极端粒形水稻品种GS5基因的序列及效应分析

Sequence and effect of extreme grain shape gene GS5 of rice(Oryza sativa L.)

为明确粒型控制基因GS5在2种极端粒型水稻中的序列差异和作用,本研究利用极端大粒型水稻品种TD70和小粒型水稻品种Kasalath对粒宽控制基因GS5进行了克隆和序列分析,根据序列比对结果设计分子标记,用来区分不同来源的GS5基因,并结合重组自交系的粒型信息分析该基因对粒型的调节作用。结果显示,该基因包含10个外显子和9个内含子,与TD70的GS5基因相比,Kasalath的GS5基因第1外显子上编码的第31位氨基酸由甘氨酸变成丙氨酸,同时在第36、37位缺失2个甘氨酸。以这2个氨基酸的缺失为基础,设计简单重复序列(SSR)分子标记并在2个品种及其重组自交系(RIL)中进行了验证。利用该标记可以在含有GS5-T的品种中扩增出216 bp的片段,在含有GS5-K的品种中扩增出210 bp的片段。对重组自交系的检测结果显示,含有GS5-T基因的株系有122个,含有GS5-K基因的株系有118个。含GS5-T基因的株系平均粒宽比含GS5-K基因的株系平均粒宽高出0.47 mm,千粒质量高出2.87 g,说明GS5是水稻粒宽性状的主效调控基因。

In order to identify the differences of sequences and role of extreme grain gene GS5 in rice, TD70 with extremely large grain and Kasalath with extremely small grain were used to clone GS5 genes. According to the se-quences differences, molecular markers were designed and the role of GS5 were analyzed through based on the grain shape of RIL. GS5 contained ten exons and nine introns. Compared with GS5 of TD70, GS5 of Kasalath showed a mutation changing the amino acid from Gly to Ala in +31 and deleted two glys in +36 and +37 at the first exon. Based on this deletion, a simple sequence repeat ( SSR) molecular marker was designed and veri-fied in the recombinant inbred lines ( RILs) . The marker could amplify a 216-bp fragment in rice with GS5-T and a 210-bp fragment in rice with GS5-K. In the 240 RILs, GS5-T genotype were 122 and GS5-k genotype were 118. The gain width of lines with GS5-T was 0. 47 mm wider than those of lines with GS5-K,and the 1 000-grain weight (kgw) of lines with GS5-T was 2. 87 g heavier than those of lines with GS5-K. These indicated that GS5 was the major gene controlling grain width.