CaMi, a root-knot nematode resistance gene from hot pepper (Capsium annuum L.) confers nematode resistance in tomato
CaMi, a root-knot nematode resistance gene from hot pepper (Capsium annuum L.) confers nematode resistance in tomato
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CaMi，一种来自辣椒 (Capsium annuum L.) 的根结线虫抗性基因，赋予番茄抗线虫性
DOI：
10.1007/s00299-007-0304-0
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发表时间：
2007-07-01
影响因子：
6.2
通讯作者：
Ye, Zhibiao
中科院分区：
文献类型：
--
作者：
Chen, Rugang;Li, Hanxia;Ye, Zhibiao
几种根结线虫（Meloidogyne spp.）在不同辣椒品种中发现了抗病基因。然而，它们中没有一个是克隆的。本研究采用简并PCR扩增结合RACE技术，从辣椒抗根结线虫品系PR 205中克隆了一个候选抗根结线虫基因（命名为CaMi）。表达谱分析表明，该基因在根、叶和花中高度表达，在茎中表达水平较低，在果实中未检测到。为了验证CaMi的功能，构建了含有CaMi基因组DNA的正义载体，并将其转移到感根结线虫的番茄植株中。16个转基因植株携带1至5个拷贝的T-DNA插入产生两个线虫易感番茄品种。RT-PCR分析表明，CaMi基因在不同的转基因植株中表达量不同。线虫检测结果表明，部分转基因株系对根结线虫的抗性比未转基因的感病株系有显著提高，且抗性具有遗传性。超微结构分析表明，在感病株系中，线虫导致虫瘿或根结的形成，而在抗性转基因植株中，CaMi基因引发了过敏反应（HR），线虫周围有许多坏死细胞。
Several root-knot nematode (Meloidogyne spp.) resistance genes have been discovered in different pepper (Capsium annuum L.) lines; however, none of them has yet been cloned. In this study, a candidate root-knot nematode resistance gene (designated as CaMi) was isolated from the resistant pepper line PR 205 by degenerate PCR amplification combined with the RACE technique. Expression profiling analysis revealed that this gene was highly expressed in roots, leaves, and flowers and expressed at a lower level in stems and was not detectable in fruits. To verify the function of CaMi, a sense vector containing the genomic DNA spanning the full coding region of CaMi was constructed and transferred into root-knot nematode susceptible tomato plants. Sixteen transgenic plants carrying one to five copies of T-DNA inserts were generated from two nematode susceptible tomato cultivars. RT-PCR analysis revealed that the expression levels of CaMi gene varied in different transgenic plants. Nematode assays showed that the resistance to root-knot nematodes was significantly improved in some transgenic lines compared to untransformed susceptible plants, and that the resistance was inheritable. Ultrastructure analysis showed that nematodes led to the formation of galls or root knots in the susceptible lines while in the resistant transgenic plants, the CaMi gene triggered a hypersensitive response (HR) as well as many necrotic cells around nematodes.