Application of brassinolide alleviates cold stress at the booting stage of rice

The objective of the study was to determine the physiological mechanisms of plants in response to brassinolide(BR) alleviating cold water stress on rice. In this study, physiological responses of rice to exogenous BR and cold water submergence were investigated using the chilling-tolerant cultivar Kongyu 131(KY131) and the chilling-sensitive cultivar Kenjiandao 6(KJD6). A total of 2 mg L^-1 BR increased activities of superoxide dismutase(SOD) and peroxidase(POD) and the contents of soluble sugar, soluble protein, and chlorophyll, but decreased the malondialdehyde(MDA) content in KY131 and KJD6 under cold water stress. The observed decreases in SOD and POD activities and MDA content recovered quickly after plants were returned to irrigation with water at temperatures of about 23.0°C in 2014. Additionally, the contents of nitrogen(N), phosphorous(P), and potassium(K) were increased by BR treatment under cold water stress. Exposure to BR also raised the percentage of high effective leaf area and leaf area index at the heading stage. Furthermore, it promoted soluble sugar synthesis, increased the rate of dry matter accumulation, and enhanced the export and translocation rates of the stem-sheath. The yield in KJD6 was significantly(P≤0.01 and P≤0.05) higher than that of the control in 2013 and 2014, respectively. The effect of BR treatment on rice leaf SOD and POD activities, MDA, chlorophyll, P, and stem-sheath K contents were more significant in KJD6 than in KY131. In conclusion, exogenous BR effectively reduced the physiological and metabolic damage in rice due to cold stress at the booting stage, promoted functional recovery in plants that received irrigation with water at a normal temperature following cold stress, and mitigated the effects of cold water stress on yield.The two varieties exhibited differential responses to BR;the weaker cold-resistant variety was more sensitive to BR and displayed stronger responses to exogenous BR.

Protective Roles of Brassinolide on Rice Seedlings under High Temperature Stress

Two indica rice （Oryza sativa L.） materials, Xieqingzao B （sensitive to heat stress） and 082 （tolerant to heat stress） were used to study the role of brassinolide （BR） in protection of rice seedlings from heat stress. Young seedlings were subjected to high temperature （38℃/30℃） and sprayed with 0.005 mg/L of BR. Analysis was conducted on the contents of chlorophyll, protein and malondialdehyde （MDA）, the leakage of electrolyte, the activities of peroxidase （POD） and superoxide dismutase （SOD） and their isozymes expression levels in leaves. Under the high temperature treatment, application of BR significantly increased the contents of chlorophyll and protein, and the activities of POD and SOD, and reduced the content of MDA and the leakage of electrolyte in the leaves of the heat-sensitive material Xieqingzao B, whereas BR had less effect on those of the heat-tolerant material 082 relatively. The BR treatment enhanced the expression of POD isozymes in the leaves of both materials. Under the high temperature stress and BR treatment, the expression of four SOD isozymes reduced in 082, but the expression of two SOD isozymes increased in Xieqingzao B. This suggests that BR plays an important role in protection of rice seedlings from heat stress by enhancing the activities or expression level of protective enzymes in the leaves. The materials with various heat-tolerance might differ in the mechanism of response to heat stress with BR application.

Gibberellins,brassinolide,and ethylene signaling were involved in flower differentiation and development in Nelumbo nucifera

Hormones play important roles in vegetative and reproductive processes;however,the regulatory roles of hormones in Nelumbo nucifera(Lotus)growth and development are unclear.In this study,nine types of endogenous hormones,including gibberellins(GA_1,GA_3,and GA_4),indole-3-acetic acid(IAA),brassinolide(BR),ethylene(ETH),jasmonic acid(JA),abscisic acid(ABA),and zeatin(ZT)were detected in dormant shoot tips,vegetative shoot tips,developing leaf buds,and developing flower buds of lotus.The results indicated that GA,ETH,and BR signaling can promote vegetative and reproductive development of lotus.GA signaling regulates plant height and stimulates flower bud differentiation.GA levels were the highest in the flower buds;exogenous GA3+4 increased plant height by approximately 90%,increased flower quantity by nearly 40%,and advanced flowering by 4 d.Suppressing GA biosynthesis using paclobutrazol decreased plant height and flower quantity by 38%and 87.1%,respectively,and delayed flowering by 15.6 d.ETH signaling has positive regulatory effects on vegetative growth and flower development.The ETH concentration in the developing leaf buds was at least 50%higher than that in other samples.Ethephon spraying led to remarkable increases in plant height and leaf thickness and extended the flowering duration.BR signaling acts as a growth promoter during vegetative and reproductive development in lotus.The highest BR levels were detected in the vegetative shoot tips.External application of28-epihomobrassinolide resulted in growth-promoting phenotypes including longer scapes,thicker leaves,and prolonged flowering.

Effects of Natural Brassinolide on Seed Germination and Hypocotyl Elongation of Beans

Seeds of soybeans and mung beans were soaked into five different concentrations （0, 0.05, 0.10, 0.20, 0.30 mg/L） of natural brassinolide （ NBR ） solution. According to the results, natural brassinolide treatment could improve seed germination rate and hypocotyl-radicle ratio of soybeans and mung beans and promote the growth of sprouts. To be specific, seed germination rate of soybeans reached the highest in 0.05 mg/L natural brassinolide treatment, which was im- proved by 25.0 percentage points compared with the control group, and the sprout length was improved by 4.33 em; 0.30 mg/L natural brassinolide exhibited the most significant promotion effect on seed germination and sprout growth of mung beans, seed germination rate was improved by 18.3 percentage points and sprout length was improved by 7.29 cm; hypocotyl-radiele ratio of soybean and mung bean sprouts reached the highest （2.96, 1.43 ） in 0.05 mg/L natural brassinolide treatment.

Effect of Natural Brassinolide on Germination of Ailanthus altissima Seeds

The germination capacity of Ailanthus altissima seeds improved after the seeds were soaked with different concentrations of natural brassinolide （NBR）. The germination rate and germination energy of the seeds increased by 17.6% and 18.8%, and the mean germination speed （i.e., germination time） of the seeds was shortened by 1.4 d under the optimal concentration （0.4 mg·L^-1） treatment, compared with the control. After hypocotyls of A.altissima were treated with NBR, the elongation of the hypocotyls increased. Among different concentrations of the NBR, 0.4 mg·L^-1 NBR appeared to be the optimal concentration for the elongation of A.altissima hypocotyls.

Foliar Application of Brassinolide Induced Regulation of Grain Yield and Quality,Antioxidant Responses and Aroma in Fragrant Rice

Brassinolide(BR)is a new green plant growth regulator.The present field study was conducted on two fragrant rice cultivars(i.e.,Meixiangzhan-2 and Xiangyaxiangzhan)to study the effects of foliar application of BR on fragrant rice performance.At the heading stage,BR solutions at 0.05,0.15,0.25 and 0.50 mg L-1 were sprayed on fragrant rice at 600 liters per hectare;these treatments were named as BR1,BR2,BR3 and BR4,respectively.The treatment sprayed with distilled water was taken as a control(CK).Compared with CK,the BR2 treatment significantly enhanced the chlorophyll concentration and net photosynthetic rate for Meixiangzhan-2,and Xiangyaxiangzhan.The BR3 and BR4 treatments increased the concentrations of chlorophyll a,chlorophyll b and carotenoid,and also enhanced net photosynthetic rate by 31.91%and 40.43%,respectively.Higher grain yields were recorded in the BR2 treatment than on CK on Meixiangzhan-2,while on Xiangyaxiangzhan,the BR3 and BR4 treatments increased grain yield compared with CK.In relation to CK,higher head rice rates were recorded in the BR2 treatment for Meixiangzhan-2,and in the BR3 and BR4 treatments for Xiangyaxiangzhan.BR treatments(BR2 for Meixiangzhan-2,BR3 and BR4 for Xiangyaxiangzhan)also significantly enhanced the activities of GPX,SOD and CAT by 10.22%to 23.00%,and reduced the malonaldehyde concentration.In addition,we observed that some BR treatments(BR2 for Meixiangzhan-2,BR3 and BR4 for Xiangyaxiangzhan)decreased the grain 2-acetyl-1-pyrroline concentration of fragrant rice.

STUDIES ON STEROIDAL PLANT GROWTH REGULATOR 24. STEREOCONTROLLED CONSTRUCTION OF THE SIDE CHAIN OF BRASSINOLIDE AND HOMOBRASSINOLIDE VIA A TANDEM VICINAL DIALKYLATION OF PYRANONE MOIETY

A stereocontrolled construction of the side chain of brassinclide and homobrassinolide has been achieved via the tandem vicinal dialkylation of the pyranone moiety as a key step.

Studies on the Model Synthesis of the Brassinolide and Dolicholide Side Chains

A stereoselective synthesis of brassinolide and dolicholide, which involves construction of the side chain enantiomers by a highly stereoselective aldol reaction of aldehyde 5 with the anion of α-silyloxy ketone 6 is described.

STUDY ON THE SYNTHESIS OF BRASSINOLIDE AND RELATED COMPOUNDS 15.FORMAL SYNTHESIS OF BRASSINOLIDE VIA STEREOSELECTIVE SULFENATE-SULFOXIDE TRANSFORMATION

A formal synthesis of the natural growth promoting steroid brassinolide is described,which involves construction of side chain by 1,3-sulfoxide-hydroxyl transposition with methylation from(24S)- 22-E-24-sulfoxide 6 and(24R)-22-E-24-sulfoxide 9,respectively to (22S)-23-E-24-methyl compound 4.

Effect and Its Mechanism of Brassinolide-regulated Starch Metabolism in Rice Germination

The study was aimed to explore the effect and mechanism of brassinolide（ BL） regulated starch metabolism in rice endosperm during seed germination.The radicle elongation of rice seeds treated with 1 μmol/L BL was inhibited during germination. The analysis on rice seeds with a GUS-fused promoter showed that BL had different regulatory effects on Wx,SBEI,and AGPS1. The effect of BL treatment on the physicochemical properties of rice starch was further investigated by scanning electron microscopy,Fourier transform infrared spectroscopy,and X-ray diffraction. The results showed that the starch treated with BL maintained better crystallinity and orderly structure,indicating that during the germination process,the degradation of starch in endosperm was slow,which might be one of the reasons for the slow radicle growth in the early stages of seed germination. This study provided important clues for further analysis of the molecular mechanisms underlying BR-regulated rice seed germination.

Brassinolide类物质的合成

对Brassinolide类物质的合成进行了概述 ,并对其构效关系进行了对比以及简单介绍了其在农业生产上的运用。

叶面喷施胺鲜酯及其与油菜素内酯复配液对油用牡丹生理特性及产量的影响

为筛选出适合油用牡丹高产高效栽培中的植物生长调节剂应用技术,本试验以凤丹为材料,分别于盛花期(4月7日)、籽粒形成期(4月18日)、果荚与籽粒快速生长期(5月10日)叶面喷施不同质量浓度的胺鲜酯(D1、D2和D3)及其与油菜素内酯复配液(BD1、BD2和BD3),研究其对植株生理特性、籽粒产量指标(百粒重、单果籽粒重、单株籽粒重及籽粒产量)的影响。结果表明,与对照组相比,喷施植物生长调节剂处理的牡丹叶片生理特性和籽粒产量关键参数均有明显提高:7月3日时,BD2处理叶片SOD活性较对照显著提高5.24%;5月19日和7月3日时,所有处理叶片MDA含量均较对照显著降低;7月3日时,所有处理叶片可溶性糖含量与对照均有显著性差异,其中BD2处理最高,较对照增加33.84%;6月10日时,所有处理叶片总叶绿素含量均显著高于对照,其中BD3处理增幅最大,为98.11%;3个测定时期,除6月10日的BD3处理外其他处理叶片净光合速率均显著高于对照,且随着胺鲜酯质量浓度的提高呈现先增加后降低趋势。所有处理单株籽粒重及籽粒产量均显著高于对照,其中BD3增幅均最大,分别为10.45%与10.44%。相关性分析表明,SOD活性与Chl a、Chl b、Car、总叶绿素含量和净光合速率呈极显著正相关,与可溶性糖含量呈显著正相关,与MDA含量呈极显著负相关;总叶绿素含量与净光合速率呈极显著正相关,净光合速率与单果籽粒重、单株籽粒重和籽粒产量呈显著正相关。综之,12、16 mg/L胺鲜酯与0.05 mg/L油菜素内酯复配喷施油用牡丹植株的生理特性表现优异,并可获得较高籽粒产量。

外源油菜素内酯对铅胁迫下花生幼苗的缓解效应

油菜素内酯(EBR)作为第六大植物激素,具有缓解植物抗逆性的效应。为探究EBR对Pb胁迫下植物生理特征的缓解效应,试验以花生为材料,采用土壤盆栽法,测定了不同质量浓度Pb胁迫下花生种子萌发、形态指标,以筛选出最适Pb胁迫质量浓度,研究在该质量浓度下外源施加EBR(0、0.01、0.05、0.10、0.50、1.00 mg/L)对花生的种子萌发、幼苗形态指标和生理指标的影响。结果表明,在单一Pb(NO_(3))_(2)胁迫下,花生的发芽势、发芽率、胚根长、株高和根长均在大于300 mg/L时显著降低。与单一300 mg/L Pb(NO_(3))_(2)胁迫处理相比,外源添加0.10 mg/L EBR后,花生的发芽势、发芽率、胚根长、株高和根长分别增加28.95%、11.76%、27.96%、6.18%、15.96%,总叶绿素含量增加67.34%,可溶性蛋白、可溶性糖含量分别增加19.48%、13.33%,抗氧化酶SOD、POD活性分别增加51.98%、58.62%,丙二醛、游离脯氨酸含量分别降低1.67%、20.73%,超氧阴离子自由基(O_(2)·^(-))积累量减少。说明施加0.10 mg/L外源EBR对Pb胁迫下花生幼苗具有缓解作用,能降低Pb胁迫对花生幼苗的伤害,提高其抗逆性。

应用芸乐收拌种对金麦1号产量品质的影响

近年来小麦生产中各种类型病虫害防治的药剂比较多,为了解药剂各成分效果,本研究于2022—2023年以强筋小麦品种金麦1号为材料,选择市场上推广的芸乐收套餐,利用其主要成分芸苔素内酯(Y)、吡唑醚菌酯(B)及其混合剂(YB)进行拌种,以不拌种做对照(CK),系统地研究了拌种处理后金麦1号的净光合速率、产量及品质等变化规律,为科学高效地应用套餐提供科学依据.试验结果表明:不同处理对金麦1号产量和品质有显著影响,拌种处理较CK处理有显著增产效果,增产3.63%~17.43%;部分品质指标有一定改善.

油菜素内酯对盐碱胁迫下菊花幼苗生长及生理特性的影响

以菊花耐盐品种‘绚秋江月’和盐敏感品种‘绚秋尽染’为试材,用NaCl和NaHCO3按1∶1(质量比)配制成100 mmol/L复合盐碱处理液,对园林小菊幼苗进行盐碱胁迫处理,对其叶片喷施不同浓度(0.001、0.010、0.100、1.000 mg/L)外源油菜素内酯(BR),以喷施H2O为对照(CK),研究BR对盐碱胁迫下园林小菊幼苗生长及生理指标的影响。结果表明:与对照相比,在盐碱胁迫下外源喷施0.100 mg/L BR,‘绚秋江月’和‘绚秋尽染’叶片相对含水量分别提高了8.11%、16.95%;SPAD值分别增加了9.55%和13.97%;相对电导率分别下降了27.63%和24.69%;丙二醛(MDA)含量分别下降了41.24%和67.38%;脯氨酸(Pro)含量分别提高了86.49%和69.46%;过氧化氢酶(CAT)活性分别增大了16.25%和18.14%;过氧化物酶(POD)活性分别增大了46.15%和68.38%;超氧化物歧化酶(SOD)活性分别增大了12.36%和16.32%;抗坏血酸过氧化物酶(APX)活性分别增大了76.88%和95.04%。外源喷施0.100 mg/L BR可以更好地促进盐碱胁迫下园林小菊幼苗的生长发育,提高抗氧化酶活性,增强生物膜的稳定性,从而起到缓解盐碱胁迫对菊花幼苗的伤害,且对盐敏感品种‘绚秋尽染’盐碱受害的缓解效果更佳。

芸苔素内酯浓度对干旱胁迫大白菜幼苗生长及生理指标的影响

【目的】探明不同浓度芸苔素内酯对干旱胁迫大白菜幼苗抗旱性的调控作用,为芸苔素内酯在大白菜生产中的应用提供参考。【方法】以大白菜胜丽118为试验材料,苗期喷施不同浓度(0.05 mg/L、0.1 mg/L、0.5 mg/L、1 mg/L)28-表高芸苔素内酯后,选用10%浓度的聚二乙醇-6000溶液模拟干旱胁迫,测定大白菜生长和生理生化指标,分析不同浓度芸苔素内酯处理大白菜幼苗生理活性差异。【结果】随芸苔素内酯浓度升高,大白菜幼苗长势呈先良好后衰败变化;从大白菜幼苗表型看,芸苔素内酯浓度0.05 mg/L、0.1 mg/L处理的耐旱效果最明显。干旱胁迫下叶片POD和CAT活性随芸苔素内酯浓度升高呈先增强后减弱趋势,MDA含量随浓度升高呈先降后升趋势。芸苔素内酯浓度过高大白菜幼苗叶绿素相对含量变低。【结论】喷施适宜浓度的芸苔素内酯可提高干旱胁迫下大白菜幼苗的抗氧化酶活性,有效缓解干旱胁迫造成的损害,适宜的芸苔素内酯浓度为0.05~0.1 mg/L。

植物生长调节剂在大豆中的应用

植物生长调节剂可显著提升大豆产量,对保障国家粮食安全具有重要意义。文章综述大豆中应用的植物生长调节剂类型及常用植物生长调节剂研究现状,展望大豆化控发展前景,旨在为植物生长调节剂在大豆生产中的应用提供理论依据。

Plant Phosphatidylcholine-Hydrolyzing Phospholipases C NPC3 and NPC4 with Roles in Root Development and Brassinolide Signaling in Arabidopsis thaliana

Phosphatidylcholine-hydrolyzing phospholipase C （PC-PLC） catalyzes the hydrolysis of phosphatidylcholine （PC） to generate phosphocholine and diacylglycerol （DAG）. PC-PLC has a long tradition in animal signal transduction to generate DAG as a second messenger besides the classical phosphatidylinositol splitting phospholipase C （PI-PLC）. Based on amino acid sequence similarity to bacterial PC-PLC, six putative PC-PLC genes （NPC1 to NPC6） were identified in the Arabidopsis genome. RT-PCR analysis revealed overlapping expression pattern of NPC genes in root, stem, leaf, flower, and silique. In auxin-treated PNPc3：GUS and PNPc4：GUS seedlings, strong increase of GUS activity was visible in roots, leaves, and shoots and, to a weaker extent, in brassinolide-treated （BL） seedlings. PNPc4：GUS seedlings also responded to cytokinin with increased GUS activity in young leaves. Compared to wild-type, T-DNA insertional knockouts npc3 and npc4 showed shorter primary roots and lower lateral root density at low BL concentrations but increased lateral root densities in response to exogenous 0.05-1.0 I^M BL BL-induced expression of TCH4 and LRX2, which are involved in cell expansion, was impaired but not impaired in repression of CPD, a BL biosynthesis gene, in BL-treated npc3 and npc4. These observations suggest NPC3 and NPC4 are important in BL-mediated signaling in root growth. When treated with 0.1 I^M BL, DAG accumulation was observed in tobacco BY-2 cell cultures labeled with fluorescent PC as early as 15 min after application. We hypothesize that at least one PC-PLC is a plant signaling enzyme in BL signal transduction and, as shown earlier, in elicitor signal transduction.

不同浓度芸薹素内酯对蔓性千斤拔幼苗生长的影响

【目的】探讨芸薹素内酯(BR)对蔓性千斤拔(Flemingia philippinensis)幼苗的调控效应,以期为蔓性千斤拔规范化栽培提供技术支撑。【方法】以蔓性千斤拔幼苗为研究对象,采用单因素完全随机区组试验设计,对4种不同浓度的芸薹素内酯处理(CK:0 mg/L、T1:0.025 mg/L、T2:0.033 mg/L、T3:0.05 mg/L)的蔓性千斤拔幼苗的农艺性状、生物量、根冠比、叶面积与比叶重等进行比较分析。【结果】喷施芸薹素内酯对蔓性千斤拔幼苗的株高、叶片数、分枝数、主茎直径、主根长和直径、单株生物量和叶面积均表现出较显著的正向调控作用,但对根冠比和比叶重(幼苗生长前中期)有显著负向调控作用,且低浓度处理(T1)的效果明显优于T2和T1处理;与CK相比较,喷施后35 d,T1处理的株高和分枝数分别增加33.40%和48.8%,其主根直径和主茎直径分别增宽22.55%和22.45%;单株叶面积和生物量分别显著提高了79.45%和82.40%;其主根长增加了12.27%;但在叶片数上不同浓度芸薹素内酯处理间均无显著差异;在幼苗生长后期不同芸薹素内酯处理的比叶重与CK间差异均不显著。【结论】喷施芸薹素内酯对蔓性千斤拔幼苗的个体生长性能有显著的促进作用,以BR质量浓度为0.025 mg/L的处理效果较好。