Taking advantage of the defense-dependent dwarfism of acd6-1, we have developed a forward genetic screen to isolate acd6-1 suppressors (sups) that are larger plants with possibly reduced defense. T-DNA tagging is used to mutagenize acd6-1 to facilitate cloning of the disrupted genes. From screening 36,000 T-DNA mutagenized acd6-1 lines, we have identified 60 putative sups that will be further analyzed for their suppression phenotypes. We have cloned a few suppressor genes and are now focusing on characterizing the function of these genes in plant defense regulation.