Hamill J D, Robins R J, Parr A J, Evans D M, Furze J M, Rhodes M J
Department of Genetics and Microbiology, AFRC Institute of Food Research, Norwich, UK.
Plant Mol Biol. 1990 Jul;15(1):27-38. doi: 10.1007/BF00017721.
Transformed root cultures of Nicotiana rustica have been generated in which the gene from the yeast Saccharomyces cerevisiae coding for ornithine decarboxylase has been integrated. The gene, driven by the powerful CaMV35S promoter with an upstream duplicated enhancer sequence, shows constitutive expression throughout the growth cycle of some lines, as demonstrated by the analysis of mRNA and enzyme activity. The presence of the yeast gene and enhanced ornithine decarboxylase activity is associated with an enhanced capacity of cultures to accumulate both putrescine and the putrescine-derived alkaloid, nicotine. Even, however, with the very powerful promoter used in this work the magnitude of the changes seen is typically only in the order of 2-fold, suggesting that regulatory factors exist which limit the potential increase in metabolic flux caused by these manipulations. Nevertheless, it is demonstrated that flux through a pathway to a plant secondary product can be elevated by means of genetic manipulation.
已培育出黄花烟草的转化根培养物，其中整合了酿酒酵母中编码鸟氨酸脱羧酶的基因。该基因由具有上游重复增强子序列的强大花椰菜花叶病毒35S启动子驱动，通过对mRNA和酶活性的分析表明，在某些品系的整个生长周期中呈组成型表达。酵母基因的存在和鸟氨酸脱羧酶活性的增强与培养物积累腐胺和腐胺衍生生物碱尼古丁的能力增强有关。然而，即使在这项工作中使用了非常强大的启动子，所观察到的变化幅度通常也仅为2倍左右，这表明存在限制这些操作引起的代谢通量潜在增加的调节因子。尽管如此，已证明通过基因操作可以提高通向植物次生产物的途径的通量。
