| Abstract Detail
Plant-Pathogen Interactions Lu, Hua [1], Gamelin, Emily [2], Salimian, Sasan [1], Ferrari, Susan [2], Greenberg, Jean [2]. Utilization of defense-dependent dwarfism of acd6-1 in a high throughput identification of novel defense genes in Arabidopsis. Plant diseases caused by pathogens are among the greatest deterrents in agriculture worldwide. A network of defense proteins perceives and transduces defense signals during infection. One of these proteins, ACD6 (ACCELERATED CELL DEATH 6), is an ankyrin repeat protein that positively regulates plant defenses through the key defense signal molecule salicylic acid (SA). acd6-1, a gain of function allele of ACD6, confers small size and constitutive defense phenotypes. The size of acd6-1 plants is increased when the defense signaling strength is reduced. We exploited the defense-dependent size change in acd6-1 in a T-DNA-induced mutant screen to identify novel defense components. We isolated acd6-1 suppressors (sups) that have an increased size and possibly reduced defense signaling. From an initial screen of 36,000 mutant lines, 60 putative sups were identified and two SUP genes were cloned. sup1 is an allele of SA INDUCTION-DEFICIENT 2 (a gene involved in SA biosynthesis). SUP2 encodes a predicted mitochondrial protein with unknown function. The sup2 mutation suppresses acd6-1 conferred dwarfism, constitutive defense, and high SA levels, suggesting that SUP2 regulates SA-mediated defense. Importantly, sup2, in the absence of the acd6-1 mutation, confers increased susceptibility to Pseudomonas syringae. Therefore, we have validated the potential of this facile genetic screen in identifying novel defense genes. Identification and characterization of defense components is key to advancing our understanding of defense mechanisms and designing strategies to increase plant disease resistance. Our genetic screen is a powerful approach to identifying the proteins that regulate defense responses, deciphering how these proteins affect antimicrobial activities, and determining how the defense regulatory networks are coordinated. Log in to add this item to your schedule
1 - University of Maryland Baltimore County, Dept. of Biological Sciences, 1000 Hilltop Circle, Baltimore, MD, 21250 2 - University of Chicago, Dept. of Molecular Genetics and Cell Biology, 1103 57th Street, Chicago, IL, 60637 3 - University of Chicago, Dept. of Molecular Genetics and Cell Biology, 1103 57th Street, Chicago, IL, 60637
Keywords: defense Pseudomonas Signaling suppressor screen.
Presentation Type: Plant Biology Abstract Session: P Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton Date: Sunday, July 8th, 2007 Time: 8:00 AM Number: P15010 Abstract ID:188 |