Physiological Responses of Pea Plants to Salinity and Gibberellic Acid

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.

Effect of Pre-Harvest Application of Gibberellic Acid on Fruit Quality and Shelf Life of Mandarin (Citrus reticulata Blanco)

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. GA3 at 10, 20, and 30 ppm as against of control were evaluated. Observations on fruit weight (g), fruit firmness (kg/cm2), 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 GA3 at 20 ppm retained higher fruit weight (128.6 g), more firmness (3.54 kg/cm2), 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 GA3 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 GA3 at 30 ppm both with ambient (1.02%) and cellar condition (8.21%) as against control with ambient (5.54%) and cellar (21.58%).

Effect of Dominant Semi-Dwarf Gene on Plant Height and Its Related Traits and Sensitivity to Gibberellic Acid in Rice

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.

Sweet Cherry (<i>Prunus avium</i>L.) Fruit Drop Reduction by Plant Growth Regulators (Naphthalene Acetic Acid NAA and Gibberellic Acid GA₃)

This study was conducted during 2019/2020 on sweet cherry trees (Prunus Avium L.) (Bing and Hardy Giant) cultivar planted at Sergaya-Al_Zabadani area of Rural Damascus, to reduce fruit drop of sweet cherry. The experiment included 4 foliar applications: T1: control, T2: GA3 (100 ppm), T3: NAA (20 ppm), T4: (100 ppm GA3 + 20 ppm NAA). Fruit set and fruit drop percentage, fruiting factor, and yield were recorded. The results showed that treatment with (100 ppm GA3 + 20 ppm NAA) recorded higher fruit set percentage (73.81% and 75.62%), and fruiting factor (48.38% and 50.04%) respectively; In addition to fruit yield (40.19 and 41.21 kg/tree) for both cultivars, compared to the control (9.13, 6.60 kg/tree). Therefore, it can be concluded that GA3 + NAA treatment reduced Sweet cherry fruit drop better than other treatments, where fruit drop percentage didn’t exceed (63.11% and 62.01%) in both cultivars (Bing and Hardy Giant) respectively, compared to the control (80.92% and 80.64%).

GID1 modulates stomatal response and submergence tolerance involving abscisic acid and gibberellic acid signaling in rice

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.

Effects of Gibberellic Acid on Primary Terpenoids and △^9 -Tetrahydrocannabinol in Cannabis sativa at Flowering Stage

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.

Control of Negative Gravitropism and Tension Wood Formation by Gibberellic Acid and Indole Acetic Acid in Fraxinus mandshurica Rupr. var. japonica Maxim Seedlings

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.

Insights into pH-dependent transformation of gibberellic acid in aqueous solution:Transformation pathway,mechanism and toxicity estimation

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.

Downregulation of the Basic Peroxidase Isoenzyme from Zinnia elegans by Gibberellic Acid

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.

Separation of gibberellic acid (GA3) by macroporous adsorption resins

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.

Effects of Gibberellic Acid (GA_(3)) and Salicylic Acid (SA) postharvest treatments on the quality of fresh Barhi dates at different ripening levels in the Khalal maturity stage during controlled atmosphere storage

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.

Roles of abscisic acid and gibberellins in maintaining primary and secondary dormancy of Korean pine seeds

Primary dormancy of seeds of Korean pine(Pinus koraiensis Sieb.et Zucc.)after dispersal in the autumn and the induction of secondary dormancy the fi rst summer following seed dispersal limit the regeneration of mixed broadleaved Korean pine forests in Northeast China.This study was to determine how changes in the levels of abscisic acid(ABA)and gibberellic acid(GA)maintain primary and secondary dormancy of Korean pine seeds under germination conditions.We transferred seeds with one of fi ve primary dormancy states or three secondary dormancy states to germination conditions and measured changes in the levels of ABA,GA 1+3(GA 1 and GA 3)and GA 4+7(GA 4 and GA 7)in the seed coat,megagametophyte and embryo during incubation.Seed coat ABA levels in primary dormant seeds(PDS)and ABA levels in various parts of secondary dormant seeds(SDS)gradually declined during incubation but were still higher than in seeds for which dormancy was progressively released.GA 4+7 and GA 1+3 levels in embryos greatly decreased 35%and 24%,respectively,during incubation of SDS,and thus,the ratio of ABA to GA 4+7 in embryos and megagametophytes signifi cantly increased.The ratio of ABA to GA 1+3 in various parts of SDS increased slightly during incubation.In contrast,in seeds for which secondary dormancy was already released,GA 4+7 and GA 1+3 levels in the embryo,GA 4+7/ABA ratio in the embryo and seed coat,and the GA 1+3/ABA in the embryo and megagametophyte signifi cantly increased during incubation.There was no trend in the changes in the levels of ABA,GA 4+7 or GA 1+3 in embryos and megagametophytes of PDS or the levels of GA 4+7 or GA 1+3 in megagametophytes of SDS during incubation.The results suggest that high ABA levels in the seed coat maintain primary dormancy of Korean pine seeds.Maintenance of secondary dormancy involves a reduction of GA 4+7,GA 1+3,GA 4+7/ABA,and GA 1+3/ABA and the retention of high ABA levels.

Effects of Exogenous Plant Hormones on Growth Status and Secondary Metabolism of Houttuynia cordata Thunb.

[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.

Effects of tallowtree seed coat on seed germination

We measured physiological parameters including water uptake in-vitro embryo germination ratio, and seed coat structure observed by scanning electron microscopy （SEM） to explore the influence of seed coat on the germination of seeds of tallow tree （Sapium sebiferum （Linn） Roxb.）. Tallow tree seeds had good water permeability. We found that germination of cabbage seeds was inhibited when cabbage seeds were soaked in extracted solutions from tallow tree seed coat. Seed coat structure at the side of the radicle appeared to be a barrier to seed germination. We tested methods to break tallow tree seed dormancy. Dormancy of tallow tree seeds was overcome by soaking the seeds in 500 mg·L^-1 or 1000 mg·L^-1 GA3, followed by 100 days of cold stratification.

cDNA-Amplified fragment length polymorphism analysis reveals differential gene expression induced by exogenous MeJA and GA_3 in oilseed rape (Brassica napus L.) flowers

The transition of a plant from vegetative to reproductive stage is controlled by a large group of genes, which respond to environmental and endogenous stimuli. Application of methyl jasmonate （MeJA） and gibberellins （GA3） to oilseed plants （Brassica napus L.） interrupts the delicate endogenous balance and results in various floral organ abnormalities. Exogenous MeJA or GA3 influences the transcriptome at the initial fiowenng stage in Arabidopsis, but the corresponding changes of transcriptome in floral tissues of oilseed rape remain unknown. In this study, cDNA-amplified fragment length polymorphism （cDNA-AFLP） was analyzed to identify genes whose expression was modulated by application of MeJA and GA3 to flower buds. A total of 2 787 cDNA fragments were counted using 64 primer pair combinations, and bands larger than 50 bp were compared among four treatments, namely, water control, MeJA （50 μmol L-1）, MeJA （100 μmol L-1）, and GA3 （50 μmol L-1）. Overall, 168 transcript-derived fragments （TDFs） were differentially expressed among the treatments. The expression pattern of some TDFs was confirmed by semi-quantitative RT-PCR analysis, and a group of 106 differentially displayed TDFs was cloned and sequenced. Homologs of Arabidopsis genes were identified and classified into 12 functional categories. A total of 34, 39, and 24 TDFs were responsive to GA3, MeJA, and both GA3 and MeJA, respectively. This finding indicated that cross-talk between these two hormones may be involved in regulating flower development. This study provides potential target genes for manipulation in terms of flowering time and floral organ initiation, important agronomic traits of oilseed rape.

Micropropagation and Acclimatization of Common Oregano (Origanum vulgare L. Subsp. vulgare) by Shoot Tip Culture

Origanum vulgare L. is a commercially valued species with remarkable biological properties. It is subject to over-exploitation practices that seriously threaten its sustainability for future generations. Thus, micropropagation serves as a tool for the protection and domestication of this species. In this study, we established an in vitro vegetative propagation protocol for Origanum vulgare. This is done through the axillary bud technique by carrying out various tests. Six culture media (MS, MSm, N30K, SD, SH and B5) were tested. Therefore, SD was chosen for the following experiments. Seven cytokinins (adenine (Ad), N6-(2-isopentenyl) (2ip), zeatin (Zeat), kinetin (Kin), benzyladenine (BAP), 1,3-diphenylurea (DPU) and thidiazuron (TDZ) at 5 concentrations (0.44, 1.33, 2.22, 3.11 and 4.44 μM/L) were evaluated. Thus, Kin at 3.11 μM allowed high regeneration of vitroplants, optimal elongation, total rooting of explants, maximum bud multiplication, and absence of hyperhydric explants. In fact, the integration of auxins (indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), and 1-naphthaleneacetic acid (NAA)) into the culture medium and their combinations with 3.11 μM Kinetin contributed to the optimization of the root part. Thus, it was improved in particular in the case of 3.11 μM Kin and 6.27 μM IBA. Three polyamines (Putrescine, Spermidine and Spermine) at different concentrations (1.134, 3.402, 5.67, 7.938 and 11.34 μM/L) combined at 3.11 μM Kin and 6.27 μM IBA were tested. In fact, 1.304 μM putrescine was considered to be the most suitable for in vitro culture of explants, since it allowed optimal propagation of buds and roots, also a high rate of regeneration and rhizogenesis. GA3 at 1.15 μM combined with 3.11 μM Kin and 6.27 μM IBA permitted maximum bud multiplication. The acclimatization was carried out successfully using vitroplants showing good foliar and root development. Thus, three months after acclimatization, the seedlings were transferred into large pots under natural light and temperature conditions. Almost all acclimatized plants developed flowers in the first year between May and July.

The coupled effect of light and temperature on dormancy release and germination of Pinus koraiensis seeds

Elucidating the regulatory mechanisms of environmental factors on seed dormancy and germination will provide guidance for tree regeneration.Toward understanding the coupled effect of light and temperature on dormancy release and germination of Pinus koraiensis seeds,we set up three light conditions(L200:200μmol m^(-2) s^(-1),L20:20μmol m^(-2) s^(-1),L0:0μm^(-2) s^(-1))and four storage temperatures[T-5:-5°C(50 days),T5:-5°C(50 days)+5°C(50 days),T25:-5°C(50 days)+5°C(50 days)+25°C(50 days),T15:-5°C(50 days)+5°C(50 days)+25°C(50 days)+15°C(50 days)]using imbibed seeds,then quantified phytohormones gibberellic acid(GA_(3))and abscisic acid(ABA)during the stratification.Germination percentage(G_(P)),mean germination time(T_(M)),and germination value(G_(V))under 25/15°C temperature and the three light conditions were then determined.Phytohormone levels and germination performances were significantly affected by light and temperature.No consistent trend was found between the phytohormone levels and G_(P) caused by light levels.Under the three light conditions,ABA concentrations in the embryo and endosperm decreased as storage temperature shifted from T-5 to T25 and increased from T25 to T15;GA_(3) decreased in nearly all four storage temperatures.G_(P) reached 40–60%in T25 storage without light irradiance.In the three light conditions,G_(P) and G_(V) were higher at T5 and T25 than at T-5 and T15;so T5 and T25 are considered as optimum storage temperatures for dormancy release and germination.At optimum temperatures,light(L200,L20)significantly increased the G_(P) and G_(V) compared with the dark(L0).At L200 and L20,significant negative correlations between G_(V) and the ABA concentrations and positive correlations between G_(V) and GA/ABA in the seed embryo were found.Temperature played a more important role in primary dormancy release and germination;light was unnecessary for primary dormancy release.Light facilitated seed germination at optimum temperatures.The dormancy release and germination of P.koraiensis seeds were controlled by a decrease in ABA concentrations or an increase in GA/ABA induced by temperature variations.

Metabolic disturbance and phytochemical changes in Andrographis paniculata and possible action mode of andrographolide

Objecive: To explore the effect of gibberellic acid(GA_3) and its inhibitor paclobutrazol(PBZ)on chemical composition and their pharmacological effects on Andrographis paniculata(Burm.f.) Wall. ex Nees, and to clarify action mode of andrographolide.Methods: The chemical composition was extracted by sequential extraction with hexane, dichloromethane, ethyl acetate and methanol, respectively. Andrographolide and its derivatives were evaluated by HPLC. Moreover, the metabolic profiling was analyzed by GC-MS. Inhibitory effect of crude extracts was tested against Staphylococcus aureus using agar well diffusion method. Mode of action was tested against mutant yeast by spotting assay. Andrographolide were tested for their mode of action against eukaryotes. Rsults: Among different solvents, dichloromethane gave the highest yield of crude(3.58% DW), with the highest andrographolide content(8.3 mg/g DW). The effect of plant hormone(10 mg/L GA_3 or PBZ) on phytochemical variations and bioactivity of Andrographis paniculata was demonstrated. It was found that PBZ promoted sesquiterpene compounds about 3.5 times over than GA_3 treatment. But inhibitory effect of extracts against Staphylococcus aureus was highest in GA_3 treated plants; andrographolide and 14-deoxy-11,12-didehydroandrographolide contents were significantly higher than those of water or PBZ. It was found that there were 11 strains involving in ergosterol biosynthesis, V-ATPase activity and homeostasis, and superoxide detoxification process. In this regard, andrographolide might cause the damage on the lipid bilayer of yeast cell and plasma membrane by interfering ergosterol biosynthesis.Conclusions: It is found that GA_3 promotes andrographolide and 14-deoxy-11,12-didehydroandrographolide content while PBZ promotes sesquiterpene content. Andrographolide might cause the damage on the lipid bilayer of yeast cell and plasma membrane by interfering ergosterol biosynthesis. It might also affect mitochondria electron transport chain, leading to the occurrence of ROS, which can further harm cell organelles. However, the library screening is the first step to investigate mode of action of andrographolide.

Enhancement of seed germination in Macaranga peltata for use in tropical forest restoration

We used pre-sowing treatments v/z., soaking seeds in concen- trated sulphudc acid （CSA）, gibberellic acid （GA）, combined treatment of CSA ＋ GA and mechanical scarification to overcome seed dormancy and enhance synchronous germination of Macaranga peltata seeds. We analysed percent seed germination data by logistic regression and con- finned that except in GA treatment, time and acid concentration together were crucial for enhancing germination. The combination treatment of CSA and GA resulted in higher percent germination （up to 74%） than either treatment used separately, but produced defective seedlings （26%）. Mechanical scarification of seed coat had the greatest impact in enhanc- ing germination （78%） and reducing imbibition time （6 days） against the control （0%）. Germination studies and SEM analysis confirmed that seed germination in M. peltata was inhibited by seed coat dormancy.

Isolation and Characterization of Storage Protein Subunit-null-dwarf Mutants in Soybean(Glycine max(L.) Merr.)

Dwarfing is useful to reduce plant height,when breeding high-yielding and non-lodging crops.In this study,a set of natural storage protein subunit-null dwarf mutants of soybean was reported that showed strongly reduced plant stature and deficiency in various 7S and 11S subunits,designated as snd1 mutants.Under normal growth conditions,the snd1 mutants showed a severe dwarf phenotype,with plant height of about 25 cm.Compared with wild-type DN47,the mutant snd1 exhibited no obvious morphological differences at the early stage of development.All the snd1 mutants examined had fewer nodes and shorter than normal internodes;the leaves were similar in shape to normal parents,but were dark-green at the mature stage.The flower size was similar to DN47;however,the flowering period was shorter than in the wild-type.Significant variation was noted for protein content,oil content of the seeds and size of seeds(weight of 100 seeds)among 17 snd1 dwarf lines.Genetic analysis indicated that the dwarfism of snd1 was controlled by a single recessive gene.The snd1 dwarf mutant had markedly different dynamic levels of the endogenous hormones gibberellin(GA),brassinosteroid,indole-3-acetic acid and abscisic acid,at the seedling stage.Exogenous GA3 treatment led to recovery of the plant height phenotype of the snd1 mutant;GA3 at 0.1 mm had the largest effect on enhancing plant height.Using molecular markers,snd1 gene was approximately mapped in an interval of 603 kb between markers Satt166 and Satt561 on chromosome 19.Snd1 mutant provided valuable material for hypoallergenic soybean breeding and the snd1 gene might be a novel gene related to plant height in soybean.