过表达玉米转录因子ZmWRKY101基因提高拟南芥植株的耐盐力

Overexpression of a maize transcription factor ZmWRKY101 improving salt tolerance of Arabidopsis plants

WRKY是植物细胞中特有的一类转录因子,在逆境胁迫应答中具有重要的调控作用。本研究基于非生物胁迫诱导的玉米转录组数据库,鉴定了1个WRKY基因,该基因含有855 bp的完整开放读码框,编码285个氨基酸,在C端含有1个保守的WRKYGQK结构域和锌指结构,属于第II组WRKY转录因子,命名为ZmWRKY101。烟草叶表皮细胞亚细胞定位显示,ZmWRKY101蛋白定位在细胞核中。定量表达分析表明,ZmWRKY101在玉米的根、叶和雄穗中具有较高的表达水平,而在花丝和胚中表达水平最低。PEG、NaCl和ABA处理能够显著诱导ZmWRKY101的表达水平,其中NaCl诱导上调了17.6倍;而低温处理抑制了该基因的表达。在拟南芥中过表达ZmWRKY101通过提高抗氧化酶活性及抗胁迫相关基因的表达水平,继而改进植株的耐盐性。上述结果表明,ZmWRKY101基因通过改进抗氧化系统参与对盐胁迫的信号转导。

WRKY are a unique class of transcription factors in plant cells,which play an important regulatory role in stress response.Based on the non-stress-induced maize transcriptome database,a WRKY gene with a complete open reading frame of 855 bp was identified.The gene named ZmWRKY101 encodes 285 amino acids,containing a conserved WRKYGQK domain and zinc fingers at the C-terminus.The structure belongs to group II WRKY transcription factor.Subcellular localization in tobacco leaf epidermal cells revealed that ZmWRKY101 protein was localized in the nucleus.Quantitative expression analysis showed that ZmWRKY101 had higher expression levels in roots,leaves and tassels of maize,while the lowest expression level in cornsilks and embryos.PEG,NaCl and ABA treatments could significantly induce the expression levels of ZmWRKY101,especially 17.6 fold upregulation in NaCl treatment,while low temperature treatment inhibited the gene expression.Overexpression of ZmWRKY101 in Arabidopsis thaliana improved the salt tolerance of plants by improving antioxidant enzyme activities and expression levels of stress-related genes.The above results indicated that ZmWRKY101 was involved in signal transduction of salt stress by the antioxidant system.