Resistance-breaking population of Meloidogyne incognita utilizes plant peroxidase to scavenge reactive oxygen species, thereby promoting parasitism on tomato carrying Mi-1 gene.
Resistance conferred by the Mi-1 gene from Solanum peruvianum is effective and widely used for controlling root-knot nematodes (RKNs, Meloidogyne spp.). However, breakdown of resistance by RKNs seriously threatens the durable application of the resistance resource. Here, a resistance-breaking population of M. incognita was selected from an avirulent population by continuously inoculating on Mi-1-carrying tomato. Histological observations showed the resistance-breaking population would not induce hypersensitive response (HR) when infecting Mi-1-carrying tomato, while avirulent population did. A total of 308 differentially expressed genes (DEGs) were identified from Mi-1-carrying tomato upon infection with resistance-breaking versus avirulent populations by RNA-seq. The expression patterns of 23 selected DEGs were validated by quantitative real-time PCR (qRT-PCR). Subsequently, seven out of nine highly up-regulated DEGs were successfully knocked down in Mi-1-carrying tomato by tobacco rattle virus (TRV) mediated RNAi. The TRV line targeting a peroxidase gene showed a much higher magnitude of reactive oxygen species (ROS) and distinct reduction of pathogenicity upon infection of the resistance-breaking population compared with that of TRV::gfp line. Our results suggested that plant peroxidase might be exploited by resistance-breaking population of M. incognita to scavenge ROS, so as to overcome Mi-1-mediated resistance.
Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, PR China.
Tinglong
T
Guan
Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, PR China.
Jinhua
J
Shen
Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, PR China.
Yang
Y
Fa
Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, PR China.
Yishi
Y
Su
Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, PR China. Electronic address: xuanwang@njau.edu.cn.
Xuan
X
Wang
Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, PR China. Electronic address: lihm@njau.edu.cn.
Hongmei
H
Li
D000818:Animals; D060467:Disease Resistance / Q000502:physiology; D018551:Solanum lycopersicum / Q000378:metabolism / Q000469:parasitology*; D009195:Peroxidase / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D014431:Tylenchoidea / Q000502:physiology*
C117349:MI-1 protein, Lycopersicon esculentum; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D009195:Peroxidase
Hypersensitive response; Mi-1-mediated resistance; Reactive oxygen species; Resistance-breaking population; Root-knot nematode; Virus-induced gene silencing