Characterization of mutant tobacco mosaic virus coat protein that interferes with virus cell-to-cell movement
Characterization of mutant tobacco mosaic virus coat protein that interferes with virus cell-to-cell movement
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DOI：
10.1073/pnas.062041499
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发表时间：
2002-03-19
影响因子：
11.1
通讯作者：
Beachy, RN
中科院分区：
文献类型：
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作者：
Bendahmane, M;Szécsi, J;Beachy, RN
烟草花叶病毒（TMV）外壳蛋白（CP）在植物中的表达赋予对TMV和相关烟草花叶病毒感染的抗性。CP的某些突变体（CPT 42 W）提供比野生型（wt）CP高得多的抗性水平。在本工作中，在非转基因和转基因烟草BY-2原生质体和表达wt CP或CPT 42 W的烟草Xanthi-nn植株中，跟踪由含有wt CP或突变体CPT 42 W与绿色荧光蛋白（GFP）融合的TMV克隆（TMV-CP：GFP，TMV-CPT 42 W：GFP）和含有TMV运动蛋白（MP）：GFP的克隆的RNA转录物诱导的感染。在非转基因和野生型CP转基因植物上，TMV-CP：GFP产生了扩大的、高度荧光的盘状区域。在表达CPT 42 W的植物上，通过TMV-CP：GFP或TMV-MP：GFP-CP的感染产生较小尺寸的感染位点，其特征在于低荧光，反映病毒传播水平降低以及CP：GFP和MP：GFP两者的积累降低。TMV-CPT 42 W：GFP在非转基因植株上不能产生可见的感染位点，但在产生MP的MP转基因植株上产生正常的感染位点。TMV感染的转基因BY-CPT 42 W原生质体导致非常低水平的MP积累，而在BY-CP原生质体（含有wt CP），感染产生更高水平的MP比非转基因BY-2细胞。结果表明，wt CP对MP的产生具有积极影响，而CPT 42 W对MP积累和/或功能具有负面影响。这种效应导致含有Cp-T42 W的植物对TMV感染具有非常高水平的抗性。这份报告表明，CP的植物病毒调节生产的MP，和一个突变CP干扰MP积累和细胞到细胞的感染运动。
Expression of tobacco mosaic virus (TMV) coat protein (CP) in plants confers resistance to infection by TMV and related tobamoviruses. Certain mutants of the CP (CPT42W) provide much greater levels of resistance than wild-type (wt) CP. In the present work, infection induced by RNA transcripts of TMV clones that contain wt CP or mutant CPT42W fused to the green fluorescent protein (GFP) (TMV-CP:GFP, TMV-CPT42W:GFP) and clones harboring TMV movement protein (MP):GFP were followed in nontransgenic and transgenic tobacco BY-2 protoplasts and Nicotiana tabaccum Xanthi-nn plants that express wt CP or CPT42W. on nontransgenic and wt CP transgenic plants, TMV-CP:GFP produced expanding, highly fluorescent disk-shaped areas. On plants expressing CPT42W, infection by TMV-CP:GFP or TMV-MP:GFP-CP produced infection sites of smaller size that were characterized by low fluorescence, reflecting reduced levels of virus spread and reduced accumulation of both CP:GFP and MP:GFP. TMV-CPT42W:GFP failed to produce visible infection sites on nontransgenic plants, yet produced normal infection sites on MP-transgenic plants that produce MP. TMV infection of transgenic By-CPT42W protoplasts resulted in very low levels of MP accumulation, whereas on BY-CP protoplasts (containing wt CP), infection produced higher levels of MP than in nontransgenic BY-2 cells. The results suggest that wt CP has a positive effect on the production of MP, whereas the CPT42W has a negative effect on MP accumulation and/or function. This effect results in very high levels of resistance to TMV infection in plants containing Cp-T42W. This report shows that the CP of a plant virus regulates production of the MP, and that a mutant CP interferes with MP accumulation and cell-to-cell movement of infection.