Contribution of the non-effector members of the HrpL regulon, iaaL and matE, to the virulence of Pseudomonas syringae pv. tomato DC3000 in tomato plants

摘要: Background: The phytohormone indole-3-acetic acid (IAA) is widely distributed among plant-associated bacteria. Certain strains of the Pseudomonas syringae complex can further metabolize IAA into a less biologically active amino conjugate, 3-indole-acetyl-e-L-lysine, through action iaaL gene. In P. and savastanoi strains, gene found in synteny with an upstream gene, here called matE, encoding putative MATE family transporter. pv. tomato (Pto) DC3000, pathogen Arabidopsis plants, HrpL sigma factor controls expression suite virulence-associated genes via binding to hrp box promoters, including that However, significance activation virulence Pto DC3000 still unclear. Results: A conserved motif genomes strains. although promoter region matE only genomospecies 3 this bacterial group, we showed also belongs regulon. We demonstrated transcribed both independently as part operon pathogen. Deletion either or resulted reduced fitness plants. addition, used multicolor fluorescence imaging visualize responses plants wild-type its ΔmatE ΔiaaL mutants. Activation secondary metabolism prior development visual symptoms was observed leaves after challenges all changes were strongest challenged by strain, indicating lower infected Conclusions: Our results provide new evidence for roles non-type III effector belonging regulon virulence.