水稻NOL(NYC1-like)基因序列多样性、单倍型效应以及表达谱分析

DNA Sequence Diversity, Haplotype Effects and Expression Profiling Analysisof NOL(NYC1-like) Gene in Rice

NOL(NYC1-like)基因编码的蛋白在体外试验中显示出Chlb还原酶活性,但是该基因序列变异是如何影响水稻持绿表型的目前还没有报道。本研究利用本实验室的533份已测序的核心种质材料,对该基因的序列进行了多样性分析,本研究将出现频率>5%的SNP用于数据分析。该基因含有7种单倍型,Hap1和Hap4中SNP位点大致相同,Hap2、Hap3、Hap6含有相似的SNP位点。在单倍型效应分析中,考虑了核心种质的群体结构影响因素,将每个亚群的单倍型叶绿素含量进行了t-test。结果发现Ind亚群中hap4与hap3的差异极显著,hap3与hap4不仅在第一个外显子(181 bp)处产生非同义突变,而且还含有大量的启动子区的变异位点,这些位点有待于后期的功能验证。通过本实验室的表达谱数据库显示,在用植物激素处理的3份水稻材料幼苗中的NOL基因表达量非常高,这说明NOL基因与植物激素的调控有关,其次发现在衰老的叶片中表达量比较高,说明在叶片衰老后期NOL基因参与叶绿素的降解。研究结果从RNA水平为NOL基因调控叶绿素降解作用机理奠定了理论基础。

NOL protein encoded by the NOL（NYC1-like） has showed Chlb reductase activity in vitro, but how this gene influence the ＂staying green＂phenotype still unclear. In this study, we analyzed the diversity of the NYC1 gene sequence, using the sequenced data of the 533 copies of the core collection in our lab and SNPs that have more than 5% occurrence will be used for data analysis.We found that the NYC1 have 7 haplotypes, the SNP loci in Hap1 and Hap4, in Hap2, Hap3 and Hap6 are almost the same respectively.When analyzing the effect of haplotype,group construction of the core collection materials are considered, and t-test were performed to determine the content of chlorophyll in each subgroup. Our results showed that the difference in Ind sub group was significant,not only a Non-synonymous mutation happens at the first exon（181 bp） in both hap3 and hap4, but also numerous variable sites were found in the promoter regions. By analyzing the expression profile database, we found that NOL have very high expression in the three rice seedling materials that treated with plant hormone, indicating that NOL may involve in regulation of plant hormones. Besides, NOL also showed high expression level in senescence leaves, pointing that the NOL may participate in the chlorophyll degrade process in the leave-senesc-ence stage. All this results provides theoretical foundation to elucidate the role of NOL in chlorophyll degrade at RNA level.