Tomato Atypical Receptor Kinase 1 (TARK1) is a pseudokinase required for postinvasion immunity. TARK1 was originally identified as a target of the Xanthomonas euvesicatoria effector protein Xanthomonas outer protein N (XopN), a suppressor of early defense signaling. How TARK1 participates in immune signal transduction is not well understood. To gain insight into TARK1’s role in tomato (Solanum lycopersicum) immunity, we used a proteomics approach to isolate and identify TARK1-associated immune complexes formed during infection. We found that TARK1 interacts with proteins predicted to be associated with stomatal movement. TARK1 CRISPR mutants and overexpression (OE) lines did not display differences in light-induced stomatal opening or abscisic acid-induced stomatal closure; however, they did show altered stomatal movement responses to bacteria and biotic elicitors. Notably, we found that TARK1 CRISPR plants were resistant to Pseudomonas syringae pathovar tomato strain DC3000-induced stomatal reopening, and TARK1 OE plants were insensitive to P. syringae pathovar tomato strain DC3118 (coronatine deficit)-induced stomatal closure. We also found that TARK1 OE in leaves resulted in increased susceptibility to bacterial invasion. Collectively, our results indicate that TARK1 functions in stomatal movement only in response to biotic elicitors and support a model in which TARK1 regulates stomatal opening postelicitation.

番茄非典型受体激酶1（TARK1）是入侵后免疫所必需的假激酶。TARK1最初被确定为是Xanthomonas euvesicatoria效应蛋白Xanthomonas外部蛋白N（XopN）的靶标，后者是早期防御信号的抑制剂。尚未完全了解TARK1如何参与免疫信号转导。深入了解TARK1在番茄中的作用（茄子（Solanum lycopersicum））免疫，我们使用蛋白质组学方法来分离和鉴定在感染过程中形成的与TARK1相关的免疫复合物。我们发现，TARK1与预计与气孔运动相关的蛋白质相互作用。TARK1 CRISPR突变体和过表达（OE）品系在光诱导的气孔开放或脱落酸诱导的气孔关闭方面未显示差异；然而，它们确实显示出对细菌和生物激发子的气孔运动反应发生了改变。值得注意的是，我们发现TARK1 CRISPR植物对丁香假单胞菌致病性番茄菌株DC3000诱导的气孔重开具有抗性，而TARK1 OE植物对P不敏感。丁香科致病番茄菌株DC3118（冠状动脉缺损）诱导的气孔关闭。我们还发现，叶片中的TARK1 OE导致对细菌入侵的敏感性增加。总体而言，我们的结果表明TARK1仅在响应生物激发子时才在气孔运动中起作用，并支持TARK1在诱导后调节气孔开放的模型。