Suzuki M, Koide Y, Hattori T, Nakamura K, Asahi T
Laboratory of Biochemistry, School of Agriculture, Nagoya University, Japan.
Plant Cell Physiol. 1995 Sep;36(6):1067-74. doi: 10.1093/oxfordjournals.pcp.a078849.
Deletion analysis of the promoter region of a gene for catalase, cat2, from castor bean (Ricinus communis) was performed to identify the cis-regulatory elements responsible for the expression of a beta-glucuronidase (GUS) fusion gene during seed formation and postembryonic development in transgenic tobacco. The analysis showed that multiple cis-elements contribute to the activity of the cat2 promoter during seed formation and postembryonic development. The 5'-upstream regions from -1,241 to -816 bp, from -720 to -682 bp, and from -632 to -535 bp, relative to the site of initiation of translation of cat2, contributed positively to the activity of the cat2 promoter during both stages. By contrast, the region from -816 to -720 bp had a negative effect at both stages. The region from -682 to -632 bp contributed positively to the activity during seed formation but negatively during postembyonic development. Histochemical analysis revealed that the multiple cis-elements determined not only the level of expression of the chimeric gene but also the tissue-specificity of such expression. For example, the region from -1,241 to -816 bp allowed expression of the chimeric gene in the axis of the embryo of the dry seed, as well as in the cortex of the middle part of the hypocotyl and at the base of epicotyl in the young seedling.
为了鉴定在转基因烟草种子形成和胚后发育过程中负责β-葡萄糖醛酸酶（GUS）融合基因表达的顺式调控元件，对蓖麻（Ricinus communis）过氧化氢酶基因cat2的启动子区域进行了缺失分析。分析表明，多个顺式元件在种子形成和胚后发育过程中对cat2启动子的活性有贡献。相对于cat2翻译起始位点，从-1241至-816 bp、从-720至-682 bp以及从-632至-535 bp的5'-上游区域在两个阶段均对cat2启动子的活性有正向贡献。相比之下，-816至-720 bp区域在两个阶段均有负面影响。-682至-632 bp区域在种子形成过程中对活性有正向贡献，但在胚后发育过程中有负向影响。组织化学分析表明，多个顺式元件不仅决定了嵌合基因的表达水平，还决定了这种表达的组织特异性。例如，-1241至-816 bp区域使得嵌合基因在干种子胚轴、幼嫩幼苗下胚轴中部皮层以及上胚轴基部表达。
