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United States Department of Agriculture

Agricultural Research Service

Research Project: PSEUDOMONAS SYSTEMS BIOLOGY

Location: Plant-Microbe Interactions Research

Title: Analysis of the small RNA spf in the plant pathogen Pseudomonas syringae pv. tomato strain DC3000

Authors
item Park, So Hae -
item Bao, Zhongmeng -
item Butcher, Bronwyn -
item D'Amico, Katherine
item Xu, Yun -
item Stodghill, Paul
item Schneider, David
item Cartinhour, Samuel
item Filiatrault, Melanie

Submitted to: Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 27, 2014
Publication Date: March 5, 2014
Citation: Park, S., Bao, Z., Butcher, B., D'Amico, K.M., Xu, Y., Stodghill, P., Schneider, D.J., Cartinhour, S.W., Filiatrault, M.J. 2014. Analysis of the small RNA spf in the plant pathogen Pseudomonas syringae pv. tomato strain DC3000. Microbiology. 160(Pt 5):941-953.

Interpretive Summary: In order to respond to and survive changes experienced in their surrounding environment and during infection, bacteria must quickly modulate the expression of genes involved in metabolism and virulence factor production. One important class of regulators involved in these pathways is RNA regulators. Currently, there is a lack of understanding of the role of RNA regulators in the plant pathogen Pseudomonas syringae pv. tomato. Here, we found that the RNA regulator Spot 42 is regulated by a sigma factor called RpoE. We also found that deletion of Spot 42 makes the bacteria more susceptible to oxidative stress, a condition experienced during infection. Furthermore we were able to link the RNA regulator Spot 42 to the expression of a virulence factor alginate. Because of these newly described results, we will be able to further evaluate if this RNA regulator is involved in infection. Understanding how RNA regulators regulate metabolism and virulence in the plant pathogen Pseudomonas syringae pv. tomato will help us better understand the disease caused by this bacterium and lead to the development of more effective control strategies.

Technical Abstract: Bacteria contain small non-coding RNAs (ncRNAs) that are typically responsible for altering transcription, translation, or mRNA stability. ncRNAs are important because they often regulate virulence factors and susceptibility to various stresses. Here, the regulation of a recently described ncRNA of P. syringae DC3000, spot 42 (now referred to as spf) was investigated. A putative RpoE binding site was identified upstream of spf in DC3000. We determined that RpoE regulates the expression of spf. We also found that deletion of spfresults in increased sensitivity to hydrogen peroxide compared to the wild-type strain, suggesting that spf plays a role in susceptibility to oxidative stress. Furthermore we demonstrate that expression of alg8 is influenced byspf, suggesting that this ncRNA plays a role in alginate biosynthesis. Structural and comparative genomic analyses show this ncRNA is well conserved among the pseudomonads. Our findings provide new information on the regulation and role of this ncRNA in P. syringae.

Last Modified: 7/28/2014
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