水稻基因组加倍对籽粒大小调控基因表达的影响

发布时间：2018-05-10 06:26

  本文选题：水稻 + 基因组加倍　； 参考：《遗传》2016年12期

【摘要】：水稻是最重要的粮食作物之一,提高水稻产量一直是育种的主要目标。水稻四倍体相对于二倍体具有籽粒变大、粒重增加的特点,研究基因组加倍后籽粒大小基因的调控模式,在育种应用方面具有十分重要的意义。本文以二倍体-四倍体水稻为材料,分析6个控制籽粒大小基因在幼穗发育中的表达差异,同时结合转基因实验,探讨基因剂量增加对基因表达水平和籽粒大小的影响。结果发现:基因组加倍后,水稻的发育进程不变,但株高增加,叶片变宽,籽粒变大,增大后的籽粒在籼稻表现为长、宽均增加显著,而在粳稻中长度比宽度增加更为明显。进一步分析控制籽粒大小基因的表达差异情况,发现这些基因的表达不仅受发育时期的影响,在籼粳亚种间也明显不同,即受遗传背景的影响。在基因组加倍的情况下,正调控基因GS5、HGW的表达普遍高于对应的二倍体;负调控基因GS3在籼稻D9311中趋于下调或沉默,而在粳稻DBl中趋于上调,GW2在D9311中上调,而在DBl中趋于沉默。通过转基因实验分析负调控基因GW2在二倍体Bl中的表达趋势,发现其在基因剂量线性增加的情况下,表达水平高于二倍体和四倍体,导致其籽粒变小。本研究结果有助于了解水稻中控制籽粒大小的基因在二倍体和四倍体中的表达模式,为高产育种提供理论依据。
[Abstract]:Rice is one of the most important food crops. Compared with diploid, tetraploid rice has the characteristics of increasing grain size and grain weight. It is very important to study the regulation pattern of grain size gene after genome doubling. In this paper, diploid tetraploid rice was used to analyze the expression differences of six genes controlling grain size in young panicle development, and the effects of gene dosage on gene expression and grain size were discussed. The results showed that after the genome doubling, the development process of rice was unchanged, but the plant height increased, the leaf became wider and the grain became larger. The grain length and width increased significantly in indica rice, but in japonica rice, the length ratio width increased more obviously. It was found that the expression of these genes was not only affected by the developmental period, but also significantly different between indica and japonica subspecies, that is, by genetic background. Under the condition of genome doubling, the expression of the positive regulatory gene GS5HGW was generally higher than that of the corresponding diploid, while the negative regulatory gene GS3 tended to be down-regulated or silenced in indica rice D9311, while in japonica rice DBl it tended to up-regulate the expression of GW2 in D9311, but silenced in DBl. The expression trend of negative regulatory gene GW2 in diploid Bl was analyzed by transgenic experiment. It was found that the expression level of GW2 in diploid Bl was higher than that in diploid and tetraploid when the gene dose was linearly increased, which resulted in the grain becoming smaller. The results of this study are helpful to understand the expression patterns of genes controlling grain size in diploid and tetraploid rice and to provide theoretical basis for high yield breeding.
【作者单位】： 四川农业大学水稻研究所西南作物基因资源与遗传改良教育部重点实验室;临沂大学药学院;
【基金】：国家重点研发计划(编号:2016YFD0100406)资助~~
【分类号】：S511
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本文编号：1868190