Overexpression of an alfalfa GDP-mannose 3, 5-epimerase gene enhances acid, drought and salt tolerance in transgenic Arabidopsis by increasing ascorbate accumulation
- 769 Downloads
GDP-mannose 3′, 5′-epimerase (GME) catalyses the conversion of GDP-d-mannose to GDP-l-galactose, an important step in the ascorbic acid (ascorbic acid) biosynthetic pathway in higher plants. In this study, a novel cDNA fragment (MsGME) encoding a GME protein was isolated and characterised from alfalfa (Medicago sativa). An expression analysis confirmed that MsGME expression was induced by salinity, PEG and acidity stresses. MsGME overexpression in Arabidopsis enhanced tolerance of the transgenic plants to salt, drought and acid. Real-time PCR analysis revealed that the transcript levels of GDP-d-mannose pyrophosphorylase (GMP), l-galactose-phosphate 1-P phosphatase (GP) and GDP-l-galactose phosphorylase (GGP) were increased in transgenic Arabidopsis (T3 generation). Moreover, the ascorbate content was increased in transgenic Arabidopsis. Our results suggest that MsGME can effectively enhance tolerance of transgenic Arabidopsis to acid, drought and salt by increasing ascorbate accumulation.
KeywordsAcid tolerance Alfalfa Arabidopsis Ascorbic acid Drought tolerance GDP-mannose 3′, 5′-epimerase Salt tolerance Transgenic plants
This study was supported by the National Basic Research Program of China (2014CB138704) and the National Natural Science Foundation of China (31072072).
- Chang CCC, Slesak I, Jorda L, Sotnikov A, Melzer M, Miszalski Z, Mullineaux PM, Parker JE, Karpinska B, Karpinski S (2009) Arabidopsis chloroplastic glutathione peroxidases play a role in cross talk between photooxidative stress and immune response. Plant Physiol 150:670–683PubMedCrossRefPubMedCentralGoogle Scholar
- Dutilleul C, Garmier M, Noctor G, Mathieu C, Chetrit P, Foyer CH, de Paepe R (2003) Leaf mitochondria modulate whole cell redox homeostasis, set antioxidant capacity, and determine stress resistance through altered signaling and diurnal regulation. Plant Cell 15:1212–1226PubMedCrossRefPubMedCentralGoogle Scholar
- Gilbert L, Alhagdow M, Nunes-Nesi A, Quemener B, Guillon F, Bouchet B, Faurobert M, Gouble B, Page D, Garcia V (2009) The GDP-d-mannose 3, 5-epimerase (GME) plays a key role at the intersection of ascorbate and non-cellulosic cell wall biosynthesis in tomato. Plant J 60:499–508PubMedCrossRefGoogle Scholar
- Hebda P, Behrman E, Barber G (1979) The guanosine 5′- diphosphate d-mannose: guanosine 5′-diphosphate l-galactose epimerase of Chlorella pyrenoidosa. Chemical synthesis of guanosine 50-diphosphate l-galactose and further studies of the enzyme and the reaction it catalyzes. Arch Biochem Biophys 194:496–502PubMedCrossRefGoogle Scholar
- Ioannidi E, Kalamaki M, Engineer C, Pateraki I, Alexandrou D, Mellidou I, Giovannonni J, Kanellis A (2009) Expression profiling of ascorbic acid-related genes during tomato fruit development and ripening and in response to stress conditions. J Exp Bot 60:663–678PubMedCrossRefPubMedCentralGoogle Scholar
- Nishikirni M, Fukuyama R, Minoshima S, Shimizu N, Yagi K (1994) Cloning and chromosomal mapping of the human non-functional gene for l-gulono-g-lactone oxidase, the enzyme for l-ascorbic acid biosynthesis missing in man. J Biol Chem 269:13685–13688Google Scholar
- Wolucka B, Persiau G, Van Doorsselaere J, Davey M, Demol H, Vandekerckhove J, Van Montagu M, Zabeau M, Boerjan W (2001) Partial purification and identification of GDP-mannose 3′, 5′-epimerase of Arabidopsis thaliana, a key enzyme of the plant vitamin C pathway. Proc Natl Acad Sci USA 98:14843–14848PubMedCrossRefPubMedCentralGoogle Scholar