GhWRKY44在干旱胁迫下的功能鉴定

Functional identification of GhWRKY44 under drought stress

【目的】解析GhWRKY44基因在干旱胁迫下的功能,为棉花抗旱育种提供候选基因资源。【方法】以陆地棉(Gossypium hirsutum L.)CQJ-5叶片cDNA为模板进行聚合酶链式反应(polymerase chain reaction,PCR),获得GhWRKY44基因编码序列,并进行生物信息学分析。利用实时荧光PCR(quantitative real-time PCR,qRT-PCR)分析GhWRKY44基因在脱落酸(abscisic acid,ABA)和聚乙二醇(polyethylene glycol,PEG)6000处理下的表达模式。利用病毒诱导的基因沉默(virus-induced gene silencing,VIGS)技术研究GhWRKY44基因在干旱胁迫下的功能。【结果】GhWRKY44编码的蛋白属于Ⅰa类WRKY成员,与GbWRKY44亲缘关系较近。GhWRKY44受PEG 6000和ABA诱导表达。干旱胁迫下,与对照棉株相比,GhWRKY44沉默棉株的叶片萎蔫程度更重,植株存活率和叶片叶绿素含量(soil and plant analyzer development,SPAD值)显著降低。脱水处理6 h和7 h,GhWRKY44基因沉默棉株的叶片失水率显著高于对照。【结论】沉默GhWRKY44基因降低棉花抗旱性,GhWRKY44是棉花抗旱性的正调控因子。

[Objective]This research aims to analysis the function of GhWRKY44 gene under drought stress,and to provide candidate gene resources for drought-resistant breeding in cotton.[Methods]The coding sequence of GhWRKY44 gene was obtained by polymerase chain reaction(PCR)from the cDNA of CQJ-5(Gossypium hirsutum)leaves.And bioinformatics analysis was performed.The expression pattern of GhWRKY44 gene under the treatment of abscisic acid(ABA)and polyethylene glycol(PEG)6000 were analyzed by quantitative real-time PCR(qRT-PCR).The function of GhWRKY44 genes under drought stress was investigated by using the virus-induced gene silencing(VIGS)technology.[Results]The protein encoded by GhWRKY44 is a member of classⅠa WRKY,and is closely related to GbWRKY44.The expression of GhWRKY44 was induced by PEG 6000 and ABA.Compared with the control cotton plants,GhWRKY44 silenced cotton plants showed more severe leaf wilting,and plant survival rate and leaf chlorophyll content(soil and plant analyzer development,SPAD value)were significantly reduced under drought stress.With 6 h and 7 h of dehydration treatment,the leaf water loss rate of GhWRKY44 silenced cotton plants was significantly higher than that of control plants.[Conclusion]Silencing of GhWRKY44 gene reduced drought tolerance of cotton,and GhWRKY44 is a positive regulator of drought tolerance in cotton.