玉米ZmSCL7的克隆及功能研究

Cloning and Functional Study of ZmSCL7 in Zea mays

【目的】对玉米SCARECROW-LIKE 7(SCL7)进行克隆与表达研究,了解该基因表达的分子机制及其应用。【方法】以玉米叶片总RNA为模板,根据同源克隆策略设计简并引物,利用RT-PCR结合RACE技术,获得ZmSCL7的全长cDNA序列。利用同源性比对进行序列分析,通过Northern杂交分析ZmSCL7在不同逆境胁迫下的表达特征,对转基因烟草进行Western blot分析,并测定最大光化学效率、叶绿素、丙二醛和脯氨酸含量验证该基因的抗盐功能。【结果】获得ZmSCL7全长cDNA序列1 653 bp,编码550个氨基酸。Northern杂交表明该基因在NaCl、H2O2和低温处理条件下上调表达,在ABA处理条件下下调表达。与对照相比,转ZmSCL7烟草在200 mmol.L-1NaCl时萌发受到较小抑制,且最大光化学效率、叶绿素和脯氨酸含量上升,丙二醛含量下降。【结论】ZmSCL7作为一个转录因子受多种逆境胁迫诱导,该基因的过量表达提高了烟草的抗盐性。

【Objective】The aim of this study is to clone SCARECROW-LIKE 7（SCL7）gene,to analyze its molecular mechanisms and promote their applications in breeding.【Method】 The total RNA from the leaves of tobacco was used as the template to design the degenerate primers based on homology cloning strategy,and then the full-length cDNA sequence of zmSCL7 was obtained through a combined reverse transcription-PCR（RT-PCR）.Bioinformatics method was used to analyze the sequence characteristics of this gene.Northern blot was used to investigate the expression pattern.Western blot was used to investigate the transgenic analysis.Chlorophyll content,Fv/Fm,MDA and proline content were investigated for functional verification of salt resistance.【Result】The results indicated that cDNA of ZmSCL7 was 1 653 bp and contained a single open reading frame of 550 amino acid residues.Northern blot indicated that the mRNA accumulation of ZmSCL7 was induced by low temperatures,salt stress,abscisic acid（ABA） and H2O2.Additionally,compared with the control,transgenic ZmSCL7 tobacco,germination was inhibited less.Chlorophyll content,Fv/Fm,proline content increased and MDA content decreased.【Conclusion】ZmSCL7,a transcription factor,was induced by a variety of stress and could increase salt tolerance by overexpression in tobacco.