蒺藜苜蓿低温胁迫响应基因MtbHLH-1的克隆及功能分析  

Isolation and Functional Analysis of the Low-Temperature-Responsive Gene MtbHLH-1 in Medicago truncatula

作　　者：李宇伟[1] 连瑞丽[1] 王新民[1] 

机构地区：[1]郑州牧业工程高等专科学校药物工程系,郑州450011

出　　处：《中国农业科学》2012年第16期3430-3436,共7页Scientia Agricultura Sinica

基　　金：河南省杰出青年科学基金项目(074100510018);河南省重大科技攻关项目(072201120001)

摘　　要：【目的】克隆蒺藜苜蓿(Medicago truncatula)低温胁迫响应基因MtbHLH-1,并对其进行序列特征分析,研究MtbHLH-1对牧草蒺藜苜蓿耐低温能力的影响。【方法】利用RT-PCR技术获得蒺藜苜蓿MtbHLH-1全长的cDNA序列。对该序列进行生物信息学分析,采用半定量RT-PCR研究MtbHLH-1的低温(4℃)表达模式。【结果】测序结果显示,cDNA片段全长778 bp,包含一个741 bp完整的开放阅读框,编码246个氨基酸残基,命名为MtbHLH-1,GenBank登录号为JN800447。氨基酸BLAST分析表明,MtbHLH-1氨基酸序列与已报道的其它植物(大豆、拟南芥、烟草、小麦和玉米等)bHLH氨基酸序列具有45%—73%相似性。半定量RT-PCR研究表明,MtbHLH-1在低温胁迫条件下上调表达。【结论】从蒺藜苜蓿中克隆了低温胁迫碱性/螺旋-环-螺旋转录因子MtbHLH-1,半定量分析表明其在蒺藜苜蓿抗冷过程中起作用。[Objective]This study is aimed to characterize the low-temperature-responsive gene MtbHLH-1 in M. truncatula by clone and analyse its sequence, and study the function of MtbHLH-1 in low temperature response. [Method] The full-length cDNA sequence of MtbHLH-1 was isolated by RT-PCR. The obtained cDNA sequence and the deduced amino acid sequence were analysed. Semi-quantitative RT-PCR was used to assess the expression of MtbHLH-1 in response to low temperature （4℃） stress. [Result]The sequencing result showed that the cloned cDNA （designated as MtbHLH-1, GenBank Accession No. JN800447） was 778 bp, contains an open reading frame （ORF） of 741 bp, and encoding a protein with 246 amino acids. BLASTp search revealed 45% to 73% similarities between the MtbHLH-1 protein and those reported bHLHs from other species, such as Glycine max, Arabidopsis thaliana, Nicotiana tabacum, Triticum aestivum and Zea mays. The qRT-PCR result showed that MtbHLH-1 was expressed upregulatedly in response to low temperature stress. [Conclusion] The cold stress response transcription factor MtbHLH-1 was cloned from M. truncatula and the semi-quantitative analysis of the gene MtbHLH-I under low temperature demonstrate that the MtbHLH-1 gene probably improved low temperature stress tolerant capacities.

关 键 词：蒺藜苜蓿 gtbIILE-1 bHLH转录因子 功能分析 

分 类 号：S541.9[农业科学—作物学]