1
|
Sun Y, Chen Z, Wang G, Lv H, Mao Y, Ma K, Wang Y. De novo production of versatile oxidized kaurene diterpenes in Escherichia coli. Metab Eng 2022; 73:201-213. [DOI: 10.1016/j.ymben.2022.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 07/24/2022] [Accepted: 08/01/2022] [Indexed: 10/16/2022]
|
2
|
Zheng J, Zhuang Y, Mao HZ, Jang IC. Overexpression of SrDXS1 and SrKAH enhances steviol glycosides content in transgenic Stevia plants. BMC PLANT BIOLOGY 2019; 19:1. [PMID: 30606102 PMCID: PMC6318952 DOI: 10.1186/s12870-018-1600-2] [Citation(s) in RCA: 196] [Impact Index Per Article: 39.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 12/12/2018] [Indexed: 05/19/2023]
Abstract
BACKGROUND Stevia rebaudiana produces sweet-tasting steviol glycosides (SGs) in its leaves which can be used as natural sweeteners. Metabolic engineering of Stevia would offer an alternative approach to conventional breeding for enhanced production of SGs. However, an effective protocol for Stevia transformation is lacking. RESULTS Here, we present an efficient and reproducible method for Agrobacterium-mediated transformation of Stevia. In our attempts to produce transgenic Stevia plants, we found that prolonged dark incubation is critical for increasing shoot regeneration. Etiolated shoots regenerated in the dark also facilitated subsequent visual selection of transformants by green fluorescent protein during Stevia transformation. Using this newly established transformation method, we overexpressed the Stevia 1-deoxy-d-xylulose-5-phosphate synthase 1 (SrDXS1) and kaurenoic acid hydroxylase (SrKAH), both of which are required for SGs biosynthesis. Compared to control plants, the total SGs content in SrDXS1- and SrKAH-overexpressing transgenic lines were enhanced by up to 42-54% and 67-88%, respectively, showing a positive correlation with the expression levels of SrDXS1 and SrKAH. Furthermore, their overexpression did not stunt the growth and development of the transgenic Stevia plants. CONCLUSION This study represents a successful case of genetic manipulation of SGs biosynthetic pathway in Stevia and also demonstrates the potential of metabolic engineering towards producing Stevia with improved SGs yield.
Collapse
Affiliation(s)
- Junshi Zheng
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, 117604 Singapore
- Department of Biological Sciences, National University of Singapore, Singapore, 117558 Singapore
| | - Yan Zhuang
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, 117604 Singapore
| | - Hui-Zhu Mao
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, 117604 Singapore
| | - In-Cheol Jang
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, 117604 Singapore
- Department of Biological Sciences, National University of Singapore, Singapore, 117558 Singapore
| |
Collapse
|
3
|
Singh G, Singh G, Singh P, Parmar R, Paul N, Vashist R, Swarnkar MK, Kumar A, Singh S, Singh AK, Kumar S, Sharma RK. Molecular dissection of transcriptional reprogramming of steviol glycosides synthesis in leaf tissue during developmental phase transitions in Stevia rebaudiana Bert. Sci Rep 2017; 7:11835. [PMID: 28928460 PMCID: PMC5605536 DOI: 10.1038/s41598-017-12025-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 09/01/2017] [Indexed: 12/18/2022] Open
Abstract
Stevia is a natural source of commercially important steviol glycosides (SGs), which share biosynthesis route with gibberellic acids (GAs) through plastidal MEP and cytosolic MVA pathways. Ontogeny-dependent deviation in SGs biosynthesis is one of the key factor for global cultivation of Stevia, has not been studied at transcriptional level. To dissect underlying molecular mechanism, we followed a global transcriptome sequencing approach and generated more than 100 million reads. Annotation of 41,262 de novo assembled transcripts identified all the genes required for SGs and GAs biosynthesis. Differential gene expression and quantitative analysis of important pathway genes (DXS, HMGR, KA13H) and gene regulators (WRKY, MYB, NAC TFs) indicated developmental phase dependent utilization of metabolic flux between SGs and GAs synthesis. Further, identification of 124 CYPs and 45 UGTs enrich the genomic resources, and their PPI network analysis with SGs/GAs biosynthesis proteins identifies putative candidates involved in metabolic changes, as supported by their developmental phase-dependent expression. These putative targets can expedite molecular breeding and genetic engineering efforts to enhance SGs content, biomass and yield. Futuristically, the generated dataset will be a useful resource for development of functional molecular markers for diversity characterization, genome mapping and evolutionary studies in Stevia.
Collapse
Affiliation(s)
- Gopal Singh
- Biotechnology Department, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, India
- Academy of Scientific and Innovative Research, New Delhi, India
| | - Gagandeep Singh
- Biotechnology Department, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, India
| | - Pradeep Singh
- Biotechnology Department, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, India
| | - Rajni Parmar
- Biotechnology Department, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, India
- Academy of Scientific and Innovative Research, New Delhi, India
| | - Navgeet Paul
- Biotechnology Department, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, India
| | - Radhika Vashist
- Biotechnology Department, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, India
| | - Mohit Kumar Swarnkar
- Biotechnology Department, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, India
| | - Ashok Kumar
- Agrotechnology of Medicinal, Aromatic and Commercially Important Plants, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, India
| | - Sanatsujat Singh
- Agrotechnology of Medicinal, Aromatic and Commercially Important Plants, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, India
| | - Anil Kumar Singh
- Biotechnology Department, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, India
- ICAR-Indian Institute of Agricultural Biotechnology, PDU Campus, IINRG, Namkum, Ranchi, Jharkhand, India
| | - Sanjay Kumar
- Biotechnology Department, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, India
| | - Ram Kumar Sharma
- Biotechnology Department, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, India.
- Academy of Scientific and Innovative Research, New Delhi, India.
| |
Collapse
|