Abstract
Plant defense responses at stomata and apoplast are the most important early events during plant-bacteria interactions. The key components for the signaling of stomatal defense and nonhost resistance have not been fully characterized. Here we report the newly identified small GTPase, Nucleolar GTP-binding protein 1 (NOG1), functions for plant immunity against bacterial pathogens. Virus-induced gene silencing of NOG1 compromised nonhost resistance in N. benthamiana and tomato. Comparative genomic analysis showed that two NOG1 copies are present in all known plant species: NOG1-1 and NOG1-2. Gene downregulation and overexpression studies of NOG1-1 and NOG1-2 in Arabidopsis revealed the novel function of these genes in nonhost resistance and stomatal defense against bacterial pathogens, respectively. Specially, NOG1-2 regulates guard cell signaling in response to biotic and abiotic stimuli through jasmonic acid (JA)- and abscisic acid (ABA)-mediated pathways. The results here provide valuable information on the new functional role of small GTPase, NOG1, in guard cell signaling and early plant defense in response to bacterial pathogens.
Highlights
Plant pathogens that are able to cause disease in a given plant species are considered host pathogens while those that are unable to do so are nonhost pathogens
We identified two small G-proteins, Nucleolar GTP-binding protein 1-1 (NOG1-1) and 1-2 (NOG1-2), which play an important role in the regulation of nonhost resistance and stomatal defense against bacterial pathogens
We showed that Nucleolar GTPbinding protein 1 (NOG1)-1 and NOG1-2 are involved in plant defense against bacterial pathogens
Summary
Plant pathogens that are able to cause disease in a given plant species are considered host pathogens while those that are unable to do so are nonhost pathogens. We identified two small G-proteins, Nucleolar GTP-binding protein 1-1 (NOG1-1) and 1-2 (NOG1-2), which play an important role in the regulation of nonhost resistance and stomatal defense against bacterial pathogens. The TRAFAC class is divided into seven families: TrmE (Probable tRNA modification GTPase in E. coli), Era (E. coli Ras-like protein), YfgK, YihA, OBG, Hflx and classic translation factor family[19]. The orthologs of these organelle-targeted small GTPases were found in plants, suggesting the horizontal transfer of eubacteria-derived small GTPases into plants. We showed that NOG1-1 and NOG1-2 are involved in plant defense against bacterial pathogens
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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.
