SlWRKY30 and SlWRKY81 synergistically modulate tomato immunity to Ralstonia solanacearum by directly regulating SlPR-STH2

Fengfeng Dang; Jinhui Lin; Yajing Li; Ruoyun Jiang; Yudong Fang; Fei Ding; Shuilin He; Yanfeng Wang

doi:10.1093/hr/uhad050

SlWRKY30 and SlWRKY81 synergistically modulate tomato immunity to Ralstonia solanacearum by directly regulating SlPR-STH2

Hortic Res. 2023 Mar 15;10(5):uhad050. doi: 10.1093/hr/uhad050. eCollection 2023 May.

Authors

Fengfeng Dang^{1

2}, Jinhui Lin³, Yajing Li¹, Ruoyun Jiang⁴, Yudong Fang¹, Fei Ding⁵, Shuilin He³, Yanfeng Wang²

Affiliations

¹ State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China.
² Shaanxi Key Laboratory of Chinese Jujube, Yan'an University, Yan'an, Shaanxi 716000, China.
³ College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
⁴ College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
⁵ School of Life Sciences, Liaocheng University, Liaocheng 252000, China.

Abstract

Bacterial wilt is a devastating disease of tomato (Solanum lycopersicum) caused by Ralstonia solanacearum that severely threatens tomato production. Group III WRKY transcription factors (TFs) are implicated in the plant response to pathogen infection; however, their roles in the response of tomato to R. solanacearum infection (RSI) remain largely unexplored. Here, we report the crucial role of SlWRKY30, a group III SlWRKY TF, in the regulation of tomato response to RSI. SlWRKY30 was strongly induced by RSI. SlWRKY30 overexpression reduced tomato susceptibility to RSI, and also increased H₂O₂ accumulation and cell necrosis, suggesting that SlWRKY30 positively regulates tomato resistance to RSI. RNA sequencing and reverse transcription-quantitative PCR revealed that SlWRKY30 overexpression significantly upregulated pathogenesis-related protein (SlPR-STH2) genes SlPR-STH2a, SlPR-STH2b, SlPR-STH2c, and SlPR-STH2d (hereafter SlPR-STH2a/b/c/d) in tomato, and these SlPR-STH2 genes were directly targeted by SlWRKY30. Moreover, four group III WRKY proteins (SlWRKY52, SlWRKY59, SlWRKY80, and SlWRKY81) interacted with SlWRKY30, and SlWRKY81 silencing increased tomato susceptibility to RSI. Both SlWRKY30 and SlWRKY81 activated SlPR-STH2a/b/c/d expression by directly binding to their promoters. Taking these results together, SlWRKY30 and SlWRKY81 synergistically regulate resistance to RSI by activating SlPR-STH2a/b/c/d expression in tomato. Our results also highlight the potential of SlWRKY30 to improve tomato resistance to RSI via genetic manipulations.