论文部分内容阅读
【目的】水稻色素不仅对其自身生长发育有重要生理作用,而且在水稻育种、农副产品改良等方面运用比较广泛。对水稻色素相关基因进行表型分析和基因定位,为进一步研究色素代谢途径及调控机理奠定基础。【方法】利用EMS诱变粳稻长粒粳(CLJ),在突变体库内筛选到一个金黄色颖壳与节间突变体gh881;在成熟期,测定野生型与gh881的主要农艺性状;将gh881与野生型及中恢8015杂交,观察BC1F1及F1植株表型,并对BC1F2及F2表型分离进行卡方检验,对gh881进行遗传分析;利用F2群体和图位克隆的方法对gh881突变基因进行定位;采用q PCR检测颖壳颜色相关基因在gh881与野生型不同发育时期的幼穗、节间以及剑叶叶鞘的相对表达量。【结果】与野生型相比,突变体的颖壳与节间均呈金黄色;除单株有效穗数外,gh881突变体的株高、每穗总粒数及实粒数、结实率和千粒重等性状均极显著降低。遗传分析和基因定位结果表明,gh881的突变表型受1对隐性核基因控制,位于第2染色体短臂,并最终将该基因精细定位于标记FH-13和RH-25之间,物理距离约33.2 kb,该区域中包含4个开放阅读框(ORFs)。【结论】序列分析结果表明,发现其中一个编码肉桂醇脱氢酶(CAD)的基因OsC AD2(Os02g0187800)的3 563 bp处发生了1个单碱基突变(G转换为A),导致该基因编码区的第297位氨基酸由甘氨酸突变为天冬氨酸,由此认为该突变体为OsC AD2基因单碱基突变的新等位基因。q RT-PCR结果表明,突变体的节间中OsCAD2相对表达量极显著下调,而在剑叶叶鞘及穗部则基本都是极显著增加,其他相关基因也发生显著变化,证实OsCAD2是木质素代谢中的重要基因,且可能与其他相关基因存在反馈调节。
【Objective】 Rice pigment not only has an important physiological effect on its own growth and development, but also is widely used in rice breeding, agricultural and sideline products improvement. Phenotypic analysis and gene mapping of rice pigment-related genes laid the foundation for further study of pigment metabolism and regulatory mechanisms. 【Method】 A golden yellow glume and internode mutant gh881 was screened in the mutant library by EMS mutagenesis. The main agronomic traits of wild-type and gh881 were determined at the mature stage. The gh881 The wild type and Zhonghui 8015 were crossed to observe the phenotypes of BC1F1 and F1 plants. The phenotypic differences between BC1F2 and F2 were analyzed by chi-square test and the genetic analysis of gh881 was carried out. The gh881 mutant gene was cloned by F2 population and map cloning Q-PCR was used to detect the relative expression of husks color-related genes in young spikes, internodes and leaf sheaths at different developmental stages of gh881 and wild-type. 【Result】 The results showed that the gh881 mutant had the golden yellow color compared with the wild type. The gh881 mutant had the highest plant height, the total number of grains per spike, the number of real grains, the seed setting rate and Thousand grain weight and other traits were significantly reduced. The results of genetic analysis and gene mapping indicated that the mutant phenotype of gh881 was controlled by a pair of recessive nuclear genes located on the short arm of chromosome 2 and finally the gene was finely mapped between the markers FH-13 and RH-25. The physical distance About 33.2 kb, this region contains 4 open reading frames (ORFs). 【Conclusion】 Sequence analysis showed that one single-base mutation (G to A) occurred at 3 563 bp of OsC AD2 (Os02g0187800), one of the genes encoding cinnamyl alcohol dehydrogenase (CAD), resulting in the gene The amino acid at position 297 of the coding region was mutated from glycine to aspartic acid. Therefore, the mutant was considered as a new allele with single-base mutation of OsC AD2 gene. q RT-PCR results showed that the relative expression level of OsCAD2 in the internode of the mutant was significantly down-regulated, whereas in the leaf sheath and panicle of the flag leaf were all significantly increased, and other related genes also changed significantly, confirming that OsCAD2 is a lignin Metabolism of important genes, and may have feedback regulation of other related genes.