PgLOX6 encoding a lipoxygenase contributes to jasmonic acid biosynthesis and ginsenoside production in Panax ginseng.
Ginsenosides, the valuable pharmaceutical compounds in Panax ginseng, are triterpene saponins that occur mainly in ginseng plants. It was shown that in vitro treatment with the phytohormone jasmonic acid (JA) is able to increase ginsenoside production in ginseng plants. To understand the molecular link between JA biosynthesis and ginsenoside biosynthesis, we identified a JA biosynthetic 13-lipoxygenase gene (PgLOX6) in P. ginseng that promotes ginsenoside production. The expression of PgLOX6 was high in vascular bundles, which corresponds with expression of ginsenoside biosynthetic genes. Consistent with the role of PgLOX6 in synthesizing JA and promoting ginsenoside synthesis, transgenic plants overexpressing PgLOX6 in Arabidopsis had increased amounts of JA and methyl jasmonate (MJ), increased expression of triterpene biosynthetic genes such as squalene synthase (AtSS1) and squalene epoxidase (AtSE1), and increased squalene content. Moreover, transgenic ginseng roots overexpressing PgLOX6 had around 1.4-fold increased ginsenoside content and upregulation of ginsenoside biosynthesis-related genes including PgSS1, PgSE1, and dammarenediol synthase (PgDDS), which is similar to that of treatment with MJ. However, MJ treatment of transgenic ginseng significantly enhanced JA and MJ, associated with a 2.8-fold increase of ginsenoside content compared with the non-treated, non-transgenic control plant, which was 1.4 times higher than the MJ treatment effect on non-transgenic plants. These results demonstrate that PgLOX6 is responsible for the biosynthesis of JA and promotion of the production of triterpenoid saponin through up-regulating the expression of ginsenoside biosynthetic genes. This work provides insight into the role of JA in biosynthesizing secondary metabolites and provides a molecular tool for increasing ginsenoside production.
Graduate School of Biotechnology and Ginseng Bank, College of Life Sciences, Kyung Hee University, Yongin, 446-701, Republic of Korea.|Department of Crop Science, Chungbuk National University, Cheongju 361-763, Korea.
Shadi
S
Rahimi
Department of Oriental Medicinal Biotechnology, College of Life Sciences, Kyung Hee University, Yongin, 446-701, Republic of Korea yujinkim@khu.ac.kr dcyang@khu.ac.kr.|State Key Laboratory of Hybrid Rice, Shanghai Jiao Tong University-University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
Yu-Jin
YJ
Kim
Graduate School of Biotechnology and Ginseng Bank, College of Life Sciences, Kyung Hee University, Yongin, 446-701, Republic of Korea.|Department of Oriental Medicinal Biotechnology, College of Life Sciences, Kyung Hee University, Yongin, 446-701, Republic of Korea.
Johan
J
Sukweenadhi
State Key Laboratory of Hybrid Rice, Shanghai Jiao Tong University-University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.|School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Urrbrae, South Australia 5064, Australia.
Dabing
D
Zhang
Graduate School of Biotechnology and Ginseng Bank, College of Life Sciences, Kyung Hee University, Yongin, 446-701, Republic of Korea yujinkim@khu.ac.kr dcyang@khu.ac.kr.|Department of Oriental Medicinal Biotechnology, College of Life Sciences, Kyung Hee University, Yongin, 446-701, Republic of Korea.
Deok-Chun
DC
Yang
D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000378:metabolism; D003517:Cyclopentanes / Q000378:metabolism*; D017343:Genes, Plant / Q000235:genetics / Q000502:physiology; D036145:Ginsenosides / Q000096:biosynthesis* / Q000378:metabolism; D005964:Glucosyltransferases / Q000378:metabolism; D008084:Lipoxygenase / Q000235:genetics / Q000378:metabolism*; D053858:Metabolic Networks and Pathways; D054883:Oxylipins / Q000378:metabolism*; D005894:Panax / Q000201:enzymology / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D030821:Plants, Genetically Modified; D013185:Squalene / Q000378:metabolism; D050603:Squalene Monooxygenase / Q000378:metabolism
D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D036145:Ginsenosides; D054883:Oxylipins; D010940:Plant Proteins; C011006:jasmonic acid; D013185:Squalene; D008084:Lipoxygenase; D050603:Squalene Monooxygenase; D005964:Glucosyltransferases; C000597589:SS1 protein, Arabidopsis
Ginsenoside; Panax ginseng; jasmonic acid; lipoxygenase; secondary metabolite; squalene; triterpene; vascular bundles.