The impact of increased shading stress on agronomic traits,photosynthetic performance and antioxidants activities in leaves of two soybeans cultivars(D16 and E93)was studied.Soybean seedlings were grown in pots and ex...The impact of increased shading stress on agronomic traits,photosynthetic performance and antioxidants activities in leaves of two soybeans cultivars(D16 and E93)was studied.Soybean seedlings were grown in pots and exposed to no shade(S0),slight shade(S1),moderate shade(S2),and heavy shade(S3).Our findings showed that under the S3 in both cultivars,leaf fresh weight(LFW),specific leaf area(SLA)and leaf thickness decreased signifiantly,accompanied by a reduction in photochemical parameters including the maximum quantum yield(Fv/Fm)and electron transport rate(ETR).Furthermore,compared to SO,S1 significantly increased the ETR,sucrose content and the activity of catalase(CAT)in both D16 and E93 cultivars while S2 and S3 decreased the activity.However,under all treatments of shading stress,the antioxidant activities of superoxide dismutase(SOD)and peroxidase(POD)were lowered in both cultivars.Such morphological and physiological plasticity to adapt S1 compensates for the decrease in biomass and leads to seed weight compared to that obtained with an amount of normal light.Through configuring the space in the intercropping systems,S1 could be helpful for optimum growth and yield.Redesigning photosynthesis through S1 for the intercropping systems could be a smart approach.展开更多
Soybean is often intercropped with maize,sugarcane,and sorghum.Because of the shade coming from the latter,the soybean stem lodging is often a very serious problem in intercropping systems.The aim of this study is to ...Soybean is often intercropped with maize,sugarcane,and sorghum.Because of the shade coming from the latter,the soybean stem lodging is often a very serious problem in intercropping systems.The aim of this study is to characterize the possible mechanisms in the stem of shade-induced promotion of seedling soybean lodging in intercropping systems at the proteome level.We found that the soybean stem became slender and prone to lodging when it was planted with maize in an intercropping system.The inhibition of lignin biosynthesis and lack of photosynthate(soluble sugar)for the biosynthesis of the cell wall led to the lower internode breaking strength.A total of 317 proteins were found to be affected in the soybean stem in response to shade.Under the shade stress,the down-expression of key enzymes involving the phenylpropanoid metabolic pathway inhibited lignin biosynthesis.The up-regulation of expansin and XTHs protein expression relaxed the cell wall and promoted the elongation of internodes.Although the expression of the enzymes involving sucrose synthesis increased in the soybean stem,the lack of a carbon source prevented rapid stem growth.This metabolic deficit is the principal cause of the lower cellulose content in the stem of intercropped soybean,which leads to weakened stems and a propensity for lodging.展开更多
基金Funded by the National Key Research and Development Program of China(2018YFD1000905).
文摘The impact of increased shading stress on agronomic traits,photosynthetic performance and antioxidants activities in leaves of two soybeans cultivars(D16 and E93)was studied.Soybean seedlings were grown in pots and exposed to no shade(S0),slight shade(S1),moderate shade(S2),and heavy shade(S3).Our findings showed that under the S3 in both cultivars,leaf fresh weight(LFW),specific leaf area(SLA)and leaf thickness decreased signifiantly,accompanied by a reduction in photochemical parameters including the maximum quantum yield(Fv/Fm)and electron transport rate(ETR).Furthermore,compared to SO,S1 significantly increased the ETR,sucrose content and the activity of catalase(CAT)in both D16 and E93 cultivars while S2 and S3 decreased the activity.However,under all treatments of shading stress,the antioxidant activities of superoxide dismutase(SOD)and peroxidase(POD)were lowered in both cultivars.Such morphological and physiological plasticity to adapt S1 compensates for the decrease in biomass and leads to seed weight compared to that obtained with an amount of normal light.Through configuring the space in the intercropping systems,S1 could be helpful for optimum growth and yield.Redesigning photosynthesis through S1 for the intercropping systems could be a smart approach.
基金supported by the National Natural Science Foundation of China (31671626 and 31201170)
文摘Soybean is often intercropped with maize,sugarcane,and sorghum.Because of the shade coming from the latter,the soybean stem lodging is often a very serious problem in intercropping systems.The aim of this study is to characterize the possible mechanisms in the stem of shade-induced promotion of seedling soybean lodging in intercropping systems at the proteome level.We found that the soybean stem became slender and prone to lodging when it was planted with maize in an intercropping system.The inhibition of lignin biosynthesis and lack of photosynthate(soluble sugar)for the biosynthesis of the cell wall led to the lower internode breaking strength.A total of 317 proteins were found to be affected in the soybean stem in response to shade.Under the shade stress,the down-expression of key enzymes involving the phenylpropanoid metabolic pathway inhibited lignin biosynthesis.The up-regulation of expansin and XTHs protein expression relaxed the cell wall and promoted the elongation of internodes.Although the expression of the enzymes involving sucrose synthesis increased in the soybean stem,the lack of a carbon source prevented rapid stem growth.This metabolic deficit is the principal cause of the lower cellulose content in the stem of intercropped soybean,which leads to weakened stems and a propensity for lodging.
