Journal Article

Transcriptome analysis of Clavibacter michiganensis subsp. michiganensis-infected tomatoes: a role of salicylic acid in the host response

Isobe, Sachiko, Sato, Masaru, Hirakawa, Hideki, Yamamoto, Eiji, Hasegawa, Yoshinori, Kouzai, Yusuke, Naito, Yoshiki, Nishizawa, Yoko, Yokotani, Naoki

2021

Overview

Bacterial canker of tomato ( Solanum lycopersicon ) caused by the Gram-positive bacterium Clavibacter michiganensis subsp. michiganensis ( Cmm ) is an economically important disease . To understand the host defense response to Cmm infection, transcriptome sequences in tomato cotyledons were analyzed by RNA-seq. Overall, 1788 and 540 genes were upregulated and downregulated upon infection, respectively. Gene Ontology enrichment analysis revealed that genes involved in the defense response, phosphorylation, and hormone signaling were over-represented by the infection. Induced expression of defense-associated genes suggested that the tomato response to Cmm showed similarities to common plant disease responses. After infection, many resistance gene analogs (RGAs) were transcriptionally upregulated, including the expressions of some receptor-like kinases (RLKs) involved in pattern-triggered immunity. The expressions of WRKYs , NACs , HSFs , and CBP60s encoding transcription factors (TFs) reported to regulate defense-associated genes were induced after infection with Cmm . Tomato genes orthologous to Arabidopsis EDS1 , EDS5/SID1 , and PAD4/EDS9 , which are causal genes of salicylic acid (SA)-deficient mutants, were upregulated after infection with Cmm . Furthermore, Cmm infection drastically stimulated SA accumulation in tomato cotyledons. Genes involved in the phenylalanine ammonia lyase pathway were upregulated, whereas metabolic enzyme gene expression in the isochorismate synthase pathway remained unchanged. Exogenously applied SA suppressed bacterial growth and induced the expression of WRKYs , suggesting that some Cmm -responsive genes are regulated by SA signaling, and SA signaling activation should improve tomato immunity against Cmm .

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Acids / Agriculture / Ammonia / Arabidopsis / Bacteria / Bacteria, Phytopathogenic / bacterial canker / bacterial growth / Binding sites / Biomedical and Life Sciences / Canker / Clavibacter michiganensis michiganensis / Clavibacter michiganensis subsp. michiganensis / Cotyledons / Deficient mutant / Disease / Diseases and pests / Economic importance / Gene expression / gene ontology / Genes / Genetic aspects / Genomes / Gram-positive bacteria / Immunity / Infections / Isochorismate synthase / Kinases / Life Sciences / Pathogens / Phenylalanine / phenylalanine ammonia-lyase / Phosphorylation / phosphotransferases (kinases) / Physiological aspects / Plant bacterial diseases / Plant diseases / Plant immunity / Plant immunology / Plant Sciences / Plant-pathogen relationships / Proteins / resistance genes / RNA-seq / Roles / Salicylic acid / sequence analysis / Signal transduction / Signaling / Solanum lycopersicum / Tomato / Tomatoes / transcription (genetics) / Transcription factors / Transcriptome / Transcriptomes / transcriptomics / Tree Biology