Open AccessThe type VI protein secretion system contributes to biofilm formation and seed‐to‐seedling transmission of A cidovorax citrulli on melon
Author(s) -
Tian Yanli,
Zhao Yuqiang,
Wu Xinrong,
Liu Fengquan,
Hu Baishi,
Walcott Ronald R.
Publication year - 2015
Publication title -
molecular plant pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.945
H-Index - 103
eISSN - 1364-3703
pISSN - 1464-6722
DOI - 10.1111/mpp.12159
Subject(s) - seedling , biology , melon , microbiology and biotechnology , biofilm , virulence , type vi secretion system , colonization , inoculation , mutant , bacteria , gene , horticulture , genetics
Summary The type VI protein secretion system ( T6SS ) is essential for the virulence of several Gram‐negative bacteria. In this study, we identified a T6SS gene cluster in A cidovorax citrulli , a plant‐pathogenic bacterium that causes bacterial fruit blotch ( BFB ) of cucurbits. One T6SS cluster, of approximately 25 kb in length and comprising 17 genes, was found in the A . citrulli AAC00 ‐1 genome. Seventeen A . citrulli mutants were generated, each with a deletion of a single T6SS core gene. There were significant differences in BFB seed‐to‐seedling transmission between wild‐type A . citrulli strain, xjl12, and Δ vas D , Δ imp K , Δ imp J and Δ imp F mutants (71.71%, 9.83%, 8.41%, 7.15% and 5.99% BFB disease index, respectively). In addition, we observed that these four mutants were reduced in melon seed colonization and biofilm formation; however, they were not affected in virulence when infiltrated into melon seedling tissues. There were no significant differences in BFB seed‐to‐seedling transmission, melon tissue colonization and biofilm formation between xjl12 and the other 13 T6SS mutants. Overall, our results indicate that T6SS plays a role in seed‐to‐seedling transmission of BFB on melon.