title: Shade avoidance: phytochrome signalling and other aboveground neighbour detection cues.
abstract: Plants compete with neighbouring vegetation for limited resources. In competition for light, plants adjust their architecture to bring the leaves higher in the vegetation where more light is available than in the lower strata. These architectural responses include accelerated elongation of the hypocotyl, internodes and petioles, upward leaf movement (hyponasty), and reduced shoot branching and are collectively referred to as the shade avoidance syndrome. This review discusses various cues that plants use to detect the presence and proximity of neighbouring competitors and respond to with the shade avoidance syndrome. These cues include light quality and quantity signals, mechanical stimulation, and plant-emitted volatile chemicals. We will outline current knowledge about each of these signals individually and discuss their possible interactions. In conclusion, we will make a case for a whole-plant, ecophysiology approach to identify the relative importance of the various neighbour detection cues and their possible interactions in determining plant performance during competition.
authors: Plant Ecophysiology, Institute of Environmental Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands r.pierik@uu.nl.
authors: Ronald
authors: R
authors: Pierik
authors: Centre for Integrative Genomics, University of Lausanne, CH-1015 Lausanne, Switzerland.
authors: Mieke
authors: M
authors: de Wit
mesh_terms: D000222:Adaptation, Physiological / Q000528:radiation effects; D008027:Light; D010834:Phytochrome / Q000378:metabolism*; D035261:Plant Components, Aerial / Q000378:metabolism*; D015398:Signal Transduction / Q000528:radiation effects; D013997:Time Factors; D055549:Volatile Organic Compounds / Q000378:metabolism
chemical_list: D055549:Volatile Organic Compounds; D010834:Phytochrome
keywords: Arabidopsis; canopy; competition; cryptochrome; mechanostimulation; phytochrome; shade avoidance.