谷子SiPRR37基因对光温、非生物胁迫的响应特点及其有利等位变异鉴定

从谷子品种延谷11号克隆生物钟基因SiPRR37,通过生物信息学分析、组织特异性表达分析、4种不同光温组合条件的昼夜表达模式分析以及对NaCl、ABA、PEG、低温、Fe 5种非生物胁迫的响应特点分析,揭示SiPRR37参与谷子光温互作调控以及应对非生物胁迫的作用机制;并对160份谷子材料重测序检测SiPRR37基因的突变位点进行单倍型分析,探究该基因对谷子主要农艺性状的影响。结果表明,SiPRR37基因蛋白质编码区(sequence coding for amino acids in protein,CDS)全长2247 bp,编码748个氨基酸,含有REC和CCT 2个结构域,基于PRR37蛋白的系统进化分析发现,谷子与糜子、高粱、玉米亲缘关系最近;启动子预测分析发现,SiPRR37启动子区存在光、温、生长素、赤霉素、脱落酸、茉莉酸甲酯、干旱和盐胁迫等多种应答元件。SiPRR37相对表达量从高到低依次为根、穗颈、穗、顶叶、次顶叶、茎秆;4个光温组合条件SiPRR37均只在光照期出现1个表达峰,无论高温(27℃)还是低温(22℃),短日照相比长日照表达峰均要提前,无论长日照还是短日照,低温(22℃)相比高温(27℃)表达峰均要提前;NaCl、低温(15℃)胁迫能够抑制SiPRR37表达,PEG模拟干旱胁迫和Fe胁迫能够诱导SiPRR37基因表达,SiPRR37参与了ABA信号传导过程。位于SiPRR37 CDS区的10个SNP将160份谷子材料分为19个单倍型,其中3个单倍型(Hap_7、Hap_10、Hap_19)是改善穗部性状的有利单倍型。谷子SiPRR37基因表达具有昼夜节律性,同时受光周期和温度调控,并且参与了谷子对盐胁迫、低温胁迫、干旱胁迫和铁胁迫的应答反应,同时SiPRR37与抽穗期和多个穗部性状相关,在开展谷子高产分子辅助选育中具有一定应用潜力。

Responsive features of SiPRR37 to photoperiod and temperature,abiotic stress and identification of its favourable allelic variations in foxtail millet(Setaria italica L.)

In this study,the clock gene SiPRR37 was cloned from the foxtail millet variety Yangu 11,and bioinformatics analysis,tissue specific expression analysis,diurnal expression patterns analysis under four different photo-thermal combinational conditions and responsive characteristics analysis to five abiotic stresses such as NaCl,ABA,PEG,low temperature and Fe were performed to reveal the mechanisms that SiPRR37 participated in regulating of photo-thermal interaction and coped with abiotic stresses.Mutation sites of SiPRR37 were detected by re-sequencing of 160 millet materials,which were used for haplotype analysis to explore the effect of SiPRR37 on main agronomic traits.The results showed that the CDS length of SiPRR37 gene was 2247 bp,which encoded 748 amino acids and contained REC and CCT domains.The phylogenetic analysis based on PRR37 proteins showed that foxtail millet had the closest relationship with broomcorn millet,sorghum and maize.Promoter prediction analysis found that various responsive elements to light,temperature,auxin,GA,ABA,MeJA,drought and salt stresses were detected in promoter region of SiPRR37.The decreasing order of relative expression level of SiPRR37 was root,panicle neck,panicle,parietal leaf,secondary parietal leaf and stem.Under four photo-thermal combinational conditions,SiPRR37 gave only one expression peak during the light period,and regardless of high temperature(27℃)or low temperature(22℃),the expression peak advanced under short-day condition compared to long-day condition,regardless of long-day or short-day,the expression peak advanced at low temperature(22℃)compared to high temperature(27℃).The expression of SiPRR37 was inhibited by NaCl and low temperature(15℃)stresses,induced by PEG-simulated drought stress and Fe stress.SiPRR37 participated in ABA signaling transduction process.The 10 SNPs in CDS region of SiPRR37 divided 160 millet materials into 19 haplotypes,of which Hap_7,Hap_10 and Hap_19 were favorable haplotypes for improving panicle traits.SiPRR37 exhibited circadian expression,and was regulated by photoperiod and temperature simultaneously.SiPRR37 participated in the responses of foxtail millet to salt stress,low temperature stress,drought stress and Fe stress.At the same time,SiPRR37 was correlated with heading stage and multiple panicle traits,showing certain application potential in high-yield molecular-assisted breeding of foxtail millet.