Mechanisms of response to ultraviolet-b radiation — A whole plant perspective.

Wargent, Jason J. and Paul, Nigel D. (2007) Mechanisms of response to ultraviolet-b radiation — A whole plant perspective. Comparative Biochemistry and Physiology - Part A: Molecular and Integrative Physiology, 146 (4 Supp). S228. ISSN 1095-6433

Abstract

Plant responses to ultraviolet (UV) radiation are numerous, resulting in rapid and permanent alteration to numerous aspects of plant form, physiology and biochemistry. Such responses to UV and UV-B (290–320 nm) radiation in particular have been previously studied largely due to concerns over ozone depletion, but a recent refocus towards the effects of environmentally relevant UV-B doses has provided an opportunity to investigate the mechanistic basis for several well defined plant responses. We have characterised some of these underlying mechanisms using a combination of crop species and Arabidopsis mutants, in an effort to build up a model of whole-plant response. (1) The role of UV in regulating leaf growth has been investigated using Lactuca sativa as a model species in a top-down approach, whereby leaf expansion rate, leaf biophysical properties, cell growth and cell wall peroxidase content have been subject to UV-B mediated change. (2) Upregulation of secondary metabolite biosynthesis has also been characterised in L. sativa, with UV absorbing compounds increased according to UV-B, plus leaf anthocyanin (pigment compound) concentration elevated by 60% in plants exposed to the highest UV dose compared to control. (3) The importance of various key pathways to the UV whole plant response are also currently under investigation with a selection of A. thaliana mutants. Such findings will not only add to the understanding of fundamental photobiological responses, but are also currently being successfully integrated into sustainable agronomic practice.