PDF(Pubmed)
Abstract：
BACKGROUND: Generating elite rice varieties with high yield and superior quality is the main goal of rice breeding programs. Key agronomic traits, including grain size and seed germination characteristics, affect the final yield and quality of rice. The RGA1 gene, which encodes the α-subunit of rice G-protein, plays an important role in regulating rice architecture, seed size and abiotic stress responses. However, whether RGA1 is involved in the regulation of rice quality and seed germination traits is still unclear.
RESULTS: In this study, a rice mutant small and round grain 5 (srg5), was identified in an EMS-induced rice mutant library. Systematic analysis of its major agronomic traits revealed that the srg5 mutant exhibited a semi-dwarf plant height with small and round grain and reduced panicle length. Analysis of the physicochemical properties of rice showed that the difference in rice eating and cooking quality (ECQ) between the srg5 mutant and its wild-type control was small, but the appearance quality was significantly improved. Interestingly, a significant suppression of rice seed germination and shoot growth was observed in the srg5 mutant, which was mainly related to the regulation of ABA metabolism. RGA1 was identified as the candidate gene for the srg5 mutant by BSA analysis. A SNP at the splice site of the first intron disrupted the normal splicing of the RGA1 transcript precursor, resulting in a premature stop codon. Additional linkage analysis confirmed that the target gene causing the srg5 mutant phenotype was RGA1. Finally, the introduction of the RGA1 mutant allele into two indica rice varieties also resulted in small and round rice grains with less chalkiness.
CONCLUSIONS: These results indicate that RGA1 is not only involved in the control of rice architecture and grain size, but also in the regulation of rice quality and seed germination. This study sheds new light on the biological functions of RGA1, thereby providing valuable information for future systematic analysis of the G-protein pathway and its potential application in rice breeding programs.
RESULTS: In this study, a rice mutant small and round grain 5 (srg5), was identified in an EMS-induced rice mutant library. Systematic analysis of its major agronomic traits revealed that the srg5 mutant exhibited a semi-dwarf plant height with small and round grain and reduced panicle length. Analysis of the physicochemical properties of rice showed that the difference in rice eating and cooking quality (ECQ) between the srg5 mutant and its wild-type control was small, but the appearance quality was significantly improved. Interestingly, a significant suppression of rice seed germination and shoot growth was observed in the srg5 mutant, which was mainly related to the regulation of ABA metabolism. RGA1 was identified as the candidate gene for the srg5 mutant by BSA analysis. A SNP at the splice site of the first intron disrupted the normal splicing of the RGA1 transcript precursor, resulting in a premature stop codon. Additional linkage analysis confirmed that the target gene causing the srg5 mutant phenotype was RGA1. Finally, the introduction of the RGA1 mutant allele into two indica rice varieties also resulted in small and round rice grains with less chalkiness.
CONCLUSIONS: These results indicate that RGA1 is not only involved in the control of rice architecture and grain size, but also in the regulation of rice quality and seed germination. This study sheds new light on the biological functions of RGA1, thereby providing valuable information for future systematic analysis of the G-protein pathway and its potential application in rice breeding programs.
摘要：
背景：产生高产优质的优良水稻品种是水稻育种计划的主要目标。关键农艺性状,包括籽粒大小和种子萌发特性，影响水稻的最终产量和品质。RGA1基因,编码水稻G蛋白的α亚基，在调节水稻结构方面发挥着重要作用，种子大小和非生物胁迫响应。然而,RGA1是否参与水稻品质和种子萌发性状的调控尚不清楚。
结果：在这项研究中，水稻突变体小而圆的谷物5（srg5），在EMS诱导的水稻突变体文库中鉴定。对其主要农艺性状的系统分析表明，srg5突变体表现出半矮株高，粒小而圆，穗长减少。对水稻理化性质的分析表明:srg5突变体与其野生型对照在稻米食味和蒸煮品质(ECQ)上差异较小,但外观质量明显改善。有趣的是,在srg5突变体中观察到水稻种子发芽和芽生长的显着抑制，主要与ABA代谢调控有关。通过BSA分析将RGA1鉴定为srg5突变体的候选基因。第一个内含子剪接位点的SNP破坏了RGA1转录物前体的正常剪接，导致提前终止密码子。另外的连锁分析证实引起srg5突变表型的靶基因是RGA1。最后,将RGA1突变等位基因引入两个in稻品种也导致了小而圆的稻粒，白垩较少。
结论：这些结果表明，RGA1不仅参与水稻结构和籽粒大小的控制，而且还在调节稻米品质和种子萌发。这项研究为RGA1的生物学功能提供了新的思路，从而为将来对G蛋白途径的系统分析及其在水稻育种计划中的潜在应用提供了有价值的信息。
结果：在这项研究中，水稻突变体小而圆的谷物5（srg5），在EMS诱导的水稻突变体文库中鉴定。对其主要农艺性状的系统分析表明，srg5突变体表现出半矮株高，粒小而圆，穗长减少。对水稻理化性质的分析表明:srg5突变体与其野生型对照在稻米食味和蒸煮品质(ECQ)上差异较小,但外观质量明显改善。有趣的是,在srg5突变体中观察到水稻种子发芽和芽生长的显着抑制，主要与ABA代谢调控有关。通过BSA分析将RGA1鉴定为srg5突变体的候选基因。第一个内含子剪接位点的SNP破坏了RGA1转录物前体的正常剪接，导致提前终止密码子。另外的连锁分析证实引起srg5突变表型的靶基因是RGA1。最后,将RGA1突变等位基因引入两个in稻品种也导致了小而圆的稻粒，白垩较少。
结论：这些结果表明，RGA1不仅参与水稻结构和籽粒大小的控制，而且还在调节稻米品质和种子萌发。这项研究为RGA1的生物学功能提供了新的思路，从而为将来对G蛋白途径的系统分析及其在水稻育种计划中的潜在应用提供了有价值的信息。
