铁皮石斛外源lea3基因的转化及耐盐性分析

Transformation of lea3 Gene into Dendrobium candidum Wall. ex Lindl for Enhancing Its Salt Tolerance

利用基因枪法将来源于大麦(Hordeum vulgare L.)的抗旱耐盐基因lea3导入铁皮石斛(Dendrobium candidum Wall.ex Lindl)的类原球茎(PLBs)中,经膦丝菌素类除草剂PPT筛选2次获得抗性PLBs,于无选择压下分化获得不定芽,再经PPT筛选和生根壮苗培养获得转化植株.对转化植株进行除草剂PPT叶片涂抹检测和lea3基因的PCR检测,表明lea3基因已整合到6个株系7株铁皮石斛转化植株基因组中,转化频率为1.05%.与对照相比,获得的转基因植株的耐盐胁迫能力明显增强,表明遗传转化lea3基因可用于石斛抗旱耐盐新品种的选育.

The present paper reports that the plasmid pBY520 containing lea3 gene and bar gene was bombarded by gene gun transformation into Protocorm-like bodies （PLBs） from Dendrobium candidum Wall.ex Lindl.After PPT screening,the obtained resistant PLBs were cultured on differentiation media without PPT to regenerate shoots.Then the resistant shoots were treated with PPT screening again and the finally regenerated plants were obtained on the rooting medium.PPT resistance tests and lea3 gene PCR analysis showed that 6 putative transgenic lines had the lea3 gene integrated.The transformation rate was 1.05%.Compared with control plants,the transgenic plants were more tolerant to salt stress （1.5% NaCl）,suggesting that the transformation of the lea3 gene could be used to select Dendrobium cultivars with enhanced tolerance to drought and salt stress.