A root-knot nematode-secreted protein is injected into giant cells and targeted to the nuclei
A root-knot nematode-secreted protein is injected into giant cells and targeted to the nuclei
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DOI：
10.1111/j.1469-8137.2012.04164.x
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发表时间：
2012-06-01
期刊：
影响因子：
9.4
通讯作者：
Rosso, Marie-Noelle
中科院分区：
文献类型：
--
作者：
Jaouannet, Maelle;Perfus-Barbeoch, Laetitia;Rosso, Marie-Noelle
根结线虫（RKN）是一种专性体内寄生虫，能在数周内与宿主保持活体营养关系，并诱导根细胞分化为专门的摄食细胞。在这些过程中，线虫效应物在食道腺中合成，并通过类似螺旋管的口针注入植物组织中，当然起着中心作用。在线虫效应的搜索中，我们使用表达序列标签（EST）数据集的比较基因组学，以确定南方根结线虫基因编码的蛋白质可能分泌的感染的早期步骤。我们确定了三个基因特异性表达的食道腺的寄生虫少年编码预测分泌蛋白。其中一个基因，Mi-BMP 1是一个先驱基因，在数据库中没有相似性，并预测了核定位信号。我们证明，RKN分泌Mi-101内的饲养网站，并显示Mi-101针对饲养细胞的细胞核。RKN以前被证明在感染组织的质外质中分泌蛋白质。我们的研究结果表明，线虫定居在喂养网站也提供植物细胞内的蛋白质通过他们的口针。注射到饲养细胞内的蛋白质Mi-Bil 1靶向细胞核，在那里它可以操纵宿主细胞的核功能。
Root-knot nematodes (RKNs) are obligate endoparasites that maintain a biotrophic relationship with their hosts over a period of several weeks and induce the differentiation of root cells into specialized feeding cells. Nematode effectors synthesized in the oesophageal glands and injected into the plant tissue through the syringe-like stylet certainly play a central role in these processes. In a search for nematode effectors, we used comparative genomics on expressed sequence tag (EST) datasets to identify Meloidogyne incognita genes encoding proteins potentially secreted upon the early steps of infection. We identified three genes specifically expressed in the oesophageal glands of parasitic juveniles that encode predicted secreted proteins. One of these genes, Mi-EFF1 is a pioneer gene that has no similarity in databases and a predicted nuclear localization signal. We demonstrate that RKNs secrete Mi-EFF1 within the feeding site and show Mi-EFF1 targeting to the nuclei of the feeding cells. RKNs were previously shown to secrete proteins in the apoplasm of infected tissues. Our results show that nematodes sedentarily established at the feeding site also deliver proteins within plant cells through their stylet. The protein Mi-EFF1 injected within the feeding cells is targeted at the nuclei where it may manipulate nuclear functions of the host cell.