Over-expression of strawberry d-galacturonic acid reductase in potato leads to accumulation of vitamin C with enhanced abiotic stress tolerance

• Published in: Plant science (Limerick) Vol. 177; no. 6; pp. 659 - 667
• Main Authors: Hemavathi, Upadhyaya, Chandrama Prakash, Young, Ko Eun, Akula, Nookaraju, Kim, Hyun soon, Heung, Jeon Jae, Oh, Oh Man, Aswath, Chenna Reddy, Chun, Se Chul, Kim, Doo Hwan, Park, Se Won
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 01-12-2009; [Ireland]: Elsevier Science Ireland Ltd; Elsevier
• Subjects: Abiotic stress; ascorbic acid; Biological and medical sciences; chlorophyll; d-Galacturonic acid reductase; Fragaria ananassa; fruit crops; Fundamental and applied biological sciences. Psychology; galacturonic acid; genes; genome; genomics; HPLC; molecular sequence data; oxidoreductases; plant stress; potatoes; promoter regions; senescence; Solanum tuberosum; Solanum tuberosum L; strawberries; transgenic plants; tubers; Vitamin C; d-Galacturonic acid reductase; Solanum tuberosum L; Abiotic stress; HPLC; Vitamin C; Ascorbic acid; Small fruits; Rosaceae; Plant biology; HPLC chromatography; Environmental factor; Abiotic factor; Potato; Dicotyledones; Strawberry; Angiospermae; Solanaceae; Fragaria; Enzyme; Solanum tuberosum; D-Galacturonic acid reductase; Tolerance; Stress; Spermatophyta; Oxidoreductases; Tuber plant; Galacturonic acid; Reductase
• ISSN: 0168-9452; 1873-2259
• DOI: 10.1016/j.plantsci.2009.08.004

Vitamin C (ascorbic acid) is an essential component for collagen biosynthesis and also for the proper functioning of the cardiovascular system in humans. Unlike most of the animals, humans lack the ability to synthesize ascorbic acid on their own due to a mutation in the gene encoding the last enzyme of ascorbate biosynthesis. As a result, vitamin C must be obtained from dietary sources like plants. In this study, we have developed transgenic potato plants (
Solanum tuberosum L. cv. Taedong Valley) over-expressing strawberry
GalUR gene under the control of
CaMV 35S promoter with increased ascorbic acid levels. Integration of the
GalUR gene in the plant genome was confirmed by PCR and Southern blotting. Ascorbic acid (AsA) levels in transgenic tubers were determined by high-performance liquid chromatography (HPLC). The over-expression of
GalUR resulted in 1.6–2-fold increase in AsA in transgenic potato and the levels of AsA were positively correlated with increased GalUR activity. The transgenic lines with enhanced vitamin C content showed enhanced tolerance to abiotic stresses induced by methyl viologen (MV), NaCl or mannitol as compared to untransformed control plants. The leaf disc senescence assay showed better tolerance in transgenic lines by retaining higher chlorophyll as compared to the untransformed control plants. Present study demonstrated that the over-expression of
GalUR gene enhanced the level of AsA in potato tubers and these transgenics performed better under different abiotic stresses as compared to untransformed control.