Strategies to increase vitamin C in plants: from plant defense perspective to food biofortification

Abstract

Vitamin C participates in several physiological processes, among others, immune stimulation, synthesis of collagen, hormones, neurotransmitters, and iron absorption. Severe deficiency leads to scurvy, whereas a limited vitamin C intake causes general symptoms, such as increased susceptibility to infections, fatigue, insomnia, and weight loss. Surprisingly vitamin C deficiencies are spread in both developing and developed countries, with the latter actually trying to overcome this lack through dietary supplements and food fortification. Therefore new strategies aimed to increase vitamin C in food plants would be of interest to improve human health. Interestingly, plants are not only living bioreactors for vitamin C production in optimal growing conditions, but also they can increase their vitamin C content as consequence of stress conditions. An overview of the different approaches aimed at increasing vitamin C level in plant food is given. They include genotype selection by “classical” breeding, bio-engineering and changes of the agronomic conditions, on the basis of the emerging concepts that plant can enhance vitamin C synthesis as part of defense responses.

Fruit quality of Brazilian genotypes of feijoa at harvest and after storage

“…fresh weight in the skin after 39 hours under ambient conditions. In plants, vitamin C production occurs via the rapid conversion of L-galactono-1,4-lactone (GAL) into L-ascorbic acid by the enzyme GAL dehydrogenase (Locato et al, 2013). The enzymatic activity of GAL dehydrogenase increases under low-temperature storage (Smirnoff & Wheeler, 2000).…”

Constitutive expression of pathogenesis-related proteins and antioxydant enzyme activities triggers maize resistance towards Fusarium verticillioides

“…The amount of ROS depends on the type and amount of enzymatic and non-enzymatic scavenging molecules that include: superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), peroxidase (POD) and the antioxidants ascorbate (ASC) and glutathione (GSH) (Mittler et al 2004). ASC levels and ASC-GSH cycle components are tightly linked to plant tolerance to biotic and abiotic stresses (Locato et al 2013;Paciolla et al 2004;.…”

Integrated bioinformatics to decipher the ascorbic acid metabolic network in tomato

“…This was probably due to selection during the tomato domestication/breeding process of agronomical traits negatively associated with AsA content (Locato et al 2013). Hence, enhancing nutritional quality of cultivated tomato fruit by increasing AsA content is still a desirable goal.…”

“…Additional improvements arose from genetic and genomics-based methods. These approaches were employed to identify genes encoding the enzymes involved in the AsA metabolism, even if most of them are still confined to the model plant species A. thaliana (Locato et al 2013). Nowadays, it is well known that several biosynthetic pathways converge to generate the final AsA pool (Valpuesta and Botella 2004), and it is generally accepted that the galactose Wheeler-Smirnoff pathway is the primary route in plants (Smirnoff and Wheeler 2000;Smirnoff et al 2001;Laing et al 2007).…”