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ARS Home » Northeast Area » Washington, D.C. » National Arboretum » Floral and Nursery Plants Research » Research » Publications at this Location » Publication #367881
Research Project: Detection, Identification, and Characterization of New and Emerging Viral and Bacterial Diseases of Ornamental Plants

Location: Floral and Nursery Plants Research

Title: A LuxR-type regulator, AcrR, regulates flagellar assembly and contributes to virulence, motility, biofilm formation and growth ability of Acidovorax citrulli

Author
item GUAN, WEI - Chinese Academy Of Agricultural Sciences
item WANG, TIELIN - Chinese Academy Of Medical Sciences
item Huang, Qi
item TIAN, ERYUAN - Chinese Academy Of Agricultural Sciences
item LIU, BO - Chinese Academy Of Agricultural Sciences
item YANG, YUWEN - Chinese Academy Of Agricultural Sciences
item ZHAO, TINGCHANG - Chinese Academy Of Agricultural Sciences

Submitted to: Molecular Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/20/2019
Publication Date: 1/16/2020
Citation: Guan, W., Wang, T., Huang, Q., Tian, E., Liu, B., Yang, Y., Zhao, T. 2020. A LuxR-type regulator, AcrR, regulates flagellar assembly and contributes to virulence, motility, biofilm formation and growth ability of acidovorax citrulli. Molecular Plant Pathology. 00:1-13. https://doi.org/10.1111/mpp.12910.
DOI: https://doi.org/10.1111/mpp.12910

Interpretive Summary: Bacterial fruit blotch disease, caused by the bacterium Acidovorax citrulli, causes losses worldwide in watermelons and other melons. An ARS scientist in Beltsville, MD collaborated with Chinese scientists to identify a regulatory gene sequence in this bacterium, called AcrR, that positively affects the bacterium’s gliding and swimming motilities, and its ability to form flagella and disease symptoms in watermelon seedlings. However, this regulatory gene exerts negative control on the ability of the bacterium to bind to the host surface. Our study will help scientists to better understand this bacterium in order develop effective disease control strategies.

Technical Abstract: LuxR-type regulators regulate many bacterial processes and play important roles in bacterial motility and virulence. Acidovorax citrulli is a seed-borne bacterial pathogen responsible for bacterial fruit blotch, which causes great losses in melon and watermelon worldwide. We identified a LuxR-type, nonquorum sensing-related regulator, AcrR, in the group II strain Aac-5 of A. citrulli. Additionally, we found that the acrR mutant lost twitching motility and flagellar formation and showed reduced virulence and swimming motility, whereas it showed increased biofilm formation and growth ability. Transcriptomic analysis revealed that 393 genes were differentially expressed in the acrR mutant of A. citrulli, including 32 genes involved in flagellar assembly. Our results suggest that AcrR may act as a global regulator affecting multiple important biological functions of A. citrulli.