Mutations in GERANYLGERANYL DIPHOSPHATE SYNTHASE 1 affect chloroplast development in Arabidopsis thaliana (Brassicaceae)

• Published in: American journal of botany Vol. 100; no. 10; pp. 2074 - 2084
• Main Authors: Ruppel, Nicholas J, Kropp, Kelsey N, Davis, Phillip A, Martin, Arielle E, Luesse, Darron R, Hangarter, Roger P
• Format: Journal Article
• Language: English
• Published: United States Botanical Society of America 01-10-2013; Botanical Society of America, Inc
• Subjects: Abscisic acid; albino; Alkyl and Aryl Transferases - chemistry; Alkyl and Aryl Transferases - genetics; Alkyl and Aryl Transferases - metabolism; alleles; Arabidopsis - drug effects; Arabidopsis - enzymology; Arabidopsis - genetics; Arabidopsis Proteins - chemistry; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; biochemical pathways; Biochemistry; Biosynthesis; Brassicaceae; carotenoids; chlorophyll; Chloroplasts; Chloroplasts - drug effects; Chloroplasts - metabolism; diterpenoids; Flowers & plants; Flowers - drug effects; Gene Expression Regulation, Plant - drug effects; Germination - drug effects; GGPS; gibberellic acid; Hypocotyl - drug effects; Hypocotyl - growth & development; isoprenoid; leaves; MEP pathway; methylerythritol 4‐phosphate pathway; mutants; Mutation; Mutation - genetics; Phenotype; photosynthesis; Photosynthesis - drug effects; Physiology and Biochemistry; Pigments, Biological - metabolism; Plant Growth Regulators - pharmacology; Plant Leaves - cytology; Plant Leaves - genetics; Plastids; point mutation; Temperature; transfer DNA; variegation; Arabidopsis thaliana; GGPS; MEP pathway; methylerythritol 4-phosphate pathway; photosynthesis; chlorophyll; variegation; Brassicaceae; isoprenoid
• ISSN: 0002-9122; 1537-2197
• DOI: 10.3732/ajb.1300124

• Premise of the study: Within plastids, geranylgeranyl diphosphate synthase is a key enzyme in the isoprenoid biosynthetic pathway that catalyzes the formation of geranylgeranyl diphosphate, a precursor molecule to several biochemical pathways including those that lead into the biosynthesis of carotenoids and abscisic acid, prenyllipids such as the chlorophylls, and diterpenes such as gibberellic acid.• Methods: We have identified mutants in the GERANYLGERANYL DIPHOSPHATE SYNTHASE 1 (GGPS1) gene, which encodes the major plastid-localized enzyme geranylgeranyl diphosphate synthase in Arabidopsis thaliana.• Key results: Two T-DNA insertion mutant alleles (ggps1-2 and ggps1-3) were found to result in seedling-lethal albino and embryo-lethal phenotypes, respectively, indicating that GGPS1 is an essential gene. We also identified a temperature-sensitive leaf variegation mutant (ggps1-1) in A. thaliana that is caused by a point mutation. Total chlorophyll and carotenoid levels were reduced in ggps1-1 white tissues as compared with green tissues. Phenotypes typically associated with a reduction in gibberellic acid were not seen, suggesting that gibberellic acid biosynthesis is not noticeably altered in the mutant. In contrast to other variegated mutants, the ggps1-1 green sector photosynthetic rate was not elevated relative to wild-type tissues. Chloroplast development in green sectors of variegated leaves appeared normal, whereas cells in white sectors contained abnormal plastids with numerous electron translucent bodies and poorly developed internal membranes.• Conclusions: Our results indicate that GGPS1 is a key gene in the chlorophyll biosynthetic pathway.