Simultaneous stresses of salinity and drought often coincide during rice-growing seasons in saline lands,primarily due to insufficient water resources and inadequate irrigation facilities.Consequently,combined salinit...Simultaneous stresses of salinity and drought often coincide during rice-growing seasons in saline lands,primarily due to insufficient water resources and inadequate irrigation facilities.Consequently,combined salinity-drought stress poses a major threat to rice production.In this study,two salinity levels(NS,non-salinity;HS,high salinity)along with three drought treatments(CC,control condition;DJ,drought stress imposed at jointing;DH,drought stress imposed at heading)were performed to investigate their combined influences on leaf photosynthetic characteristics,biomass accumulation,and rice yield formation.Salinity,drought,and their combination led to a shortened growth period from heading to maturity,resulting in a reduced overall growth duration.Grain yield was reduced under both salinity and drought stress,with a more substantial reduction under the combined salinity-drought stress.The combined stress imposed at heading caused greater yield losses in rice compared with the stress imposed at jointing.Additionally,the combined salinity-drought stress induced greater decreases in shoot biomass accumulation from heading to maturity,as well as in shoot biomass and nonstructural carbohydrate(NSC)content in the stem at heading and maturity.However,it increased the harvest index and NSC remobilization reserve.Salinity and drought reduced the leaf area index and SPAD value of flag leaves and weakened the leaf photosynthetic characteristics as indicated by lower photosynthetic rates,transpiration rates,and stomatal conductance.These reductions were more pronounced under the combined stress.Salinity,drought,and especially their combination,decreased the activities of ascorbate peroxidase,catalase,and superoxide dismutase,while increasing the contents of malondialdehyde,hydrogen peroxide,and superoxide radical.Our results indicated a more significant yield loss in rice when subjected to combined salinity-drought stress.The individual and combined stresses of salinity and drought diminished antioxidant enzyme activities,inhibited leaf photosynthetic functions,accelerated leaf senescence,and subsequently lowered assimilate accumulation and grain yield.展开更多
以大豆分离蛋白为原料,通过酸性偏移结合热诱导对其进行大豆分离蛋白微凝胶(soy protein isolate microgel,SPIM)化改性,利用荧光光谱、红外色谱、原子力学显微镜等探究蛋白质的结构变化、分子间相互作用、凝胶的微观形态、凝胶特性,考...以大豆分离蛋白为原料,通过酸性偏移结合热诱导对其进行大豆分离蛋白微凝胶(soy protein isolate microgel,SPIM)化改性,利用荧光光谱、红外色谱、原子力学显微镜等探究蛋白质的结构变化、分子间相互作用、凝胶的微观形态、凝胶特性,考察热诱导温度(25、45、55、65、75、85℃)对SPIM结构和特性的影响。结果表明:SPIM形成过程中二级结构β-折叠相对含量增多,静电相互作用、疏水相互作用、氢键作用参与了微凝胶的自组装;随着热诱导温度的升高,SPIM表面疏水性指数先增加后减小,热稳定性逐渐增强。与单独酸性偏移相比,酸性偏移结合75℃热诱导形成的微凝胶比表面积显著增大(P<0.05),乳化活性、乳化稳定性和持水性显著升高(P<0.05)。酸性偏移结合热诱导是一种有效调控蛋白质微凝胶结构和特性的方法,通过精准控温可以提升微凝胶的质量。展开更多
Light deficiency is a growing abiotic stress in rice production.However,few studies focus on shading effects on grain yield and quality of rice in East China.It is also essential to investigate proper nitrogen(N)appli...Light deficiency is a growing abiotic stress in rice production.However,few studies focus on shading effects on grain yield and quality of rice in East China.It is also essential to investigate proper nitrogen(N)application strategies that can effectively alleviate the negative impacts of light deficiency on grain yield and quality in rice.A two-year field experiment was conducted to explore the effects of shading(non-shading and shading from heading to maturity)and panicle N application(NDP,decreased panicle N rate;NMP,medium panicle N rate;NIP,increased panicle N rate)treatments on rice yield-and quality-related characteristics.Compared with non-shading,shading resulted in a 9.5-14.8%yield loss(P<0.05),mainly due to lower filled-grain percentage and grain weight.NMP and NIP had higher(P<0.05)grain yield than NDP under non-shading,and no significant difference was observed in rice grain yield among NDP,NMP,and NIP under shading.Compared with NMP and NIP,NDP achieved less yield loss under shading because of the increased filled-grain percentage and grain weight.Shading reduced leaf photosynthetic rate after heading,as well as shoot biomass weight at maturity,shoot biomass accumulation from heading to maturity,and nonstructural carbohydrate(NSC)content in the stem at maturity(P<0.05).The harvest index and NSC remobilization reserve of NDP were increased under shading.Shading decreased(P<0.05)percentages of brown rice,milled rice,head rice,and amylose content while increasing(P<0.05)chalky rice percentage,chalky area,chalky degree,and grain protein.NMP demonstrated a better milling quality under non-shading,while NDP demonstrated under shading.NDP exhibited both lower chalky rice percentage,chalky area,and chalky degree under non-shading and shading,compared with NMP and NIP.NDP under shading decreased amylose content and breakdown but increased grain protein content and setback,contributing to similar overall palatability to non-shading.Our results suggested severe grain yield and quality penalty of rice when subjected to shading after heading.NDP improved NSC remobilization,harvest index,and sink-filling efficiency and alleviated yield loss under shading.Besides,NDP would maintain rice’s milling,appearance,and cooking and eating qualities under shading.Proper N management with a decreased panicle N rate could be adopted to mitigate the negative effects of shading on rice grain yield and quality.展开更多
基金financed by the National Key Research and Development Program,China(Grant Nos.2022YFE0113400 and 2022YFD1500402)National Natural Science Foundation of China(Grant No.32001466)+3 种基金Scientific and Technological Innovation Fund of Carbon Emissions Peak and Neutrality of Jiangsu Provincial Department of Science and Technology,China(Grant Nos.BE2022304 and BE2022305)Joints Funds of the National Natural Science Foundation of China(Grant No.U20A2022)Postdoctoral Research Foundation of China(Grant No.2020M671628)the Priority Academic Program Development of Jiangsu Higher Education Institutions,China.
文摘Simultaneous stresses of salinity and drought often coincide during rice-growing seasons in saline lands,primarily due to insufficient water resources and inadequate irrigation facilities.Consequently,combined salinity-drought stress poses a major threat to rice production.In this study,two salinity levels(NS,non-salinity;HS,high salinity)along with three drought treatments(CC,control condition;DJ,drought stress imposed at jointing;DH,drought stress imposed at heading)were performed to investigate their combined influences on leaf photosynthetic characteristics,biomass accumulation,and rice yield formation.Salinity,drought,and their combination led to a shortened growth period from heading to maturity,resulting in a reduced overall growth duration.Grain yield was reduced under both salinity and drought stress,with a more substantial reduction under the combined salinity-drought stress.The combined stress imposed at heading caused greater yield losses in rice compared with the stress imposed at jointing.Additionally,the combined salinity-drought stress induced greater decreases in shoot biomass accumulation from heading to maturity,as well as in shoot biomass and nonstructural carbohydrate(NSC)content in the stem at heading and maturity.However,it increased the harvest index and NSC remobilization reserve.Salinity and drought reduced the leaf area index and SPAD value of flag leaves and weakened the leaf photosynthetic characteristics as indicated by lower photosynthetic rates,transpiration rates,and stomatal conductance.These reductions were more pronounced under the combined stress.Salinity,drought,and especially their combination,decreased the activities of ascorbate peroxidase,catalase,and superoxide dismutase,while increasing the contents of malondialdehyde,hydrogen peroxide,and superoxide radical.Our results indicated a more significant yield loss in rice when subjected to combined salinity-drought stress.The individual and combined stresses of salinity and drought diminished antioxidant enzyme activities,inhibited leaf photosynthetic functions,accelerated leaf senescence,and subsequently lowered assimilate accumulation and grain yield.
文摘以大豆分离蛋白为原料,通过酸性偏移结合热诱导对其进行大豆分离蛋白微凝胶(soy protein isolate microgel,SPIM)化改性,利用荧光光谱、红外色谱、原子力学显微镜等探究蛋白质的结构变化、分子间相互作用、凝胶的微观形态、凝胶特性,考察热诱导温度(25、45、55、65、75、85℃)对SPIM结构和特性的影响。结果表明:SPIM形成过程中二级结构β-折叠相对含量增多,静电相互作用、疏水相互作用、氢键作用参与了微凝胶的自组装;随着热诱导温度的升高,SPIM表面疏水性指数先增加后减小,热稳定性逐渐增强。与单独酸性偏移相比,酸性偏移结合75℃热诱导形成的微凝胶比表面积显著增大(P<0.05),乳化活性、乳化稳定性和持水性显著升高(P<0.05)。酸性偏移结合热诱导是一种有效调控蛋白质微凝胶结构和特性的方法,通过精准控温可以提升微凝胶的质量。
基金This work was financed by the National Natural Science Foundation of China(U20A2022,31901448 and 32001466)the Postdoctoral Research Foundation of China(2020M671628 and 2020M671629)+2 种基金the Natural Science Foundation of the Jiangsu Higher Education Institutions,China(19KJB210004)the Key Research and Development Program of Jiangsu Province,China(BE2019343)the Priority Academic Program Development of Jiangsu Higher Education Institutions,China.
文摘Light deficiency is a growing abiotic stress in rice production.However,few studies focus on shading effects on grain yield and quality of rice in East China.It is also essential to investigate proper nitrogen(N)application strategies that can effectively alleviate the negative impacts of light deficiency on grain yield and quality in rice.A two-year field experiment was conducted to explore the effects of shading(non-shading and shading from heading to maturity)and panicle N application(NDP,decreased panicle N rate;NMP,medium panicle N rate;NIP,increased panicle N rate)treatments on rice yield-and quality-related characteristics.Compared with non-shading,shading resulted in a 9.5-14.8%yield loss(P<0.05),mainly due to lower filled-grain percentage and grain weight.NMP and NIP had higher(P<0.05)grain yield than NDP under non-shading,and no significant difference was observed in rice grain yield among NDP,NMP,and NIP under shading.Compared with NMP and NIP,NDP achieved less yield loss under shading because of the increased filled-grain percentage and grain weight.Shading reduced leaf photosynthetic rate after heading,as well as shoot biomass weight at maturity,shoot biomass accumulation from heading to maturity,and nonstructural carbohydrate(NSC)content in the stem at maturity(P<0.05).The harvest index and NSC remobilization reserve of NDP were increased under shading.Shading decreased(P<0.05)percentages of brown rice,milled rice,head rice,and amylose content while increasing(P<0.05)chalky rice percentage,chalky area,chalky degree,and grain protein.NMP demonstrated a better milling quality under non-shading,while NDP demonstrated under shading.NDP exhibited both lower chalky rice percentage,chalky area,and chalky degree under non-shading and shading,compared with NMP and NIP.NDP under shading decreased amylose content and breakdown but increased grain protein content and setback,contributing to similar overall palatability to non-shading.Our results suggested severe grain yield and quality penalty of rice when subjected to shading after heading.NDP improved NSC remobilization,harvest index,and sink-filling efficiency and alleviated yield loss under shading.Besides,NDP would maintain rice’s milling,appearance,and cooking and eating qualities under shading.Proper N management with a decreased panicle N rate could be adopted to mitigate the negative effects of shading on rice grain yield and quality.
