【摘要】 盆栽条件下研究不同钾素施入量对不同穗型水稻品种灌浆成熟期籽粒碳氮代谢相关酶基因转录表达量的影响,旨在为阐明钾素营养对水稻淀粉品质形成分子调控机理提供理论依据。结果表明,灌浆过程中籽粒碳氮代谢相关酶基因GBSS1、AGPL2、SSSⅠ、SBEⅡb、ISA1和GS1:3转录表达量呈先升后降趋势,转录因子OsRSR1基因转录表达量呈先降后升趋势;随钾素施入量增加,灌浆期间籽粒GBSS1基因转录表达量逐渐下调,对其衰减率影响小;籽粒AGPL2、SSSⅠ、SBEⅡb、ISAⅠ基因转录表达量逐渐上调,而AGPL2衰减率先升后降,SSSⅠ衰减率降低,SBEⅡb衰减率升高,对ISAⅠ衰减率无明显影响;使籽粒转录因子RSR1基因转录表达量逐渐下调,而上升率升高;使籽粒GS1:3基因转录表达量逐渐上调,衰减率先升后降。基因转录表达量调控是外源钾素对生物性状调控作用分子基础,外源钾素营养对稻米蒸煮食味品质影响通过籽粒碳氮代谢相关酶基因转录表达量调控实现。更多还原

【Abstract】 Two different types of rice varieties were used to investigate the effects of different soil potassium concentrations on gene expression related to carbon-nitrogen metabolism in rice grains at filling stage, to clarify the molecular mechanism of potassium nutrition on the formation of rice starch quality. The results showed that during the grain filling process, the expression level of carbon-nitrogen metabolism genes, GBSSⅠ, AGPL2, SSSⅠ, SBEⅡb, ISAⅠ and GS1:3, increased firstly, and then decreased, while Os RSR1 gene expression exhibited the opposite trend. The increase of soil potassium concentration inhibits GBSS1 gene expression at filling stage with few effects on its attenuation rate,promotesthe expression of AGPL2, SSSⅠ, SBEⅡb and ISA1. However, with respect of the attenuation rate, AGPL2 increased first and then decreased, SSS Ⅰ decreased, SBE Ⅱ b increased, ISA1 had no significant changes. In addition, the Os RSR1 expression was gradually down-regulated, while the rising rate increased, but the GS1:3 expression level was gradually up-regulated, and the attenuation rate first increased and then decreased. Taken together, the gene transcription and expression was the molecular basis for the regulation of exogenous potassium on biological traits. The effects of exogenous potassium nutrition on the cooking and eating quality of rice could be achieved via regulation of the transcription and expression of genes related to grain carbonnitrogen metabolism.更多还原