Expression of the Hevea brasiliensis (H.B.K.) Mull. Arg. 3-Hydroxy-3-Methylglutaryl-Coenzyme A Reductase 1 in Tobacco Results in Sterol Overproduction.

摘要: A genomic fragment encoding one (HMGR1) of the three 3-hydroxy-3-methylglutaryl coenzyme reductases (HMGRs) from Hevea brasiliensis (H.B.K.) Mull. Arg. (M.-L. Chye, C.-T. Tan, N.-H. Chua [1992] Plant Mol Biol 19: 473–484) was introduced into Nicotiana tabacum L. cv xanthi via Agrobacterium transformation to study influence hmg1 gene product on plant isoprenoid biosynthesis. Transgenic plants were morphologically indistinguishable control wild-type and displayed same developmental pattern. lines showed an increase in level total sterols up 6-fold, probably because increased expression mRNA a corresponding enzymatic activity for HMGR, when compared with not expressing transgene. In addition pathway end products, campesterol, sitosterol, stigmasterol, some biosynthetic intermediates such as cycloartenol also accumulated transgenic tissues. Most overproduced detected steryl-esters likely be stored cytoplasmic lipid bodies. These data strongly support conclusion that HMGR is key limiting enzyme phytosterol