Zhao Chaoyang, Shukle Richard, Navarro-Escalante Lucio, Chen Mingshun, Richards Stephen, Stuart Jeffrey J
Department of Entomology, Purdue University, West Lafayette, IN 47907, United States.
USDA-ARS and Department of Entomology, Purdue University, West Lafayette, IN 47907, United States.
J Insect Physiol. 2016 Jan;84:22-31. doi: 10.1016/j.jinsphys.2015.10.001. Epub 2015 Oct 9.
The genetic tractability of the Hessian fly (HF, Mayetiola destructor) provides an opportunity to investigate the mechanisms insects use to induce plant gall formation. Here we demonstrate that capacity using the newly sequenced HF genome by identifying the gene (vH24) that elicits effector-triggered immunity in wheat (Triticum spp.) seedlings carrying HF resistance gene H24. vH24 was mapped within a 230-kb genomic fragment near the telomere of HF chromosome X1. That fragment contains only 21 putative genes. The best candidate vH24 gene in this region encodes a protein containing a secretion signal and a type-2 serine/threonine protein phosphatase (PP2C) domain. This gene has an H24-virulence associated insertion in its promoter that appears to silence transcription of the gene in H24-virulent larvae. Candidate vH24 is a member of a small family of genes that encode secretion signals and PP2C domains. It belongs to the fraction of genes in the HF genome previously predicted to encode effector proteins. Because PP2C proteins are not normally secreted, our results suggest that these are PP2C effectors that HF larvae inject into wheat cells to redirect, or interfere, with wheat signal transduction pathways.
黑森瘿蚊（HF，麦瘿蚊）在遗传方面易于操作，这为研究昆虫诱导植物形成虫瘿的机制提供了契机。在此，我们通过鉴定在携带HF抗性基因H24的小麦（Triticum spp.）幼苗中引发效应子触发免疫的基因（vH24），利用新测序的HF基因组证明了这种能力。vH24被定位在HF染色体X1端粒附近一个230 kb的基因组片段内。该片段仅包含21个推定基因。该区域中最有可能的vH24基因编码一种含有分泌信号和2型丝氨酸/苏氨酸蛋白磷酸酶（PP2C）结构域的蛋白质。该基因在其启动子中有一个与H24毒力相关的插入序列，这似乎使该基因在具有H24毒力的幼虫中沉默转录。候选vH24是一个编码分泌信号和PP2C结构域的小基因家族的成员。它属于HF基因组中先前预测编码效应蛋白的那部分基因。由于PP2C蛋白通常不分泌，我们的结果表明，这些是HF幼虫注入小麦细胞以重定向或干扰小麦信号转导途径的PP2C效应子。
