The biosynthetic pathway of the nonsugar, high-intensity sweetener mogroside V from Siraitia grosvenorii.
The consumption of sweeteners, natural as well as synthetic sugars, is implicated in an array of modern-day health problems. Therefore, natural nonsugar sweeteners are of increasing interest. We identify here the biosynthetic pathway of the sweet triterpenoid glycoside mogroside V, which has a sweetening strength of 250 times that of sucrose and is derived from mature fruit of luo-han-guo (Siraitia grosvenorii, monk fruit). A whole-genome sequencing of Siraitia, leading to a preliminary draft of the genome, was combined with an extensive transcriptomic analysis of developing fruit. A functional expression survey of nearly 200 candidate genes identified the members of the five enzyme families responsible for the synthesis of mogroside V: squalene epoxidases, triterpenoid synthases, epoxide hydrolases, cytochrome P450s, and UDP-glucosyltransferases. Protein modeling and docking studies corroborated the experimentally proven functional enzyme activities and indicated the order of the metabolic steps in the pathway. A comparison of the genomic organization and expression patterns of these Siraitia genes with the orthologs of other Cucurbitaceae implicates a strikingly coordinated expression of the pathway in the evolution of this species-specific and valuable metabolic pathway. The genomic organization of the pathway genes, syntenously preserved among the Cucurbitaceae, indicates, on the other hand, that gene clustering cannot account for this novel secondary metabolic pathway.
Institute of Plant Sciences, Agricultural Research Organization-Volcani Center, Bet Dagan 5025000, Israel.
Maxim
M
Itkin
Institute of Plant Sciences, Agricultural Research Organization-Newe Ya'ar Center, Ramat Yishay 3009500, Israel.
Rachel
R
Davidovich-Rikanati
Institute of Plant Sciences, Agricultural Research Organization-Volcani Center, Bet Dagan 5025000, Israel.
Shahar
S
Cohen
Institute of Plant Sciences, Agricultural Research Organization-Newe Ya'ar Center, Ramat Yishay 3009500, Israel.
Vitaly
V
Portnoy
Institute of Plant Sciences, Agricultural Research Organization-Volcani Center, Bet Dagan 5025000, Israel.
Adi
A
Doron-Faigenboim
Institute of Plant Sciences, Agricultural Research Organization-Newe Ya'ar Center, Ramat Yishay 3009500, Israel.
Elad
E
Oren
Institute of Plant Sciences, Agricultural Research Organization-Newe Ya'ar Center, Ramat Yishay 3009500, Israel.
Shiri
S
Freilich
Institute of Plant Sciences, Agricultural Research Organization-Newe Ya'ar Center, Ramat Yishay 3009500, Israel.
Galil
G
Tzuri
Institute of Plant Sciences, Agricultural Research Organization-Newe Ya'ar Center, Ramat Yishay 3009500, Israel.
Nadine
N
Baranes
Institute of Plant Sciences, Agricultural Research Organization-Volcani Center, Bet Dagan 5025000, Israel.
Shmuel
S
Shen
Institute of Plant Sciences, Agricultural Research Organization-Volcani Center, Bet Dagan 5025000, Israel.
Marina
M
Petreikov
Consultant, Protein Modelling, Gedera 7042703, Israel.
Rotem
R
Sertchook
Department of Biological Services, Weizmann Institute of Science, Rehovot 7610001, Israel.
Shifra
S
Ben-Dor
Department of Chemistry, Bar-Ilan University, Qiryat Ono 5290000, Israel.
Hugo
H
Gottlieb
Roy J. Carver Biotechnology Center, University of Illinois, Urbana, IL 61801.
Alvaro
A
Hernandez
Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, TN 38163.
David R
DR
Nelson
Institute of Plant Sciences, Agricultural Research Organization-Newe Ya'ar Center, Ramat Yishay 3009500, Israel.
Harry S
HS
Paris
Institute of Plant Sciences, Agricultural Research Organization-Newe Ya'ar Center, Ramat Yishay 3009500, Israel.
Yaakov
Y
Tadmor
Institute of Plant Sciences, Agricultural Research Organization-Newe Ya'ar Center, Ramat Yishay 3009500, Israel.
Yosef
Y
Burger
Institute of Plant Sciences, Agricultural Research Organization-Newe Ya'ar Center, Ramat Yishay 3009500, Israel.
Efraim
E
Lewinsohn
Institute of Plant Sciences, Agricultural Research Organization-Newe Ya'ar Center, Ramat Yishay 3009500, Israel.
Nurit
N
Katzir
Institute of Plant Sciences, Agricultural Research Organization-Volcani Center, Bet Dagan 5025000, Israel; vcaris@agri.gov.il.
Arthur
A
Schaffer
D053898:Biosynthetic Pathways; D019662:Cucurbitaceae / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004851:Epoxide Hydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling / Q000379:methods; D018506:Gene Expression Regulation, Plant; D005964:Glucosyltransferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D062105:Molecular Docking Simulation; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017422:Sequence Analysis, DNA / Q000379:methods; D050603:Squalene Monooxygenase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D014315:Triterpenes / Q000378:metabolism*
D010940:Plant Proteins; D014315:Triterpenes; C041740:mogroside V; D003577:Cytochrome P-450 Enzyme System; D050603:Squalene Monooxygenase; D005964:Glucosyltransferases; D004851:Epoxide Hydrolases
functional genomics; metabolic pathway discovery; mogrosides