Keywords: 
• Hevea brasiliensis /
• 3-hydroxy-3-methylglutaryl coenzyme A（HMG-CoA） synthase1（HbHMGS1） /
• promoter analysis /
• GUS staining

Abstract: 3-hydroxy-3-methylglutaryl coenzyme A（HMG-CoA） synthase（HMGS） is an important enzyme in the mevalonate（MVA） pathway of isoprenoid biosynthesis, which regulates the rubber biosynthetic pathway in rubber tree（Hevea brasiliensis） in coordination with other genes. However, little information is available about the regulation of HMGS gene expression. The full-length HbHMGS1 promoter was cloned, its promoter sequence analyzed with PlantCARE database, and a series of 5′deletion constructs constructed. The constructs including CaMV35 S-GUS were transformed into tobacco and Arabidopsis thaliana by using the Agrobacterium-mediated method, and characterized quantitatively and ualitatively in transgenic plants with the GUS gene as a reporter gene. The GUS histochemical staining was observed in the leaves of tobacco and different tissues of T2 transgenic Arabidopsis plants at the young and mature developmental stages. When the T2 transgenic Arabidopsis plants containing the HbHMGS1 promoter were exposed to light and darkness, the activity of GUS protein 96 h after light treatment increased quickly to about 3.2 times of that 72 h after light treatment, and the GUS activity of leaves 72 h and 96 h after dark treatment increased to 1.38 and 2.13 times of that 48-h after dark treatment, respectively. Quantitative detection of the GUS protein activity in response to heat shock and drought treatments showed that the 699-bp sequence from-699 to the start codon-1 might be the major heat shock response region, and that the drought response region was mainly located in the 213-bp sequence from-213 to the start codon-1. These results indicated the HbHMGS1promoter may play important roles in regulating of expression of the HbHMGS1 gene in response to light, heat-shock and drought.