Abstract：Leaf is photosynthetic organ of plants which plays an important role in energy fixation and utilization. The study of acting elements and their functions of light-inducible, and stem and leaf-specific expression promoter have important theoretical significance and application value on research for regulation of gene expression. The 1 556 bp sequence of light-inducible, stem and leaf-specific expression promoter ST-LS1 was isolated from potato (Solanum tuberosum L.) genome by PCR assay. The result from sequence analysis showed that the fragment shared 99.68% identity with the reported ST-LS1 promoter (GenBank accession No. X04753.1), and which contained shoot-specific expression and light responsive cis-acting element as-2-box, and cis-acting element G-box with light effect. The plant expression vector pBⅠ121-ST-LS1 was constructed by fusing the fragment with GUS gene, which was transferred to tobacco(Nicotiana tabacum) by Agrobacterium tumefaciens system and obtained the transgenic tobacco plants. Both qRT-PCR and histochemical assay of GUS activity revealed that the GUS gene expression could be detected in the leaf and stem of the transgenic tobacco plants transformed with GUS gene driven by ST-LS1 promoter, while could not be detected in root of the transgenic plant. The result from the transgenic plants under treatment for 20 d with darkness, constant temperature light, natural light culture demonstrated that there was no GUS gene expression in the transgenic plants under darkness treatment, while GUS gene expression was higher in the leaf and stem of the transgenic plants under natural light culture compared with constant temperature light condition. The results could provide theoretical and applied basis for crop improvement using genetic engineering.
