Serratia plymuthica HK9 ‐3 enhances tomato resistance against Phytophthora capsici by modulating antioxidant defense systems and rhizosphere micro‐ecological condition

作者：Yuanyuan Wang, Fengzhi Piao, Yancui Di, Jinxin Xu, Zichen Wang, Tao Wang, Pengju Li, Chunyan Hu, Nanshan Du, Tao Zhang, Xiaoxing Dong, Han Dong, Shunshan Shen, Zhixin Guo · 发表于：Physiologia Plantarum · 年份：2024 · DOI：10.1111/ppl.14323 · 被引用次数：14 · 研究领域：Plant-Microbe Interactions and Immunity、Legume Nitrogen Fixing Symbiosis、Nematode management and characterization studies

Tomatoes are frequently challenged by various pathogens, among which Phytophthora capsici (P. capsici) is a destructive soil-borne pathogen that seriously threatens the safe production of tomatoes. Plant growth-promoting rhizobacteria (PGPR) positively induced plant resistance against multiple pathogens. However, little is known about the role and regulatory mechanism of PGPR in tomato resistance to P. capsici. Here, we identified a new strain Serratia plymuthica (S. plymuthica), HK9-3, which has a significant antibacterial effect on P. capsici infection. Meanwhile, stable colonization in roots by HK9-3, even under P. capsici infection, improved tomato growth parameters, root system architecture, photosynthetic capacity, and boosted biomass. Importantly, HK9-3 colonization significantly alleviated the damage caused by P. capsici infection through enhancing ROS scavenger ability and inducing antioxidant defense system and pathogenesis-related (PR) proteins in leaves, as evidenced by elevating the activities of peroxidase (POD), superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO), and chitinase, β-1,3-glucanase, and increasing the transcripts of POD, SOD, CAT, APX1, PAL1, PAL2, PAL5, PPO2, CHI17 and β-1,3-glucanase genes. Notably, HK9-3 colonization not only effectively improved soil microecology and soil fertility, but also significantly enhanced fruit yield by 44.6% and improved quality. Our study...