Cell-wall-based regulation of stomatal defense in Arabidopsis
L. ZHANG (1), W. Zeng (2), J. Chen (3), S. He (4) (1) Department of Plant Biology, DOE Plant Research Laboratory, Michigan State University, U.S.A.; (2) DOE Plant Research Laboratory, Michigan State University, U.S.A.; (3) Department of Computer Science and Engineering, DOE Plant Research Laboratory, Michigan State University, U.S.A.; (4) Department of Plant Biology, DOE Plant Research Laboratory, Howard Hughes Medical Institute, Michigan State University, U.S.A.

Recent studies have shown that plants reduce stomatal aperture as an innate immune response to restrict pathogen infection, whereas highly evolved pathogens produce virulence factors, such as coronatine (COR) from the bacterial pathogen Pseudomonas syringae pv. tomato (Pst) DC3000, to counteract stomatal defense. COR-deficient mutants of Pst DC3000 are compromised in virulence, especially via surface inoculation. We previously isolated eight Arabidopsis (scord) mutants that exhibit increased susceptibility to a COR-deficient mutant of Pst DC3000. scord6 and scord7 are found to be defective in bacterium-triggered stomatal closure. With map-based cloning and next generation sequencing, we identified the SCORD6 and SCORD7 genes. SCORD6 is involved in the do novo synthesis of GDP-L-fucose and SCORD7 belongs to the Trichome Birefringence-Like protein family, of which two members were proposed to be xyloglucan-specific O-acetyltransferases. scord6 is defective in salicylic acid (SA)-mediated stomatal closure, while scord7 mutant is affected in a SA and abscisic acid (ABA)-mediated stomatal closure. The identification of SCORD6 and SCORD7 highlights plant cell-wall-based regulation of stomatal defense and contributes to the general understanding of the multifaceted host defense mechanisms against pathogen infection in plants.

Abstract Number: C18-3, P15-433
Session Type: Concurrent