Natural Variation Identifies Genes Affecting Drought-Induced Abscisic Acid Accumulation in Arabidopsis thaliana

The impact of environmental stress such as drought on plant productivity is of increasing concern because of climate change and increasing demands on land and water resources for agriculture. The stress hormone Abscisic Acid (ABA) accumulates in drought-stressed plants and controls stress resistance responses. Despite the importance of ABA, it is not known how plants control ABA levels during stress. We measured stress-induced ABA accumulation of nearly 300 Arabidopsis thaliana accessions originating from environments differing in climate and stress factors. There was wide natural variation in ABA accumulation and Genome Wide Association Analysis identified candidate genes influencing ABA accumulation. Analysis of gene knock out mutants confirmed that we had identified new genes affecting ABA accumulation. The new stress-related genes we identified can be lead to better understand stress sensing and signaling mechanisms and ultimately to new strategies to improve plant productivity in stressful environments.