Transcription activator-like effectors of Xanthomonas oryzae pv. oryzae hijack host transcriptional regulation through OsWRKYs

Abstract

Transcription activator-like effectors (TALEs) mimic eukaryotic transcriptional activators and translocate into host plant cells via the bacterial type III secretion system (T3SS) during pathogenic interactions. They play a crucial role in disease development by regulating host genes. Despite this, the regulatory mechanisms by which TALEs control OsWRKY transcription factors (TFs) remain poorly understood. In this study, we show that two TALEs from Xanthomonas oryzae pv. oryzae (Xoo) individually modulate two OsWRKY TFs, resulting in increased susceptibility and reduced host defense. Specifically, Xoo1219 and Xoo2145 activate the expression of OsWRKY104 and OsWRKY55, respectively, through direct interactions. OsWRKY104 increases the susceptibility to Xoo by activating OsSWEET11 and OsSWEET14, while OsWRKY55 suppresses host defense against Xoo by directly regulating OsWRKY62. These findings suggest that TALEs hijack the host's OsWRKY TFs to create a favorable environment for bacterial survival.