Molecular characterization of three 3-hydroxy-3-methylglutaryl-CoA reductase genes including pathogen-induced Hmg2 from pepper (Capsicum annuum).

Abstract

Sesquiterpene phytoalexins, a class of plant defense metabolites, are synthesized from the cytosolic acetate/mevalonate pathway in isoprenoids biosynthetic system of plants. The 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) catalyzes the synthesis of mevalonate, which is the specific precursor of this pathway, as a multi gene family. Three kinds of cDNA clones encoding HMGR were isolated from Korean red pepper (Capsicum annuum L. cv. NocKwang) and the HMGR2 gene (Hmg2) was especially obtained from a cDNA library constructed with Phytophthora capsici-infected pepper root RNAs. The Hmg2 encoding a 604-amino-acid peptide had typical features as an elicitor-induced isoform among HMGRs on its gene structure and had a predicted amino acid sequence homology. In addition, the expression of Hmg2 was rapidly induced within 1 h in response to a fungal pathogen and continuously increased up to 48 h. Together with sesquiterpene cyclase gene that was strongly induced 24 h after pathogen-infection, the Hmg2 and farnesyl pyrophosphate synthase gene were coordinately and sequentially regulated for the biosynthesis of defense-related sesquiterpene phytoalexins in pepper.

• Authors: Sun Hwa Ha, Jong Bum Kim, Young Soo Hwang, Shin Woo Lee
• Journal: Biochimica et biophysica acta (Biochim Biophys Acta) Vol. 1625 Issue 3 Pg. 253-60 (Feb 20 2003) ISSN: 0006-3002 [Print] Netherlands
• PMID: 12591612 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• HMGB2 Protein
• Isoenzymes
• Phytosterols
• RNA, Messenger
• Sesquiterpenes
• Hydroxymethylglutaryl CoA Reductases
• Hydroxymethylglutaryl-CoA-Reductases, NADP-dependent
• Alkyl and Aryl Transferases
• Geranyltranstransferase

Topics

• Alkyl and Aryl Transferases (biosynthesis, genetics)
• Amino Acid Sequence
• Capsicum (enzymology, genetics, metabolism, parasitology)
• Cloning, Molecular
• Gene Expression Regulation, Enzymologic
• Gene Library
• Geranyltranstransferase
• HMGB2 Protein (biosynthesis, genetics)
• Hydroxymethylglutaryl CoA Reductases (biosynthesis, genetics)
• Hydroxymethylglutaryl-CoA-Reductases, NADP-dependent (biosynthesis, genetics)
• Isoenzymes (genetics)
• Molecular Sequence Data
• Phytophthora (pathogenicity)
• Phytosterols (biosynthesis)
• RNA, Messenger (analysis)
• Sequence Alignment
• Sesquiterpenes (metabolism)