Phloem-feeding insects cause massive losses in agriculture and horticulture. Host plant resistance to phloem-feeding insects is often mediated by changes in phloem composition, which deter insect settling and feeding and decrease viability. Here, we report that rice plant resistance to the phloem-feeding brown planthopper (BPH) is associated with fortification of the sclerenchyma tissue, which is located just beneath the epidermis and a cell layer or two away from the vascular bundle in the rice leaf sheath. We found that BPHs prefer to feed on the smooth and soft region on the surface of rice leaf sheaths called the long-cell block. We identified Bph30 as a rice BPH resistance gene that prevents BPH stylets from reaching the phloem due to the fortified sclerenchyma. Bph30 is strongly expressed in sclerenchyma cells and enhances cellulose and hemicellulose synthesis, making the cell walls stiffer and sclerenchyma thicker. The structurally fortified sclerenchyma is a formidable barrier preventing BPH stylets from penetrating the leaf sheath tissues and arriving at the phloem to feed. Bph30 belongs to a novel gene family, encoding a protein with two leucine-rich domains. Another member of the family, Bph40, also conferred resistance to BPH. Collectively, the fortified sclerenchyma-mediated resistance mechanism revealed in this study expands our understanding of plant-insect interactions and opens a new path for controlling planthoppers in rice.

以韧皮部为食的昆虫造成农业和园艺业的巨大损失。寄主植物对以韧皮部为食的昆虫的抗性通常由韧皮部成分的变化介导，这会阻止昆虫的定居和取食并降低生存能力。在这里，我们报道水稻植物对以韧皮部为食的褐飞虱 (BPH) 的抗性与强化厚壁组织有关，该组织位于表皮下方和远离水稻叶鞘维管束的一两个细胞层. 我们发现 BPH 更喜欢以水稻叶鞘表面光滑柔软的区域为食，称为长细胞块。我们将Bph30鉴定为水稻 BPH 抗性基因，由于强化的厚壁组织，该基因阻止 BPH 管心针到达韧皮部。Bph30在巩膜细胞中强烈表达，增强纤维素和半纤维素的合成，使细胞壁更硬，更厚。结构上强化的厚壁组织是一个强大的屏障，可防止 BPH 管心针穿透叶鞘组织并到达韧皮部进食。Bph30属于一个新的基因家族，编码具有两个富含亮氨酸结构域的蛋白质。该家族的另一成员Bph40也对 BPH 具有抗性。总的来说，本研究揭示的强化的厚壁组织介导的抗性机制扩展了我们对植物-昆虫相互作用的理解，并为控制水稻飞虱开辟了一条新途径。