Role of Stomata in Nonhost Disease Resistance
K. MYSORE (1), S. Lee (2), A. Kaundal (2), R. Vemanna (2), M. Senthil-kumar (2), M. Kang (3), C. Rojas (2), S. Oh (2), S. Roy Choudhury (4), H. Lee (2), Y. Ishiga (2), R. Allen (3), S. Pandey (5) (1) The Samuel Roberts Noble Foundation, Ardmore, OK, U.S.A.; (2) The Samuel Roberts Noble Foundation, , U.S.A.; (3) Oklahoma State University, , U.S.A.; (4) Donald Danforth Center, U.S.A.; (5) Donald Danforth Plant Science

Plant defense responses at stomata and apoplast are the most important early events during plant-bacteria interactions. We have identified couple of novel genes that play a role in regulating stomatal opening. NONHOST RESISTANCE (NHR) 1 is a novel GTPase encoding gene required for plant immunity against bacterial pathogens. Two NHR1 copies were identified in a number of plant species: NHR1A and NHR1B. Functional studies in Arabidopsis revealed that NHR1A is involved in stomatal defense and NHR1B in nonhost resistance against bacterial pathogens. NHR1A regulates guard cell signaling in response to biotic and abiotic stimulus through jasmonic acid (JA)- and abscisic acid (ABA)-mediated pathways. Jasmonate-zim-domain protein (JAZ) 9 interacts with NHR1A. General Control Non Repressible-4 (GCN4) that encodes AAA+-ATPase is another gene that regulates stomatal opening. Silencing of GCN4 in Nicotiana benthamiana and Arabidopsis showed compromised nonhost resistance and causes defective stomata that are unable to close during pathogen infection and thus enables bacteria to enter the apoplast and cause disease. The GCN4-GFP protein is localized to plasma membrane, cytoplasm and predominately to guard cells. AtGCN4 interacts with proteins such as RIN4 and 14-3-3 and destabilize plasma membrane H+- ATPase complex to keep the stomata closed during pathogen infection. We identified NHR1 and GCN4 as new modulators that regulates stomatal aperture under different stress conditions.

Abstract Number: P17-574
Session Type: Poster