The gene geranylgeranyl reductase of peach (Prunus persica [L.] Batsch) is regulated during leaf development and responds differentially to distinct stress factors.
Plant geranylgeranyl hydrogenase (CHL P) reduces free geranylgeranyl diphosphate to phytil diphosphate, which provides the side chain to chlorophylls, tocopherols, and plastoquinones. In peach, the single copy gene (PpCHL P) encodes a deduced product of 51.68 kDa, which harbours a transit peptide for cytoplasm-to-chloroplast transport and a nicotinamide binding domain. The PpCHL P message was abundant in chlorophyll-containing tissues and flower organs, but barely detected in the roots and mesocarp of ripening fruits, suggesting that transcription was related to plastid types and maturation. The message was not revealed in shoot apical meristems, but spread thoroughly in leaf cells during the early stages and was located mainly in the palisade of mature leaves, which exhibited higher transcript levels than young ones. Hence, the transcription of PpCHL P was likely to be regulated during leaf development. Gene expression was monitored in leaves responding to natural dark, cold, wounding, stress by imposed darkening, and during the curl disease. Transcription was stimulated by light, but repressed by dark and cold stress. In darkened leaves, the PpCHL P message was augmented concomitantly with that of CATALASE. In wounded leaves, the message decreased, but recovered rapidly, whereas in curled leaves, a reduction in gene expression was related to leaf damage intensity. However, transcript signals increased locally both in cells mechanically wounded by a needle and in those naturally injured by the pathogenic fungus Taphrina deformans. These data suggest that PpCHL P expression was regulated by photosynthetic activity and was possibly involved in the defence response.
Institute of Biology and Agricultural Biotechnology-Section of Rome, National Research Council of Italy (CNR), via Salaria km 29,300, I-00016, Monterotondo Scalo, Rome, Italy. giannino@mlib.cnr.it
Donato
D
Giannino
Emiliano
E
Condello
Leonardo
L
Bruno
Giulio
G
Testone
Andrea
A
Tartarini
Radiana
R
Cozza
Anna Maria
AM
Innocenti
Maria Beatrice
MB
Bitonti
Domenico
D
Mariotti
D000595:Amino Acid Sequence; D001483:Base Sequence; D003080:Cold Temperature; D017124:Conserved Sequence; D017931:DNA Primers; D018076:DNA, Complementary / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant / Q000235:genetics*; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000235:genetics*; D010802:Phylogeny; D018515:Plant Leaves / Q000201:enzymology* / Q000254:growth & development; D016133:Polymerase Chain Reaction; D027861:Prunus / Q000145:classification / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D017931:DNA Primers; D018076:DNA, Complementary; D010088:Oxidoreductases; C110920:geranylgeranyl reductase