反义NR转基因株的分子检测和生理特性的研究

SOUTHERN AND NORTHERN BLOT GROWTH DEVELOPMENT AND PHYSIOLOGICAL CHARACTERISTICS IN MUTANTS OF ANTI - NR GENE

为了研究NR基因的作用,通过番茄反义NR转基因株的southern,northern杂交,从入地成活的139个卡那霉素筛选出的转化株中,鉴定出了2株突变体,并对其相关的生长发育、生理指标进行了测定。研究结果显示:NR基因的表达被抑制后.突变体细胞膜透性、蒸腾作用和气孔导度比野生型植株的高,但呼吸作用低于野生型;果实成熟推迟。各突变体植株的分枝数减少,节间明显伸长,茎增粗;特别是NR2突变体节间最长、且生长健壮、茎粗、叶大、开花多,但不易结实、花粉粒数量减少、花粉萌发率仅2％～3％。总之,乙烯受体蛋白NR基因被抑制后,突变体植株表现出促进生长,推迟发育和成熟,即乙烯的作用被抑制的现象。说明NR基因是乙烯生物合成和信号转导的正调节因子。

To understand the function of NR gene, mutants of anti - NR gene were obtained by Agrobacterium - mediated gene transformation, and Southern - blot and Northern - blot were performed to study their growth, development and physiological characteristics. The inhibition of NR gene expression in the mutants resulted in higher cytomembrane permeability, transpiration rate and stomatal conductivity and lower respiration rate as compared with the wild type. The mutants, Mutant NR2 in particular, grew stronger with more branches, longer internodes and thicker stems. The ripening of their fruits was postponed and the number of pollen grains was reduced. In general, the growth of the mutants was accelerated and their development and maturation were retarded, suggesting that NR gene is a positive regulatory factor the biosynthesis of ethylene and its signal transducn'on.