A QTL of eggplant shapes the rhizosphere bacterial community, co-responsible for resistance to bacterial wilt

Chao Gong; Zhenshuo Wang; Zhiliang Li; Baojuan Sun; Wenlong Luo; Shanwei Luo; Shuting Chen; Peiting Mai; Zhenxing Li; Ye Li; Yikui Wang; Tao Li

doi:10.1093/hr/uhad272

A QTL of eggplant shapes the rhizosphere bacterial community, co-responsible for resistance to bacterial wilt

Hortic Res. 2023 Dec 19;11(2):uhad272. doi: 10.1093/hr/uhad272. eCollection 2024 Feb.

Authors

Chao Gong¹, Zhenshuo Wang², Zhiliang Li¹, Baojuan Sun¹, Wenlong Luo¹, Shanwei Luo¹, Shuting Chen¹, Peiting Mai¹, Zhenxing Li¹, Ye Li³, Yikui Wang⁴, Tao Li¹

Affiliations

¹ Guangdong Academy of Agricultural Sciences, Guangdong Key Laboratory for New Technology Research of Vegetables, Vegetable Research Institute, Guangzhou, 510640, China.
² Department of Plant Pathology, MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China.
³ Harbin Academy of Agricultural Sciences, Harbin, Heilongjiang, 150029, China.
⁴ Institute of Vegetable, Guangxi Academy of Agricultural Sciences, Nanning, Guangxi, 530007, China.

Abstract

Resistant crop cultivars can recruit beneficial rhizobacteria to resist disease. However, whether this recruitment is regulated by quantitative trait loci (QTL) is unclear. The role of QTL in recruiting specific bacteria against bacterial wilt (BW) is an important question of practical significance to disease management. Here, to identify QTL controlling BW resistance, Super-BSA was performed in F₂ plants derived from resistant eggplant cultivar R06112 × susceptible cultivar S55193. The QTL was narrowed down through BC₁F₁-BC₃F₁ individuals by wilting symptoms and KASP markers. Rhizosphere bacterial composition of R06112, S55193, and resistant individuals EB158 (with the QTL) and susceptible individuals EB327 (without QTL) from BC₂F₁ generation were assessed by Illumina sequencing-based analysis, and the activation of plant immunity by the bacterial isolates was analyzed. Evidence showed that BW-resistant is controlled by one QTL located at the 270 kb region on chromosome 10, namely EBWR10, and nsLTPs as candidate genes confirmed by RNA-Seq. EBWR10 has a significant effect on rhizobacteria composition and significantly recruits Bacillus. pp. A SynCom of three isolated Bacillus. pp trains significantly reduced the disease incidence, changed activities of CAT, PPO, and PAL and concentration of NO, H₂O₂, and O₂^-, activated SA and JA signaling-dependent ISR, and displayed immune activation against Ralstonia solanacearum in eggplant. Our findings demonstrate for the first time that the QTL can recruit beneficial rhizobacteria, which jointly promote the suppression of BW. This method charts a path to develop the QTL in resistant cultivar-driven probiotics to ameliorate plant diseases.