狗蔷薇RaWUS基因的超量表达诱导转基因烟草根尖形成不定芽

Overexpression of RaWUS Gene of Rosa canina Inducing Shoot Regeneration from Root Tip of Transgenic Tobacco

WUSCHEL是植物干细胞命运的决定基因,在植物发育过程中WUSCHEL基因的表达决定着干细胞的形成和器官的发生。从狗蔷薇的类原球茎中克隆出其同源基因;经过对其进行蛋白质序列比对和系统发育分析,将其命名为RaWUS基因。构建在XVE系统下的化学调控的表达载体。在该系统下,RaWUS基因的超量表达能诱导转基因烟草根尖形成不定芽;同时显微观察表明,根部的皮层中有圆球形的分生组织干细胞团的产生。结果表明:RaWUS基因的过量表达能够促使根的皮层中薄壁细胞转变成为分生组织干细胞而形成不定芽在根尖异位发生,说明其能够在植物的根尖中诱导茎尖分生组织干细胞的活性和发育的可塑性。

WUSCHEL is plant stem cell organizer gene,and its expression determines stem cell formation and morphogenesis during plant development.We cloned its homologue gene from protocorm-like body in Rosa canina,and named it as RaWUS gene through homology comparison of amino acid sequences alignment and phylogenetic analysis.A chemical inducible expression vector was constructed under XVE system.Under the system,overexpression of RaWUS gene was able to induce adventitious shoots from root tips of transgenic tobacco,and microobservation results showed that spherical meristem stem cell mass was produced in cortex in the root.Our research result suggests overexpression of RaWUS gene can transform parenchymatous cell into meristematic stem cell and induce shoot stem cell activity and development plasticity in the root.