杨树PePIF3基因的克隆与表达分析

Cloning and Expression Analysis of Poplar PePIF3 Gene

生物节律基因直接影响植物的生长发育,光敏色素相互作用因子3(phytochrome-interacting factor3,PIF3)属碱性螺旋-环-螺旋转录因子家族,是生物节律中的一个关键因子,在分子水平上对植物所受到的环境变化起协同调控作用。本研究以‘南林895’杨(Populus deltoides×P.euramericana’Nanlin 895’)为材料,通过克隆获得杨树Pe PIF3基因,分别为Pe PIF3-1和Pe PIF3-2序列,长度为1686 bp和2142 bp,编码561个氨基酸和713个氨基酸,且均为亲水性蛋白。对Pe PIF3进行多序列比对分析,发现其与毛果杨和胡杨同源性最高。组织特异性分析显示PePIF3在杨树幼叶中表达量最高,在柄、茎和根组织中表达都较低。对自然条件下的杨树成熟叶中PePIF3的生物节律性变化规律分析发现其在黑暗中不断累积,上午表达量达最高,以后呈下降趋势。在全黑暗条件下,14 h前PePIF3-1和Pe PIF3-2二者的表达量变化趋势相似,但14 h后二者的表达量呈相反变化趋势。

Biorhythm genes directly affect plant growth and development.Phytochrome-interacting factor 3(PIF3)is a family of basic helix-loop-helix transcription factors,which is a key factor in biological rhythm.It plays a synergistic role in the environmental changes that plants receive.In this study,’Nanlin 895’(Populus deltoides×P.euramericana)was used to clone the PePIF3 gene,which was Pe PIF3-1 and PePIF3-2,respectively,with a length of 1686 bp and 2142 bp.It encodes 561 amino acids and 713 amino acids and is a hydrophilic protein.Multi-sequence alignment analysis of Pe PIF3 showed that it had the highest homology with Populus trichocarpa and Populus euphratica.Tissue-specific analysis showed that Pe PIF3 was expressed most in young leaves and low in petiole,stem and root tissues.The analysis of the rhythmic changes of PePIF3 in mature leaves of poplar under natural conditions showed that it accumulated continuously in the dark,and the expression level reached the highest at10 h,and then decreased.Under the condition of total darkness,the expression changes of PePIF3-1 and PePIF3-2 were similar at 14 h,but the expression levels of the two were opposite after 14 h.