粳稻杂种后代胚乳淀粉分支酶基因表达特性分析

选用籽粒直链淀粉含量有显著差异的亲本和杂种后代,分析籽粒灌浆过程中直链淀粉积累和淀粉分支酶活性以及淀粉分支酶基因mRNA表达量等变化特点。结果表明,直链淀粉含量高的亲本及后代在灌浆过程中合成和积累的直链淀粉量显著高于直链淀粉含量低的亲本及后代;直链淀粉含量高的亲本及后代的淀粉分支酶活性均比直链淀粉含量低的亲本及后代高,灌浆不同时期的籽粒直链淀粉含量与淀粉分支酶活性间均呈正相关;亲本及杂种后代籽粒OsSBE1和OsSBE3的mRNA表达量随灌浆进程逐渐增加,达到峰值后又逐渐下降,呈单峰曲线变化,其表达量峰值都出现在抽穗后17 d,在灌浆过程中胚乳OsSBE4基因的mRNA表达量相对比较小;杂种后代籽粒淀粉分支酶基因mRNA表达量随籽粒直链淀粉含量的变化发生变化,且能超亲表达;直链淀粉含量和淀粉分支酶活性高的基因型其SBE1和SBE3的mRNA表达量也高,低的基因型其mRNA表达量也低,SBE4的表达量与此相反。

Analysis of gene expression characteristics of branch enzymes involved in japonica hybrid progeny

In this study,the amylase content which had significant difference in parents and hybrid progeny were used to analyze the characteristics of changes in the SBE gene relative expression,the accumulated amylose content and enzymes activities during grain filling.The results showed that the accumulated amylose content and enzymes activities in parents and hybrid progeny with high amylose contents were significantly higher than the low.The amylose content were positively correlated with enzymes activities during grain filling;the relative expression level of OsSBE1 and OsSBE3 activities increased to a peak and declined during grain filling with a single-peak curve.The expression peak appeared 17 d after heading.The expression of OsSBE4 was relatively small.The progeny with relative expression level of SBE gene changed with the change of the amylose content,and transgressive expression;the high genotypes of amylose content and enzymes activities increased with the relative expression level of OsSBE1 and OsSBE3,the low genotypes also had the low expression.The expression of OsSBE4 was to the contrary.