瞬时表达葡萄病毒A外壳蛋白基因对烟草中病毒转录的影响

Transient Expressing Coat Protein Gene From Grapevine virus A to Interfere With Virus Transcription in the Nicotiana benthamiana

为验证葡萄病毒基因在模式植株上瞬时表达对接种宿主中病毒复制与感病症状的影响,本研究以一株鲜食葡萄无核王子混合感染葡萄病毒A(GVA)的不同变异株为试验材料,克隆其中一个变异株的外壳蛋白基因的部分核酸序列。在p BI121质粒35S启动子后插入具有发夹结构的外壳蛋白基因片段并转化农杆菌EHA105。农杆菌瞬时浸润本氏烟叶片5 d后,以摩擦接种GVA侵染性克隆的体外转录物作为处理组,只单独接种病毒侵染性克隆体外转录物的烟草作为对照组。结果表明,GVA体外转录产物接种30 d后,对照组植株系统叶表现黄化症状,而瞬时表达具有发夹结构的病毒外壳蛋白基因的处理组植株症状不明显,且系统叶上病毒基因的转录量相对较低,表明宿主叶片上瞬时表达病毒结构基因,可诱导植物产生抗病性,该结果为抗病葡萄种质的创制提供了一定的理论依据。

To verify that the transcient expression of vivus gene from Grapevine virus A in model plant affect the virus replication and inducible symptom in the host. A grapevine vine（ Vitis vinifera L. × Vitis labrusca L.） was co-infection with different Grapevine virus A（ GVA） variants. Partial sequence of the virus coat protein gene was cloned from one variant,the coat protein with hairpin structure was inserted into the downstream of 35 S promoter in p BI121. The overexpression plasmid was then transformed into agrobacterium EHA105. After 5 days of agrobacterium infiltration on Nicotiana benthamiana using EHA105 culture,plants were inoculated by in vitro transcripts from a GVA infectious clone,the plants only inoculated by virus without agro-infiltration application were used as control. After 30 days of virus inoculations,yellowish symptoms were observed in control group,while only slight symptoms appeared in the treated group by transcient expression of virus gene and with relative lower accumulations of GVA.