The type three effector AvrRpm1Pma from Pseudomonas syringae pv. maculicola (Pma) triggers an RPM1-mediated immune response linked to phosphorylation of RIN4 (RPM1-interacting protein 4) in Arabidopsis. However, the effector-resistance (R) gene interaction is not well established with different AvrRpm1 effectors from other pathovars. We investigated the AvrRpm1-triggered immune responses in Nicotiana species and isolated Rpa1 (Resistance to Pseudomonas syringae pv. actinidiae 1) via a reverse genetic screen in Nicotiana tabacum. Transient expression and gene silencing were performed in combination with co-immunoprecipitation and growth assays to investigate the specificity of interactions that lead to inhibition of pathogen growth. Two closely related AvrRpm1 effectors derived from Pseudomonas syringae pv. actinidiae biovar 3 (AvrRpm1Psa ) and Pseudomonas syringae pv. syringae strain B728a (AvrRpm1Psy ) trigger immune responses mediated by RPA1, a nucleotide-binding leucine-rich repeat protein with an N-terminal coiled-coil domain. In a display of contrasting specificities, RPA1 does not respond to AvrRpm1Pma , and correspondingly AvrRpm1Psa and AvrRpm1Psy do not trigger the RPM1-mediated response, demonstrating that separate R genes mediate specific immune responses to different AvrRpm1 effectors. AvrRpm1Psa co-immunoprecipitates with RPA1, and both proteins co-immunoprecipitate with RIN4. In contrast with RPM1, however, RPA1 was not activated by the phosphomimic RIN4T166D and silencing of RIN4 did not affect the RPA1 activity. Delivery of AvrRpm1Psa by Pseudomonas syringae pv. tomato (Pto) in combination with transient expression of Rpa1 resulted in inhibition of the pathogen growth in N. benthamiana. Psa growth was also inhibited by RPA1 in N. tabacum.

中文翻译：

---

Rpa1 介导对 avrRpm1Psa 的免疫反应，并赋予对丁香假单胞菌 pv 的抵抗力。猕猴桃科。


来自丁香假单胞菌 pv 的三型效应子 AvrRpm1Pma。 maculicola (Pma) 在拟南芥中触发与 RIN4（RPM1 相互作用蛋白 4）磷酸化相关的 RPM1 介导的免疫反应。然而，效应子-抗性 (R) 基因与其他致病变种的不同 AvrRpm1 效应子之间的相互作用尚未得到很好的建立。我们研究了烟草属物种中 AvrRpm1 触发的免疫反应，并通过烟草中的反向遗传筛选分离出 Rpa1（对丁香假单胞菌 pv. actinidiae 1 的抗性）。瞬时表达和基因沉默与免疫共沉淀和生长测定相结合，以研究导致病原体生长抑制的相互作用的特异性。源自丁香假单胞菌 pv 的两个密切相关的 AvrRpm1 效应子。猕猴桃生物变种 3 (AvrRpm1Psa ) 和丁香假单胞菌 pv.丁香菌株 B728a (AvrRpm1Psy ) 触发由 RPA1 介导的免疫反应，RPA1 是一种具有 N 末端卷曲螺旋结构域的核苷酸结合富含亮氨酸的重复蛋白。在对比特异性的显示中，RPA1 不响应 AvrRpm1Pma ，相应地 AvrRpm1Psa 和 AvrRpm1Psy 不触发 RPM1 介导的响应，表明单独的 R 基因介导针对不同 AvrRpm1 效应子的特异性免疫响应。 AvrRpm1Psa 与 RPA1 共免疫沉淀，两种蛋白均与 RIN4 共免疫沉淀。然而，与 RPM1 相比，RPA1 不会被拟磷化 RIN4T166D 激活，并且 RIN4 的沉默不会影响 RPA1 活性。丁香假单胞菌 pv. 传递 AvrRpm1Psa。番茄 (Pto) 与 Rpa1 瞬时表达相结合，抑制了本塞姆氏烟草中病原体的生长。在烟草中，RPA1 也抑制 Psa 生长。