Cloning and Deletion Analysis of HbMVK Promoter from Rubber Tree（Hevea brasiliensis）

Key words: 
• rubber tree /
• rubber biosynthesis /
• MVK gene promoter /
• promoter deletion analysis /
• GUS staining analysis

Abstract: Mevalonate kinase（MVK） is an important enzyme in natural rubber biosynthesis pathway of rubber tree（Hevea brasiliensis）.The promoter of HbMVK gene from rubber tree was cloned by using PCR and analyzed with bioinformatics tools to observe the fine structure and function of rubber tree MVK promoter.The HbMVK promoter sequence is 1 696 bp in length,containing some elements or mortifs such as CAAT-box,TATA-box,CAT-box,LTR,GARE-motif,TCA-element,etc.Based on the element distribution,plant expression vectors were constructed with HbMVK promoter and its serious deletion fragments were fused to reportergene GUS（encoding β-glucuronidase）,which were transformed into Arabidopsis thaliana.GUS histochemical staining of T2 transgenic seedlings showed that the full-length HbMVK promoter and its -1386 bp deletion fragment weakly drove GUS expression in transgenic seedling hypocotyls.The 5’-1 221 bp and -725 bp deletion fragments of HbMVK promoter were observed to strongly drive GUS expression,and the -325 bp deletion fragment of HbMVK promoter completely lost promoter activity,suggesting that the core promoter regulatory elements were located between -325 bp and -725 bp.This study might provide an important basis for further research on the regulation of HbMVK expression.