Skip to main content
ARS Home » Northeast Area » Washington, D.C. » National Arboretum » Floral and Nursery Plants Research » Research » Publications at this Location » Publication #380865
Research Project: Detection, Identification, and Characterization of New and Emerging Viral and Bacterial Diseases of Ornamental Plants

Location: Floral and Nursery Plants Research

Title: Transcriptomic and functional analyses reveal roles of AclR, a luxR-type global regular in regulating motility and virulence of Acidovorax citrulli

Author
item GUAN, WEI - Chinese Academy Of Agricultural Sciences
item WANG, TIELIN - Chinese Academy Of Medical Sciences
item ZHAO, MEI - University Of Georgia
item Huang, Qi
item TIAN, ERVUAN - Chinese Academy Of Agricultural Sciences
item LIU, YANFENG - Chinese Academy Of Agricultural Sciences
item LIU, B0 - 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-Microbe Interactions
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/28/2021
Publication Date: 6/6/2021
Citation: Guan, W., Wang, T., Zhao, M., Huang, Q., Tian, E., Liu, Y., Liu, B., Yang, Y., Zhao, T. 2021. Transcriptomic and functional analyses reveal roles of AclR, a luxR-type global regular in regulating motility and virulence of Acidovorax citrulli. Molecular Plant-Microbe Interactions. https://doi.org/10.1094/MPMI-01-21-0020-R.
DOI: https://doi.org/10.1094/MPMI-01-21-0020-R

Interpretive Summary: Bacterial fruit blotch of melons, caused by the bacterium Acidovorax citrulli, causes serious economic loses worldwide in melon crops, including watermelon. One promising method to control this and other bacterial pathogens is by studying gene expression and regulation in the pathogen. A team of scientists from China and the U.S. characterized a regulator called AclR in this bacterium that is involved with motility. They found that this regulator enhances the bacterium’s ability to move and cause disease symptoms in watermelon seedlings, but it decreases the ability of the bacterium to form a biofilm that helps the bacterium bind to the surface of seedlings. These results may be useful in developing strategies to control this bacterium.

Technical Abstract: LuxR-type transcriptional regulators are essential for many physiological processes in bacteria, including pathogenesis. Acidovorax citrulli is a seedborne bacterial pathogen responsible for bacterial fruit blotch, which causes great losses in melon and watermelon worldwide. However, the LuxR-type transcriptional factors in A. citrulli have not been well studied. Here, we characterized a LuxR-type regulator, AclR, in the group II strain Aac-5 of A. citrulli by mutagenesis, virulence and motility assays, and transcriptomic analysis. Deletion of aclR resulted in impaired twitching and swimming motility and flagellar formation and diminished virulence but increased biofilm formation. Transcriptomic analysis revealed that 1379 genes were differentially expressed in the aclR-mutant strain, including 29 genes involved in flagellar assembly and 3 involved in pili formation, suggesting a regulatory role for AclR in multiple important biological functions of A. citrulli. Together, our results not only indicate that AclR plays a global role in transcriptional regulation in A. citrulli influencing motility, biofilm formation, and virulence, but also provide perspective regarding the regulatory network of biological functions in A. citrulli.