State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling, China.
Shaanxi Key State Laboratory of Crop Heterosis, Northwest A&F University, Yangling, China.
Mol Plant Pathol. 2022 Feb;23(2):188-203. doi: 10.1111/mpp.13153. Epub 2021 Oct 31.
Diverse pathogen effectors convergently target conserved components in plant immunity guarded by intracellular nucleotide-binding domain leucine-rich repeat receptors (NLRs) and activate effector-triggered immunity (ETI), often causing cell death. Little is known of the differences underlying ETI in different plants triggered by the same effector. In this study, we demonstrated that effector RipAW triggers ETI on Nicotiana benthamiana and Nicotiana tabacum. Both the first 107 amino acids (N ) and RipAW E3-ligase activity are required but not sufficient for triggering ETI on N. benthamiana. However, on N. tabacum, the N fragment is essential and sufficient for inducing cell death. The first 60 amino acids of the protein are not essential for RipAW-triggered cell death on either N. benthamiana or N. tabacum. Furthermore, simultaneous mutation of both R75 and R78 disrupts RipAW-triggered ETI on N. tabacum, but not on N. benthamiana. In addition, N. tabacum recognizes more RipAW orthologs than N. benthamiana. These data showcase the commonalities and specificities of RipAW-activated ETI in two evolutionally related species, suggesting Nicotiana species have acquired different abilities to perceive RipAW and activate plant defences during plant-pathogen co-evolution.
不同的病原体效应子通过细胞内核苷酸结合域富含亮氨酸重复受体(NLRs)靶向植物免疫中保守的成分,并激活效应子触发的免疫(ETI),通常导致细胞死亡。对于由相同效应子触发的不同植物中的 ETI 差异,人们知之甚少。在这项研究中,我们证明了效应子 RipAW 在 Nicotiana benthamiana 和 Nicotiana tabacum 上触发 ETI。前 107 个氨基酸(N 端)和 RipAW E3 连接酶活性对于在 N. benthamiana 上触发 ETI 是必需的,但不是充分的。然而,在 N. tabacum 上,N 片段对于诱导细胞死亡是必需的和充分的。该蛋白的前 60 个氨基酸对于在 N. benthamiana 或 N. tabacum 上的 RipAW 触发细胞死亡不是必需的。此外,同时突变 R75 和 R78 会破坏 N. tabacum 上 RipAW 触发的 ETI,但不会破坏 N. benthamiana 上的 ETI。此外,N. tabacum 识别的 RipAW 同源物比 N. benthamiana 多。这些数据展示了两种进化上相关的物种中 RipAW 激活的 ETI 的共性和特异性,表明 Nicotiana 物种在植物-病原体共同进化过程中获得了不同的感知 RipAW 和激活植物防御的能力。