辣椒CaSn基因超表达增强转基因烟草对南方根结线虫的抗性

Overexpression of Pepper CaSn Gene Enhances Resistance to Meloidogyne incognita in Transgenic Plants

CaSn基因是在辣椒(Capsicum annuum)‘Santaka’中发现的新型抗菌肽Snakin家族基因。通过RT-PCR,将CaSn基因从辣椒中分离并构建到pBI-121植物表达载体,通过农杆菌EHA105介导转化白肋烟(Nicotiana tabacum‘White burley’),筛选到10个独立的转基因株系,并对T1代植株进行抗南方根结线虫(Meloidogyne incognita)鉴定及靶标基因表达分析。结果表明CaSn已转入白肋烟,能够进行超量表达,并且转CaSn基因白肋烟上的根结数量比转空载体对照和非转基因对照减少70%,同时不同转基因烟草株系间对南方根结线虫的抗性也存在着一定差别。通过试验证明了辣椒中的抗菌肽基因CaSn具有抗南方根结线虫作用,对于植物抗线虫资源的挖掘及利用提供了重要理论依据。

The CaSn gene is a small cysteine-rich antimicrobial peptide encoding gene and belongs to the snakin family. The gene was cloned from pepper （Capsicum annuum ＇Santaka＇ ） by RT-PCR and constructed to the plant expression vector pBI-121, and transformed into burley tobacco via agrobacterium mediated method. The CaSn transgenic plants were selected by PCR and GUS staining analyses, and ten independent transgenic tobacco plants had been obtained. The CaSn gene was stably inherited and overexpressed in transgenic T1 generation plants by RT-qPCR detection. Compared to the empty vector control and non-transgenetic control plants, the number of the root-knots in the transgenic plants was reduced by 70%. Meanwhile, difference was also shown in 10 independent transgenic lines in terms oftheir resistance to root-knot nematodes. This study indicated that the CaSn participated in defense against root-knot nematodes, and had an important role in excavating and utilization of nematodes-resistant germplasms of plants.