Zhou Jianuan, Hu Ming, Hu Anqun, Li Chuhao, Ren Xinyue, Tao Min, Xue Yang, Chen Shanshan, Tang Chongzhi, Xu Yiwu, Zhang Lianhui, Zhou Xiaofan
Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China.
Guangdong Tianhe Agricultural Means of Production Co., Ltd., Guangzhou, China.
Front Plant Sci. 2022 Apr 26;13:852750. doi: 10.3389/fpls.2022.852750. eCollection 2022.
Bacterial soft rot is one of the most destructive diseases of taro () worldwide. In recent years, frequent outbreaks of soft rot disease have seriously affected taro production and became a major constraint to the development of taro planting in China. However, little is known about the causal agents of this disease, and the only reported pathogens are two species and . In this study, we report taro soft rot caused by two novel strains, LJ1 and LJ2, isolated from taro corms in Ruyuan County, Shaoguan City, Guangdong Province, China. We showed that LJ1 and LJ2 fulfill Koch's postulates for taro soft rot. The two pathogens can infect taro both individually and simultaneously, and neither synergistic nor antagonistic interaction was observed between the two pathogens. Genome sequencing of the two strains indicated that LJ1 represents a novel species of the genus , for which the name " sp. nov." is proposed, while LJ2 belongs to . Pan-genome analysis revealed multiple pathogenicity-related differences between LJ1, LJ2, and other species, including unique virulence factors, variation in the copy number and organization of Type III, IV, and VI secretion systems, and differential production of plant cell wall degrading enzymes. This study identifies two new soft rot Pectobacteriaceae (SRP) pathogens causing taro soft rot in China, reports a new case of co-infection of plant pathogens, and provides valuable resources for further investigation of the pathogenic mechanisms of SRP.
细菌性软腐病是全球芋头最具毁灭性的病害之一。近年来，软腐病频繁爆发，严重影响了芋头生产，成为我国芋头种植发展的主要制约因素。然而，对该病的致病因子了解甚少，唯一报道的病原菌是两种[具体菌名未给出]菌。在本研究中，我们报道了从中国广东省韶关市乳源县芋头球茎中分离出的两株新型[具体菌名未给出]菌株LJ1和LJ2引起的芋头软腐病。我们证明LJ1和LJ2符合芋头软腐病的科赫法则。这两种病原菌既能单独感染芋头，也能同时感染，且两种病原菌之间未观察到协同或拮抗相互作用。对这两株菌株的基因组测序表明，LJ1代表[具体菌属名未给出]属的一个新物种，为此提出了“[具体新物种名] sp. nov.”的名称，而LJ2属于[具体菌属名未给出]。泛基因组分析揭示了LJ1、LJ2与其他[具体菌属名未给出]菌之间在多个致病性相关方面的差异，包括独特的毒力因子、III型、IV型和VI型分泌系统拷贝数和组织方式的变化以及植物细胞壁降解酶的不同产生情况。本研究鉴定出两种在中国引起芋头软腐病的新的软腐果胶杆菌科（SRP）病原菌，报道了植物病原菌共感染的新病例，并为进一步研究SRP的致病机制提供了有价值的资源。
