Article

The Tomato cis-Prenyltransferase Gene Family.

Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, 48109, USA.
The Plant Journal (Impact Factor: 6.82). 11/2012; DOI: 10.1111/tpj.12063
Source: PubMed

ABSTRACT cis-Prenyltransferases (CPTs) are predicted to be involved in the synthesis of long-chain polyisoprenoids, all with >5 isoprene (C5) units. Recently, we identified a short-chain CPT, neryl diphosphate synthase (NDPS1), in tomato (Solanum lycopersicum). Here, we searched the tomato genome and identified and characterized its entire CPT gene family, which is composed of seven members (SlCPT1-7, with NDPS1 designated as SlCPT1). Six SlCPT genes encode proteins with N-terminal targeting sequences, which, when fused to the green fluorescent protein (GFP), mediated GFP transport to the plastids of Arabidopsis protoplasts. The SlCPT3-GFP fusion protein was localized to the cytosol. Enzymatic characterization of recombinant SlCPT proteins demonstrated that SlCPT6 produces Z,Z-FPP and SlCPT2 catalyzes the formation of nerylneryl diphosphate, while SlCPT4, SlCPT5, and SlCPT7 synthesize longer chain products (C25-C55). While no in vitro activity could be demonstrated for SlCPT3, its expression in the Saccharomyces cerevisiae dolichol biosynthesis mutant (rer2) complemented the temperature sensitive growth defect. Transcripts of SlCPT2, SlCPT4, SlCPT5, and SlCPT7 are present at low levels in multiple tissues, SlCPT6 is exclusively expressed in red fruit and roots, and SlCPT1, SlCPT3 and SlCPT7 are highly expressed in trichomes. RNA interference-mediated suppression of NDPS1 led to a large decrease in β-phellandrene (which is made from neryl diphosphate), with greater reductions achieved with the general 35S promoter compared to the trichome-specific MKS1 promoter. Phylogenetic analysis revealed CPT gene families in both eudicots and monocots and that all the short-chain CPTs from tomato (SlCPT1, SlCPT2, and SlCPT6) are closely linked to terpene synthase gene clusters. © 2012 The Authors. The Plant Journal © 2012 Blackwell Publishing Ltd.

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