English

Abstract

We set up six light conditions to investigate the changes in the development of Arabidopsis thaliana hypocotyls and roots. Seedlings grown for 96 h under darkness were scored with shorter roots and longer hypocotyls. In shoot-shaded conditions, seedlings were unable to carry out photosynthesis, resulting in insufficient stored nutrients for root development. In the three groups of different light intensities applied to the roots, total light caused stress in the entire seedlings and the length of roots and hypocotyls were shorter than in conditions when roots were growing within light-dark gradients. Importantly, root lengths were higher within light-dark gradients than in total light. Different light treatments did significantly affect root growth and hypocotyl growth. The addition of ATP-competitive mTOR kinase inhibitor (AZD), drastically reduced root, however, this did not occur with hypocotyl length.   Key words: Total light, total dark, gradient light, shoot dark with light blocker, light blocker, shoot dark.