Overexpression in Catharanthus roseus hairy roots of a truncated hamster 3-hydroxy-3-methylglutaryl-CoA reductase gene.
Catharanthus roseus (L.) G. Don hairy roots harboring hamster 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) (EC 1.1.1.88) cDNA without membrane-binding domain were evaluated by quantifying the levels of sterols and some indol-alkaloids. Clone 236, with the highest hybridization signal, had the lowest soluble and microsomal HMGR activity and produced more ajmalicine and catharanthine than the control but had reduced campesterol concentration. Clone 19, with low hybridization signal, had high soluble HMGR activity and produced high levels of campesterol and five to seven times more serpentine than the control but a low level of ajmalicine and no accumulation of catharanthine. These results suggest a possible role for HMGR in indole alkaloid biosynthesis and a possible cosuppression of both the endogenous and foreign HMGR genes in clone 236.
Ayora-Talavera
Teresa
T
Unidad de Bioquimica y Biología Molecular de Plantas, Centro de Investigación Científica de Yucatán, Mérida Yucatán, Mexico.
Chappell
Joseph
J
Lozoya-Gloria
Edmundo
E
Loyola-Vargas
Victor M
VM
D000818:Animals; D015139:Blotting, Southern; D030008:Catharanthus / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D006224:Cricetinae; D004247:DNA / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D006903:Hydroxymethylglutaryl CoA Reductases / Q000737:chemistry* / Q000235:genetics*; D008956:Models, Chemical; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012231:Rhizobium / Q000378:metabolism; D013997:Time Factors
D018076:DNA, Complementary; D004247:DNA; D006903:Hydroxymethylglutaryl CoA Reductases