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植物寄生线虫食道腺中表达的寄生基因编码的分泌蛋白在线虫侵入寄主植物、建立取食位点和抑制寄主的防御反应过程中起重要作用。利用植物寄生线虫食道腺削减cDNA文库及基于同源克隆等方法,鉴定了这些过程中起作用的分支酸变位酶(CM)基因。带有氨基酸末端信号肽的根结线虫CM、孢囊线虫CM与细菌CM的蛋白质序列非常相似。mRNA原位杂交表明,CM基因专门存在于植物寄生线虫的亚腹食道腺中。RT-PCR分析表明,它们的转录丰度在线虫寄生的早期丰度较高,在后期较低或者难以检测到。Southern杂交表明,这些CM基因为多基因家族。CM的蛋白质在专性内寄生线虫中广泛存在,表明这种多功能的酶在控制线虫侵染植物的过程中起重要作用。
The secreted proteins encoded by the parasitic genes expressed in the esophageal glands of plant parasitic nematodes play an important role in nematodes invade host plants, establishing feeding sites and inhibiting the host defense response. Using the plant parasitic nematode esophageal gland reduction cDNA library and based on homologous cloning and other methods, identified in these processes play a role in chorismate mutase (CM) gene. The root-knot nematode CM with the amino acid terminal signal peptide, the cyst nematode CM is very similar to the bacterial CM protein sequence. In situ hybridization showed that CM gene was found in the subepithelial gland of plant parasitic nematodes. RT-PCR analysis showed that their abundance of transcripts was higher at earlier stages of nematode parasitism and lower or hardly detectable at later stages. Southern hybridization showed that these CM genes are multigene families. CM proteins are widespread in obligate endoparasitic nematodes, suggesting that this versatile enzyme plays an important role in controlling nematode infestations in plants.