超量表达PhWRIL1基因抑制矮牵牛叶片外植体再生不定芽

Overexpression of PhWRIL1 Gene Suppresses Adventitious Shoot Regeneration from Leaf Explants in Petunia

许多研究发现AP2/ERF家族euANT支基因超量表达可以促进植物生长和离体再生。但尚未有关于与euANT支亲缘关系很近的AP2/ERF基因basalANT进化支基因超量表达对离体培养中不定芽再生影响的研究。本研究中从矮牵牛中克隆了一个basalANT基因,命名为PhWRIL1。Real-time PCR结果显示,PhWRIL1的m RNA在矮牵牛各种组织中均有表达,表达量处于中等水平,在成熟组织中比幼嫩组织中更高。超量表达PhWRIL1的矮牵牛植株严重矮化,但开花时间没有显著变化。测定再生能力的结果表明:PhWRIL1超量表达的转基因植株叶片外植体的愈伤组织和芽的诱导与生长明显减少。这些结果表明PhWRIL1在矮牵牛中超量表达抑制了离体培养过程中不定芽的再生能力,在植物发育过程中basalANT和euANT基因可能发挥相反的作用。

AP2/ERF genes play important roles in plant development and stress responses. A number of studies observed that overexpression of euANT clade genes of the AP2/ERF family can promote plant growth and in vitro regeneration. However,although the basalANT clade is closely related to the euANT,few studies have been done on the influences of overexpression of basalANT genes on de novo organogenesis in tissue culture. In this work,a basalANT gene was cloned from petunia genome,and designated PhWRIL1. Real-time PCR showed that PhWRIL1 m RNA accumulated in various tissues at moderate levels and were more abundant in the aged tissues than the young tissues. Petunia transgenic plants overexpressing PhWRIL1 showed heavily dwarfed phenotype,but the flowering time was not affected significantly. Regeneration capacity assay showed that the induction and growth of callus and shoot were reduced clearly in transgenic plants overexpressing PhWRIL1. These results showed that overexpression of PhWRIL1 suppressed shoot regeneration in plant tissue culture and suggested that basalANT and euANT genes can play opposite effects in plant development.