Showing papers on "Gibberellic acid published in 2018"
TL;DR: In this paper, various methods were tested including the removal of the seed coat after cold moist stratification and treatment with GA 3, and GA 3 was used to break dormancy and increase the germination of Prunus avium L. seeds.
Abstract: To break dormancy and increase the germination of Prunus avium L. (mazzard cherry) seeds, various methods were tested including the removal of the seed coat after cold moist stratification and treatment with GA 3 ,
76 citations
TL;DR: In this paper, conditions were investigated in which the position of this transition zone was positively or negatively affected by high levels of gibberellic acid (GA) in plants overexpressing the GA biosynthesis gene GA20-OXIDASE (GA20OX-1OE).
Abstract: Summary
Growth is characterized by the interplay between cell division and cell expansion, two processes that occur separated along the growth zone at the maize leaf. To gain further insight into the transition between cell division and cell expansion, conditions were investigated in which the position of this transition zone was positively or negatively affected. High levels of gibberellic acid (GA) in plants overexpressing the GA biosynthesis gene GA20-OXIDASE (GA20OX-1OE) shifted the transition zone more distally, whereas mild drought, which is associated with lowered GA biosynthesis, resulted in a more basal positioning. However, the increased levels of GA in the GA20OX-1OE line were insufficient to convey tolerance to the mild drought treatment, indicating that another mechanism in addition to lowered GA levels is restricting growth during drought. Transcriptome analysis with high spatial resolution indicated that mild drought specifically induces a reprogramming of transcriptional regulation in the division zone. “Leaf Growth Viewer” was developed as an online searchable tool containing the high-resolution data.
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62 citations
TL;DR: Gibberellic acid is a plant growth hormone that promotes cell expansion and division and the product’s cost still limits its large and continuous application.
Abstract: Gibberellic acid is a plant growth hormone that promotes cell expansion and division. Studies have aimed at optimizing and reducing production costs, which could make its application economically viable for different cultivars. Gibberellins consist of a large family of plant growth hormones discovered in the 1930s, which are synthesized via the terpenes route from the geranylgeranyl diphosphate and feature a basic structure formed by an ent-gibberellane tetracyclic skeleton. Among them, only four have biological activity, including gibberellic acid (GA3), which acts as a natural plant growth regulator, especially for stem elongation, seed germination, and increased fruit size. It can be obtained from plants, fungi, and bacteria. There are also some reports about microalgae GA3 producers. Fungi, especially Gibberella fujikuroi, are preferred for GA3 production via submerged fermentation or solid-state fermentation. Many factors may affect its production, some of which are related to the control and scale-up of fermentation parameters. Different GA3 products are available on the market. They can be found in liquid or solid formulations containing only GA3 or a mixture of other biological active gibberellins, which can be applied on a wide variety of cultivars, including crops and fruits. However, the product’s cost still limits its large and continuous application. New low-cost and efficient GA3 production alternatives are surely welcome. This review deals with the latest scientific and technological advances on production, recovery, formulation, and applications of this important plant growth hormone.
60 citations
TL;DR: A transgenerational transmission mechanism for the GA-priming effect on clonal offspring growth and biomass production in L. chinensis is implied, as a single seed treatment with GA3 lasted for at least two years.
Abstract: Seed priming is a widely used technique in crops to obtain uniform germination and high-quality seedlings In this study, we found a long-term effect of seed priming with gibberellic acid-3 (GA3) on plant growth and production in Leymus chinensis Seeds were germinated on agar plates containing 0–200 μM GA3, and the germinated seedlings were transplanted to clay planting pots and grown for about one year The clonal tillers grown from the mother plants were transplanted to field conditions in the second year Results showed that GA3 treatment significantly increased seed germination rate by 14–27% GA3 treatment also promoted subsequent plant growth and biomass production, as shown by a significant increase in plant height, tiller number, and fresh and dry weight in both pot (2016) and field (2017) conditions It is particularly noteworthy that the growth-promoting effect of a single seed treatment with GA3 lasted for at least two years In particular, GA3 treatment at 50 μM increased aboveground fresh and dry weight by 1682% and 1089% in pot-grown conditions, and 645% and 1262% in field-grown conditions, respectively These results imply a transgenerational transmission mechanism for the GA-priming effect on clonal offspring growth and biomass production in L chinensis
48 citations
TL;DR: It is shown that the calcium sensor, CML39, is important in various developmental processes from seeds to mature plants, as well as during germination and seedling establishment, and RNA sequencing analysis of cml39 seedlings suggests that changes in chromatin modification may underlie some of the phenotypes associated with cML39 mutants, consistent with previous reports that orthologs of Cml39 participate in gene silencing.
Abstract: We show that the calcium sensor, CML39, is important in various developmental processes from seeds to mature plants. This study bridges previous work on CML39 as a stress-induced gene and highlights the importance of calcium signalling in plant development. In addition to the evolutionarily-conserved Ca2+ sensor, calmodulin (CaM), plants possess a large family of CaM-related proteins (CMLs). Using a cml39 loss-of-function mutant, we investigated the roles of CML39 in Arabidopsis and discovered a range of phenotypes across developmental stages and in different tissues. In mature plants, loss of CML39 results in shorter siliques, reduced seed number per silique, and reduced number of ovules per pistil. We also observed changes in seed development, germination, and seed coat properties in cml39 mutants in comparison to wild-type plants. Using radicle emergence as a measure of germination, cml39 mutants showed more rapid germination than wild-type plants. In marked contrast to wild-type seeds, the germination of developing, immature cml39 seeds was not sensitive to cold-stratification. In addition, germination of cml39 seeds was less sensitive than wild-type to inhibition by ABA or by treatments that impaired gibberellic acid biosynthesis. Tetrazolium red staining indicated that the seed-coat permeability of cml39 seeds is greater than that of wild-type seeds. RNA sequencing analysis of cml39 seedlings suggests that changes in chromatin modification may underlie some of the phenotypes associated with cml39 mutants, consistent with previous reports that orthologs of CML39 participate in gene silencing. Aberrant ectopic expression of transcripts for seed storage proteins in 7-day old cml39 seedlings was observed, suggesting mis-regulation of early developmental programs. Collectively, our data support a model where CML39 serves as an important Ca2+ sensor during ovule and seed development, as well as during germination and seedling establishment.
45 citations
TL;DR: The studied Mortierella strains had some important traits that led them to be considered as microbial biofertilizers components, improving plant growth in difficult temperate climates.
Abstract: The endogenous pool of phytoregulators in plant tissues supplied with microbial secondary metabolites may be crucial for the development of winter wheat seedlings during cool springs The phytohormones may be synthesized by psychrotrophic microorganisms in lower temperatures occurring in a temperate climate Two fungal isolates from the Spitzbergen soils after the microscopic observations and “the internal transcribed spacer” (ITS) region molecular characterization were identified as Mortierella antarctica (MA DEM7) and Mortierella verticillata (MV DEM32) In order to study the synthesis of indoleacetic acid (IAA) and gibberellic acid (GA), Mortierella strains were grown on media supplemented with precursor of phytohormones tryptophan at 9, 15 °C, and 20 °C for nine days The highest amount of IAA synthesis was identified in MV DEM32 nine-day-culture at 15 °C with 15 mM of tryptophan At the same temperature (15 °C), the significant promoting effect (about 40% root and shoot fresh weight) of this strain on seedlings was observed However, only MA DEM-7 had the ACC (1-aminocyclopropane-1-carboxylate) deaminase activity with the highest efficiency at 9 °C and synthesized IAA without tryptophan Moreover, at the same conditions, the strain was confirmed to possess the strong promoting effect (about 40% root and 24% shoot fresh weight) on seedlings Both strains synthesized GA in all tested terms and temperatures The studied Mortierella strains had some important traits that led them to be considered as microbial biofertilizers components, improving plant growth in difficult temperate climates
39 citations
TL;DR: Most metabolites that were severely reduced in NM plants following the N depletion remained unaltered in starved AM plants compared with those normally fertilized, suggesting that the symbiosis buffered the stress, improving plant development in a stressed environment.
Abstract: In low nutritive environments, the uptake of N by arbuscular mycorrhizal (AM) fungi may confer competitive advantages for the host. The present study aims to understand how mycorrhizal tomato plants perceive and then prepare for an N depletion in the root environment. Plants colonized by Rhizophagus irregularis displayed improved responses to a lack of N than nonmycorrhizal (NM) plants. These responses were accomplished by a complex metabolic and transcriptional rearrangement that mostly affected the gibberellic acid and jasmonic acid pathways involving DELLA and JAZ1 genes, which were responsive to changes in the C/N imbalance of the plant. N starved mycorrhizal plants showed lower C/N equilibrium in the shoots than starved NM plants and concomitantly a downregulation of the JAZ1 repressor and the increased expression of the DELLA gene, which translated into a more active oxylipin pathway in mycorrhizal plants. In addition, the results support a priorization in AM plants of stress responses over growth. Therefore, these plants were better prepared for an expected stress. Furthermore, most metabolites that were severely reduced in NM plants following the N depletion remained unaltered in starved AM plants compared with those normally fertilized, suggesting that the symbiosis buffered the stress, improving plant development in a stressed environment.
38 citations
TL;DR: It is reported that the aspartic protease ASPG1 plays an important role in the process of dormancy, viability and germination of Arabidopsis seeds, and its function is associated with degradation of SSPs and regulation of gibberellic acid signaling inArabidopsis.
Abstract: Seed storage proteins (SSPs) provide free amino acids and energy for the process of seed germination. Although degradation of SSPs by the aspartic proteases isolated from seeds has been documented in vitro, there is still no genetic evidence for involvement of aspartic proteases in seed germination. Here we report that the aspartic protease ASPG1 (ASPARTIC PROTEASE IN GUARD CELL 1) plays an important role in the process of dormancy, viability and germination of Arabidopsis seeds. We show that aspg1-1 mutants have enhanced seed dormancy and reduced seed viability. A significant increase in expression of DELLA genes which act as repressors in the gibberellic acid signal transduction pathway were detected in aspg1-1 during seed germination. Seed germination of aspg1-1 mutants was more sensitive to treatment with paclobutrazol (PAC; a gibberellic acid biosynthesis inhibitor). In contrast, seed germination of ASPG1 overexpression (OE) transgenic lines showed resistant to PAC. The degradation of SSPs in germinating seeds was severely impaired in aspg1-1 mutants. Moreover, the development of aspg1-1 young seedlings was arrested when grown on the nutrient-free medium. Thus ASPG1 is important for seed dormancy, seed longevity and seed germination, and its function is associated with degradation of SSPs and regulation of gibberellic acid signaling in Arabidopsis.
37 citations
TL;DR: It is demonstrated that HA is effective for rooting in evergreen azalea microshoots, and this effect was related to physiological and metabolic changes during adventitious root formation.
36 citations
TL;DR: The role of endosymbiont Piriformospora indica in counteracting salinity stress to Pakchoi plants was determined by studying physiological, biochemical, and molecular mechanisms.
35 citations
TL;DR: Study of the effects of exogenously applied ABA on nutrients uptake of rice roots under simulated acid rain (SAR) stress indicates that proper concentration of exogenous ABA could enhance tolerance of rice Roots to SAR stress by promoting nutrients uptake and balancing endogenous hormones.
Abstract: Application of proper ABA can improve acid tolerance of rice roots by balancing endogenous hormones and promoting nutrient uptake. Abscisic acid (ABA) has an important signaling role in enhancing plant tolerance to environmental stress. To alleviate the inhibition on plant growth and productivity caused by acid rain, it is crucial to clarify the regulating mechanism of ABA on adaptation of plants to acid rain. Here, we studied the effects of exogenously applied ABA on nutrients uptake of rice roots under simulated acid rain (SAR) stress from physiological, biochemical and molecular aspects. Compared to the single SAR treatment (pH 4.5 or 3.5), exogenous 10 μM ABA alleviated the SAR-induced inhibition of root growth by balancing endogenous hormones (abscisic acid, indole-3-acetic acid, gibberellic acid and zeatin), promoting nutrient uptake (nitrate, P, K and Mg) in rice roots, and increasing the activity of the plasma membrane H+-ATPase by up-regulating expression levels of genes (OSA2, OSA4, OSA9 and OSA10). However, exogenous 100 μM ABA exacerbated the SAR-caused inhibition of root growth by disrupting the balance of endogenous hormones, and inhibiting nutrient uptake (nitrate, P, K, Ca and Mg) through decreasing the activity of the plasma membrane H+-ATPase. These results indicate that proper concentration of exogenous ABA could enhance tolerance of rice roots to SAR stress by promoting nutrients uptake and balancing endogenous hormones.
TL;DR: Priming seeds of these crops with 0.2 g/L GA3 significantly improved germination percentage, reduced mean germination time, increased shoot and root length, and total weight of the crops when the salinity level is less than 8 dS/m, however, shoots of all crops performed better than the roots.
Abstract: Low seed germination, poor seedling establishment, and less crop productivity are commonly observed problems in salt-affected soils. Genetic modification of plants for creating good varieties and selection of crop plants that have best performance on saline soils are the major accomplishments done to minimize the problem. In addition, application of Gibberellic Acid (GA3) has been reported to increase germination percentage and seedling growth performance of crop plants under salt stress. The objective of the present study was therefore to investigate the effect of GA3 on germination and early seedling growth of three important crops under saline conditions. To this effect an experiment was conducted as factorial with completely randomized design with three replicates. The factors of the experiment were salinity with four levels (0, 4, 6, 8, and 12 dS/m), hormone (GA3 at 0.2 g/L versus no GA3) and the three crops (Zea mays L., Pisums sativum Var. abyssinicum A. Braun, and Lathyrus sativus L). Consequently, priming seeds of these crops with 0.2 g/L GA3 significantly improved germination percentage, reduced mean germination time, increased shoot and root length, and total weight of the crops (P < 0.05) when the salinity level is less than 8 dS/m. However, shoots of all crops performed better than the roots.
TL;DR: Among the tested compounds, ascorbic acid had an apparent growth-promoting effect and ACC moderately and AVG and ABA severely inhibited the growth of L. minor.
Abstract: Gibberellic acid (GA3), indole-3-acetic acid (IAA), salicylic acid (SA), abscidic acid (ABA), jasmonic acid (JA) 1-amino cyclopropane-1-carboxylic acid (ACC) and aminoethoxyvinylglycine (AVG) are popular growth regulators of plants. However, the effects of their exogenous addition on the biomass production of aquatic plants, including Lemnoideae plants, "duckweeds," are largely unknown. In this study, the growth of Lemna minor was tested for 10 d in Hoagland medium containing each compound at different concentrations of 0-50 μM. GA3, IAA, and SA were found to have no apparent positive effect on the growth at all concentrations tested. Conversely, ACC and JA moderately and AVG and ABA severely inhibited the growth of L. minor. Among the tested compounds, ascorbic acid had an apparent growth-promoting effect.
TL;DR: It is suggested that the feminizing pathway in cultivated spinach is epistatic to the masculinizing pathway, and a unified model for alternative sexual development is presented and the implications for established theory are discussed.
Abstract: While unisexual flowers have evolved repeatedly throughout angiosperm families, the actual identification of sex-determining genes has been elusive, and their regulation within populations remains largely undefined. Here, we tested the mechanism of the feminization pathway in cultivated spinach (Spinacia oleracea), and investigated how this pathway may regulate alternative sexual development. We tested the effect of gibberellic acid (GA) on sex determination through exogenous applications of GA and inhibitors of GA synthesis and proteasome activity. GA concentrations in multiple tissues were estimated by enzyme-linked immunosorbent assay analysis. Gene function was investigated and pathway analysis was performed through virus-induced gene silencing. Relative gene expression levels were estimated by quantitative reverse transcription-polymerase chain reaction. Inhibition of GA production and proteasome activity feminized male flowers. However, there was no difference in GA content in tissues between males and females. We characterized a single DELLA family transcription factor gene (GIBBERELLIC ACID INSENSITIVE (SpGAI)) and observed inflorescence expression in females two-fold higher than in males. Reduction of SpGAI expression in females to male levels phenocopied exogenous GA application with respect to flower development. These results implicate SpGAI as the feminizing factor in spinach, and suggest that the feminizing pathway is epistatic to the masculinizing pathway. We present a unified model for alternative sexual development and discuss the implications for established theory.
TL;DR: Novel evidence is provided that the recruitment of different Mediterranean species may be enhanced by different smoke compounds, and that synergetic and inhibitory effects of chemical compounds are important in the germination ecology of plants.
TL;DR: In this article, the effects of GA on photosynthesis, nutrient partitioning and endogenous hormones at different leaf locations (1 and 6) were investigated with Camellia oleifera.
Abstract: To investigate the effects of gibberellic acid (GA) on photosynthesis, nutrient partitioning and endogenous hormones at different leaf locations (1 and 6), Camellia oleifera was treated with four l...
TL;DR: It is reported that GRAS2 plays a vital role in regulating fruit weight in tomato (Solanum lycopersicum), and it is established that the expression ofGRAS2 was elevated in ovaries and maintained at a constant level in fertilized ovules.
Abstract: GRAS family transcription factors are involved in multiple biological processes in plants. Here, we report that GRAS2 plays a vital role in regulating fruit weight in tomato (Solanum lycopersicum). We establish that the expression of GRAS2 was elevated in ovaries and maintained at a constant level in fertilized ovules. Reduction of GRAS2 expression in transgenic plants reduced fruit weight through modulating ovary growth and cell size. At the metabolic level, downregulation of GRAS2 decreased activities of the gibberellic acid biosynthesis and signal transduction pathways, leading to insufficient levels of active gibberellic acid during the initial ovary development of tomato. Moreover, genotypic diversity of GRAS2 was consistent with the molecular basis of fruit weight evolution, suggesting that GRAS2 contributes to the molecular basis of the evolution of fruit weight in tomato. Collectively, these findings enhance our understanding of GRAS2 functions, in fruit development of tomato, and demonstrate a strong association between the GRAS gene family and fruit development.
TL;DR: In this article, the authors investigated the effects of indole-3-butyric acid (IBA) and naphthalene acetic acid (NAA) at a concentration of 2 ǫ L−1 on the formation of adventitious roots of azalea and their impact on biochemical changes and endogenous hormones.
Abstract: Based on the importance of producing in vitro adventitious roots, this study was carried out to investigate the effects of indole-3-butyric acid (IBA) and naphthalene acetic acid (NAA) at a concentration of 2 mg L−1 on the formation of adventitious roots of azalea and their impact on biochemical changes and endogenous hormones. The rooting percentage, root number, and root length were increased in the microshoots of both studied cultivars (‘Mingchao’ and ‘Zihudie’) when the growth medium was supplemented with IBA. Additionally, peroxidase, indole acetic acid oxidase, hydrogen peroxide, and soluble protein contents were improved in both cultivars by auxin treatments especially during the first 7 days of the rooting period. However, application of IBA and NAA increased catalase and polyphenol oxidase in both cultivars during the first 14 and 28 days of culture. The increase in endogenous indole acetic acid (IAA) levels was accompanied by low activity of IAAO during most periods of root induction of microshoots in all treatments. Endogenous gibberellic acid levels were increased after 7 days of culture and then increased again after 28 days of culture. In contrast, the levels of endogenous zeatin riboside and isopentenyl adenosine were decreased with auxin treatments in the first period of the rooting process and then increased after 21 and 28 days of culture. The present study demonstrated that IBA at a concentration of 2 mg L−1 has a strong effect on azalea rooting. Moreover, the efficiency of IBA and NAA effects on biochemical changes during adventitious root induction was investigated, which may provide new horizons of in vitro rooting production and provide valuable information for the micropropagation of Rhododendron plants.
TL;DR: Results suggest that U. lactuca extract-derived silver nanoparticles could be used as biostimulants for the enhancement of somatic embryogenesis and plant regeneration rate in G. superba.
Abstract: An efficient protocol for somatic embryogenesis and plant regeneration from rhizome explants of Gloriosa superba L. was developed using various plant growth regulators (PGRs), Ulva lactuca extracts (ULE), and phycomolecule-coated U. lactuca silver nanoparticles (ULAgNPs). Callus was initiated from rhizome explants on the Murashige and Skoog (MS) medium supplemented with various concentrations of 2,4-dichlorophenoxyacetic acid (1.0–5.0 mg L−1), α-naphthaleneacetic acid (NAA) (0.5 mg L−1), ULE (10–50%), and ULAgNPs (0.1–0.5 mg L−1). Callus was cultured on MS medium fortified with various concentrations and combinations of 6-benzylaminopurine (BAP) (0.5–2.5 mg L−1), kinetin (KIN) (0.5–2.5 mg L−1), ULAgNPs (0.1–0.5 mg L−1), and 20% ULE along with 0.5 mg L−1 NAA for the development of somatic embryos (SEs). The maximum percentage of embryo maturation (100%) was observed on the medium containing 0.5 mg L−1 ULAgNPs, 2.0 mg L−1 BAP, 0.5 mg L−1 abscisic acid (ABA), 0.5 mg L−1 silver nitrate (AgNO3), and 20% ULE. The highest percentage of embryo germination (86.1%) was noticed on the MS medium containing 0.3 mg L−1 ULAgNPs, 5.0 mg L−1 gibberellic acid (GA3), 2.0 mg L−1 BAP, 0.5 mg L−1 adenine sulfate (AdS), and 20% ULE. Well-rooted plantlets were successfully acclimatized in the greenhouse with 70% survival rate. Results suggest that U. lactuca extract-derived silver nanoparticles could be used as biostimulants for the enhancement of somatic embryogenesis and plant regeneration rate in G. superba.
TL;DR: Novel insights are provided into the effects of GA3 in regulating vegetative and reproductive growth of kenaf as well as improving its fiber properties.
TL;DR: The characterization of GIM2 demonstrates that it plays a role in seed germination by affecting the GA metabolic pathway in Arabidopsis by changing the expression levels of a set of GA- and/or ABA-related genes.
Abstract: The phytohormones gibberellic acid (GA) and abscisic acid (ABA) antagonistically control seed germination. High levels of GA favor seed germination, whereas high levels of ABA hinder this process. The direct relationship between GA biosynthesis and seed germination ability need further investigation. Here, we identified the ABA-insensitive gain-of-function mutant germination insensitive to ABA mutant 2 (gim2) by screening a population of XVE T-DNA-tagged mutant lines. Based on two loss-of-function gim2-ko mutant lines, the disruption of GIM2 function caused a delay in seed germination. By contrast, upregulation of GIM2 accelerated seed germination, as observed in transgenic lines overexpressing GIM2 (OE). We detected a reduction in endogenous bioactive GA levels and an increase in endogenous ABA levels in the gim2-ko mutants compared to wild type. Conversely, the OE lines had increased endogenous bioactive GA levels and decreased endogenous ABA levels. The expression levels of a set of GA- and/or ABA-related genes were altered in both the gim2-ko mutants and the OE lines. We confirmed that GIM2 has dioxygenase activity using an in vitro enzyme assay, observing that GIM2 can oxidize GA12 . Hence, our characterization of GIM2 demonstrates that it plays a role in seed germination by affecting the GA metabolic pathway in Arabidopsis.
TL;DR: In this article, the potential objectives for GA3 and PBZ as affected by salinity through altering the phytohormones and biochemical parameters in sweet sorghum were investigated.
Abstract: The phytohormones are important in plant adaptation to abiotic and biotic stresses by facilitating a wide range of adaptive responses. Application of gibberellic acid (GA3) and paclobutrazol (PBZ) as GA3 inhibitors have been shown to affect salinity tolerance through modulating phytohormones. The aim of this study was to find out the potential objectives for GA3 and PBZ as affected by salinity through altering the phytohormones and biochemical parameters in sweet sorghum. Following seed germination, seedlings were cultured in Hoagland nutrient solution containing NaCl supplemented with GA3 and PBZ for 12 days. The results were analyzed by principal component analysis to identify the best target(s) for salinity, GA3, and PBZ in sweet sorghum. Paclobutrazol associated with salt improved root/shoot length, carotenoid, and total chlorophyll by modulating cytokinin (CK)/GA3, indole acetic acid (IAA)/GA3, and total polyamines/GA3 ratios. Gibberellic acid-treated plants not exposed to salinity treatments notably improved phytohormones content such as cytokinin, auxin, abscisic acid (ABA), and polyamines resulting in increased stem growth. Moreover, the main objectives of GA3 were ABA, spermidine, and ABA/GA3 ratio in response to salinity. Though GA3 and PBZ have different roles against salt stress, ABA/GA3 ratio was a similar target of GA3 and PBZ. This work suggests that altered levels of GA3 resulting from PBZ- and GA3-treated plants cause different allocation patterns in sweet sorghum by regulation of CK/GA3, IAA/GA3, and total polyamines/GA3 ratio. Also, accumulation chlorophyll pigments, carotenoids, and water soluble carbohydrates of sorghum plants under salinity regulated by total polyamines/GA3 and ABA/GA3 ratios positively correlated with PBZ application.
TL;DR: The inclusion of Arbuscular Mycorrhizal (AM) fungi and Azotobacter chroococcum to tissue culture of raised saplings during acclimatization enhanced their survival and resulted in a significant increase of plant growth.
Abstract: In vitro selected salt tolerant saplings of Morus alba (cv. Sujanpuri) were raised from nodal explants with axillary buds collected during three different periods of the year. The growth and shoot/root multiplication of the nodal explants collected between November to February and July to October were found to be better than those collected between March to June. In cultures, shoot multiplication was induced by the application of 2.5 mg/l of 6-benzylaminopurine (BAP) and 0.3 mg/l of gibberellic acid (GA 3 ), while rooting by 1.0 mg/l of indolebutyric acid (IBA). Sodium chloride (NaCl) was added to induce salt stress and its concentration was gradually increased from 0.1% (w/v) onwards. The salt tolerance was observed up to 0.4% (w/v) NaCl and 100% mortality of explants was noted above this concentration. The inclusion of Arbuscular Mycorrhizal (AM) fungi and Azotobacter chroococcum to tissue culture of raised saplings during acclimatization enhanced their survival and resulted in a significant increase of plant growth. After the transfer of plants to salt affected wasteland, only NaCl-treated saplings survived, whereas those developed without NaCl resulted in 100% mortality.
TL;DR: It is concluded that seed pre-treated with PGRs affected hormone content, induced sugar accumulation in apical buds and regulated genes involved in floral induction, which impacted floral bud differentiation.
TL;DR: The role of PAs, and their interactions with the other germination regulators, in the regulation of seed dormancy in S. sebiferum was highlighted and treatment with SCE upregulated the transcription level of the dormancy-related gene, gibberellins suppressing genes, abscisic acid biosynthesis and signalling genes.
Abstract: Sapium sebiferum, an ornamental and bio-energetic plant, is propagated by seed. Its seed coat contains germination inhibitors and takes a long time to stratify for germination. In this study, we discovered that the S. sebiferum seed coat (especially the tegmen) and endospermic cap (ESC) contained high levels of proanthocyanidins (PAs). Seed coat and ESC removal induced seed germination, whereas exogenous application with seed coat extract (SCE) or PAs significantly inhibited this process, suggesting that PAs in the seed coat played a major role in regulating seed germination in S. sebiferum. We further investigated how SCE affected the expression of the seed-germination-related genes. The results showed that treatment with SCE upregulated the transcription level of the dormancy-related gene, gibberellins (GAs) suppressing genes, abscisic acid (ABA) biosynthesis and signalling genes. SCE decreased the transcript levels of ABA catabolic genes, GAs biosynthesis genes, reactive oxygen species genes and nitrates-signalling genes. Exogenous application of nordihydroguaiaretic acid, gibberellic acid, hydrogen peroxide and potassium nitrate recovered seed germination in seed-coat-extract supplemented medium. In this study, we highlighted the role of PAs, and their interactions with the other germination regulators, in the regulation of seed dormancy in S. sebiferum.
TL;DR: It is suggested that gibberellic acid regulates the expression of the biosynthesis of lignin genes, generating changes in cell wall composition and pedicel structure that result in an increase in berry drop.
TL;DR: The new QTLs discovered in this study will be useful to further elucidate the molecular mechanisms underlying the responses of tomato seeds to high temperature and eventually lead to identification of the causal genes regulating these responses.
Abstract: Exposing imbibed seeds to high temperatures may lead to either thermo-inhibition of germination or thermo-dormancy responses. In thermo-inhibition, seed germination is inhibited but quickly resumed when temperatures are lowered. Upon prolonged exposure to elevated temperatures, thermo-dormancy may be induced and seeds are not able to germinate even at optimal temperatures. In order to explore underlying physiological and molecular aspects of thermo-induced secondary dormancy, we have investigated the physiological responses of tomato seeds to elevated temperatures and the molecular mechanisms that could explain the performance of tomato seeds at elevated temperature. In order to investigate how tomato seeds respond to high temperature we used two distinct tomato accessions: Solanum lycopersicum (cv. Moneymaker) (MM) and Solanum pimpinellifolium accession CGN14498 (PI). MM seeds did not germinate under high temperature conditions while seeds of PI reached a maximum germination of 80%. Despite the high germination percentage of PI, germinated seeds did not produce healthy seedling at 37 °C. By using a candidate gene approach we have tested if similar molecular pathways (abscisic acid (ABA) and gibberellic acid (GA)) present in lettuce and Arabidopsis, are regulating thermo-inhibition and thermo-dormancy responses in tomato. We showed that the ABA biosynthesis pathway genes NCED1 and NCED9 were upregulated whereas two of the GA-biosynthesis regulators (GA3ox1 and GA20ox1) were downregulated in tomato thermo-dormant seeds at elevated temperature. To identify novel regulators of tomato seed performance under high temperature, we screened a Recombinant Inbred Line (RIL) population derived from a cross between the two tomato accessions MM and PI for thermo-inhibition and dormancy induction. Several QTLs were detected, particularly for thermo-dormancy, which may be caused by new regulators of thermo-inhibition and thermo-dormancy in tomato. None of the genes studied in this research were co-locating with the detected QTLs. The new QTLs discovered in this study will therefore be useful to further elucidate the molecular mechanisms underlying the responses of tomato seeds to high temperature and eventually lead to identification of the causal genes regulating these responses.
TL;DR: This data is the first comprehensive analysis of the underlying transcriptional response mechanism of floral differentiation following GA3 treatment in J. curcas, which helps in engineering high-yielding varieties of Jatropha.
Abstract: Jatropha curcas L. seeds an oilseed plant with great potential for biodiesel production. However, low seed yield, which was limited by its lower female flowers, was a major drawback for its utilization. Our previous study found that the flower number and female-to-male ratio were increased by gibberellin treatment. Here, we compared the transcriptomic profiles of inflorescence meristem at different time points after gibberellic acid A3 (GA3) treatment. The present study showed that 951 differentially expressed genes were obtained in response to gibberellin treatment, compared with control samples. The 6-h time point was an important phase in the response to exogenous gibberellin. Furthermore, the plant endogenous gibberellin, auxin, ethylene, abscisic acid, and brassinolide-signaling transduction pathways were repressed, whereas the genes associated with cytokinin and jasmonic acid signaling were upregulated for 24-h time point following GA3 treatment. In addition, the floral meristem determinacy genes (JcLFY, JcSOC1) and floral organ identity genes (JcAP3, JcPI, JcSEP1-3) were significantly upregulated, but their negative regulator (JcSVP) was downregulated after GA3 treatment. Moreover, the effects of phytohormone, which was induced by exogenous plant growth regulator, mainly acted on the female floral differentiation process. To the best of our knowledge, this data is the first comprehensive analysis of the underlying transcriptional response mechanism of floral differentiation following GA3 treatment in J. curcas, which helps in engineering high-yielding varieties of Jatropha.
TL;DR: In this article, the effect of 10 μM thidiazuron (TDZ), 200 μM gibberellic acid 3 (GA), 300 μM 5-aminolevulinic acid (AA) or 300 μm glutamic acid (GLU) on the reduction of leaf yellowing of potted geranium plants during transport and permanence to retail shelves was evaluated.