), mesosulfuron-methyl (15 g ai ha−1), tribenuron-methyl (13 g ai ha−1), and thifensulfuron/tribenuron-methyl treatments (16 and 32 g ai ha−1). Winter wheat injury was evaluated, but symptoms were negligible for most treatments. Winter wheat yields declined with increasing hairy vetch biomass. Fall herbicides may be prioritized to reduce hairy vetch competition during the fall and early spring growing season. Our research has established that several synthetic auxin and ALS-inhibiting herbicides, applied POST in fall or spring, can be safely used in winter wheat to control hairy vetch in an integrated weed management program.
17
Procházka, Pavel, Přemysl Štranc, Kateřina Pazderů, Jan Vostřel, and Jan Řehoř. "Use of biologically active substances in hops." Plant, Soil and Environment 64, No. 12 (November 30, 2018): 626–32. http://dx.doi.org/10.17221/655/2018-pse.
Abstract:
In four-year experiments, hop was treated with 7 biologically active substances in two terms during vegetation: Lignohumate max (a mixture of humic acids and fulvic acids), Lexin (a mixture of humic acids and fulvic acids enriched with auxins), Lexenzym (a mixture of humic acids and fulvic acids enriched with auxins, phytohormones and enzymes precursors), Ascophyllum nodosum seaweed extract, synthetic auxin, humic acids and fulvic acids alone. The chlorophyll content was monitored after the application both in the vine leaves and in the branch leaves. After harvesting of the hops from the individual treatments, the yield of dry hops was determined and the cones were analysed for the content of alpha bitter acids. The results show that the most effective hop treatment was the application of Lexin and Lexenzym. The Lexenzym treatment provided a yield of dry hops of 1.86 t/ha, i.e. 0.47 t/ha higher compared with untreated control. The Lexin treatment provided yield higher by 0.41 t/ha of dry hops compared with the untreated control, while the harvested cones contained the most alpha-bitter acids (4.57%).
18
Vande Broek, Ann, Mark Lambrecht, Kristel Eggermont, and Jos Vanderleyden. "Auxins Upregulate Expression of the Indole-3-Pyruvate Decarboxylase Gene in Azospirillum brasilense." Journal of Bacteriology 181, no. 4 (February 15, 1999): 1338–42. http://dx.doi.org/10.1128/jb.181.4.1338-1342.1999.
Abstract:
ABSTRACT Transcription of the Azospirillum brasilense ipdC gene, encoding an indole-3-pyruvate decarboxylase involved in the biosynthesis of indole-3-acetic acid (IAA), is induced by IAA as determined by ipdC-gusA expression studies and Northern analysis. Besides IAA, exogenously added synthetic auxins such as 1-naphthaleneacetic acid, 2,4-dichlorophenoxypropionic acid, andp-chlorophenoxyacetic acid were also found to upregulateipdC expression. No upregulation was observed with tryptophan, acetic acid, or propionic acid or with the IAA conjugates IAA ethyl ester and IAA-l-phenylalanine, indicating structural specificity is required for ipdC induction. This is the first report describing the induction of a bacterial gene by auxin.
19
Narasimhan, Madhumitha, Michelle Gallei, Shutang Tan, Alexander Johnson, Inge Verstraeten, Lanxin Li, Lesia Rodriguez, et al. "Systematic analysis of specific and nonspecific auxin effects on endocytosis and trafficking." Plant Physiology 186, no. 2 (March 18, 2021): 1122–42. http://dx.doi.org/10.1093/plphys/kiab134.
Abstract:
Abstract The phytohormone auxin and its directional transport through tissues are intensively studied. However, a mechanistic understanding of auxin-mediated feedback on endocytosis and polar distribution of PIN auxin transporters remains limited due to contradictory observations and interpretations. Here, we used state-of-the-art methods to reexamine the auxin effects on PIN endocytic trafficking. We used high auxin concentrations or longer treatments versus lower concentrations and shorter treatments of natural indole-3-acetic acid (IAA) and synthetic naphthalene acetic acid (NAA) auxins to distinguish between specific and nonspecific effects. Longer treatments of both auxins interfere with Brefeldin A-mediated intracellular PIN2 accumulation and also with general aggregation of endomembrane compartments. NAA treatment decreased the internalization of the endocytic tracer dye, FM4-64; however, NAA treatment also affected the number, distribution, and compartment identity of the early endosome/trans-Golgi network, rendering the FM4-64 endocytic assays at high NAA concentrations unreliable. To circumvent these nonspecific effects of NAA and IAA affecting the endomembrane system, we opted for alternative approaches visualizing the endocytic events directly at the plasma membrane (PM). Using total internal reflection fluorescence microscopy, we saw no significant effects of IAA or NAA treatments on the incidence and dynamics of clathrin foci, implying that these treatments do not affect the overall endocytosis rate. However, both NAA and IAA at low concentrations rapidly and specifically promoted endocytosis of photo-converted PIN2 from the PM. These analyses identify a specific effect of NAA and IAA on PIN2 endocytosis, thus, contributing to its polarity maintenance and furthermore illustrate that high auxin levels have nonspecific effects on trafficking and endomembrane compartments.
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Chekan, Jonathan R., Chayanid Ongpipattanakul, Terry R. Wright, Bo Zhang, J. Martin Bollinger, Lauren J. Rajakovich, Carsten Krebs, Robert M. Cicchillo, and Satish K. Nair. "Molecular basis for enantioselective herbicide degradation imparted by aryloxyalkanoate dioxygenases in transgenic plants." Proceedings of the National Academy of Sciences 116, no. 27 (June 17, 2019): 13299–304. http://dx.doi.org/10.1073/pnas.1900711116.
Abstract:
The synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D) is an active ingredient of thousands of commercial herbicides. Multiple species of bacteria degrade 2,4-D via a pathway initiated by the Fe(II) and α-ketoglutarate (Fe/αKG)-dependent aryloxyalkanoate dioxygenases (AADs). Recently, genes encoding 2 AADs have been deployed commercially in herbicide-tolerant crops. Some AADs can also inactivate chiral phenoxypropionate and aryloxyphenoxypropionate (AOPP) herbicides, albeit with varying substrate enantioselectivities. Certain AAD enzymes, such as AAD-1, have expanded utility in weed control systems by enabling the use of diverse modes of action with a single trait. Here, we report 1) the use of a genomic context-based approach to identify 59 additional members of the AAD class, 2) the biochemical characterization of AAD-2 fromBradyrhizobium diazoefficiensUSDA 110 as a catalyst to degrade (S)-stereoisomers of chiral synthetic auxins and AOPP herbicides, 3) spectroscopic data that demonstrate the canonical ferryl complex in the AAD-1 reaction, and 4) crystal structures of representatives of the AAD class. Structures of AAD-1, an (R)-enantiomer substrate-specific enzyme, in complexes with a phenoxypropionate synthetic auxin or with AOPP herbicides and of AAD-2, which has the opposite (S)-enantiomeric substrate specificity, reveal the structural basis for stereoselectivity and provide insights into a common catalytic mechanism.
21
Traversari, Silvia, Sonia Cacini, and Beatrice Nesi. "Seaweed Extracts as Substitutes of Synthetic Hormones for Rooting Promotion in Rose Cuttings." Horticulturae 8, no. 7 (June 21, 2022): 561. http://dx.doi.org/10.3390/horticulturae8070561.
Abstract:
In the horticultural sector, the achievement of an efficient and eco-friendly sustainable production of plants is nowadays challenging. Indeed, in plant vegetative propagation of woody ornamentals, the substitution of chemical products used to promote rooting of cuttings with natural extracts would be a desirable goal. Thus, the aim of this work was to test the replacement of synthetic phytoregulators, such as auxins and brassinosteroids, with biostimulants, such as seaweed extracts, for the rooting promotion of rose cuttings. The rooting rate and biometric parameters of control cuttings treated with distilled water were compared with those of cuttings treated with synthetic hormones, i.e., auxins or 22(S),23(S)-homobrassinolide, or two commercial products based on low temperature seaweed extracts, i.e., Kelpak® and Phylgreen. Two scented hybrid tea rose cultivars were used to assess possible genotype-dependent effects, i.e., ‘Michelangelo®’ and ‘Cosmos®’. Auxins confirmed their role in root growth enhancement in ornamental plant cuttings. Like these phytoregulators, Kelpak® improved the survival rate and root biometric parameters of both rose cuttings, highlighting its suitability for the replacement of synthetic products used for rooting promotion in rose propagation. Brassinosteroids showed a species-dependent effect, increasing the root biomass in ‘Cosmos®’ while it resulted as distilled water in ‘Michelangelo®’. Phylgreen did not improve the rooting of both rose cuttings, highlighting the necessity of evaluating the applicability and methodology for this product before its use. In conclusions, our results highlighted the possibility to replace chemical products in rose cutting production.
22
Mielecki, Jakub, Piotr Gawroński, and Stanisław Karpiński. "Aux/IAA11 Is Required for UV-AB Tolerance and Auxin Sensing in Arabidopsis thaliana." International Journal of Molecular Sciences 23, no. 21 (November 2, 2022): 13386. http://dx.doi.org/10.3390/ijms232113386.
Abstract:
In order to survive, plants have, over the course of their evolution, developed sophisticated acclimation and defense strategies governed by complex molecular and physiological, and cellular and extracellular, signaling pathways. They are also able to respond to various stimuli in the form of tropisms; for example, phototropism or gravitropism. All of these retrograde and anterograde signaling pathways are controlled and regulated by waves of reactive oxygen species (ROS), electrical signals, calcium, and hormones, e.g., auxins. Auxins are key phytohormones involved in the regulation of plant growth and development. Acclimation responses, which include programmed cell death induction, require precise auxin perception. However, our knowledge of these pathways is limited. The Aux/IAA family of transcriptional corepressors inhibits the growth of the plant under stress conditions, in order to maintain the balance between development and acclimation responses. In this work, we demonstrate the Aux/IAA11 involvement in auxin sensing, survival, and acclimation to UV-AB, and in carrying out photosynthesis under inhibitory conditions. The tested iaa11 mutants were more susceptible to UV-AB, photosynthetic electron transport (PET) inhibitor, and synthetic endogenous auxin. Among the tested conditions, Aux/IAA11 was not repressed by excess light stress, exclusively among its phylogenetic clade. Repression of transcription by Aux/IAA11 could be important for the inhibition of ROS formation or efficiency of ROS scavenging. We also hypothesize that the demonstrated differences in the subcellular localization of the two Aux/IAA11 protein variants might indicate their regulation by alternative splicing. Our results suggest that Aux/IAA11 plays a specific role in chloroplast retrograde signaling, since it is not repressed by high (excess) light stress, exclusively among its phylogenetic clade.
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Timergalin, Maxim D., Arina V. Feoktistova, Timur V. Rameev, Gaisar G. Khudaygulov, Sergei N. Starikov, and Sergei P. Chetverikov. "Agroecological aspects of application of Pseudomonas sp. DA1.2 in overcoming herbicidal stress in wheat." BIO Web of Conferences 23 (2020): 03009. http://dx.doi.org/10.1051/bioconf/20202303009.
Abstract:
This article submits results of laboratory and field experiments on the effect of an auxin-producing bacterial strain Pseudomonas sp. DA1.2 in comparison with Pseudomonas koreensis IB-4 on wheat plants in conjunction with the “Chistalan” herbicide treatment. Our work shows the positive effect of bacterial treatments on plant growth, the relative water content in leaves and the role of bacteria in the redistribution of ABA and IAA in wheat shoots under conditions of herbicidal stress. Application of Pseudomonas sp. DA1.2 together with the herbicide in the field of the steppe zone led to an increase in yield by 20% relative to the control variant. This bacterial strain helps to overcome herbicidal stress and is a promising agent for improving the technology of using synthetic auxins herbicides.
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Wang, Ren, Ellie Himschoot, Matteo Grenzi, Jian Chen, Alaeddine Safi, Melanie Krebs, Karin Schumacher, et al. "Auxin analog-induced Ca2+ signaling is independent of inhibition of endosomal aggregation in Arabidopsis roots." Journal of Experimental Botany 73, no. 8 (January 27, 2022): 2308–19. http://dx.doi.org/10.1093/jxb/erac019.
Abstract:
Abstract Much of what we know about the role of auxin in plant development derives from exogenous manipulations of auxin distribution and signaling, using inhibitors, auxins, and auxin analogs. In this context, synthetic auxin analogs, such as 1-naphthalene acetic acid (1-NAA), are often favored over the endogenous auxin, indole-3-acetic acid (IAA), in part due to their higher stability. While such auxin analogs have proven instrumental in revealing the various faces of auxin, they display in some cases bioactivities distinct from IAA. Here, we focused on the effect of auxin analogs on the accumulation of PIN proteins in brefeldin A-sensitive endosomal aggregations (BFA bodies), and correlation with the ability to elicit Ca2+ responses. For a set of commonly used auxin analogs, we evaluated if auxin analog-induced Ca2+ signaling inhibits PIN accumulation. Not all auxin analogs elicited a Ca2+ response, and their differential ability to elicit Ca2+ responses correlated partially with their ability to inhibit BFA-body formation. However, in tir1/afb and cngc14, 1-NAA-induced Ca2+ signaling was strongly impaired, yet 1-NAA still could inhibit PIN accumulation in BFA bodies. This demonstrates that TIR1/AFB–CNGC14-dependent Ca2+ signaling does not inhibit BFA body formation in Arabidopsis roots.
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Teixeira Da Silva, Jaime A. "Response of Hybrid Cymbidium (Orchidaceae) Protocorm-Like Bodies to 26 Plant Growth Regulators." Botanica Lithuanica 20, no. 1 (June 1, 2014): 3–13. http://dx.doi.org/10.2478/botlit-2014-0001.
Abstract:
Abstract Teixeira da Silva J.A., 2014: Response of hybrid Cymbidium (Orchidaceae) protocorm-like bodies to 26 plant growth regulators [Cymbidium (Orchidaceae) hibrido į protokormą panašių kūnelių reakcija į 26 augalų augimo reguliatorius]. - Bot. Lith., 20(1): 3-13. Plant growth regulators (PGRs) are one of the most effective means of controlling plant organogenesis in vitro. Hybrid orchid production relies on effective protocols to maximize clonal shoot output. This is best achieved when protocormlike bodies (PLBs) are propagated. In a bid to deepen orchidologists’ understanding of basic responses of Cymbidium to PGRs, this study aimed to establish the organogenic response of hybrid Cymbidium Twilight Moon ‘Day Light’ half-PLBs or PLB thin cell layers (TCLs) to a single application of PGRs (6 auxins; 7 cytokinins; 3 alternative PGRs), 3 herbicides or 7 growth inhibitors/retardants at 4 concentrations (1, 2, 4 or 8 mg·1-1) as well as a control (0 mg·1-1), both in the light and in the dark. The control (PGR-containing TC medium) performed best, but all auxins and growth inhibitors and retardants were toxic to neo-PLB formation, resulting in 100% death. A synthetic auxin (BSAA), a cytokinin (4-CPPU) and two herbicides (dicamba and picloram) were equally toxic. No auxins, TIBA, GA3 or SA induced any organogenic response. 1 or 2 mg·1-1 2,4-D or 1 mg·1-1 TDZ induced embryogenic callus, but 2-8 mg·1-1 2,4-D resulted in abnormal shoots. TDZ induced direct multiple shoots. Only five remaining cytokinins (Ads, BA, Kin, ZR, 2iP) could form neo-PLBs, but always significantly less than the controls, independent of the explant used (half- PLBs or tTCLs) and light conditions (light vs darkness). These five cytokinins could be useful for neo-PLB induction of other Cymbidium hybrids. A new concept, the average cumulative value or ACV, is introduced
26
Mito, N., and A. B. Bennett. "The diageotropica Mutation and Synthetic Auxins Differentially Affect the Expression of Auxin-Regulated Genes in Tomato." Plant Physiology 109, no. 1 (September 1, 1995): 293–97. http://dx.doi.org/10.1104/pp.109.1.293.
27
Singh, Gaurav, Katarzyna Retzer, Stanislav Vosolsobě, and Richard Napier. "Advances in Understanding the Mechanism of Action of the Auxin Permease AUX1." International Journal of Molecular Sciences 19, no. 11 (October 30, 2018): 3391. http://dx.doi.org/10.3390/ijms19113391.
Abstract:
In over 40 years of research on the cellular uptake of auxin it is somewhat chastening that we have elaborated so little on the original kinetic descriptions of auxin uptake by plant cells made by Rubery and Sheldrake in 1974. Every aspect of that seminal work has been investigated in detail, and the uptake activity they measured is now known to be attributed to the AUX1/LAX family of permeases. Recent pharmacological studies have defined the substrate specificity of AUX1, biochemical studies have evaluated its permeability to auxin in plant cell membranes, and rigourous kinetic studies have confirmed the affinity of AUX1 for IAA and synthetic auxins. Advances in genome sequencing have provided a rich resource for informatic analysis of the ancestry of AUX1 and the LAX proteins and, along with models of topology, suggest mechanistic links to families of eukaryotic proton co-transporters for which crystal structures have been presented. The insights gained from all the accumulated research reflect the brilliance of Rubery and Sheldrake’s early work, but recent biochemical analyses are starting to advance further our understanding of this vitally important family of auxin transport proteins.
28
Vondráková, Zuzana, Kateřina Eliášová, Lucie Fischerová, and Martin Vágner. "The role of auxins in somatic embryogenesis of Abies alba." Open Life Sciences 6, no. 4 (August 1, 2011): 587–96. http://dx.doi.org/10.2478/s11535-011-0035-7.
Abstract:
AbstractThe somatic embryogenesis of conifers is a process susceptible to exogenous phytohormonal treatments. We report the effects of the synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D) and the auxin inhibitor p-chlorophenoxyisobutyric acid (PCIB) on the endogenous level of the auxin indole-3-acetic acid (IAA) and on the anatomical composition of early somatic embryos of Abies alba (European silver fir). The embryogenic suspensor mass (ESM) of Abies alba proliferated on a medium supplemented by 2,4-D as well as on an auxin-free medium. The endogenous level of IAA was significantly higher in the ESM cultivated on a medium supplemented by 2,4-D. The decrease in the endogenous level of IAA in the first week of maturation is one of the most important stimuli responsible for the subsequent development of embryos. However, suppression of IAA synthesis by an auxin inhibitor did not stimulate the development of embryos. The maturation of somatic embryos from the globular to the cotyledonary stage occurs when the concentration of endogenous auxin in the ESM (including the embryos) increases. Early somatic embryos proliferating on a medium supplemented by auxin had an increased probability of maturing successfully. Exogenous auxin treatment during maturation did not compensate for the auxin deficiency during proliferation.
29
Yokota, K., K. Murashita, S. Takita, M. Nonaka, S. Kato, and T. Suyama. "FLOWER THINNING EFFECT OF SYNTHETIC AUXINS ON âFUJIâ APPLE." Acta Horticulturae, no. 394 (September 1995): 105–12. http://dx.doi.org/10.17660/actahortic.1995.394.9.
30
Mayerová, Markéta, Jan Mikulka, Michaela Kolářová, and Josef Soukup. "Impact of 40 Years Use of Different Herbicide Strategies and Crop Rotations on Weed Communities in Two Sites of the Czech Republic." Agriculture 13, no. 1 (December 29, 2022): 102. http://dx.doi.org/10.3390/agriculture13010102.
Abstract:
Understanding the impact of farming practices on the composition of weed communities has important implications for the sustainability of weed management strategies. This study analyses data from a 40-year experiment established at two sites in the Czech Republic in 1972. The impact of herbicide strategies on the weed communities was evaluated in multi-crop rotation (MCR) with 50% cereals, and simple crop rotations (SCR) with 75% cereals. The following two herbicide strategies were compared: (1) simple treatment with synthetic auxins only in the simple crop rotation, and (2) targeted herbicide combinations with particular use of sulfonylureas, triazines, ureas and synthetic auxins. Untreated plots were included for reference purposes. Results showed that crop was the major factor determining weed community composition and explained 18% of the total variation in the case of untreated controls. However, herbicide treatment reduced the crop effect to 11%. The highest average increase of Shannon´s diversity index was by 25.4% after 44 years at the untreated plots in SCR, and it decreased by 15.1% at the treated plots in MCR. Weed species evenness € increased at all plots by an average of 23%. Simpson´s dominance index decreased at untreated plots in both crop rotations and plots treated with auxins, with the highest 44.8% decrease at the untreated plots in SCR. On the contrary, Simpson´s index increased by 33,3% on the treated plots in MCR. Herbicide selection depended on the occurrence and density of target weed species, and led to greater decrease in weed diversity and population densities in the diversified crop rotations.
31
Seldimirova, O. A., I. R. Galin, and S. N. Abramov. "MORPHOGENESIS PATHWAYS IN VITRO IN ISOLATED ANTER CULTURE OF WHEAT: THE ROLE OF PHYTOHORMONE BALANCE." ÈKOBIOTEH 6, no. 1 (2023): 53–63. http://dx.doi.org/10.31163/2618-964x-2023-6-1-53-63.
Abstract:
The study is aimed to the study of the peculiarities of the induction of morphogenesis pathways in vitro of morphogenetically competent anther cells - microspores in the isolated anther culture of a number of spring soft wheat genotypes, recommended for cultivation in the climatic conditions of the Republic of Bashkortostan. The content of IAA in seedlings of the studied genotypes of spring sof wheat was analyzed to determine the class of the genotype – characterized by high or low auxin content. Such morphogenesis pathways in vitro as embryoidogenesis, polyembryoidogenesis and callusogenesis have been identified and studied. Morpho-histological assessment of androclinic structures is given. It was established that the induction of a certain morphogenesis pathway in vitro is determined mainly by the balance between the content of endogenous auxin IAA in anthers before inoculation on a nutrient medium and the concentration of exogenous synthetic auxin 2,4-D in the composition of the nutrient medium. The fundamental possibility of regulation of morphogenesis pathways in vitro in isolated anther culture of wheat by selecting for each genotype an adequate balance of endogenous and exogenous auxins for the induction of a specific pathway has been shown.
32
de Castro, Vander A., Valber G. O. Duarte, Danúbia A. C. Nobre, Geraldo H. Silva, Vera R. L. Constantino, Frederico G. Pinto, Willian R. Macedo, and Jairo Tronto. "Plant growth regulation by seed coating with films of alginate and auxin-intercalated layered double hydroxides." Beilstein Journal of Nanotechnology 11 (July 24, 2020): 1082–91. http://dx.doi.org/10.3762/bjnano.11.93.
Abstract:
Auxins are a class of organic substances known as plant-growth regulators, which act on plant physiology, promoting its full development. However, due to the great instability of these substances among the diversity of crops and cultivation environments, it is necessary to seek more efficient modes of application, which lead to a homogeneous distribution and promote a sustained release according to the plants demand. Seed coating, using films containing a biodegradable polymer and auxins intercalated into layered compounds, emerges as a very promising approach to a new form of growth regulator application. Thus, the presented work had three aims: (i) the synthesis and characterization of an organic–inorganic hybrid material containing a layered double hydroxide (LDH) of zinc and aluminum and the synthetic auxin 1-naphthalenoacetic acid (ZnAl-NAA-LDH), (ii) the coating of bean seeds (Phaseolus vulgaris L.) with composite films produced from mixtures of alginate polymer and ZnAl-NAA-LDH, and (iii) the evaluation of the plant response by bioassays. The hybrid ZnAl-NAA-LDH was characterized by a set of analytical techniques, including powder X-ray diffraction, thermogravimetric analysis coupled to differential scanning calorimetry and mass spectrometry, specific surface area measurement, and scanning electron microscopy. Bioassays were performed with the seeds coated with the composite film to assess the germination rate and germination speed index of the seeds, as well as biometric analyses including measurements of root area, root fresh matter, and shoot length of the plants. The bioassay performed in soil pots showed that the alginate film containing ZnAl-NAA-LDH yields an enhancement regarding root area, fresh root matter and shoot length of plants. Thus, films produced from a mixture of alginate and the hybrid material containing the growth regulator intercalated into LDH can be a viable alternative to enhance plant development, which can be included in seed management.
33
Titan, Primoz, Jernej Iskra, Koji Murai, and Vladimir Meglic. "Chemically induced male sterility in common wheat mediated by Aegilops cytoplasm." Genetika 52, no. 1 (2020): 245–56. http://dx.doi.org/10.2298/gensr2001245t.
Abstract:
Several approaches have been proposed, in the past, for the development of hybrid wheat varieties. Nevertheless, common wheat hybrids today account for less than 1% of the world's wheat production. The reason for the limited success of hybrid wheat varieties is the fact that to date, a simple and efficient system for the production of hybrid seed has not been developed. A two-line system using photoperiod-sensitive cytoplasmic male sterility (PCMS) caused by Aegilops crassa Boiss. cytoplasm seems to be very promising way to produce hybrid wheat seed on large scale. Non-desirable side effects of PCMS system are the unreliable sterility of the male sterile lines under different latitudes. Therefore, we tried to connect male sterility system based on Ae. crassa cytoplasm with chemical induction of male sterility. The presented results reveal that the majority of male sterility genes are conserved in the Ae. crassa cytoplasm and that their effects can be promoted by chemical signals, such as synthetic auxins (e.g., 2,4-Dichlorophenoxyacetic acid). Our research work represents the development of a novel male sterility system which is controlled by chemical signals (e.g., synthetic auxins and their pro-herbicide analogues) and mediated by Ae. crassa cytoplasm.
34
Guak, Sunghee, Michael Beulah, Norman E. Looney, and Leslie H. Fuchigami. "Thinning `Fuji' Apple Blossoms with Synthetic Auxins (MCPB-ethyl or NAA) and Ethephon with or without Postbloom Thinning with Carbaryl." Journal of the American Society for Horticultural Science 127, no. 2 (March 2002): 165–70. http://dx.doi.org/10.21273/jashs.127.2.165.
Abstract:
Three experiments were conducted at two locations, two at Summerland, British Columbia, Canada and one at Corvallis, Ore., to evaluate synthetic auxins (MCPB-ethyl or NAA) and ethephon as blossom thinners for `Fuji' apple [Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf.]. These experiments also involved application of carbaryl at 1000 mg·L-1 in the postbloom period. All blossom thinners were sprayed at 85% full bloom while carbaryl was applied at 11-mm fruit diameter. Within these experiments, MCPB-ethyl at up to 20 mg·L-1 or NAA at up to 21 mg·L-1 increased whole flower cluster removal linearly with rate; however, with the Corvallis experiment MCPB-ethyl failed to result in any thinning. Neither auxin treatment consistently reduced fruit set on the remaining clusters, resulting in “clustering”. Bloom-time application of ethephon at 100 mg·L-1 with NAA further reduced crop load. Carbaryl reduced total crop load by increasing both whole cluster removal and number of sites with a single fruit. Return flowering was not improved by the auxin treatments except where there was very excessive crop reduction. Ethephon or carbaryl promoted return flowering with the carbaryl effect being more pronounced. However, this carbaryl effect was significantly countered by the bloom-time auxin whereas ethephon overcame the negative effects of the auxin treatments. The combined use of ethephon and carbaryl was effective in terms of both crop reduction and return flowering benefits. Chemical names used: 1-naphthyl N-methylcarbamate (carbaryl); 2-chloroethylphosphonic acid (ethephon); ethyl 4-(4-chloro-2-methylphenoxy) butanoate (MCPB-ethyl); and 2-(1-naphthyl) acetic acid (NAA).
35
Mendel, Peter. "EVALUATION OF SELECTED CHARACTERISTICS IN INDUSTRIAL HEMP AFTER PHYTOHORMONAL TREATMENT." Pakistan Journal of Agricultural Sciences 57, no. 01 (January 1, 2020): 1–7. http://dx.doi.org/10.21162/pakjas/20.7586.
Abstract:
Plant growth and development is significantly influenced by phytohormones – endogenous molecules present naturally in plants. The best known plant hormones are auxins and cytokinins. This study examined the possible effect of externally applied plant hormone analogues (growth regulators): 1-naphthyl acetic acid (NAA) and 6-benzyl aminopurine (BAP) on industrial fibre hemp (Cannabis sativa L., variety Bialobrzeskie). Plants were treated with three different concentrations of NAA (5, 10 and 20 mg/l) and three different concentrations of BAP (10, 25 and 50 mg/l). Morphological and physiological characteristics, such as apical dominance, shoot branching, fibre properties, and flavonoid content were evaluated. The chosen variety of hemp had a significant response to exogenous application of growth regulators, as has been observed with other plant species. Most notably, completely understood and controlled synthetic auxin tretament has a potential to increase the bark fibre yield of hemp.
36
Böttcher, Christine, Paul K. Boss, and Christopher Davies. "Delaying Riesling grape berry ripening with a synthetic auxin affects malic acid metabolism and sugar accumulation, and alters wine sensory characters." Functional Plant Biology 39, no. 9 (2012): 745. http://dx.doi.org/10.1071/fp12132.
Abstract:
An improved understanding of the hormonal control of grape (Vitis vinifera L.) berry ripening and the ability to manipulate it are of interest scientifically and commercially. Grapes are nonclimacteric fruit with ethylene unlikely to have a principal role in berry ripening but there are several other hormones thought to be involved. In this work, a significant delay in Riesling berry ripening was achieved through preripening treatments with the synthetic auxin 1-naphthaleneacetic acid (NAA). The initiation of sugar accumulation was delayed and the rate of sugar accumulation was lower in NAA-treated fruit, resulting in a 15-day delay in harvest. NAA treatments also reduced the rate of decline in malic acid levels that occurs during ripening, and increased the synchronicity of malic acid and berry sugar accumulation. Sensory panel assessment revealed a significant difference between wine made from control and NAA-treated fruit. Analysis of the volatile composition of the wines’ headspace showed that the concentration of several compounds was altered significantly by the NAA treatment. These data provide further support for the involvement of auxins in inhibiting ripening and suggest that auxin treatments may be useful in controlling both winery intake, and fruit and wine composition.
37
Frisch, Carl H., and N. D. Camper. "Effect of synthetic auxins on callus induction from tea stem tissue." Plant Cell, Tissue and Organ Culture 8, no. 3 (1987): 207–13. http://dx.doi.org/10.1007/bf00040947.
38
Ramaih, Shashi, Mohammed Guedira, and Gary M. Paulsen. "Relationship of indoleacetic acid and tryptophan to dormancy and preharvest sprouting of wheat." Functional Plant Biology 30, no. 9 (2003): 939. http://dx.doi.org/10.1071/fp03113.
Abstract:
Preharvest sprouting of wheat (Triticum aestivum L.) involves several plant hormones, but a role for indoleacetic acid (IAA) and its precursor, tryptophan, has not been demonstrated. Our objectives were to determine the roles of IAA, tryptophan, and related compounds in germination of cultivars that differed in susceptibility to preharvest sprouting. L-Tryptophan strongly inhibited germination of embryos excised from caryopses that were highly dormant at harvest but not of embryos from caryopses that had little innate dormancy. The embryos responded similarly to indoleacetaldehyde, IAA, and synthetic auxins, suggesting that tryptophan functioned as a precursor of IAA. Indoleacetaldehyde oxidase inhibitors alleviated the adverse effects of tryptophan and indoleacetaldehyde, and an auxin antagonist decreased the inhibitory action of tryptophan and IAA on embryos from dormant caryopses, further suggesting that IAA was involved. Changes in sensitivity to IAA during afterripening also supported a role for auxin in dormancy. Embryos from caryopses that were highly dormant at harvest gradually lost sensitivity to IAA during afterripening, whereas intact caryopses were insensitive to IAA. The results implicated IAA in dormancy of wheat caryopses and indicated that the auxin might complement the role of abscisic acid in germination. The importance of using dormant caryopses and arresting afterripening in investigations of seed dormancy was noted.
39
KUZNETSOVA, O. "EFFECT OF NATURAL AND SYNTHETIC PHYTOHORMONES ON GROWTH AND DEVELOPMENT OF HIGHER BASIDIOMYCETES." Biotechnologia Acta 13, no. 5 (October 2020): 19–31. http://dx.doi.org/10.15407/biotech13.05.019.
Abstract:
The paper is aimed to analyze the current data on the influence of exogenous growth stimulators on growth and development of higher Basidiomycetes. The historical aspects about discovery and role of phytohormones in fungi physiology are reviewed. The taxa of the basidiomycetes, which are capable of synthesizing phytohormones of all known types, including Aphyllophorales, Boletales, Agaricales, Sclerodermales, Hymenogastrales, Uredinales, Ustilaginales are described. The data from different sources describing the effects of natural and synthetic growth stimulators on the development of basidiomycetes are summarized and compared. It is noted that various concentrations of phytohormones (auxins, gibberellins, cytokinins) from 0.01 to 400 mg/ml were used in the experiments to study their effects on mycelial growth. Possible causes of conflicting results obtained by different authors, such as application of diverse methods of mushroom cultivation, different media and methods of substrate sterilization, are described.
40
Carvalho, Catarina P., Alejandra Salvador, Pilar Navarro, Adela Monterde, and Jose M. Martínez-Jávega. "Effect of Auxin Treatments on Calyx Senescence in the Degreening of Four Mandarin Cultivars." HortScience 43, no. 3 (June 2008): 747–52. http://dx.doi.org/10.21273/hortsci.43.3.747.
Abstract:
The degreening process is crucial in citrus fruit for the marketing of extra-early mandarins. Nevertheless, the application of ethylene during this treatment can be associated with calyx senescence. Citrus marketing regulations do not allow either alteration to fruit quality or the presence of calyx browning, especially on product exported to the United States. In this research, four synthetic auxins were tested for control of calyx disorders caused by degreening in different Clementine cultivars: Oronules, Clemenules, Marisol, and Clemenpons. All the tested auxins reduced calyx senescence, but the best results for all cultivars were obtained by 3,5,6-trichloro-2-pyridyloxyacetic acid followed by 2,4-dichlorophenoxyacetic acid isopropyl ester. In general, the higher the doses, the smaller the calyx alterations. The most susceptible cultivar to calyx senescence was ‘Marisol’, whereas ‘Clemenules’ and ‘Clemenpons’ were the most tolerant. Treated fruit presented lower weight loss than untreated fruit. Every treatment achieved the commercial color index and no sensory alteration was observed.
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Vu Ngoc, Tu, Hien Dang Thi, Anh Huong Nguyen Thi, Ngoc Mai Pham Thi, Anh Hoang Quoc, Tien Bui Cao, Dong Bui Quang, Hong Hao Le Thi, and Son Tran Cao. "Simultaneous determination of six auxin plant growth promoters in agricultural products by liquid chromatography tandem mass spectrometry (LC-MS/MS)." Heavy metals and arsenic concentrations in water, agricultural soil, and rice in Ngan Son district, Bac Kan province, Vietnam 3, no. 2 (June 15, 2020): 71–79. http://dx.doi.org/10.47866/2615-9252/vjfc.110.
Abstract:
A highly sensitive and specific method for simultaneous determination of six synthetic auxins (4-chlorophenoxyacetic acid (4-CPA), 2-methyl-4-chlorophenoxyacetic acid (MCPA), 1-naphthalene acetic acid (NAA), 2-napthoxyacetic acid (NOA), indole-3-propionic acid (IPA), indole-3-butyric acid (IBA)) were developed using a QuEChERS-based sample extraction followed by an LC-MS/MS analysis. The method was validated and proved as meeting the AOAC International requirements for specificity, sensitivity, and accuracy in the range of 3 and 200 µg/kg. LOD and LOQ of all analytes were at 1 µg/kg and 3 µg/kg, respectively. The recoveries of six synthetic auxins were from 78.9% to 96.4% and the repeatability relative standard deviations were below 12.6%. The method was applied to simultaneously determine the content of 4-CPA, MCPA, NAA, NOA, IPA, IBA in vegetables, tubers, and fruits samples collected from different markets in Hanoi (Mai Dich, Dan Phuong, Giap Bat, Bach Mai, and Nga Tu So). MCPA was detected in 22/30 vegetable samples (3.0 ÷ 7.1 µg/kg), 9/30 tuber samples (3.2 ÷ 3.7 µg/kg); 4-CPA was detected in bean sprouts in the range from 23 to 75 µg/kg which exceeded the Maximum Residue Levels (MRL) of 10 µg/kg set by European Commission.
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Świerczyński, Sławomir. "Assessment of the Effect of Treating ‘GiSelA 5’ Softwood Cuttings with Biostimulants and Synthetic Auxin on Their Root Formation and Some of Their Physiological Parameters." Plants 12, no. 3 (February 2, 2023): 658. http://dx.doi.org/10.3390/plants12030658.
Abstract:
The ‘GiSelA 5’ rootstock is of high importance for growing sweet cherries because it significantly reduces the growth vigour of the trees and accelerates their fruiting. However, the method of its propagation using ‘in vitro’ cultures is expensive, prompting researchers to look for alternative methods of propagation. One of these is the root formation in shoot cuttings. The experiment presented in this paper compared the use of powdered synthetic auxins (Rhizopon AA, Ukorzeniacz AB) and their alcoholic solution (IAA, IBA), and the biostimulants Goteo and Bispeed as foliar sprays for root formation in softwood cuttings ‘GiSelA 5’ and measured some parameters of physiological processes. In addition, two different substrates of river sand with peat (1:2) and peat substrate with perlite (2:1) were used. Cuttings were obtained on two dates, in the first and third years in the month of June. Biostimulants increased the number of rooted cuttings (Goteo—16.1%, Bispeed—18.1%) without improving their growth and the intensity of most of the analyzed physiological processes compared to the control. Synthetic preparations also increased the percentage of rooted cuttings Rhizopon AA (24.4%), Ukorzeniacz AB (21.4%), auxin IBA (19.7%) and auxin IAA (14.7%), while simultaneously improving their growth and level of vital processes compared to the controls and biostimulants. The substrate consisting of peat with sand improved root formation by 6.2%, without significantly changing the growth parameters and vital functions of the cuttings. The earlier date of propagation increased the root formation percentage only by 4% and the number of roots by 14% of the ‘GiSelA 5’ rootstock cuttings.
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Browne, Frances B., Xiao Li, Katilyn J. Price, Ryan Langemeier, Alvaro Sanz-Saez de Jauregui, J. Scott McElroy, Yucheng Feng, and Andrew Price. "Sequential Applications of Synthetic Auxins and Glufosinate for Escaped Palmer Amaranth Control." Agronomy 10, no. 9 (September 19, 2020): 1425. http://dx.doi.org/10.3390/agronomy10091425.
Abstract:
Field and greenhouse studies were conducted to investigate the influence of sequence and timing of synthetic auxins and glufosinate on large Palmer amaranth (Amaranthus palmeri) control. Field studies were performed in Henry County, AL where treatments were applied to Palmer amaranth with average heights of 37 and 59 cm in 2018 and 2019, respectively. Sequential applications of 2,4-D/dicamba + glyphosate followed by (fb) glufosinate at labeled rates 3 or 7 days after initial treatment (DAIT) were used in addition to the reverse sequence with a 7-day interval. Time intervals of 3 or 7 days between applications did not influence Palmer amaranth control. Palmer amaranth was controlled 100% by dicamba + glyphosate fb glufosinate and 2,4-D + glufosinate fb glufosinate 7 DAIT in 2018. However, herbicide performance was reduced due to delayed application and taller plants in 2019 with up to 23% less visual injury. To further investigate Palmer amaranth response to dicamba and glufosinate applied sequentially, a greenhouse study was conducted in 2019 where physiological measurements were recorded over a 35-day period. Treatments were applied to Palmer amaranth averaging 38 cm tall and included dicamba + glyphosate fb glufosinate 7 DAIT, the reverse sequence, and a single application of dicamba + glufosinate + glyphosate. Glufosinate severely inhibited mid-day photosynthesis compared to dicamba with up to 90% reductions in CO2 assimilation 1 DAIT. In general, Palmer amaranth respiration and stomatal conductance were not affected by herbicides in this study. Applications of dicamba + glyphosate fb glufosinate 7 DAIT was the only treatment hindered Palmer amaranth regrowth with 52% reduction in leaf biomass compared to nontreated control. These data suggest Palmer amaranth infested fields are more likely to be rescued with sequential applications of synthetic auxins and glufosinate, but consistent control of large Palmer is not probable.
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Martins, João Paulo Rodrigues, Edilson Romais Schimildt, Rodrigo Sobreira Alexandre, Breno Régis Santos, and Gizele Cristina Magevski. "Effect of synthetic auxins on in vitro and ex vitro bromeliad rooting." Pesquisa Agropecuária Tropical 43, no. 2 (June 2013): 138–46. http://dx.doi.org/10.1590/s1983-40632013000200009.
Abstract:
The tissue culture can contribute to the propagation of several economic species, such as the bromeliads. This research aimed at evaluating the auxins type and concentration in the in vitro and ex vitro rhizogenesis of Neoregelia concentrica bromeliad. N. concentrica shoots were induced in a growth medium with 15.0 µM of 6-benzylaminopurine, for 80 days, followed by sub-cultivation in phytoregulator-free medium, for 45 days. In the in vitro rhizogenesis, the shoots grew in a medium supplemented with indole-3-butyric acid (IBA) or naphthalene-acetic acid (NAA), at the concentrations of 0.0 µM, 1.0 µM, 2.0 µM, 3.0 µM and 4.0 µM. In the ex vitro rhizogenesis, the bases of shoots were immersed, for 60 minutes, in IBA or NAA solutions, at the concentrations of 0.0 µM, 5.0 µM, 10.0 µM and 15.0 µM. After immersion, the shoots were planted in plastic trays with vermiculite. At the end of each rhizogenesis method, the phytotechnical parameters analysis was carried out. For the in vitro rhizogenesis, a higher number of roots were observed when the shoots were cultivated in concentrations higher than 1.0 µM of NAA, when compared to the IBA. However, the rooting rate differed only at 30 days after the in vitro growth, with a higher root induction in the shoots grown with NAA. At 60 days, the rooting rate was higher than 90% and statistically similar in all treatments. In the ex vitro rhizogenesis, a better formation of the rooting system was observed when 5.0 µM of IBA was applied, with higher rooting averages and number of roots.
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Ang, Mervin Chun-Yi, Niha Dhar, Duc Thinh Khong, Tedrick Thomas Salim Lew, Minkyung Park, Sreelatha Sarangapani, Jianqiao Cui, et al. "Nanosensor Detection of Synthetic Auxins In Planta using Corona Phase Molecular Recognition." ACS Sensors 6, no. 8 (August 10, 2021): 3032–46. http://dx.doi.org/10.1021/acssensors.1c01022.
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Ronca, F., H. Arbiza, A. Abella, M. Arias, and A. Gravina. "SYNTHETIC AUXINS EVALUATION ON FRUIT SIZE AND YIELD IN 'LISBON' TYPE LEMON." Acta Horticulturae, no. 463 (January 1998): 405–12. http://dx.doi.org/10.17660/actahortic.1998.463.52.
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Gravina, A., H. Arbiza, A. Bozzo, E. Laserre, M. Arias, and F. Ronca. "SYNTHETIC AUXINS EVALUATION ON FRUIT SIZE AND YIELD IN âELLENDALEâ TANGOR." Acta Horticulturae, no. 463 (January 1998): 413–18. http://dx.doi.org/10.17660/actahortic.1998.463.53.
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Niemczak, Michał, Łukasz Chrzanowski, Tadeusz Praczyk, and Juliusz Pernak. "Biodegradable herbicidal ionic liquids based on synthetic auxins and analogues of betaine." New Journal of Chemistry 41, no. 16 (2017): 8066–77. http://dx.doi.org/10.1039/c7nj01474k.
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Goss, Gina A., and William E. Dyer. "Physiological characterization of auxinic herbicide-resistant biotypes of kochia (Kochia scoparia)." Weed Science 51, no. 6 (December 2003): 839–44. http://dx.doi.org/10.1614/p2002-164.
Abstract:
Auxin-mediated responses of kochia biotypes resistant to dicamba (HRd) or resistant to dicamba and fluroxypyr (HRdf) were compared with those of two susceptible biotypes. Rates of shoot and root gravitropic response and patterns of apical dominance, as determined by lateral bud sprouting after decapitation, were determined in the absence of herbicide treatment. Shoots of susceptible plants reoriented toward vertical at a rate of 23.4° h−1, whereas the rates of HRd and HRdf shoot reorientation were significantly slower at 7.2° and 14.4° h−1, respectively. Root gravitropic responses were not different between resistant and susceptible biotypes. In contrast to susceptible biotypes, both apical and basal lateral buds on HRd plants elongated after decapitation, although differences between HRd and susceptible biotypes became smaller during succeeding weeks. The elongation pattern of HRdf lateral buds was intermediate to that of susceptible and HRd plants. Inhibition assays of root growth by natural and synthetic auxins showed that HRd root growth was less sensitive to dicamba, 2,4-D, naphthalene-1-acetic acid, and indole-3-acetic acid than was root growth of HRdf or the susceptible biotypes. Collectively, results support the hypothesis that auxin binding or signal transduction pathways are impaired in resistant biotypes and that HRd may contain different lesions than does HRdf.
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Feldwisch, J., R. Zettl, N. Campos, and K. Palme. "Identification of a 23 kDa protein from maize photoaffinity-labelled with 5-azido-[7-3H]indol-3-ylacetic acid." Biochemical Journal 305, no. 3 (February 1, 1995): 853–57. http://dx.doi.org/10.1042/bj3050853.
Abstract:
A 23 kDa protein (p23) was identified in microsomal extracts from maize coleoptiles by photoaffinity labelling with 5-azido-[7-3H]indol-3-ylacetic acid ([3H]N3IAA). Labelling of p23 was blocked by unlabelled IAA, N3IAA, indol-3-ylbutyric acid and indol-3-yl-lactate. In addition, labelling was efficiently decreased by tryptophan, as well as by the scavenger p-aminobenzoic acid. Labelling was, however, not affected by synthetic auxins such as 1-naphthylacetic acid or 2,4-dichlorophenoxyacetic acid. Competition data suggest that the label was probably bound via the indole ring, and hence labelling was not specific for auxins. The 23 kDa protein was solubilized from crude microsomes by extraction with Triton X-100 and purified to homogeneity by ion-exchange, size-exclusion and reversed-phase chromatography. After electroblotting, the amino acid sequences of the p23 N-terminus as well as the several tryptic peptides were obtained. Database comparisons revealed sequence identity with a maize manganese superoxide dismutase. We conclude that photoaffinity labelling of p23 was pseudo-affinity, and therefore the binding site for IAA is not specific.