Arabidopsis Biological Resource Center

Ploidy: 2

Phenotype: abscisic acid deficient, reduced level of endogenous ABA during various stages of plant and seed development; impaired in ABA biosynthesis, causing a deficiency of the epoxy-carotenoids violaxanthin and neoxanthin and an accumulation of their biosynthetic precursor zeaxanthin; slightly yellow-brown leaves; increased rate of water loss (leaf transpiration), which leads to symptoms of wilting and withering especially under low relative humidity and water stress, wilty phenotype can be restored to normal by spraying an ABA solution on the plants; reduced growth, reduced plant size and vigor, but less severe phenotype than aba1-4; greatly reduced seed dormancy, fresh seeds germinate at high frequency, seeds germinate in silique on plant at high relative humidity; considerable germination in darkness; decreased sensitivity to the presence of GA biosynthesis inhibitors such as paclobutrazol; reduced sensitivity to salt and osmotic stress during germination.