Abstract
Summary Ralstonia solanacearum, the causal agent of bacterial wilt disease, is considered one of the most destructive bacterial pathogens due to its lethality, unusually wide host range, persistence and broad geographical distribution. In spite of the extensive research on plant immunity over the last years, the perception of molecular patterns from R. solanacearum that activate immunity in plants is still poorly understood, which hinders the development of strategies to generate resistance against bacterial wilt disease. The perception of a conserved peptide of bacterial flagellin, flg22, is regarded as paradigm of plant perception of invading bacteria; however, no elicitor activity has been detected for R. solanacearum flg22. Recent reports have shown that other epitopes from flagellin are able to elicit immune responses in specific species from the Solanaceae family, yet our results show that these plants do not perceive any epitope from R. solanacearum flagellin. Searching for elicitor peptides from R. solanacearum, we found several protein sequences similar to the consensus of the elicitor peptide csp22, reported to elicit immunity in specific Solanaceae plants. A R. solanacearum csp22 peptide (csp22Rsol) was indeed able to trigger immune responses in Nicotiana benthamiana and tomato, but not in Arabidopsis thaliana. Additionally, csp22Rsol treatment conferred increased resistance to R. solanacearum in tomato. Transgenic A. thaliana plants expressing the tomato csp22 receptor (SlCORE) gained the ability to respond to csp22Rsol and became more resistant to R. solanacearum infection. Our results shed light on the mechanisms for perception of R. solanacearum by plants, paving the way for improving current approaches to generate resistance against R. solanacearum.
Highlights
Ralstonia solanacearum is a soil-borne bacterial pathogen able to cause disease in more than 250 plant species (Jiang et al, 2017; Mansfield et al, 2012)
Our results show that specific Solanaceae species, including tomato, tobacco and N. benthamiana, can perceive the csp22 peptide derived from R. solanacearum cold-shock protein, and that the reported csp22 receptor CORE (Wang et al, 2016) confers responsiveness to csp22Rsol in Arabidopsis
The amino acid sequence of the FliC gene product in R. solanacearum GMI1000 contains both flg22 and flgII-28 sequences, showing several polymorphisms compared to flg22 and flgII-28 from P. syringae strains (Clarke et al, 2013; Mueller et al, 2012a; Figure S1)
Summary
Ralstonia solanacearum is a soil-borne bacterial pathogen able to cause disease in more than 250 plant species (Jiang et al, 2017; Mansfield et al, 2012). It has an extremely versatile lifestyle, surviving in water, soil and plant debris. After invading plant tissues through wounds, root tips or cracks at the sites of lateral root emergence, R. solanacearum colonizes the root cortex, reaches the vasculature and spreads through xylem vessels, colonizing the plant systemically (Mansfield et al, 2012). Unusually wide host range, persistence and broad geographical distribution, R. solanacearum is currently considered one of the most destructive bacterial pathogens in agricultural systems
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
