Pea is a seed legume.It is rich in cellulose fibre and protein.It is also a significant source of minerals and vitamins.In this paper,we set out to better characterize the physiological responses of Pisum sativum L.to...Pea is a seed legume.It is rich in cellulose fibre and protein.It is also a significant source of minerals and vitamins.In this paper,we set out to better characterize the physiological responses of Pisum sativum L.to the combined effects of NaCl,100 mM and gibberellins(GA3).Our analysis revealed that NaCl caused a decrease in growth resulting in a reduction in root elongation,distribution and density,leaf number and leaf area,and a decrease in dry matter of roots and shoots.However,the contribution of GA3 in the salty environment induced an increase in these different parameters suggesting an improving effect of this hormone on growth of pea in presence of salt.NaCl also led to a disturbance of the photosynthetic machinery.Indeed,level of chlorophyll pigments(a and total)and photosynthetic activity were decreased compared to the control plants.However,the exogenous supply of GA3 restored this decrease in net CO_(2) assimilation,but not in chlorophyll content.Additional analyses were performed on the effect of salinity/GA3 interaction on osmolytes(soluble sugars and starch).Our results showed an increase in sugars and a decrease in starch in the presence of 100 mM NaCl.The salt-GA3 combination resulted in compensation of soluble sugar contents but not of starch contents,suggesting a beneficial effect of GA3 under saline stress conditions.Level of three main polyamines putrescine,spermidine,and spermine increased significantly in all organs of salt-treated plants.展开更多
Mandarin (Citrus reticulata Blanco) is a promising fruit crop gaining popularity for its human nutrition and economic importance in Nepal. The qualitative losses during pre-harvest stage hinder the productivity and su...Mandarin (Citrus reticulata Blanco) is a promising fruit crop gaining popularity for its human nutrition and economic importance in Nepal. The qualitative losses during pre-harvest stage hinder the productivity and subsequently shorten the on-tree storability. An experiment was conducted to assess the effect of gibberellic acid on quality and shelf life of the mandarin fruit. GA<sub>3</sub> at 10, 20, and 30 ppm as against of control were evaluated. Observations on fruit weight (g), fruit firmness (kg/cm<sup>2</sup>), rind colour (1 - 5 index), juice recovery (%), TSS/acid ratio, PLW (%), decay loss (%), and ascorbic acid (mg/100 ml) were recorded at three harvesting dates i.e. 20 Nov, 5 Dec, and 20 Dec and storage condition. It has been revealed that the fruits treated with GA<sub>3</sub> at 20 ppm retained higher fruit weight (128.6 g), more firmness (3.54 kg/cm<sup>2</sup>), better juice recovery (57.75%), and greater TSS/acid ratio (21.24) at the end of study (20 December). The PLW was found less with GA<sub>3</sub> at 30 ppm in both ambient (5.17%) and cellar (6.69%) condition as against untreated fruits (9.52% and 11.76%). Similarly, the decay loss was minimum in the fruits treated with GA<sub>3</sub> at 30 ppm both with ambient (1.02%) and cellar condition (8.21%) as against control with ambient (5.54%) and cellar (21.58%).展开更多
Gibberellins(GAs) are important phytohormones that regulate many developmental processes in plants. Clove, as the reproductive organ of garlic, dramatically affected garlic bulb development. Considering the potential ...Gibberellins(GAs) are important phytohormones that regulate many developmental processes in plants. Clove, as the reproductive organ of garlic, dramatically affected garlic bulb development. Considering the potential of gibberellins in plant development and our previous studies, we investigated the effect of soaking two types of seed cloves(seed clove-I: without root/shoot sprouting;seed clove-II: with root/shoot sprouting) in GA3 solution on axillary bud development and examined the effect of soaking seed cloves in GA3 solution on bulb development, phytohormone level and sugar content in this study.Results indicated seed clove types, soaking liquids and their interaction significantly affected the number of cloves per bulb and the rate of single-clove bulb. Moreover, soaking seed cloves in 1 mmol L^-1 GA3 solution for 24 h not only promoted axillary bud formation and secondary plant growth(equal to tillering or branching), but also slightly increased the number of cloves per bulb and changed bulb structure with a low yield and marketable quality. On the 40 th day after GA3 treatment(at axillary bud outgrowth stage), zeatin riboside(ZR) and soluble protein in stem were sharply increased with the increase of GA3, sucrose, fructose and soluble protein in leaf. However, GA3, indole-3-acetic acid(IAA), soluble sugar and sucrose in stem(3.52 ng g^-1 fresh weight(FW), 19.88 ng g^-1 FW, 237.3 mg g^-1 FW, and 8.24 mg g^-1 FW, respectively) were significantly decreased on the 40 th day after GA3 treatment, compared to the control of water treatment(5.56 ng g^-1 FW, 32.96 ng g^-1 FW, 263.6 mg g^-1 FW, and 10.37 mg g^-1 FW, respectively). To our knowledge, these novel results indicate seed cloves soaked in GA3 solution promotes axillary bud formation and outgrowth that caused the changes in plant architecture and bulb structure. Meanwhile, our findings suggest that the level of endogenous plant hormone(GA3, IAA and ZR) cooperates with the content of sugar(sucrose and fructose) in leaf and stem to regulate axillary bud outgrowth in garlic.展开更多
The experiments were carried out at the Post Graduate Research Center, to study the influence of Gibberellic Acid (50 ppm) and Oxygenated Peptone (1% aqueous solution) on chick pea (Cicer arietinum L. cv. Vijay) durin...The experiments were carried out at the Post Graduate Research Center, to study the influence of Gibberellic Acid (50 ppm) and Oxygenated Peptone (1% aqueous solution) on chick pea (Cicer arietinum L. cv. Vijay) during germination by giving pre-sowing soaking treatment for 6 hours using petriplate method. Both the treatments enhanced the germination process. GA treatment was useful to increase shoot length, mobilization efficiency, emergence index, speed of germination and co-efficient of germination while oxygenated peptone showed an upper hand in root length, shoot/root ratio, biomass and vigour index. GA led to comparatively more synthesis of nucleic acids while oxygenated peptone showed more increase in total carbohydrates and soluble protein content. However, the activity of enzymes like amylase, catalase and protease showed upper hand with oxygenated peptone as compared to GA. In fact GA is costlier and can not be used in organic farming as it enters metabolic pathways of plant and alters them. Hence the use of oxygenated peptone is recommended being less expensive and usable under organic farming condition as it does not enter the plant metabolic pathways and yet brings about significant positive effect.展开更多
Six pairs of tall and dwarf near-isogenic lines derived from a dominant semi-dwarf mutant (Y98149) were selected to study height expression and sensitivity to gibberellic acid (GA3). The lengths of the 4-5th inter...Six pairs of tall and dwarf near-isogenic lines derived from a dominant semi-dwarf mutant (Y98149) were selected to study height expression and sensitivity to gibberellic acid (GA3). The lengths of the 4-5th internode, the 3rd, 2nd, 1st internodes from the top and the panicle length in the six dwarf near isogenic lines were 97.2%, 53.3%, 65.1%, 61.9% and 94.7% of those in the six tall ones, respectively, indicating that the dominant semi-dwarfing gene significantly inhibited the internode elongation. Moreover, Y98149 (mutant type) was more sensitive to GA3 than Y98148 (wild type), and had a lower GA3 concentration in plant, about 78% of Y98148.展开更多
Lilium davidii var.unicolor(Lanzhou lily)is an important economic crop in the northwest cold and arid regions of China.Effective regulation of tiller-bulb development and plant growth is the key to improving yield and...Lilium davidii var.unicolor(Lanzhou lily)is an important economic crop in the northwest cold and arid regions of China.Effective regulation of tiller-bulb development and plant growth is the key to improving yield and quality of the lily.This study attempted to evaluate the effect of gibberellic acid(GA3)on tiller-bulb development and plant growth of Lanzhou lily by applying GA3 at various concentrations(0 mg/L,10 mg/L,30 mg/L,60 mg/L,and 100 mg/L)before planting and in the seedling period.Results showed that the 60-mg/L GA3 application had an inhibiting effect on tiller-bulb formation and increased the ratios of single and double bulbs but decreased the ratios of bulbs with three or more tiller bulbs,as com pared to the control(CK)and other GA3 treatments.The difference in flower number did not reach significant levels among the treatments.The tillering-related endogenous hormones IAA(indole-3-acetic acid)and Z(zeatin)content de creased,while IAA/Z increased with the 60-mg/L GA3 treatment during tiller initiation.And also,the shoot-bulb number and total daughter-bulb number decreased significantly with the 60-mg/L GA3 treatment.Furthermore,the 10-mg/L GA3 application promoted growth of Lanzhou lily significantly and resulted in an increase in plant height;bulb diameter;bulb circumference;and biomass of shoots,bulbs,fibrous roots,and the whole plant.Therefore,GA3 application is promising as a new regulation method for inhibiting tiller-bulb development and promoting bulb growth in Lanzhou lily production.展开更多
Solutions of gibberellic acid prepared at three concentration levels including 5, 10 and 20 mg/L, were applied at two seedless grape varieties, Thompson and Belgrade, by spraying, during the three different periods of...Solutions of gibberellic acid prepared at three concentration levels including 5, 10 and 20 mg/L, were applied at two seedless grape varieties, Thompson and Belgrade, by spraying, during the three different periods of the vine growing: before blooming, after blooming and before veraison, in order to study their influence on some cultural technological characteristics. Dimension and shape of the cluster and berry, mechanical characteristics of the berries and chemical content of the must (sugar and total acids) has been also investigated. It was noticed that the concentration of gibberellic acid had influence on the technological characteristics of the berries in all grape growing periods tested. The addition of gibberellic acid at concentration of 20 mg/L increased the weight of the cluster and berry, and increased the transportability of the berries belonging to the two seedless varieties.展开更多
Besides control of the fungal plant pathogens, another interesting aspect observed when plants are treated with Trichoderma harzianum include effects such as complete and even stand of plants, improved seed germinatio...Besides control of the fungal plant pathogens, another interesting aspect observed when plants are treated with Trichoderma harzianum include effects such as complete and even stand of plants, improved seed germination, increases in plant height and overall enhanced plant growth. No research has yet been conducted to elucidate the mechanism by which these effects occur. Improved seed germination, in particular, suggest that Trichoderma harzianum produces a metabolite that may mimic the plant growth hormone gibberellic acid. The metabolite gliotoxin, produced by Trichoderma harzianum appear to be structurally most similar to gibberellic acid. In this study, common pharmacophore generation and molecular ligand docking simulations were used to evaluate the molecular similarity between gibberellic acid, specifically GA3, and gliotoxin. For the common pharmacophore evaluation, the structure of various gibberellic acids were used to construct a pharmacophore space to which gliotoxin was aligned, and during the molecular docking simulations the gibberellic acid receptor, GID1, served as ligand target for GA3 and gliotoxin. During the common pharmacophore evaluation, gliotoxin was successfully aligned to the common pharmacophore model constructed from various gibberellic acids. Furthermore, molecular docking simulations of gliotoxin and GA3 into the gibberellic acid receptor (GIDI) yielded docking scores of-10.78 kcal/mol for the GA3 molecule from Corina and a docking score of-10.17 kcal/mol for glioto^in. The docking scores suggest that gliotoxin may be able to competitively occupy the receptor space for gibberellic acid, and as such elicit the similar physiological responses observed in literature.展开更多
This study was conducted during 2019/2020 on sweet cherry trees (<i>Prunus Avium</i> L.) (Bing and Hardy Giant) cultivar planted at Sergaya-Al_Zabadani area of Rural </span><span style="font-...This study was conducted during 2019/2020 on sweet cherry trees (<i>Prunus Avium</i> L.) (Bing and Hardy Giant) cultivar planted at Sergaya-Al_Zabadani area of Rural </span><span style="font-family:"">Dam</span><span style="font-family:"">ascus, to reduce fruit drop of sweet cherry. The experiment included 4 foliar applications: T1: control, T2: GA<sub>3</sub> (100 ppm), T3: NAA (20 <span>ppm), T4: (100 ppm GA<sub>3</sub> + 20 ppm NAA). Fruit set and fruit drop pe</span>rcentage, fruiting factor, and yield were recorded. The results showed that treatment with (100 ppm GA<sub>3</sub> + 20 ppm NAA) recorded higher fruit set percentage (73.81% and 75.62%), and fruiting factor (48.38% and 50.04%) respectively</span><span style="font-family:"">;</span><span style="font-family:""> <span>In addition to fruit yield (40.19 and 41.21 kg/tree) for both cultivars, co</span>mpared to the control (9.13, 6.60 kg/tree). Therefore, it can be concluded that GA<sub>3</sub> + NAA treatment reduced Sweet cherry fruit drop better than other treatments, <span>where fruit drop percentage didn’t exceed (63.11% and 62.01%) in both cu</span>ltivars (Bing and Hardy Giant) respectively, compared to the control (80.92% and 80.64%).展开更多
To comprehensively explore the physio-biochemical and molecular changes of paclobutrazol(PBZ) at the ideal dose under water deficit stress(WDS) conditions, we investigated the effects of 100 mg/kg PBZ applied via dren...To comprehensively explore the physio-biochemical and molecular changes of paclobutrazol(PBZ) at the ideal dose under water deficit stress(WDS) conditions, we investigated the effects of 100 mg/kg PBZ applied via drenching on various physio-biochemical and molecular parameters in three rice varieties(N22, IR64, and IR64 DTY1.1) under both mild [75%-80% relative water content(RWC)] and severe(60%-65% RWC) WDS conditions. The results showed that PBZ treatment positively influenced the physio-biochemical parameters, significantly increasing dry matter(16.27%-61.91%), RWC(6.48%-16.34%), membrane stability index(4.37%-10.35%), and total chlorophyll content(8.97%-29.09%) in the rice varieties under both mild and severe WDS. Moreover, PBZ treatment reduced drought susceptibility(0.83-0.95) and enhanced drought tolerance efficiency(60.92%-86.78%), indicating its potential as a stress-mitigating agent. Global methylation analysis revealed changes in DNA methylation patterns, indicating the regulatory influence of PBZ on gene expression. The expression analysis of genes involved in the diversification of geranylgeranyl pyrophosphate towards the biosynthesis of abscisic acid, gibberellin acid, and chlorophyll showed alterations in their expression levels, suggesting the involvement of PBZ in the isoprenoid pathway. Overall, this study provides valuable insights into the potential mechanisms by which PBZ modulates physiological and molecular responses in rice plants under WDS. The findings highlight the importance of PBZ as a promising agent for enhancing drought tolerance in rice and offer valuable information for future research in crop stress management.展开更多
[Objectives]To improve the yield and secondary metabolite content of medicinal plants and to further develop and utilize the medicinal and other functions of medicinal plants.[Methods]We used the sterile tissue cultur...[Objectives]To improve the yield and secondary metabolite content of medicinal plants and to further develop and utilize the medicinal and other functions of medicinal plants.[Methods]We used the sterile tissue culture method with Houttuynia cordata Thunb.as the research object.Different concentrations of 1-naphthalene acetic acid(NAA),auxin(indole-3-acetic acid,IAA)and gibberellin acid(GA_(3))were added to the group culture medium of H.cordata to investigate the effects of exogenous plant hormones on plant height,root length,fresh weight,morphological characteristics,four phenolics and 20 volatile compounds.[Results]The results showed that the exogenous plant hormone of 3 mg/L GA_(3)significantly increased plant height by 79.9%over the control;the exogenous plant hormone of 3 mg/L IAA significantly increased root length by 52.6%over the control;and the exogenous plant hormone of 1 mg/L GA_(3)significantly increased fresh weight of single plant by 458.2%over the control.In the treatment group of 1 mg/L NAA,chlorogenic acid content was significantly increased by 52.6%compared with the control;in the treatment group of 1 mg/L IAA,chlorogenic acid,rutin,isodendrin and quercetin content were significantly increased by 109.1%,100.6%,173.8%,and 198.7%compared with the control,respectively;in the treatment of 3 mg/L GA_(3),chlorogenic acid,rutin,isoquercitin,and quercitin content were significantly increased by 65.3%,104.9%,139.0%and 191.2%over the control.In addition,the content of volatile compounds was significantly higher in all H.cordata treated with exogenous plant hormones of 2 mg/L NAA,1 mg/L IAA,and 3 mg/L GA_(3);however,the content of volatile compounds was lower in all of the treatments with 2 mg/L GA_(3).[Conclusions]Different exogenous plant hormones have certain effects on the growth morphology and secondary metabolic content of H.cordata,which provides theoretical basis and technical support for the development and utilization of medicinal plants.展开更多
Plant responses to abiotic stresses are coordinated by arrays of growth and developmental programs. Gibberellic acid (GA) and abscisic acid (ABA) play critical roles in the developmental programs and environmental...Plant responses to abiotic stresses are coordinated by arrays of growth and developmental programs. Gibberellic acid (GA) and abscisic acid (ABA) play critical roles in the developmental programs and environmental responses, respectively, through complex signaling and metabolism networks. However, crosstalk between the two phytohormones in stress responses remains largely unknown. In this study, we report that GIBBERELLIN-INSENSITIVE DWARF 1 (GID1), a soluble receptor for GA, regulates stomata[ develop- ment and patterning in rice (Oryza sativa L.). The gidl mutant showed impaired biosynthesis of endogenous ABA under drought stress conditions, but it exhibited enhanced sensi- tivity to exogenous ABA. Scanning electron microscope and infrared thermal image analysis indicated an increase in the stomatal conductance in the gidl mutant under drought conditions. Interestingly, the gidl mutant had increased levels of chlorophyll and carbohydrates under submergence conditions, and showed enhanced reactive oxygen species (ROS)-scavenging ability and submergence tolerance compared with the wild-type. Further analyses suggested that the function of GID1 in submergence responses is partially dependent on ABA, and GA signaling by GID1 is involved in submergence tolerance by modulating carbohydrate consumption. Taken together, these findings suggest GID1 plays distinct roles in stomatal response and submergence tolerance through both the ABA and GA signaling pathways in rice.展开更多
Plants synthesize an astonishing diversity of isoprenoids, some of which play essential roles in photosynthesis, respiration, and the regulation of growth and development. Two independent pathways for the biosynthesis...Plants synthesize an astonishing diversity of isoprenoids, some of which play essential roles in photosynthesis, respiration, and the regulation of growth and development. Two independent pathways for the biosynthesis of isoprenoid precursors coexist within the plant cell: the cytosolic mevalonic acid (MVA) pathway and the plastidial methylerythritol phosphate (MEP) pathway. However, little is known about the effects of plant hormones on the regulation of these pathways. In the present study we investigated the effect of gibberellic acid (GA3) on changes in the amounts of many produced terpenoids and the activity of the key enzymes, 1-deoxy-D-xylulose 5-phosphate synthase (DXS) and 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR), in these pathways. Our results showed GA3 caused a decrease in DXS activity in both sexes that it was accompanied by a decrease in chlorophylls, carotenoids and Ag-tetrahydrocannabinol (THC) contents and an increase in α-tocopherol content. The treated plants with GA3 showed an increase in HMGR activity. This increase in HMGR activity was followed by accumulation of stigmasterol and β-sitosterol in male and female plants and campestrol in male plants. The pattern of the changes in the amounts of sterols was exactly similar to the changes in the HMGR activity. These data suggest that GA3 can probably influence the MEP and MVA pathways oppositely, with stimulatory and inhibitory effects on the produced primary terpenoids in MVA and DXS pathways, respectively.展开更多
In the present study, we Investigated the role of glbberelllc acid (GA3) and Indole acetic acid (IAA) In the gravity response of stems and tension wood formation using two-year-old stems of Fraxinus mandshurica Ru...In the present study, we Investigated the role of glbberelllc acid (GA3) and Indole acetic acid (IAA) In the gravity response of stems and tension wood formation using two-year-old stems of Fraxinus mandshurica Rupr. var. Japonica Maxim seedlings. Forty-five seedlings were used and divided Into nine groups that Included five seedlings In each group. Seedlings were treated with applications of GA3 alone at concentrations of 2.89×10^-8 and 2.89×10^-7 μmol/L, IAA alone at concentrations of 5.71×10^-8 and 5.71×10^-7 μmol/L, or their combination to the apical bud of the stem using a mlcroplpette. Seedlings were positioned horizontally after the first treatment. The same treatments were repeated six times per week. At the end of the experiment, all seedlings were harvested. Then, stem segments were cut under a light microscope. Application of exogenous GA3 at the higher concentration stimulated the upward bending of stems, whereas exogenous IAA had no effect. A synergistic effect of GA3 and IAA on upward stem bending was observed following application of the two combinations of GA3 and IAA. Moreover, application of exogenous GA3 at the higher dose stimulated wood formation on both the upper and lower sides of the stems, whereas the mixture of GA3 and IAA had a synerglstic effect on wood formation In horizontal stems. Application of exogenous IAA alone at the lower concentration (5.71×10^-8 μmol/L) or application of a mixture of the higher concentrations of GA3 (2.89×10^-7 μmol/L) and IAA (5.71×10^-7 μmol/L) Inhibited the development of gelatinous fibers (the G-layer) of tension wood on the upper side of the horizontal stems. The differentiation of gelatinous fibers of tension wood was not Inhibited by GA3 when It was applied alone, whereas the development of the gelatinous fibers of tension wood was strongly affected by the application of IAA. The findings of the present study suggest that the development of the G-layer Is not related to the dose of GA3, but needs a relatively lower concentration of IAA.展开更多
Seed germination is a key step in the life cycle of all seed plants, and it is of immense significance in agriculture.Germination is controlled by multiple environmental cues such as light and moisture,and endogenous ...Seed germination is a key step in the life cycle of all seed plants, and it is of immense significance in agriculture.Germination is controlled by multiple environmental cues such as light and moisture,and endogenous factors,especially phytohormones.Gibberellic acid (GA)has long been identified as a critical hormone in the regulation of seed germination by countering the inhibition imposed by abscisic acid (ABA)(Holdsworth et al.,2008;Lee et al.,2010).展开更多
Glucosinolates, anthocyanins, total phenols, and vitamin C, as well as antioxidant capacity, were investigated in Chinese kale sprouts treated with both glucose and gibberellic acid(GA_3). The combination of 3%(0.0...Glucosinolates, anthocyanins, total phenols, and vitamin C, as well as antioxidant capacity, were investigated in Chinese kale sprouts treated with both glucose and gibberellic acid(GA_3). The combination of 3%(0.03 g/ml) glucose and 5 μmol/L GA_3 treatment was effective in increasing glucosinolate content while glucose or GA_3 treatment alone did not influence significantly almost all individual glucosinolates or total glucosinolates. The total phenolic content and antioxidant activity of Chinese kale sprouts were enhanced by combined treatment with glucose and GA_3, which could be useful in improving the main health-promoting compounds and antioxidant activity in Chinese kale sprouts.展开更多
Gibberellic acid(GA_(3))is widely used in agriculture and maybe transfer with groundwater flow,which is an endocrine disruptor,but few studies have focused on the transformation pathway and toxicity assessment of GA_(...Gibberellic acid(GA_(3))is widely used in agriculture and maybe transfer with groundwater flow,which is an endocrine disruptor,but few studies have focused on the transformation pathway and toxicity assessment of GA_(3)and its products.Here,GA_(3)and its transformation products in aqueous solution were identified and quantified by liquid chromatography mass spectrometry hybrid ion trap time-of-flight(LCMS-IT-TOF)and high-performance liquid chromatography(HPLC),respectively.The results showed that the half-life of GA_(3)transformation in ultrapure water was 16.1–24.6 days at p H=2.0–8.0,with the lowest half-life occurring at p H=8.0 and highest half-life occurring at p H=3.3.Isomerized gibberellic acid(Iso-GA_(3))and gibberellenic acid(GEA)were the main transformation products with a little hydroxy gibberellic acid(OH-GA_(3)).In North China groundwater,the mass balance of GA_(3)and its products was 76.2%,including Iso-GA_(3)(58%),GEA(7.9%),GA_(3)(7.3%)and OH-GA_(3)(3%)after reaching transformation equilibrium.Using Gaussian 09 for chemical computation,it was found that the transformation mechanism of GA_(3)was dependent upon the bond energy and the stereochemical feature of its molecular structure.GA_(3)always isomerized from theγ-lactone ring due to the lowest bond energy between the oxygen terminus of theγ-lactone ring and A ring.While GA_(3)and its transformation products all had developmental toxicity,the predicated LC 50(96 hr)and LD 50 of the main products of GA_(3)were much lower than those of GA_(3),indicating GA_(3)would be transformed into higher toxicity derivatives in water environments,posing a significant health risk to humans and the environment.展开更多
Hypocotyl formation during the epigeal germination of seedlings is under strict hormonal regulation. In a 3 d old Zinnia elegans seedling system, gibberellic acid (GA3) exerts an opposite effect to that exerted by l...Hypocotyl formation during the epigeal germination of seedlings is under strict hormonal regulation. In a 3 d old Zinnia elegans seedling system, gibberellic acid (GA3) exerts an opposite effect to that exerted by light on hypocotyl photomorphogenesis because GAz promotes an etiolated-like growth with an inhibition of radial (secondary) growth. For this reason, the effect of GA3 on the basic peroxidase isoenzyme from Z. elegans (ZePrx), an enzyme involved in hypocotyl lignin biosynthesis, was studied. The results showed that GA3 reduces ZePrx activity, similarly to the way in which it reduces seedling secondary growth. This hormonal response is supported by the analysis of the ZePrx promoter, which contains four types of GA3-responsive cis.elements: the W Box/O2S; the Pyr Box; the GARE; and the Amy Box. Taken together, these results suggest that ZePrx is directly regulated by GA3, with this effect matching the inhibitory effect of GA on the hypocotyl secondary growth.展开更多
The adsorption effects of several macroporousadsorption resins for gibberellic acid (GA3) were investigated.The dynamic adsorption capacity is 58.38 mg/g drybeads for resin R4 and 96.46 mg/g dry beads for resin R5whic...The adsorption effects of several macroporousadsorption resins for gibberellic acid (GA3) were investigated.The dynamic adsorption capacity is 58.38 mg/g drybeads for resin R4 and 96.46 mg/g dry beads for resin R5which is consistent with the surface area. Aqueous methanol(50%, V/V) is a good eluent and the yield of GA3 isabove 95%. The concentration of GA3 could increase fivefoldafter an adsorption-elution cycle and this is importantwhen considering further crystallization of GA3 in anindustrial process.展开更多
Barhi dates at Khalal maturity stage are well-known with their pleasant taste,crispy texture,and bright yellow color.It is necessary to extend the duration of Barhi Khalal stage which is too short for effective market...Barhi dates at Khalal maturity stage are well-known with their pleasant taste,crispy texture,and bright yellow color.It is necessary to extend the duration of Barhi Khalal stage which is too short for effective marketing.This study aimed to inspect the effects of Gibberellic Acid(GA_(3))and Salicylic Acid(SA)postharvest treatments on retaining the high quality of Khalal Barhi fruits during controlled atmosphere storage.Fresh samples of Barhi fruits at Khalal stage harvested at three different ripening levels were dipped after harvesting in GA3(150 ppm)or SA(2.0 mmol/L)and subsequently stored in controlled atmosphere(0°С,5%O_(2),5%CO_(2),80%±5%RH).The results revealed that the GA_(3) and SA treatments reduced the percentage of weight loss and decay in the fruits,while the total soluble solids increased.Moreover,GA_(3) and SA treatments were significantly efficient in limiting the changes in fruit color and texture of Barhi dates compared to the control.Sensorial results support the experimental data and disclosed that the GA_(3)(150 ppm)treatment in the controlled atmosphere(CA)storage was better in conserving the quality of Barhi at the Khalal maturity stage and delaying ripening process.展开更多
文摘Pea is a seed legume.It is rich in cellulose fibre and protein.It is also a significant source of minerals and vitamins.In this paper,we set out to better characterize the physiological responses of Pisum sativum L.to the combined effects of NaCl,100 mM and gibberellins(GA3).Our analysis revealed that NaCl caused a decrease in growth resulting in a reduction in root elongation,distribution and density,leaf number and leaf area,and a decrease in dry matter of roots and shoots.However,the contribution of GA3 in the salty environment induced an increase in these different parameters suggesting an improving effect of this hormone on growth of pea in presence of salt.NaCl also led to a disturbance of the photosynthetic machinery.Indeed,level of chlorophyll pigments(a and total)and photosynthetic activity were decreased compared to the control plants.However,the exogenous supply of GA3 restored this decrease in net CO_(2) assimilation,but not in chlorophyll content.Additional analyses were performed on the effect of salinity/GA3 interaction on osmolytes(soluble sugars and starch).Our results showed an increase in sugars and a decrease in starch in the presence of 100 mM NaCl.The salt-GA3 combination resulted in compensation of soluble sugar contents but not of starch contents,suggesting a beneficial effect of GA3 under saline stress conditions.Level of three main polyamines putrescine,spermidine,and spermine increased significantly in all organs of salt-treated plants.
文摘Mandarin (Citrus reticulata Blanco) is a promising fruit crop gaining popularity for its human nutrition and economic importance in Nepal. The qualitative losses during pre-harvest stage hinder the productivity and subsequently shorten the on-tree storability. An experiment was conducted to assess the effect of gibberellic acid on quality and shelf life of the mandarin fruit. GA<sub>3</sub> at 10, 20, and 30 ppm as against of control were evaluated. Observations on fruit weight (g), fruit firmness (kg/cm<sup>2</sup>), rind colour (1 - 5 index), juice recovery (%), TSS/acid ratio, PLW (%), decay loss (%), and ascorbic acid (mg/100 ml) were recorded at three harvesting dates i.e. 20 Nov, 5 Dec, and 20 Dec and storage condition. It has been revealed that the fruits treated with GA<sub>3</sub> at 20 ppm retained higher fruit weight (128.6 g), more firmness (3.54 kg/cm<sup>2</sup>), better juice recovery (57.75%), and greater TSS/acid ratio (21.24) at the end of study (20 December). The PLW was found less with GA<sub>3</sub> at 30 ppm in both ambient (5.17%) and cellar (6.69%) condition as against untreated fruits (9.52% and 11.76%). Similarly, the decay loss was minimum in the fruits treated with GA<sub>3</sub> at 30 ppm both with ambient (1.02%) and cellar condition (8.21%) as against control with ambient (5.54%) and cellar (21.58%).
基金supported by the grants from the National Natural Science Foundation of China(31772293)the Education Development Fund Project of Northwest A&F University,China(2017)。
文摘Gibberellins(GAs) are important phytohormones that regulate many developmental processes in plants. Clove, as the reproductive organ of garlic, dramatically affected garlic bulb development. Considering the potential of gibberellins in plant development and our previous studies, we investigated the effect of soaking two types of seed cloves(seed clove-I: without root/shoot sprouting;seed clove-II: with root/shoot sprouting) in GA3 solution on axillary bud development and examined the effect of soaking seed cloves in GA3 solution on bulb development, phytohormone level and sugar content in this study.Results indicated seed clove types, soaking liquids and their interaction significantly affected the number of cloves per bulb and the rate of single-clove bulb. Moreover, soaking seed cloves in 1 mmol L^-1 GA3 solution for 24 h not only promoted axillary bud formation and secondary plant growth(equal to tillering or branching), but also slightly increased the number of cloves per bulb and changed bulb structure with a low yield and marketable quality. On the 40 th day after GA3 treatment(at axillary bud outgrowth stage), zeatin riboside(ZR) and soluble protein in stem were sharply increased with the increase of GA3, sucrose, fructose and soluble protein in leaf. However, GA3, indole-3-acetic acid(IAA), soluble sugar and sucrose in stem(3.52 ng g^-1 fresh weight(FW), 19.88 ng g^-1 FW, 237.3 mg g^-1 FW, and 8.24 mg g^-1 FW, respectively) were significantly decreased on the 40 th day after GA3 treatment, compared to the control of water treatment(5.56 ng g^-1 FW, 32.96 ng g^-1 FW, 263.6 mg g^-1 FW, and 10.37 mg g^-1 FW, respectively). To our knowledge, these novel results indicate seed cloves soaked in GA3 solution promotes axillary bud formation and outgrowth that caused the changes in plant architecture and bulb structure. Meanwhile, our findings suggest that the level of endogenous plant hormone(GA3, IAA and ZR) cooperates with the content of sugar(sucrose and fructose) in leaf and stem to regulate axillary bud outgrowth in garlic.
文摘The experiments were carried out at the Post Graduate Research Center, to study the influence of Gibberellic Acid (50 ppm) and Oxygenated Peptone (1% aqueous solution) on chick pea (Cicer arietinum L. cv. Vijay) during germination by giving pre-sowing soaking treatment for 6 hours using petriplate method. Both the treatments enhanced the germination process. GA treatment was useful to increase shoot length, mobilization efficiency, emergence index, speed of germination and co-efficient of germination while oxygenated peptone showed an upper hand in root length, shoot/root ratio, biomass and vigour index. GA led to comparatively more synthesis of nucleic acids while oxygenated peptone showed more increase in total carbohydrates and soluble protein content. However, the activity of enzymes like amylase, catalase and protease showed upper hand with oxygenated peptone as compared to GA. In fact GA is costlier and can not be used in organic farming as it enters metabolic pathways of plant and alters them. Hence the use of oxygenated peptone is recommended being less expensive and usable under organic farming condition as it does not enter the plant metabolic pathways and yet brings about significant positive effect.
基金This work was supported by the grants of National Natural Science Foundation of China(No.3037863)Natural Science Foundation of Anhui Province,China(No.01041103).
文摘Six pairs of tall and dwarf near-isogenic lines derived from a dominant semi-dwarf mutant (Y98149) were selected to study height expression and sensitivity to gibberellic acid (GA3). The lengths of the 4-5th internode, the 3rd, 2nd, 1st internodes from the top and the panicle length in the six dwarf near isogenic lines were 97.2%, 53.3%, 65.1%, 61.9% and 94.7% of those in the six tall ones, respectively, indicating that the dominant semi-dwarfing gene significantly inhibited the internode elongation. Moreover, Y98149 (mutant type) was more sensitive to GA3 than Y98148 (wild type), and had a lower GA3 concentration in plant, about 78% of Y98148.
基金supported by the Science and Technology Service Network Initiative of the Chinese Academy of Sciences (Grant No. KFJ-STS-QYZD-120)the Gansu Province Major Project of Science and Technology (Grant No. 18ZD2NA010)the National Natural Science Foundation of China (Grant No. 41801076)
文摘Lilium davidii var.unicolor(Lanzhou lily)is an important economic crop in the northwest cold and arid regions of China.Effective regulation of tiller-bulb development and plant growth is the key to improving yield and quality of the lily.This study attempted to evaluate the effect of gibberellic acid(GA3)on tiller-bulb development and plant growth of Lanzhou lily by applying GA3 at various concentrations(0 mg/L,10 mg/L,30 mg/L,60 mg/L,and 100 mg/L)before planting and in the seedling period.Results showed that the 60-mg/L GA3 application had an inhibiting effect on tiller-bulb formation and increased the ratios of single and double bulbs but decreased the ratios of bulbs with three or more tiller bulbs,as com pared to the control(CK)and other GA3 treatments.The difference in flower number did not reach significant levels among the treatments.The tillering-related endogenous hormones IAA(indole-3-acetic acid)and Z(zeatin)content de creased,while IAA/Z increased with the 60-mg/L GA3 treatment during tiller initiation.And also,the shoot-bulb number and total daughter-bulb number decreased significantly with the 60-mg/L GA3 treatment.Furthermore,the 10-mg/L GA3 application promoted growth of Lanzhou lily significantly and resulted in an increase in plant height;bulb diameter;bulb circumference;and biomass of shoots,bulbs,fibrous roots,and the whole plant.Therefore,GA3 application is promising as a new regulation method for inhibiting tiller-bulb development and promoting bulb growth in Lanzhou lily production.
文摘Solutions of gibberellic acid prepared at three concentration levels including 5, 10 and 20 mg/L, were applied at two seedless grape varieties, Thompson and Belgrade, by spraying, during the three different periods of the vine growing: before blooming, after blooming and before veraison, in order to study their influence on some cultural technological characteristics. Dimension and shape of the cluster and berry, mechanical characteristics of the berries and chemical content of the must (sugar and total acids) has been also investigated. It was noticed that the concentration of gibberellic acid had influence on the technological characteristics of the berries in all grape growing periods tested. The addition of gibberellic acid at concentration of 20 mg/L increased the weight of the cluster and berry, and increased the transportability of the berries belonging to the two seedless varieties.
文摘Besides control of the fungal plant pathogens, another interesting aspect observed when plants are treated with Trichoderma harzianum include effects such as complete and even stand of plants, improved seed germination, increases in plant height and overall enhanced plant growth. No research has yet been conducted to elucidate the mechanism by which these effects occur. Improved seed germination, in particular, suggest that Trichoderma harzianum produces a metabolite that may mimic the plant growth hormone gibberellic acid. The metabolite gliotoxin, produced by Trichoderma harzianum appear to be structurally most similar to gibberellic acid. In this study, common pharmacophore generation and molecular ligand docking simulations were used to evaluate the molecular similarity between gibberellic acid, specifically GA3, and gliotoxin. For the common pharmacophore evaluation, the structure of various gibberellic acids were used to construct a pharmacophore space to which gliotoxin was aligned, and during the molecular docking simulations the gibberellic acid receptor, GID1, served as ligand target for GA3 and gliotoxin. During the common pharmacophore evaluation, gliotoxin was successfully aligned to the common pharmacophore model constructed from various gibberellic acids. Furthermore, molecular docking simulations of gliotoxin and GA3 into the gibberellic acid receptor (GIDI) yielded docking scores of-10.78 kcal/mol for the GA3 molecule from Corina and a docking score of-10.17 kcal/mol for glioto^in. The docking scores suggest that gliotoxin may be able to competitively occupy the receptor space for gibberellic acid, and as such elicit the similar physiological responses observed in literature.
文摘This study was conducted during 2019/2020 on sweet cherry trees (<i>Prunus Avium</i> L.) (Bing and Hardy Giant) cultivar planted at Sergaya-Al_Zabadani area of Rural </span><span style="font-family:"">Dam</span><span style="font-family:"">ascus, to reduce fruit drop of sweet cherry. The experiment included 4 foliar applications: T1: control, T2: GA<sub>3</sub> (100 ppm), T3: NAA (20 <span>ppm), T4: (100 ppm GA<sub>3</sub> + 20 ppm NAA). Fruit set and fruit drop pe</span>rcentage, fruiting factor, and yield were recorded. The results showed that treatment with (100 ppm GA<sub>3</sub> + 20 ppm NAA) recorded higher fruit set percentage (73.81% and 75.62%), and fruiting factor (48.38% and 50.04%) respectively</span><span style="font-family:"">;</span><span style="font-family:""> <span>In addition to fruit yield (40.19 and 41.21 kg/tree) for both cultivars, co</span>mpared to the control (9.13, 6.60 kg/tree). Therefore, it can be concluded that GA<sub>3</sub> + NAA treatment reduced Sweet cherry fruit drop better than other treatments, <span>where fruit drop percentage didn’t exceed (63.11% and 62.01%) in both cu</span>ltivars (Bing and Hardy Giant) respectively, compared to the control (80.92% and 80.64%).
文摘To comprehensively explore the physio-biochemical and molecular changes of paclobutrazol(PBZ) at the ideal dose under water deficit stress(WDS) conditions, we investigated the effects of 100 mg/kg PBZ applied via drenching on various physio-biochemical and molecular parameters in three rice varieties(N22, IR64, and IR64 DTY1.1) under both mild [75%-80% relative water content(RWC)] and severe(60%-65% RWC) WDS conditions. The results showed that PBZ treatment positively influenced the physio-biochemical parameters, significantly increasing dry matter(16.27%-61.91%), RWC(6.48%-16.34%), membrane stability index(4.37%-10.35%), and total chlorophyll content(8.97%-29.09%) in the rice varieties under both mild and severe WDS. Moreover, PBZ treatment reduced drought susceptibility(0.83-0.95) and enhanced drought tolerance efficiency(60.92%-86.78%), indicating its potential as a stress-mitigating agent. Global methylation analysis revealed changes in DNA methylation patterns, indicating the regulatory influence of PBZ on gene expression. The expression analysis of genes involved in the diversification of geranylgeranyl pyrophosphate towards the biosynthesis of abscisic acid, gibberellin acid, and chlorophyll showed alterations in their expression levels, suggesting the involvement of PBZ in the isoprenoid pathway. Overall, this study provides valuable insights into the potential mechanisms by which PBZ modulates physiological and molecular responses in rice plants under WDS. The findings highlight the importance of PBZ as a promising agent for enhancing drought tolerance in rice and offer valuable information for future research in crop stress management.
基金Supported by Science and Technology Plan Project of Guizhou Province,China(QianKeKe Basics20201Y179)Key Field Project of Guizhou Provincial Department of Education(QJHKY2021044)+3 种基金Project of Guizhou Provincial Characteristic Key Laboratory(QJHKY2021002)Science and Technology Support Plan Project of Guizhou Province(QKHZCGeneral2021243)Science and Technology Plan Project of Liupanshui(52020-2021-PT-01)National Natural Science Foundation of China(41761010).
文摘[Objectives]To improve the yield and secondary metabolite content of medicinal plants and to further develop and utilize the medicinal and other functions of medicinal plants.[Methods]We used the sterile tissue culture method with Houttuynia cordata Thunb.as the research object.Different concentrations of 1-naphthalene acetic acid(NAA),auxin(indole-3-acetic acid,IAA)and gibberellin acid(GA_(3))were added to the group culture medium of H.cordata to investigate the effects of exogenous plant hormones on plant height,root length,fresh weight,morphological characteristics,four phenolics and 20 volatile compounds.[Results]The results showed that the exogenous plant hormone of 3 mg/L GA_(3)significantly increased plant height by 79.9%over the control;the exogenous plant hormone of 3 mg/L IAA significantly increased root length by 52.6%over the control;and the exogenous plant hormone of 1 mg/L GA_(3)significantly increased fresh weight of single plant by 458.2%over the control.In the treatment group of 1 mg/L NAA,chlorogenic acid content was significantly increased by 52.6%compared with the control;in the treatment group of 1 mg/L IAA,chlorogenic acid,rutin,isodendrin and quercetin content were significantly increased by 109.1%,100.6%,173.8%,and 198.7%compared with the control,respectively;in the treatment of 3 mg/L GA_(3),chlorogenic acid,rutin,isoquercitin,and quercitin content were significantly increased by 65.3%,104.9%,139.0%and 191.2%over the control.In addition,the content of volatile compounds was significantly higher in all H.cordata treated with exogenous plant hormones of 2 mg/L NAA,1 mg/L IAA,and 3 mg/L GA_(3);however,the content of volatile compounds was lower in all of the treatments with 2 mg/L GA_(3).[Conclusions]Different exogenous plant hormones have certain effects on the growth morphology and secondary metabolic content of H.cordata,which provides theoretical basis and technical support for the development and utilization of medicinal plants.
基金supported by grants from the National Program for Basic Research of China(2012CB114305)the National Program on High Technology Development(2012AA10A303)+1 种基金the National Natural Science Foundation of China(31271316 and J1103510 to Chang Y and Huang F)the National Program of China for Transgenic Research(2011ZX08009-003002,2011ZX08001-003)
文摘Plant responses to abiotic stresses are coordinated by arrays of growth and developmental programs. Gibberellic acid (GA) and abscisic acid (ABA) play critical roles in the developmental programs and environmental responses, respectively, through complex signaling and metabolism networks. However, crosstalk between the two phytohormones in stress responses remains largely unknown. In this study, we report that GIBBERELLIN-INSENSITIVE DWARF 1 (GID1), a soluble receptor for GA, regulates stomata[ develop- ment and patterning in rice (Oryza sativa L.). The gidl mutant showed impaired biosynthesis of endogenous ABA under drought stress conditions, but it exhibited enhanced sensi- tivity to exogenous ABA. Scanning electron microscope and infrared thermal image analysis indicated an increase in the stomatal conductance in the gidl mutant under drought conditions. Interestingly, the gidl mutant had increased levels of chlorophyll and carbohydrates under submergence conditions, and showed enhanced reactive oxygen species (ROS)-scavenging ability and submergence tolerance compared with the wild-type. Further analyses suggested that the function of GID1 in submergence responses is partially dependent on ABA, and GA signaling by GID1 is involved in submergence tolerance by modulating carbohydrate consumption. Taken together, these findings suggest GID1 plays distinct roles in stomatal response and submergence tolerance through both the ABA and GA signaling pathways in rice.
文摘Plants synthesize an astonishing diversity of isoprenoids, some of which play essential roles in photosynthesis, respiration, and the regulation of growth and development. Two independent pathways for the biosynthesis of isoprenoid precursors coexist within the plant cell: the cytosolic mevalonic acid (MVA) pathway and the plastidial methylerythritol phosphate (MEP) pathway. However, little is known about the effects of plant hormones on the regulation of these pathways. In the present study we investigated the effect of gibberellic acid (GA3) on changes in the amounts of many produced terpenoids and the activity of the key enzymes, 1-deoxy-D-xylulose 5-phosphate synthase (DXS) and 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR), in these pathways. Our results showed GA3 caused a decrease in DXS activity in both sexes that it was accompanied by a decrease in chlorophylls, carotenoids and Ag-tetrahydrocannabinol (THC) contents and an increase in α-tocopherol content. The treated plants with GA3 showed an increase in HMGR activity. This increase in HMGR activity was followed by accumulation of stigmasterol and β-sitosterol in male and female plants and campestrol in male plants. The pattern of the changes in the amounts of sterols was exactly similar to the changes in the HMGR activity. These data suggest that GA3 can probably influence the MEP and MVA pathways oppositely, with stimulatory and inhibitory effects on the produced primary terpenoids in MVA and DXS pathways, respectively.
文摘In the present study, we Investigated the role of glbberelllc acid (GA3) and Indole acetic acid (IAA) In the gravity response of stems and tension wood formation using two-year-old stems of Fraxinus mandshurica Rupr. var. Japonica Maxim seedlings. Forty-five seedlings were used and divided Into nine groups that Included five seedlings In each group. Seedlings were treated with applications of GA3 alone at concentrations of 2.89×10^-8 and 2.89×10^-7 μmol/L, IAA alone at concentrations of 5.71×10^-8 and 5.71×10^-7 μmol/L, or their combination to the apical bud of the stem using a mlcroplpette. Seedlings were positioned horizontally after the first treatment. The same treatments were repeated six times per week. At the end of the experiment, all seedlings were harvested. Then, stem segments were cut under a light microscope. Application of exogenous GA3 at the higher concentration stimulated the upward bending of stems, whereas exogenous IAA had no effect. A synergistic effect of GA3 and IAA on upward stem bending was observed following application of the two combinations of GA3 and IAA. Moreover, application of exogenous GA3 at the higher dose stimulated wood formation on both the upper and lower sides of the stems, whereas the mixture of GA3 and IAA had a synerglstic effect on wood formation In horizontal stems. Application of exogenous IAA alone at the lower concentration (5.71×10^-8 μmol/L) or application of a mixture of the higher concentrations of GA3 (2.89×10^-7 μmol/L) and IAA (5.71×10^-7 μmol/L) Inhibited the development of gelatinous fibers (the G-layer) of tension wood on the upper side of the horizontal stems. The differentiation of gelatinous fibers of tension wood was not Inhibited by GA3 when It was applied alone, whereas the development of the gelatinous fibers of tension wood was strongly affected by the application of IAA. The findings of the present study suggest that the development of the G-layer Is not related to the dose of GA3, but needs a relatively lower concentration of IAA.
文摘Seed germination is a key step in the life cycle of all seed plants, and it is of immense significance in agriculture.Germination is controlled by multiple environmental cues such as light and moisture,and endogenous factors,especially phytohormones.Gibberellic acid (GA)has long been identified as a critical hormone in the regulation of seed germination by countering the inhibition imposed by abscisic acid (ABA)(Holdsworth et al.,2008;Lee et al.,2010).
基金Project supported by the National Natural Science Foundation of China(Nos.31270343 and 31500247)the China Postdoctoral Science Foundation(No.2015M581922)
文摘Glucosinolates, anthocyanins, total phenols, and vitamin C, as well as antioxidant capacity, were investigated in Chinese kale sprouts treated with both glucose and gibberellic acid(GA_3). The combination of 3%(0.03 g/ml) glucose and 5 μmol/L GA_3 treatment was effective in increasing glucosinolate content while glucose or GA_3 treatment alone did not influence significantly almost all individual glucosinolates or total glucosinolates. The total phenolic content and antioxidant activity of Chinese kale sprouts were enhanced by combined treatment with glucose and GA_3, which could be useful in improving the main health-promoting compounds and antioxidant activity in Chinese kale sprouts.
基金supported by the National Natural Science Foundation of China(No.41772245)the National Key Research and Development Program of China(No.2019YFC1805400)the Fundamental Research Funds for the Central Universities(No.2020ZDPY0201)。
文摘Gibberellic acid(GA_(3))is widely used in agriculture and maybe transfer with groundwater flow,which is an endocrine disruptor,but few studies have focused on the transformation pathway and toxicity assessment of GA_(3)and its products.Here,GA_(3)and its transformation products in aqueous solution were identified and quantified by liquid chromatography mass spectrometry hybrid ion trap time-of-flight(LCMS-IT-TOF)and high-performance liquid chromatography(HPLC),respectively.The results showed that the half-life of GA_(3)transformation in ultrapure water was 16.1–24.6 days at p H=2.0–8.0,with the lowest half-life occurring at p H=8.0 and highest half-life occurring at p H=3.3.Isomerized gibberellic acid(Iso-GA_(3))and gibberellenic acid(GEA)were the main transformation products with a little hydroxy gibberellic acid(OH-GA_(3)).In North China groundwater,the mass balance of GA_(3)and its products was 76.2%,including Iso-GA_(3)(58%),GEA(7.9%),GA_(3)(7.3%)and OH-GA_(3)(3%)after reaching transformation equilibrium.Using Gaussian 09 for chemical computation,it was found that the transformation mechanism of GA_(3)was dependent upon the bond energy and the stereochemical feature of its molecular structure.GA_(3)always isomerized from theγ-lactone ring due to the lowest bond energy between the oxygen terminus of theγ-lactone ring and A ring.While GA_(3)and its transformation products all had developmental toxicity,the predicated LC 50(96 hr)and LD 50 of the main products of GA_(3)were much lower than those of GA_(3),indicating GA_(3)would be transformed into higher toxicity derivatives in water environments,posing a significant health risk to humans and the environment.
基金supported by grants from the MEC (BFU2006-11577/BFI)-FEDERCARM (Programa de Generación de Conocimiento Científico de Excelencia de la Fundación Sneca,Agencia de Ciencia y Tecnología de la Región de Murcia en el Marco del Ⅱ PCTRM 2007–2010,project 08610/PI/08)
文摘Hypocotyl formation during the epigeal germination of seedlings is under strict hormonal regulation. In a 3 d old Zinnia elegans seedling system, gibberellic acid (GA3) exerts an opposite effect to that exerted by light on hypocotyl photomorphogenesis because GAz promotes an etiolated-like growth with an inhibition of radial (secondary) growth. For this reason, the effect of GA3 on the basic peroxidase isoenzyme from Z. elegans (ZePrx), an enzyme involved in hypocotyl lignin biosynthesis, was studied. The results showed that GA3 reduces ZePrx activity, similarly to the way in which it reduces seedling secondary growth. This hormonal response is supported by the analysis of the ZePrx promoter, which contains four types of GA3-responsive cis.elements: the W Box/O2S; the Pyr Box; the GARE; and the Amy Box. Taken together, these results suggest that ZePrx is directly regulated by GA3, with this effect matching the inhibitory effect of GA on the hypocotyl secondary growth.
文摘The adsorption effects of several macroporousadsorption resins for gibberellic acid (GA3) were investigated.The dynamic adsorption capacity is 58.38 mg/g drybeads for resin R4 and 96.46 mg/g dry beads for resin R5which is consistent with the surface area. Aqueous methanol(50%, V/V) is a good eluent and the yield of GA3 isabove 95%. The concentration of GA3 could increase fivefoldafter an adsorption-elution cycle and this is importantwhen considering further crystallization of GA3 in anindustrial process.
文摘Barhi dates at Khalal maturity stage are well-known with their pleasant taste,crispy texture,and bright yellow color.It is necessary to extend the duration of Barhi Khalal stage which is too short for effective marketing.This study aimed to inspect the effects of Gibberellic Acid(GA_(3))and Salicylic Acid(SA)postharvest treatments on retaining the high quality of Khalal Barhi fruits during controlled atmosphere storage.Fresh samples of Barhi fruits at Khalal stage harvested at three different ripening levels were dipped after harvesting in GA3(150 ppm)or SA(2.0 mmol/L)and subsequently stored in controlled atmosphere(0°С,5%O_(2),5%CO_(2),80%±5%RH).The results revealed that the GA_(3) and SA treatments reduced the percentage of weight loss and decay in the fruits,while the total soluble solids increased.Moreover,GA_(3) and SA treatments were significantly efficient in limiting the changes in fruit color and texture of Barhi dates compared to the control.Sensorial results support the experimental data and disclosed that the GA_(3)(150 ppm)treatment in the controlled atmosphere(CA)storage was better in conserving the quality of Barhi at the Khalal maturity stage and delaying ripening process.