Molecular cloning, characterization and expression analysis of the gene encoding 1-deoxy-D-xylulose 5-phosphate reductoisomerase from Aquilaria sinensis (Lour.) Gilg

Journal of genetics

Yanhong Xu²  Jianhe Wei1 3²  Juan Liu²  Liang Liang¹ 

[1] Shandong University of Traditional Chinese Medicine, Jinan, 250355, People’s Republic of China$$;Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 151, Malianwa North Road, Haidian District, Beijing 100193, People’s Republic of China$$

关键词: sesquiterpenes biosynthesis;    1-deoxy-D-xylulose 5-phosphate reductoisomerase;    MEP pathway;    Aquilaria sinensis (Lour.) Gilg.;   

DOI  :  

学科分类：生物科学（综合）

来源: Indian Academy of Sciences

【 摘 要 】

The major constituents of agarwood oils are sesquiterpenes that are obtained from isoprenoid precursors through the plastidial methylerythritol phosphate (MEP) pathway and the cytosolic mevalonate pathway. In this study, a novel full-length cDNA of 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR), which was the second key enzyme in the plastid MEP pathway of sesquiterpenes biosynthesis was isolated from the stem of Aquilaria sinensis (Lour.) Gilg by the methods of reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE) technique for the first time, and named as AsDXR. The full-length cDNA of AsDXR was 1768 bp, containing a 1437 bp open reading frame (ORF) encoding a polypeptide of 478 amino acids with a molecular weight of 51.859 kD and the theoretical isoelectric point of 6.29. Comparative and bioinformatic analysis of the deduced AsDXR protein showed extensive homology with DXRs from other plant species, especially Theobroma cacao and Gossypium barbadense, and contained a conserved transit peptide for plastids, and extended pro-rich region and a highly conserved NADPH-binding motif owned by all plant DXRs. Southern blot analysis indicated that AsDXR belonged to a small gene family. Tissue expression pattern analysis revealed that AsDXR expressed strongly in root and stem, but weakly in leaf. Additionally, AsDXR expression was found to be activated by exogenous elicitor of MeJA (methyl jasmonate). The contents of three sesquiterpenes ($alpha$-guaiene, $alpha$-humulene and $delta$-guaiene) were significantly induced by MeJA. This study enables us to further elucidate the role of AsDXR in the biosynthesis of agarwood sesquiterpenes in A. sinensis at the molecular level.

【 授权许可】

Unknown