AUTHOR=Thomas Nicholas C. , Hendrich Connor G. , Gill Upinder S. , Allen Caitilyn , Hutton Samuel F. , Schultink Alex 

TITLE=The Immune Receptor Roq1 Confers Resistance to the Bacterial Pathogens Xanthomonas, Pseudomonas syringae, and Ralstonia in Tomato

JOURNAL=Frontiers in Plant Science

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2020.00463

DOI=10.3389/fpls.2020.00463

ISSN=1664-462X

ABSTRACT=<p><italic>Xanthomonas</italic> species, <italic>Pseudomonas syringae</italic> and <italic>Ralstonia</italic> species are bacterial plant pathogens that cause significant yield loss in many crop species. Generating disease-resistant crop varieties can provide a more sustainable solution to control yield loss compared to chemical methods. Plant immune receptors encoded by nucleotide−binding, leucine−rich repeat (NLR) genes typically confer resistance to pathogens that produce a cognate elicitor, often an effector protein secreted by the pathogen to promote virulence. The diverse sequence and presence/absence variation of pathogen effector proteins within and between pathogen species usually limits the utility of a single NLR gene to protecting a plant from a single pathogen species or particular strains. The NLR protein Recognition of XopQ 1 (Roq1) was recently identified from the plant <italic>Nicotiana benthamiana</italic> and mediates perception of the effector proteins XopQ and HopQ1 from <italic>Xanthomonas</italic> and <italic>P. syringae</italic> respectively. Unlike most recognized effectors, alleles of XopQ/HopQ1 are highly conserved and present in most plant pathogenic strains of <italic>Xanthomonas</italic> and <italic>P. syringae</italic>. A homolog of XopQ/HopQ1, named RipB, is present in most <italic>Ralstonia</italic> strains. We found that Roq1 confers immunity to <italic>Xanthomonas</italic>, <italic>P. syringae</italic>, and <italic>Ralstonia</italic> when expressed in tomato. Strong resistance to <italic>Xanthomonas perforans</italic> was observed in three seasons of field trials with both natural and artificial inoculation. The <italic>Roq1</italic> gene can therefore be used to provide safe, economical, and effective control of these pathogens in tomato and other crop species and reduce or eliminate the need for traditional chemical controls.</p>