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从水稻基因组文库中筛选得到一个水稻GST基因,命名为OsGSTL1。半定量RT-PCR分析表明OsGSTL1基因的表达不受绿磺隆、乙烯利、脱落酸、水杨酸和茉莉酸甲酯的诱导,因此该基因可能与植物抗逆性无关。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,160bp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2155bp的上游序列的PGZ2.1::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1224bp的上游序列的PGZ1.2::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OsGSTL1翻译起始位点5′端上游–2155bp至–1224bp范围内。
A rice GST gene was screened from the rice genomic library and named as OsGSTL1. Semi-quantitative RT-PCR analysis showed that the expression of OsGSTL1 gene was not induced by chlorsulfuron, ethephon, abscisic acid, salicylic acid and methyl jasmonate, so the gene may not be related to plant stress resistance. In order to study the expression characteristics of OsGSTL1 promoter in plants, the regulatory sequences upstream of the 5 ’end of the OsGSTL1 start site were fused with the GUS reporter gene and expressed transiently in onion epidermis and Arabidopsis thaliana. The results showed that in onion epidermal cells, both 160bp and longer upstream regulatory sequences activated the expression of GUS gene. In transgenic Arabidopsis PGZ2.1 :: GUS containing the upstream sequence of 2155bp possessed the characteristics of spatiotemporal expression The GUS gene was expressed specifically in cotyledons but not in roots at the early seedling stage of transgenics. However, GUS gene was expressed in roots, stems and leaves at the late stage of seedling growth. However, PGZ1.2 :: GUS, which contains a 1224 bp upstream sequence, exhibited constitutive expression. It was speculated that OsGSTL1 promoter-initiated gene expression may be related to seedling nutrient metabolism; and OsGSTL1 promoter spatiotemporal expression of related elements may be located 5 ’upstream of OsGSTL1 translation initiation site -2155bp to -1224bp range.