Molecular characterization of three 3-hydroxy-3-methylglutaryl-CoA reductase genes including pathogen-induced Hmg2 from pepper (Capsicum annuum).
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.
Ha
Sun Hwa
SH
Division of Metabolic Engineering, National Institute of Agricultural Biotechnology, RDA, 441-707, Suwon, South Korea. shha@rda.go.kr
Kim
Jong Bum
JB
Hwang
Young Soo
YS
Lee
Shin Woo
SW
D019883:Alkyl and Aryl Transferases / Q000096:biosynthesis / Q000235:genetics; D000595:Amino Acid Sequence; D002212:Capsicum / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism / Q000469:parasitology; D003001:Cloning, Molecular; D015971:Gene Expression Regulation, Enzymologic; D015723:Gene Library; D051228:Geranyltranstransferase; D024261:HMGB2 Protein / Q000096:biosynthesis / Q000235:genetics*; D006903:Hydroxymethylglutaryl CoA Reductases / Q000096:biosynthesis / Q000235:genetics*; D025782:Hydroxymethylglutaryl-CoA-Reductases, NADP-dependent / Q000096:biosynthesis / Q000235:genetics; D007527:Isoenzymes / Q000235:genetics; D008969:Molecular Sequence Data; D010838:Phytophthora / Q000472:pathogenicity; D010840:Phytosterols / Q000096:biosynthesis; D012333:RNA, Messenger / Q000032:analysis; D016415:Sequence Alignment; D012717:Sesquiterpenes / Q000378:metabolism
D024261:HMGB2 Protein; D007527:Isoenzymes; D010840:Phytosterols; D012333:RNA, Messenger; D012717:Sesquiterpenes; D006903:Hydroxymethylglutaryl CoA Reductases; D025782:Hydroxymethylglutaryl-CoA-Reductases, NADP-dependent; D019883:Alkyl and Aryl Transferases; D051228:Geranyltranstransferase