High resolution imaging as a tool for identifying quantitative trait loci that regulate photomorphogenesis in Arabidopsis thaliana

A primary component of seedling establishment is the photomorphogenic response as seedlings emerge from the soil. This process is characterized by a reduced growth rate in the hypocotyl, increased root growth, opening of the apical hook, and expansion of the cotyledons as photosynthetic organs. While fundamental to plant success, the photomorphogenic response can be highly variable. Additionally, studies of Arabidopsis thaliana are made difficult by subtle differences in growth rate between individuals. High-resolution imaging and computational processing have emerged as useful tools for quantification of such phenotypes. This study sought to: 1) develop an imaging methodology which could capture changes in growth rate as seedlings transition from darkness to blue light in real time, and 2) apply this methodology to single-QTL analysis using the Cvi x Ler RIL mapping population. Significant differences in the photomorphogenic response were observed between the parent lines and analysis ...