Abstract
We isolated a novel ABA hypersensitive mutant named ahg12 (ABA hypersensitive germination 12) in Arabidopsis. Using a map-based cloning, we identified a missense mutation in the RPT5a gene encoding a subunit of 26S proteasome. The ahg12 mutant also showed some other pleiotropic phenotypes. The combination of phenotypes observed in ahg12 is distinct from those of other subunit mutants reported so far. Additionally, the phenotypes are distinct from those of RPT5a disruptant, suggesting that the ahg12 mutation affects a part of RPT5a function. Now, we assume that this mutation is involved in the selectivity of protein degradation depending on the subunit. The ahg12 mutation is an unreported dominant mutation and expected to provide information about the unknown function of the subunit. Detailed analysis of this mutation is now ongoing.
