Light is the plant’s source of energy, harnessed in the process of photosynthesis. Plants show spectacular plasticity to ensure light capture even when grown in very dense stands where shading by neighbors is a serious threat. Responses to grow towards the light, e.g. stem elongation, are called shade avoidance.
Clearly, these are very important responses, but plants of course do also compete below ground. This simple realization prompted us to study how light signals of neighbors that trigger shade avoidance aboveground, impact on root development. Answering this question does obviously not cover the full breadth of plant competition, but is an important first step.
Postdoc Kasper van Gelderen en PhD student Chiakai Kang (finishing her PhD thesis right now) pulled this project off and our paper, with additional input from other co-authors, is available now online and open-access at the Plant Cell.
The take home message is that Far-red light enrichment of the shoot organs of Arabidopsis seedlings reduces the formation of lateral roots that themselves do not get exposed to this far-red light. The mobile transcription factor HY5 and the plant hormone auxin appear to be important mediators of this response.
Many exciting questions arise to be answered, but for now we hope you enjoy reading our paper!