谷子抽穗期基因SiGI的表达与单倍型变异分析  

Characterizations of Transcriptional and Haplotypic Variations of SiGI in Foxtail Millet

作　　者：姚琦 智慧[2] 孟强[2] 袁迪 张彬[1] 刁现民[2] 贾冠清 YAO Qi;ZHI Hui;MENG Qiang;YUAN Di;ZHANG Bin;DIAO Xianmin;JIA Guanqing(College of Agriculture,Shanxi Agricultural University,Jinzhong 030801;Institute of Crop Sciences,Chinese Academy of Agricultural Sciences,Beijing 100081)

机构地区：[1]山西农业大学农学院,晋中030801 [2]中国农业科学院作物科学研究所,北京100081

出　　处：《植物遗传资源学报》2024年第9期1552-1564,共13页Journal of Plant Genetic Resources

基　　金：国家重点研发计划(2023YFD1200704,2023YFD1200700);国家谷子高粱产业技术体系(CARS06-14.5-A04);中国农业科学院创新工程(01-ICS-07)。

摘　　要：谷子抽穗期是决定品种适应性的关键性状,解析抽穗期关键基因的表达规律及其单倍型变异特点可为提升品种改良效率奠定基础。本研究通过全基因组关联分析,发现了一个与抽穗期紧密相关的关联信号,该信号定位于谷子5号染色体的11062649 bp处,该位点附近存在一个拟南芥抽穗期基因AtGI的同源基因SiGI。使用qRT-PCR技术研究短日照(10 h光照/14 h黑暗)条件下SiGI 24 h节律变化规律,并对其进行了组织时空表达及亚细胞定位分析。利用697份谷子品种,分析SiGI编码区和启动子区的遗传多态性和单倍型变异规律,并对单倍型的表型效应进行鉴定。结果显示,SiGI在光周期响应组织(根、茎、叶等)中高表达,亚细胞定位于细胞核,在傍晚表达量上调,呈现出24 h节律性表达模式。SiGI在不同谷子品种中存在丰富的多态性,其中,启动子Hap-6单倍型较Hap-3单倍型品种的相对表达量显著上调了约1.5倍(P=0.0083)。在8个不同种植环境下,Hap-6单倍型品种的抽穗期显著提前,并在4个环境中株高显著降低。结果表明SiGI基因的Hap-6单倍型具有早熟且对产量影响较小的优势,可作为优异单倍型用于分子育种选择。The heading date of foxtail millet is a key trait that determined the adaptability of varieties,and dissection of the transcriptional pattern and haplotype variations of key genes are important for promoting cultivars improvement.In this research,SiGI was identified by genome-wide association study(GWAS),which is a key regulator responsible for foxtail millet flowering.The expression profile of SiGI was analyzed,as well as subcellular localization of SiGI was performed by using protoplasts.The 24-hour rhythm expression pattern analysis of SiGI was performed by qRT-PCR under short-day(10 h light/14 h dark)conditions.Genetic and haplotypes diversity of SiGI coding and promoter regions were analyzed by using representative 697 millet varieties,and haplotype morphological effects of SiGI was also summarized.As a result,a significant correlation signal was identified at 11062649 bp on chromosome 5,which is closely related to heading date.SiGI was found near this locus,whose homologue is AtGI.SiGI was highly expressed in photoperiod-responsive tissues(roots,stems,leaves,etc.),and subcellular localization was located in the nucleus,and the expression level was upregulated in the evening,showing a 24-hour rhythmic expression pattern.SiGI exhibits rich polymorphism in different foxtail millet varieties,and the relative expression of promoter haplotype Hap-6 was significantly upregulation by approximately 1.5-flod compared to Hap-3(P=0.0083).Heading date of Hap-6 containing varieties were significantly earlier than other haplotypes under 8 environments,and the plant height of Hap-6 containing varieties were significantly reduced under 4 environments.SiGI haplotype Hap-6 has no obvious impact on yield,and can be used as the main haplotype for molecular breeding selection.

关 键 词：全基因组关联分析 单倍型分析 节律性表达 抽穗期 谷子 

分 类 号：S515[农业科学—作物学]