Signal transduction in response to excess light: getting out of the chloroplast.
Plants are continually in danger of absorbing more light energy than they can use productively for their metabolism. Acclimation to environmental conditions therefore includes the development of mechanisms for dissipating or avoiding the accumulation of such excess excitation energy. Acclimation could be controlled by many signal transduction pathways that would be initiated by the perception of excess excitation energy both inside and outside the chloroplast. Recent studies in related areas provide models of how these signalling pathways could operate in acclimation to excess light. Components of photosynthetic electron transport chains, reactive oxygen species, redox-responsive protein kinases, thiol-regulated enzymes, chlorophyll precursors and chloroplast-envelope electron transport chains all have roles in these models.
Mullineaux
Philip
P
Department of Disease and Stress Biology, John Innes Centre, Colney, NR4 7UH, Norwich, UK. phil.mullineaux@bbsrc.ac.uk
Karpinski
Stanislaw
S
D002734:Chlorophyll / Q000378:metabolism* / Q000528:radiation effects; D002736:Chloroplasts / Q000378:metabolism* / Q000528:radiation effects; D004579:Electron Transport; D004777:Environment; D008027:Light; D045342:Light-Harvesting Protein Complexes; D008954:Models, Biological; D010084:Oxidation-Reduction; D045322:Photosynthetic Reaction Center Complex Proteins / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology* / Q000528:radiation effects
D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D017382:Reactive Oxygen Species; D002734:Chlorophyll