title: Involvement of plasma membrane redox activity and calcium homeostasis in the UV-B and UV-A/blue light induction of gene expression in Arabidopsis.
abstract: UV and blue light are important regulators of plant gene expression and development. We investigated the signal transduction processes involved in the induction of chalcone synthase (CHS) and phenylalanine ammonia-lyase (PAL) gene expression by UV-B and UV-A/blue light in an Arabidopsis cell suspension culture. Experiments with electron transport inhibitors indicated that plasma membrane redox activity is involved in both signal transduction pathways. Calcium ionophore treatment stimulated expression of the TOUCH3 gene, and this induction was strongly antagonized by UV-A/blue and UV-B light, suggesting that both light qualities may promote calcium efflux from the cytosol. Consistent with this hypothesis, experiments with specific inhibitors indicated that UV-B and UV-A/blue light regulate calcium levels in a cytosolic pool in part via the action of specific Ca2+-ATPases. On the basis of these and previous findings, we propose that plasma membrane redox activity, initiated by photoreception, is coupled to the regulation of calcium release from an intracellular store, generating a calcium signal that is required to induce CHS expression.
authors.affiliation: Plant Molecular Science Group, Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, Bower Building, University of Glasgow, Glasgow G12 8QQ, United Kingdom.
authors.forename: J C
authors.initials: JC
authors.lastname: Long
authors.forename: G I
authors.initials: GI
authors.lastname: Jenkins
mesh_terms: D000217:Acyltransferases / Q000235:genetics; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D029681:Arabidopsis Proteins; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000235:genetics; D000252:Calcium-Transporting ATPases / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism / Q000528:radiation effects; D003600:Cytosol / Q000378:metabolism; D005292:Ferricyanides / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000528:radiation effects; D017343:Genes, Plant / Q000187:drug effects / Q000528:radiation effects; D006706:Homeostasis; D008027:Light; D008954:Models, Biological; D009861:Onium Compounds / Q000494:pharmacology; D010084:Oxidation-Reduction; D010650:Phenylalanine Ammonia-Lyase / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014466:Ultraviolet Rays; D002147:Calmodulin
chemical_list: D000217:Acyltransferases; D029681:Arabidopsis Proteins; D002118:Calcium; D002135:Calcium-Binding Proteins; D000252:Calcium-Transporting ATPases; C007517:diphenyleneiodonium; D005292:Ferricyanides; C020141:flavanone synthetase; C007931:hexacyanoferrate III; D009861:Onium Compounds; D010650:Phenylalanine Ammonia-Lyase; D010940:Plant Proteins; D012333:RNA, Messenger; D018749:RNA, Plant; C572690:AT5G37780 protein, Arabidopsis; D002147:Calmodulin