Molecular cloning and overexpression of a novel UDP-glucosyltransferase elevating salidroside levels in Rhodiola sachalinensis.
Salidroside is a novel effective adaptogenic drug extracted from the medicinal plant Rhodiola sachalinensis A. Bor. Because this plant is a rare resource and has low yield, there is great interest in enhancing the production of salidroside. In this study, a putative UDP-glucosyltransferase (UGT) cDNA, UGT73B6, was isolated from Rhodiola sachalinensis using a rapid amplification of cDNA ends (RACE) method. The cDNA was 1,598 bp in length encoding 480 deduced amino acid residues with a conserved UDP-glucose-binding domain (PSPG box). Southern blot analysis of genomic DNA indicated that UGT73B6 existed as a single copy gene in the R. sachalinensis genome. Northern blot analysis revealed that transcripts of UGT73B6 were present in roots, calli and stems, but not in leaves. The UGT73B6 under 35S promoter with double-enhancer sequences from CaMV-Omega and TMV-Omega fragments was transferred into R. sachalinensis via Agrobacterium tumefaciens. PCR, PCR-Southern and Southern blot analyses confirmed that the UGT73B6 gene had been integrated into the genome of transgenic calli and plants. Northern blot analysis revealed that the UGT73B6 gene had been expressed at the transcriptional level. High performance liquid chromatography (HPLC) analysis indicated that the overexpression of the UGT73B6 gene resulted in an evident increase of salidroside content. These data suggest that the cloned UGT73B6 can regulate the conversion of tyrosol aglycon to salidroside in R. sachalinensis. This is the first cloned glucosyltransferase gene involved in salidroside biosynthesis.
Ma
Lan-Qing
LQ
Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, People's Republic of China.
Liu
Ben-Ye
BY
Gao
Dong-Yao
DY
Pang
Xiao-Bin
XB
Lü
Shi-You
SY
Yu
Han-Song
HS
Wang
Hong
H
Yan
Fang
F
Li
Zhen-Qiu
ZQ
Li
Yan-Fang
YF
Ye
He-Chun
HC
D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant; D005960:Glucosides / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D005964:Glucosyltransferases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010636:Phenols / Q000737:chemistry; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D029771:Rhodiola / Q000235:genetics* / Q000378:metabolism*
D005960:Glucosides; D010636:Phenols; D010940:Plant Proteins; D005964:Glucosyltransferases; C009172:rhodioloside