Light-dependent chloroplast development and expression of a light-harvesting chlorophyll a/b-binding protein gene in the gymnosperm Ginkgo biloba

• Published in: Plant physiology (Bethesda) Vol. 103; no. 3; pp. 727 - 732
• Main Authors: Chinn, E, Silverthorne, J
• Format: Journal Article
• Language: English
• Published: United States American Society of Plant Physiologists 01.11.1993
• Subjects: AHILAMIENTO; Amino Acid Sequence; Amino acids; ANGIOSPERMAS; ANGIOSPERME; Angiosperms; ARN MENSAJERO; ARN MESSAGER; Base Sequence; CHLOROPHYLLE; Chlorophylls; CHLOROPLASTE; Chloroplasts; Chloroplasts - physiology; Chloroplasts - radiation effects; Cloning, Molecular; CLOROFILAS; CLOROPLASTO; Conifers; CRECIMIENTO; CROISSANCE; Darkness; Development and Growth Regulation; ETAPAS DE DESARROLLO DE LA PLANTA; ETIOLEMENT; Gene Expression - radiation effects; GIMNOSPERMAS; GINKGO BILOBA; GYMNOSPERME; Gymnosperms; HIPOCOTILOS; HYPOCOTYLE; LARGURA; Light; Light-Harvesting Protein Complexes; LONGUEUR; LUMIERE; LUZ; Messenger RNA; Molecular Sequence Data; OBSCURIDAD; OBSCURITE; Photosynthetic Reaction Center Complex Proteins - biosynthesis; Photosystem II Protein Complex; Plants; PLANTULAS; PLANTULE; PROTEINAS; PROTEINE; RNA; RNA, Messenger - biosynthesis; Seedlings; Sequence Homology, Amino Acid; STADE DE DEVELOPPEMENT VEGETAL; Trees - growth & development; Trees - metabolism; Trees - radiation effects
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.103.3.727

Unlike conifers, the gymnosperm Ginkgo biloba is dependent on light for chlorophyll (Chl) synthesis and initiation of chloroplast development. Dark-grown seedlings show complete etiolation, including no detectable Chl accumulation, no leaf expansion, and increased hypocotyl elongation. When dark-grown seedlings are placed in white light, Chl synthesis and leaf expansion are initiated, but unlike angiosperms, which initiate rapid photomorphogenesis, Ginkgo takes at least 1 week to change to a normal light-regulated pattern of growth. A cDNA clone (pLhcb*Gb1) encoding a Chl a/b-binding protein of light-harvesting complex II from Ginkgo mRNA has been used as a probe for the expression of this family of mRNAs. We have found that, in common with angiosperms but in marked contrast to pines, Lhcb mRNA is expressed in a highly light-dependent manner. In addition to being expressed in light-grown leaves, this sequence is also expressed in the green tissues of immature seeds. The Lhcb mRNA appears during greening in parallel with the onset of Chl synthesis. The complete sequence of pLhcb*Gb1 has been determined and the deduced amino acid sequence was found to be of type I based on comparison with signature sequences of angiosperm and gymnosperm sequences