| ORIGINAL ARTICLE |
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| Year : 2018 | Volume
: 14
| Issue : 57 | Page : 327-334 |
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Metabolic profiling and expression analysis of key genes during leaf maturation of Stevia rebaudiana bertoni
Nazima Nasrullah, Javed Ahmad, Monica Saifi, Umara Rafiqi, Naved Quadri, Irum Gul Shah, Malik Zainul Abdin
Department of Biotechnology, Center for Transgenic and Plant Development, School of Chemical and Life Sciences, New Delhi, India
Correspondence Address:
Malik Zainul Abdin
Center for Transgenic and Plant Development, Department of Biotechnology, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi - 110 062
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/pm.pm_554_17
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Background: Stevia (Stevia rebaudiana) is a plant of nutritional and industrial importance for its diverse steviol glycosides. Stevioside, rebaudioside-A and their aglycon steviol – 200-300 times sweeter than normal sucrose are novel contenders for the development of antidiabetic drugs. Stevia leaf flavor at different harvest stages is a function of the metabolite content, which results from physiological changes during plant growth and development. Objectives: The main purpose of this study was to investigate metabolite changes during plant development using GC-MS metabolic profiling and HPTLC and to analyze expression of key genes of steviol glycoside biosynthetic pathway by qPCR. Material Methods: Metabolite data and gene expression from leaf samples of eight developmental stages underwent a variety of chemometric analyses, to identify the true differences between samples. Results: There was a significant increase of steviol from 0.23% to 6.6%, stevioside from 3.3% to 14.23%, rebaudioside-A from 0.826% to 4.99% and (+)-isomenthol showed decrease in concentration from 16.79% to 5.23% with plant growth. srUGTs, srKO, srKS, srKAH, srUGP1, and srDXR increased whereas expression of (+)-srLMS and srNMD decreased with plant progression. Metabolite and gene correlation analysis revealed the interdependencies of individual metabolites and metabolic pathways genes. Conclusion: These results will help in selecting and utilizing the appropriate traits in Stevia crop.
Abbreviations used: SG: Steviol glycosides; PCA: Principal component analysis; VIP: Variable importance in the projection; UGT: Uracil glycosyltransferase.
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