TY  - JOUR
A1  - Raffeiner, Margot
A1  - Üstün, Suayib
A1  - Guerra, Tiziana
A1  - Spinti, Daniela
A1  - Fitzner, Maria
A1  - Sonnewald, Sophia
A1  - Baldermann, Susanne
A1  - Börnke, Frederik
T1  - The Xanthomonas type-III effector XopS stabilizes CaWRKY40a to regulate defense responses and stomatal immunity in pepper (Capsicum annuum)
T2  - The plant cell
N2  - As a critical part of plant immunity, cells that are attacked by pathogens undergo rapid transcriptional reprogramming to minimize virulence. Many bacterial phytopathogens use type III effector (T3E) proteins to interfere with plant defense responses, including this transcriptional reprogramming. Here, we show that Xanthomonas outer protein S (XopS), a T3E of Xanthomonas campestris pv. vesicatoria (Xcv), interacts with and inhibits proteasomal degradation of WRKY40, a transcriptional regulator of defense gene expression. Virus-induced gene silencing of WRKY40 in pepper (Capsicum annuum) enhanced plant tolerance to Xcv infection, indicating that WRKY40 represses immunity. Stabilization of WRKY40 by XopS reduces the expression of its targets, which include salicylic acid-responsive genes and the jasmonic acid signaling repressor JAZ8. Xcv bacteria lacking XopS display significantly reduced virulence when surface inoculated onto susceptible pepper leaves. XopS delivery by Xcv, as well as ectopic expression of XopS in Arabidopsis thaliana or Nicotiana benthamiana, prevented stomatal closure in response to bacteria and biotic elicitors. Silencing WRKY40 in pepper or N. benthamiana abolished XopS's ability to prevent stomatal closure. This suggests that XopS interferes with both preinvasion and apoplastic defense by manipulating WRKY40 stability and downstream gene expression, eventually altering phytohormone crosstalk to promote pathogen proliferation.
Y1  - 2022
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/63558
SN  - 1040-4651
SN  - 1532-298X
VL  - 34
IS  - 5
SP  - 1684
EP  - 1708
PB  - Oxford Univ. Press
CY  - Cary
ER  -