Light-triggered reactions do not bias boron deficiency-induced root inhibition of Arabidopsis seedlings grown in Petri dishes

Abstract

For more than two decades, Arabidopsis thaliana plants have been routinely grown in vitro within transparent Petri dishes containing agar-based solid media. Although convenient to study root developmental, nutritional, and morphological responses to abiotic cues and to elucidate gene functions following reverse and forward genetic approaches, this system exposes roots to light during illumination of the shoots. Recently, Zheng et al. (2019) raised serious concerns as to whether root growth behavior and molecular root reactions in this experimental set-up are solely due to the designedly and chemically defined growth substrate compositions, in their case phosphate (Pi) deficiency, or are due to light-triggered reactions that are artificially induced by exposing roots to light.