Structure and nucleotide sequence of tomato HMG2 encoding 3-hydroxy-3-methyl-glutaryl coenzyme A reductase

We have isolated a gene, hmgl, for 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMCR) from Camptotheca acuminata, aChinese tree that produces the anti-cancer monoterpenoid indole alkaloid camptothecin (CPT). HMCR supplies mevalonate for the synthesis of the terpenoid component of CPT as well as for the formation of many other primary and secondary metabolites. In Camptotheca, hmgl transcripts were detected only in young seedlings and not in vegetative organs of older plants. Regulation of the hmgl promoter was studied in transgenic tobacco using three translational fusions (-1678, -1 107, -165) with the B-glucuronidase (GUS) reporter gene. Histochemical analysis of plants containing each of the three promoter fusions showed similar developmental and spatial expression patterns. In vegetative tissues, CUS staining was localized to the epidermis of young leaves and stems, particularly in glandular trichomes. Roots showed intense staining in the cortical tissues in the elongation zone and light staining in the cortex of mature roots. hmgl::CUS expression was also observed in sepals, petals, pistils, and stamens of developing flowers, with darkest staining in the ovary wall, ovules, stigmas, and pollen. Leaf discs from plants containing each of the translational fusions showed a 15-to 20-fold wound induction of hmgl::CUS expression over 72 h; however, this increase in CUS activity was completely suppressed by treatment with methyl jasmonate. Taken together, these data show that a 165-bp fragment of Camptotheca hmgl promoter is sufficient to confer developmental regulation as well as wound induction and methyl jasmonate suppression of GUS expression in transgenic tobacco.

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“…As many as four genes may be present in tomato (Park et al, 1992). Based on the appearance of cross-reacting bands in our DNA gel blots (Fig.…”

Section: Structure and Expression Of A C Acuminata Hmcr Cenementioning

confidence: 90%

Expression of a 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase Gene from Camptotheca acuminata Is Differentially Regulated by Wounding and Methyl Jasmonate

et al. 1993

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“…However, there are also some reports on the regulation of genes encoding enzymes that act upstream of terpene synthases, resulting in increased precursor pools. In cytosolic IPP synthesis, 3-hydroxy-3-methylglutaryl-coenzyme A reductase is upregulated in response to pathogens or pathogenderived elicitors in solanaceous plants like tomato (Park et al 1992), Korean red pepper (Capsicum annuum) and potato (Solanum tuberosum) (Choi et al 1992), but also by insect herbivores in potato (Korth et al 1997) and Nicotiana attenuata (Hui et al 2003). Furthermore, Kant et al (2004) have shown that transcription of deoxy-xylulose-5-phosphate synthase, involved in plastidial IPP synthesis, is upregulated in tomato upon spider mite-infestation.…”

Section: Introductionmentioning

confidence: 99%

Induction of a leaf specific geranylgeranyl pyrophosphate synthase and emission of (E,E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene in tomato are dependent on both jasmonic acid and salicylic acid signaling pathways

Ament

Schie

Bouwmeester³

et al. 2006

Planta

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Two cDNAs encoding geranylgeranyl pyrophosphate (GGPP) synthases from tomato (Lycopersicon esculentum) have been cloned and functionally expressed in Escherichia coli. LeGGPS1 was predominantly expressed in leaf tissue and LeGGPS2 in ripening fruit and Xower tissue. LeGGPS1 expression was induced in leaves by spider mite (Tetranychus urticae)-feeding and mechanical wounding in wild type tomato but not in the jasmonic acid (JA)-response mutant def-1 and the salicylic acid (SA)-deWcient transgenic NahG line. Furthermore, LeGGPS1 expression could be induced in leaves of wild type tomato plants by JA-or methyl salicylate (MeSA)-treatment. In contrast, expression of LeGGPS2 was not induced in leaves by spider mite-feeding, wounding, JA-or MeSA-treatment. We show that emission of the GGPP-derived volatile terpenoid (E,E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene (TMTT) correlates with expression of LeGGPS1. An exception was MeSA-treatment, which resulted in induction of LeGGPS1 but not in emission of TMTT. We show that there is an additional layer of regulation, because geranyllinalool synthase, catalyzing the Wrst dedicated step in TMTT biosynthesis, was induced by JA but not by MeSA.

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“…The tomato genome contains at least four HMGR genes (Park et al 1992). We examined the transcription levels of SlHMGR1, SlHMGR2, and SlHMGR3 ( Figure 3) but not that of SlHMGR4, since its sequence is not yet available in the database.…”

Section: Discussionmentioning

confidence: 99%

Molecular and genetic characterization of transgenic tomato expressing 3-hydroxy-3-methylglutaryl coenzyme A reductase

Omura

Watanabe

Iijima

et al. 2007

Plant Biotechnology

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Mevalonic acid (MVA) pathway, in parallel with methylerythritol phosphate (MEP) pathway, produces precursor metabolites for isoprenoids, and affect fruit development in plants. 3-Hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) is supposed to be a key enzyme in the MVA pathway. To understand the role of HMGR in fruit development, we previously generated transgenic tomato (Solanum lycopersicum) expressing a melon HMGR gene (CmHMGR) and observed increased fruit size in these plants. To further examine this effect, we performed molecular and genetic characterization of the transgenic tomato line in the T 4 generation. The line showed stable expression of CmHMGR mRNA and protein, an effect that could lead to the increase in fruit weight observed, which exceeded 20%. Interestingly, the CmHMGR mRNA was highly expressed during tomato fruit development, whereas expression of the endogenous HMGRs (SlHMGR1, SlHMGR2, and SlHMGR3) was lower than in the wild type, suggesting the presence of a regulatory mechanism at the transcriptional level, as in mammalian systems. A preliminary analysis using cDNA macroarray filters was performed, and genes showing more than 2.5-fold differences in expression between transgenic and wild-type plants were identified. Most of the genes involved in isoprenoid biosynthesis did not show significantly different transcription levels, but 121 annotated genes and 152 genes of unknown function were found to be differentially expressed. These results demonstrate that the transgenic tomato line expressing the HMGR gene is genetically stable and could be used as a comprehensive material to elucidate the roles of HMGRs in tomato fruit development.

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Structure and nucleotide sequence of tomato HMG2 encoding 3-hydroxy-3-methyl-glutaryl coenzyme A reductase

Cited by 52 publications

References 17 publications

Expression of a 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase Gene from Camptotheca acuminata Is Differentially Regulated by Wounding and Methyl Jasmonate

Expression of a 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase Gene from Camptotheca acuminata Is Differentially Regulated by Wounding and Methyl Jasmonate

Induction of a leaf specific geranylgeranyl pyrophosphate synthase and emission of (E,E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene in tomato are dependent on both jasmonic acid and salicylic acid signaling pathways

Molecular and genetic characterization of transgenic tomato expressing 3-hydroxy-3-methylglutaryl coenzyme A reductase

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