一个棉花纤维伸长期优势表达启动子pGhFLA1的克隆与鉴定

Identification of Promoter GhFLA1 Preferentially Expressed during Cotton fiber Elongation

棉花纤维是研究单细胞生长发育的良好模式细胞,寻找在棉花纤维发育时期优势表达的启动子,对于棉花纤维发育的功能基因组研究非常重要。本试验对发掘到的一个在纤维伸长期优势表达基因GhFLA1的启动子进行克隆,并将该启动子融合GUS转化棉花和烟草。转基因棉花的GUS蛋白染色表明,在0~20 DPA(days post anthesis)的纤维中检测到GUS蛋白,同时在柱头、雄蕊、萼片、胚根、子叶和根中也检测到GUS蛋白,但在花瓣、叶片和苞叶中没有检测到。同时GUS定量检测结果显示,pGhFLA1驱动GUS蛋白积累的高峰是在20 DPA的纤维中,其驱动GUS表达的能力是Ca MV 35S::GUS的22倍。转基因烟草组织化学染色显示pGhFLA1可以驱动GUS在叶片及叶片的表皮毛中优势表达,同时在子房、柱头、花药、苞叶、花柄基部、花瓣、种子等生殖器官上也存在GUS蛋白。启动子pGhFLA1在棉花纤维和烟草叶片的表皮毛中优势表达,可用于棉花纤维功能基因组研究,在改良纤维品质育种中具有潜在的应用价值。

Cotton(Gossypium hirsutum L.)fiber is a perfect model cell for studying cell initiation and growth,so it is critical tofind new promoters specifically or preferentially expressed in fiber for functional genomics of fiber and improvement of cottonfiber yield and quality.We found a gene GhFLA1with very high expression level in fiber elongation stage and cloned its promoter(pGhFLA1).pGhFLA1::GUS was transferred into cotton YZ1(Gossypium hirsutum)and tobacco(Nicotiana tabacum)to identifyits expression pattern in different plant tissues.GUS activity in transgenic plant was obviously detected in fiber from0DPA(dayspost anthesis)to20DPA,also in stamens,pistils,sepal,radicle,cotyledon and root,but not in petal,leaf and bract.Quantitativeanalysis of GUS activity showed that GUS expression level driven by pGhFLA1was the highest in20DPA fiber and22-foldhigher than that in CaMV35S.In transgenic tobacco,GUS activity was detected in leaf and trichome and reproductive organs likeovary,stigma,anther,bract,petal and seed.In general,the promoter pGhFLA1fusion with GUS highly expresses in cotton fiberand tobacco trichome,which could be used in fiber functional genomics research and improvement of cotton fiber quality.