小麦脱水素基因WDHN1-2的克隆及其表达分析

Cloning and Expression Analysis of Dehydrin Gene WDHN1-2 in Wheat

为进一步明确小麦脱水素基因WDHN1-2在逆境条件下的功能,以伞穗山羊草DHN1基因为探针,通过电子克隆及RT-PCR技术获得WDHN1-2基因后对其序列特征进行分析,同时利用基因表达综合数据库及半定量RT-PCR技术对该基因的表达模式进行解析。结果表明,WDHN1-2基因编码区(CDS)长为548bp,编码的氨基酸具有脱水素保守序列K、Y和S片段,与山羊草脱水素EMT25371亲缘关系最近。WDHN1-2蛋白属于稳定且高度亲水蛋白,二级结构以α-螺旋和无规则卷曲为主;该蛋白在亚细胞中定位的可能性:过氧化物酶体>细胞核>线粒体基质,可能行使转录调控的功能。表达模式分析发现,WDHN1-2基因在小麦开花后22d的胚乳中表达量最高,在ABA、PEG、NaCl及4℃低温胁迫下表达量均先上升后下降。

To investigate the function of WDHN1-2 gene in wheat, WDHN1-2 was cloned from wheat in silico and analyzed by bioinformatics usingDHN1 gene of Aegilops urnbellulata as the probe. The CDS of WDHN1-2 gene was 548 bp,and the transcript levels of WDHN1-2 reached the highest level at 22 DAP in embryo. Semi-quantitative RT-PCR analysis indicated that transcript accumulation was first increased and then decreased under low temperature, sodium chloride （NaCl）, abscisic acid （ABA） and polyethylene glycol （PEG） treatments. WDHN1-2 protein belonged to hydrophilic protein,which had typical features of DHNs that contains one Y segment,one S segment and two K segments. The secondary structure of this protein was mainly composed of alpha helix and random coil. This protein was likely to be located in the peroxisome, nucleus, and mitochondrial matrix,may play a function of transcriptional regulation.