Bacterial flagella are perceived by the innate immune systems of plants¹ and animals² alike, triggering resistance. Common to higher plants is the immunoreceptor FLAGELLIN-SENSING 2 (FLS2)³, which detects flagellin via its most conserved epitope, flg22. Agrobacterium tumefaciens, which causes crown gall disease in many crop plants, has a highly diverged flg22 epitope and evades immunodetection by plants so far studied. We asked whether, as a next step in this game of ‘hide and seek’, there are plant species that have evolved immunoreceptors with specificity for the camouflaged flg22^Atum of A. tumefaciens. In the wild grape species Vitis riparia, we discovered FLS2^XL, a previously unknown form of FLS2, that provides exquisite sensitivity to typical flg22 and to flg22^Atum. As exemplified by ectopic expression in tobacco, FLS2^XL can limit crown gall disease caused by A. tumefaciens.

^植物1和动物²的先天免疫系统都可以感知细菌鞭毛，从而引发抵抗力。高等植物共有的是免疫受体 FLAGELLIN-SENSING 2 (FLS2) ³，它通过其最保守的表位 flg22 检测鞭毛蛋白。在许多作物中引起冠瘿病的根癌农杆菌具有高度分化的flg22表位并且逃避迄今为止研究的植物的免疫检测。我们询问，作为这场“捉迷藏”游戏的下一步，是否有植物物种已经进化出对根癌农杆菌的伪装 fl​​g22 Atum 具有特异性的免疫^受体。在野生葡萄品种Vitis riparia，我们发现了 FLS2 ^XL，这是一种以前未知的 FLS2 形式，它对典型的 flg22 和 flg22 ^Atum具有极高的敏感性。以烟草中的异位表达为例，FLS2 ^{XL可以限制由}根癌农杆菌引起的冠瘿病。