一个水稻谷胱甘肽-S-转移酶启动子的特性分析

Characterization of a Glutathione S-Transferase Promoter from Rice

从水稻基因组文库中筛选得到1个水稻谷胱甘肽-S-转移酶基因,命名为OsGSTL1。为了研究OsGSTL1启动子在植物体内的表达特性,将OsGSTL1起始位点5′-端上游不同长度的调控序列与报告基因GUS融合,并在洋葱表皮瞬间表达和拟南芥中稳定表达。研究表明:在洋葱表皮细胞中,160 bp及更长的上游调控序列均能启动GUS基因的表达;而在转基因拟南芥中,含有2 155 bp的上游序列的PGL2.1::GUS具有时空表达的特性,在转基因的早期幼苗中GUS基因在子叶中特异性表达,但在根中没有表达;而在幼苗生长的后期,根、茎、叶中都有少量的表达。但包含1 224 bp的上游序列的PGL1.2::GUS却表现为组成型表达的特性。由此推测,OsGSTL1启动子启动的基因表达可能与幼苗的营养代谢相关;而OsGSTL1启动子的时空表达相关元件可能位于GST起始位点5′-端上游-2 155 bp^-1 224 bp范围内。

OsGSTL1 gene was isolated from the rice genomic library. In order to investigate the cis-elements of OsGSTL1 promoter, the promoter regions with different lengths were fused to the β-glucuronidase （GUS） reporter gene. All constructs were transformed into onion epidermal cells or A. thaliana plants to detect the expression patterns. In onion epidermal cells, the 160 bp fragment and longer ones were functional for directing GUS expression. In transgenic A. thaliaria, the 2 155 bp upstream region of OsGSTL1 gene directed the GUS expression only in cotyledon after germination, but not in the root of young seedlings. In the later seedling, the 2 155 bp upstream region of OsGSTL1 gene directed GUS expression in roots, stems, and leaves. However, the GUS gene directed by a 1224 bp upstream fragment is expressed in all the checked tis- sues. These results suggest that the spatiotemporal expression response elements of OsGSTL1 existed in the 5＇-upstream region between -2 155 and-1 224 bp.