陆地棉GhCYP94C1基因在种子萌发和开花期中的功能分析

Functional analysis of the Gh CYP94C1 gene in seed germination and flowering time of upland cotton

P450家族基因在植物的花器官发育、抗病虫害及不同的激素调控通路中都有重要作用,一直是科学界研究的热点.本研究从实验室已有的数据中筛选到基因GhCYP94C1(Cytochrome P45094C1),该基因共编码517个氨基酸.蛋白质结构分析发现,该蛋白有跨膜结构,无信号肽,为非分泌性亲水性脂溶蛋白.组织表达模式分析发现,该基因在棉花雄蕊、雌蕊和花瓣中表达量较高.分析GhCYP94C1基因启动子序列发现,启动子区域含有多种激素响应元件.通过激素处理发现,茉莉酸甲酯(methyl jasmonate,MeJA)可以促进棉花种子萌发,不同浓度的赤霉素(gibberellin,GA)和低于1.0μmol/L的脱落酸(abscisic acid,ABA)可以抑制棉花种子的萌发,而GA,ABA和MeJA均可以促进棉花幼苗的茎、根和侧根的伸长.荧光定量结果显示,GhCYP94C1基因响应GA,ABA和MeJA激素的调控.构建过表达载体转化拟南芥后,发现该基因可以促进种子的萌发、主根的伸长和提前开花.同时拟南芥中AtAP1,AtFT和AtFUL等开花节点基因表达量明显提高.构建病毒诱导基因沉默(virus-induced gene silencing,VIGS)载体(pCLCrVA-GhCYP94C1)后,VIGS植株出现晚花表型.综上所述,GhCYP94C1基因可能是影响棉花生长发育和开花时间的正调节因子,该基因的克隆为棉花早熟分子改良提供了基因资源.

P450 family genes play important roles in the development of plant floral organs,resistance to diseases and insect pests,and different hormone regulation pathways.In this study,the gene GhCYP94C1(Cytochrome P45094C1)was selected from our previous data.The gene encodes a total of 517 amino acids.Analysis of the protein structure reveals that the protein has a transmembrane structure and no signal peptide,indicating that it is non-secretory,hydrophilic and liposoluble.Tissue expression analysis showed that Gh CYP94C1 was highly expressed in cotton stamen,pistil and petal.Promoter sequence analysis showed that the promoter region of GhCYP94C1 contained a variety of hormone response elements.Methyl jasmonate(Me JA)could promote seed germination,and gibberellin(GA)and abscisic acid(ABA)lower than 1.0μmol/L could inhibit seed germination.In addition,GA,ABA and Me JA could promote the elongation of the stem,root and lateral root of cotton seedlings.q RT-PCR analysis suggested that GhCYP94C1 might be involved in the regulation pathway of GA,ABA and Me JA.Studies from Arabidopsis overexpressing GhCYP94C1 showed that this gene could promote the germination of seeds,the elongation of the main root and early flowering.And the expressions of flowering node gene AtAP1,AtFT,and AtFUL were up-regulated in transgenic Arabidopsis.The virus-induced gene silencing(pCLCrVA-Gh CYP94C1)plants showed a late-flowering phenotype.In summary,the GhCYP94C1 gene might play an important role in cotton growth and early flowering.The cloning of this gene provides a genetic resource for the molecular improvement in early maturity of cotton.