title: Elevating vitamin C content via overexpression ofmyo-inositol oxygenase and l-gulono-1,4-lactone oxidase inArabidopsisleads to enhanced biomass and tolerance to abiotic stresses.
abstract: l-Ascorbic acid (vitamin C) is an abundant metabolite in plant cells and tissues. Ascorbate functions as an antioxidant, as an enzyme cofactor, and plays essential roles in multiple physiological processes including photosynthesis, photoprotection, control of cell cycle and cell elongation, and modulation of flowering time, gene regulation, and senescence. The importance of this key molecule in regulating whole plant morphology, cell structure, and plant development has been clearly established via characterization of low vitamin C mutants ofArabidopsis, potato, tobacco, tomato, and rice. However, the consequences of elevating ascorbate content in plant growth and development are poorly understood. Here we demonstrate thatArabidopsislines over-expressing amyo-inositol oxygenase or an l-gulono-1,4-lactone oxidase, containing elevated ascorbate, display enhanced growth and biomass accumulation of both aerial and root tissues. To our knowledge this is the first study demonstrating such a marked positive effect in plant growth in lines engineered to contain elevated vitamin C content. In addition, we present evidence showing that these lines are tolerant to a wide range of abiotic stresses including salt, cold, and heat. Total ascorbate content of the transgenic lines remained higher than those of controls under the abiotic stresses tested. Interestingly, exposure to pyrene, a polycyclic aromatic hydrocarbon and known inducer of oxidative stress in plants, leads to stunted growth of the aerial tissue, reduction in the number of root hairs, and inhibition of leaf expansion in wild type plants, while these symptoms are less severe in the over-expressers. Our results indicate the potential of this metabolic engineering strategy to develop crops with enhanced biomass, abiotic stress tolerance, and phytoremediation capabilities.
authors.affiliation: Arkansas Biosciences Institute, Arkansas State University, P.O. Box 639, State University, AR 72467, USA.
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Lisko
authors.affiliation: Arkansas Biosciences Institute, Arkansas State University, P.O. Box 639, State University, AR 72467, USA.
authors.forename: Raquel
authors.initials: R
authors.lastname: Torres
authors.affiliation: Arkansas Biosciences Institute, Arkansas State University, P.O. Box 639, State University, AR 72467, USA.
authors.forename: Rodney S
authors.initials: RS
authors.lastname: Harris
authors.affiliation: Arkansas Biosciences Institute, Arkansas State University, P.O. Box 639, State University, AR 72467, USA ; Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609-2280, USA.
authors.forename: Melinda
authors.initials: M
authors.lastname: Belisle
authors.affiliation: Department of Plant Pathology, Physiology and Weed Science, Virginia Tech, Blacksburg, VA 24061, USA.
authors.forename: Martha M
authors.initials: MM
authors.lastname: Vaughan
authors.affiliation: Department of Plant Pathology, Physiology and Weed Science, Virginia Tech, Blacksburg, VA 24061, USA.
authors.forename: Berangère
authors.initials: B
authors.lastname: Jullian
authors.affiliation: Department of Plant Pathology, Physiology and Weed Science, Virginia Tech, Blacksburg, VA 24061, USA.
authors.forename: Boris I
authors.initials: BI
authors.lastname: Chevone
authors.affiliation: Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24061, USA.
authors.forename: Pedro
authors.initials: P
authors.lastname: Mendes
authors.affiliation: Department of Plant Pathology, Physiology and Weed Science, Virginia Tech, Blacksburg, VA 24061, USA.
authors.forename: Craig L
authors.initials: CL
authors.lastname: Nessler
authors.affiliation: Arkansas Biosciences Institute, Arkansas State University, P.O. Box 639, State University, AR 72467, USA ; Department of Chemistry and Physics, Arkansas State University, P.O. Box 419, State University, AR 72467, USA.
authors.forename: Argelia
authors.initials: A
authors.lastname: Lorence
keywords: Vitamin C; ascorbic acid; phytoremediation; plant growth; stress tolerance