Tao Zhang1, Yan Gao1, Mei Han2, Linmin Yang3. 1. Cultivation Base of State Key Laboratory for Ecological Restoration and Ecosystem Management of Jilin Province and Ministry of Science and Technology, College of Chinese Medicinal Materials, Jilin Agricultural University, Changchun, 130118, Jilin, People's Republic of China. 2. Cultivation Base of State Key Laboratory for Ecological Restoration and Ecosystem Management of Jilin Province and Ministry of Science and Technology, College of Chinese Medicinal Materials, Jilin Agricultural University, Changchun, 130118, Jilin, People's Republic of China. meih@jlau.edu.cn. 3. Cultivation Base of State Key Laboratory for Ecological Restoration and Ecosystem Management of Jilin Province and Ministry of Science and Technology, College of Chinese Medicinal Materials, Jilin Agricultural University, Changchun, 130118, Jilin, People's Republic of China. yanglimin@jlau.edu.cn.
Abstract
MAIN CONCLUSION: Short-term cold stress can induce the increased expression of key enzyme-encoding genes involved in secondary metabolite synthesis, thereby increasing secondary metabolite concentration. Cold stress is an ecologically limiting factor that strongly affects the physiological and biochemical properties of medicinal plants often resulting in changes of the secondary metabolic process. Ginsenosides are the main active ingredients in medicinal ginseng yet few studies exist on the effect of cold stress on the expression of ginsenosides or the molecular mechanism underlying its regulation. Here, we evaluated the effects of cold stress on the physiological characteristics and secondary metabolism of P. ginseng embryogenic calli. Physiological measurements and RNA-Seq analysis were used to dissect the metabolic and molecular responses of P. ginseng to cold conditions. We found that the dynamic accumulation of ginsenoside and various physiological indicators leads to homogenous adaptation to cold stress. Secondary metabolism of ginseng could be a compensation mechanism to facilitate its adaptation to cold stress. Combined with the changes in the endogenous hormone content, 9-cis-epoxycarotenoid dioxygenase (NCED), zeaxanthin epoxidase (ZEP), and short chain dehydrogenase (SDR) from the abscisic acid (ABA) synthesis pathway were identified as key mediators of this response. Thus, an appropriate degree of cold stress may promote accumulation of ginsenosides. Moreover, 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR2), squalene epoxidase (SE1), squalene synthase (SS), dammarenediol synthase (DS-II), and β-alanine C-28 hydroxylase (CYP716A52v2) should be considered key mediators of the cold stress response and ginsenoside biosynthesis. During industrial production, short-term cold stress should be carried out on ginseng calli to improve the quality of its medicinal materials.
MAIN CONCLUSION: Short-term cold stress can induce the increased expression of key enzyme-encoding genes involved in secondary metabolite synthesis, thereby increasing secondary metabolite concentration. Cold stress is an ecologically limiting factor that strongly affects the physiological and biochemical properties of medicinal plants often resulting in changes of the secondary metabolic process. Ginsenosides are the main active ingredients in medicinal ginseng yet few studies exist on the effect of cold stress on the expression of ginsenosides or the molecular mechanism underlying its regulation. Here, we evaluated the effects of cold stress on the physiological characteristics and secondary metabolism of P. ginseng embryogenic calli. Physiological measurements and RNA-Seq analysis were used to dissect the metabolic and molecular responses of P. ginseng to cold conditions. We found that the dynamic accumulation of ginsenoside and various physiological indicators leads to homogenous adaptation to cold stress. Secondary metabolism of ginseng could be a compensation mechanism to facilitate its adaptation to cold stress. Combined with the changes in the endogenous hormone content, 9-cis-epoxycarotenoid dioxygenase (NCED), zeaxanthin epoxidase (ZEP), and short chain dehydrogenase (SDR) from the abscisic acid (ABA) synthesis pathway were identified as key mediators of this response. Thus, an appropriate degree of cold stress may promote accumulation of ginsenosides. Moreover, 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR2), squalene epoxidase (SE1), squalene synthase (SS), dammarenediol synthase (DS-II), and β-alanine C-28 hydroxylase (CYP716A52v2) should be considered key mediators of the cold stress response and ginsenoside biosynthesis. During industrial production, short-term cold stress should be carried out on ginseng calli to improve the quality of its medicinal materials.
Authors: Manfred G Grabherr; Brian J Haas; Moran Yassour; Joshua Z Levin; Dawn A Thompson; Ido Amit; Xian Adiconis; Lin Fan; Raktima Raychowdhury; Qiandong Zeng; Zehua Chen; Evan Mauceli; Nir Hacohen; Andreas Gnirke; Nicholas Rhind; Federica di Palma; Bruce W Birren; Chad Nusbaum; Kerstin Lindblad-Toh; Nir Friedman; Aviv Regev Journal: Nat Biotechnol Date: 2011-05-15 Impact factor: 54.908