Assessing Postgermination Development in Arabidopsis thaliana Under Abiotic Stress

The abscisic acid (ABA) phytohormone is well known to regulate responses to abiotic stress, particularly tolerance to osmotic stress. Screening for phenotypes at the early plant development stages is fundamental to identify new regulators of the ABA pathway, which in turn is extremely relevant for agriculture in a global climate change context. Typically, under experimental conditions, seeds are germinated in hormone-containing plates, and postgermination development is then assessed through scoring of the appearance of green or expanded cotyledons. However, postgermination phenotypes may be either masked or exacerbated by prior defects in seed germination. To circumvent this, we propose a transfer assay to screen specifically and quickly for postgermination phenotypes affected by exogenous ABA. The assay can be applied to different forms of abiotic stress, and we provide tips to score for postgermination phenotypes in genotypes exhibiting differential development.