State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, 430072 Wuhan, China.
Institute for Plant Protection and Soil Sciences, Hubei Academy of Agricultural Sciences, 430064 Wuhan, China.
Plant Physiol. 2018 Jan;176(1):552-565. doi: 10.1104/pp.17.00755. Epub 2017 Nov 13.
The brown planthopper, , is a pest that threatens rice () production worldwide. While feeding on rice plants, planthoppers secrete saliva, which plays crucial roles in nutrient ingestion and modulating plant defense responses, although the specific functions of salivary proteins remain largely unknown. We identified an -secreted mucin-like protein (NlMLP) by transcriptome and proteome analyses and characterized its function, both in brown planthopper and in plants. is highly expressed in salivary glands and is secreted into rice during feeding. Inhibition of expression in planthoppers disturbs the formation of salivary sheaths, thereby reducing their performance. In plants, NlMLP induces cell death, the expression of defense-related genes, and callose deposition. These defense responses are related to Ca mobilization and the MEK2 MAP kinase and jasmonic acid signaling pathways. The active region of NlMLP that elicits plant responses is located in its carboxyl terminus. Our work provides a detailed characterization of a salivary protein from a piercing-sucking insect other than aphids. Our finding that the protein functions in plant immune responses offers new insights into the mechanism underlying interactions between plants and herbivorous insects.
褐飞虱，是一种威胁全球水稻生产的害虫。在取食水稻植株时，飞虱会分泌唾液，这些唾液在营养物质摄取和调节植物防御反应中起着关键作用，尽管唾液蛋白的确切功能在很大程度上仍然未知。我们通过转录组和蛋白质组分析鉴定了一种 - 分泌粘蛋白样蛋白（NlMLP），并对其功能进行了表征，包括在褐飞虱和植物中的功能。NlMLP 在唾液腺中高度表达，并在取食过程中分泌到水稻中。在飞虱中抑制 NlMLP 的表达会干扰唾液鞘的形成，从而降低其性能。在植物中，NlMLP 诱导细胞死亡、防御相关基因的表达和胼胝质沉积。这些防御反应与 Ca 动员以及 MEK2 MAP 激酶和茉莉酸信号通路有关。引发植物反应的 NlMLP 的活性区域位于其羧基末端。我们的工作详细描述了一种不同于蚜虫的刺吸式昆虫的唾液蛋白。我们发现该蛋白在植物免疫反应中起作用，为植物与草食性昆虫相互作用的机制提供了新的见解。
