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 ...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.展开更多
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...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.展开更多
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 hormo...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.展开更多
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 c...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.展开更多
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 increa...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.展开更多
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 f...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.展开更多
钙钛矿材料由于具有结构稳定、易于获取、成本低廉和易于合成等优点,在发光二极管、激光器和太阳能电池等光电器件领域具有广阔的应用前景。目前,部分适合UV-LED应用的钙钛矿具有结构不稳定性。为了寻找结构稳定的钙钛矿,此项研究利用...钙钛矿材料由于具有结构稳定、易于获取、成本低廉和易于合成等优点,在发光二极管、激光器和太阳能电池等光电器件领域具有广阔的应用前景。目前,部分适合UV-LED应用的钙钛矿具有结构不稳定性。为了寻找结构稳定的钙钛矿,此项研究利用第一性原理对无铅双钙钛矿Cs_(2)NaScX_(6)(X=Cl,Br,I)的电子及光学性质进行了理论计算。计算结果表明:Cs_(2)NaScX_(6)(X=Cl,Br,I)为直接带隙半导体,带隙值分别为5.545 e V(Cl)、4.549 eV(Br)和3.408 eV(I),Cs_(2)NaScI_(6)在紫外光范围内具有较强的光吸收。本研究内容为无铅A_(2)B^(I)B^(III)X_(6)型双钙钛矿成为UV-LED的候选材料提供理论支持。展开更多
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...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.展开更多
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.
Plant height(PH)is associated with lodging resistance and planting density,which is regulated by a complicated gene network.In this study,we identified a spontaneous dwarfing mutation in maize,m30,with decreased inter...Plant height(PH)is associated with lodging resistance and planting density,which is regulated by a complicated gene network.In this study,we identified a spontaneous dwarfing mutation in maize,m30,with decreased internode number and length but increased internode diameter.A candidate gene,ZmCYP90D1,which encodes a member of the cytochrome P450 family,was isolated by map-based cloning.ZmCYP90D1 was constitutively expressed and showed highest expression in basal internodes,and its protein was targeted to the nucleus.A G-to-A substitution was identified to be the causal mutation,which resulted in a truncated protein in m30.Loss of function of ZmCYP90D1 changed expression of hormoneresponsive genes,in particular brassinosteroid(BR)-responsive genes which is mainly involved in cell cycle regulation and cell wall extension and modification in plants.The concentration of typhasterol(TY),a downstream intermediate of ZmCYP90D1 in the BR pathway,was reduced.A haplotype conferring dwarfing without reducing yield was identified.ZmCYP90D1 was inferred to influence plant height and stalk diameter via hormone-mediated cell division and cell growth via the BR pathway.展开更多
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 i...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.展开更多
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 an...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.展开更多
基金supported by the earmarked fund for Agriculture Research System of China(CARS-01)the Agroresearch Projects in Public Interest of China(201403002 and 201303102)the National Key R&D Program of China(2016YFD0300504-2)。
文摘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.
基金This work was supported by the National Natural Science Foundation(Grant No.30671225)the Natural Science Foundation of Jiangsu Province(Grant No.BK2006069)Nantong University School Program(Grant No.06Z108).
文摘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.
基金supported by the National Natural Science Foundation of China(Grant No.31971705)Natural Science Foundation of Shanghai(Grant No.21ZR1434200)。
文摘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.
基金Supported by Key Joint Foundation for Fostering Talents of NSFC-Henan Province(U1204307)Key Project of Science and Technology of Henan Province(102102110155,142102110173,152102210334)Cultivation Fund of Luoyang Normal University(2013-PYJJ-001,10000993)
文摘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.
文摘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.
基金This study was financially supported by National Natural Science Foundation of China(31971843)Technology System of Modern Agricultural Industry in Guangdong(2020KJ105)Guangzhou Science and Technology Project(202103000075).
文摘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.
文摘钙钛矿材料由于具有结构稳定、易于获取、成本低廉和易于合成等优点,在发光二极管、激光器和太阳能电池等光电器件领域具有广阔的应用前景。目前,部分适合UV-LED应用的钙钛矿具有结构不稳定性。为了寻找结构稳定的钙钛矿,此项研究利用第一性原理对无铅双钙钛矿Cs_(2)NaScX_(6)(X=Cl,Br,I)的电子及光学性质进行了理论计算。计算结果表明:Cs_(2)NaScX_(6)(X=Cl,Br,I)为直接带隙半导体,带隙值分别为5.545 e V(Cl)、4.549 eV(Br)和3.408 eV(I),Cs_(2)NaScI_(6)在紫外光范围内具有较强的光吸收。本研究内容为无铅A_(2)B^(I)B^(III)X_(6)型双钙钛矿成为UV-LED的候选材料提供理论支持。
基金supported by the National Natural Science Foundation of China(Grant No.20072012)the Special Research Grant for Doctoral Sites in Chinese Universities(Grant No.20010730001).
文摘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.
文摘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.
基金This work was supported by the National Natural Science Foundation of China(U2004144,31971893,32101743)the Key Technologies R&D Program of Henan Province(232102111080)Yunnan Academician Expert Workstation(202305AF150082).
文摘Plant height(PH)is associated with lodging resistance and planting density,which is regulated by a complicated gene network.In this study,we identified a spontaneous dwarfing mutation in maize,m30,with decreased internode number and length but increased internode diameter.A candidate gene,ZmCYP90D1,which encodes a member of the cytochrome P450 family,was isolated by map-based cloning.ZmCYP90D1 was constitutively expressed and showed highest expression in basal internodes,and its protein was targeted to the nucleus.A G-to-A substitution was identified to be the causal mutation,which resulted in a truncated protein in m30.Loss of function of ZmCYP90D1 changed expression of hormoneresponsive genes,in particular brassinosteroid(BR)-responsive genes which is mainly involved in cell cycle regulation and cell wall extension and modification in plants.The concentration of typhasterol(TY),a downstream intermediate of ZmCYP90D1 in the BR pathway,was reduced.A haplotype conferring dwarfing without reducing yield was identified.ZmCYP90D1 was inferred to influence plant height and stalk diameter via hormone-mediated cell division and cell growth via the BR pathway.
基金Supported by the National Natural Science Foundation of China(31601275)the Project of Jiangsu Provincial Department of Education of China(17KJA210001)+1 种基金the Natural Science Foundation of Jiangsu Province(BK2014048)the Fundamental Foundation of Postgraduate Studies of China(2014M560450)
文摘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.
文摘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.
