title: Early light-induced proteins protect Arabidopsis from photooxidative stress.
abstract: The early light-induced proteins (ELIPs) belong to the multigenic family of light-harvesting complexes, which bind chlorophyll and absorb solar energy in green plants. ELIPs accumulate transiently in plants exposed to high light intensities. By using an Arabidopsis thaliana mutant (chaos) affected in the posttranslational targeting of light-harvesting complex-type proteins to the thylakoids, we succeeded in suppressing the rapid accumulation of ELIPs during high-light stress, resulting in leaf bleaching and extensive photooxidative damage. Constitutive expression of ELIP genes in chaos before light stress resulted in ELIP accumulation and restored the phototolerance of the plants to the wild-type level. Free chlorophyll, a generator of singlet oxygen in the light, was detected by chlorophyll fluorescence lifetime measurements in chaos leaves before the symptoms of oxidative stress appeared. Our findings indicate that ELIPs fulfill a photoprotective function that could involve either the binding of chlorophylls released during turnover of pigment-binding proteins or the stabilization of the proper assembly of those proteins during high-light stress.
authors.affiliation: Département d'Ecophysiologie Végétale et de Microbiologie, Laboratoire de Biologie du Développement des Plantes, UMR 163, CNRS, Université Méditerranée-Commissariat à l'Energie Atomique 1000, Saint-Paul-lez-Durance, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Hutin
authors.forename: Laurent
authors.initials: L
authors.lastname: Nussaume
authors.forename: Nicolae
authors.initials: N
authors.lastname: Moise
authors.forename: Ismaël
authors.initials: I
authors.lastname: Moya
authors.forename: Klaus
authors.initials: K
authors.lastname: Kloppstech
authors.forename: Michel
authors.initials: M
authors.lastname: Havaux
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002734:Chlorophyll / Q000378:metabolism / Q000528:radiation effects; D018076:DNA, Complementary / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D017343:Genes, Plant; D008027:Light; D009154:Mutation; D018384:Oxidative Stress; D018462:Photobiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D018076:DNA, Complementary; D018744:DNA, Plant; C078410:ELIP protein, Arabidopsis; D010940:Plant Proteins; D012333:RNA, Messenger; D018749:RNA, Plant; D002734:Chlorophyll