The signal network of ascorbate homeostasis

Abstract

Ascorbate is a crucial antioxidant for scavenging hydrogen peroxide generated from the physiological processes and environmental stresses. Besides, the endo/exogenous factors that influence ascorbate level, our knowledge of the methanol stimulation is relatively less. Methanol, a byproduct from the demethylation of pectin during the enlargement of plant cell, is effective in enhancing the expression of ascorbate-biosynthetic genes of the Smirnoff-Wheeler and galacturonate (GalUA) pathways. In our previous work, hydrogen peroxide is a product of methanol detoxification through alcohol oxidase and NADPH oxidase activation, and acts as a secondary messenger for the activation of ascorbate-related genes. In this addendum, we propose a working model of the signaling network for ascorbate homeostasis in association with the apoplastic factors, such as methanol and oligogalacturonide during the growth and development of plant cell.

Genotype x Environment interaction in the yield and fruit quality of passion fruit germplasm grown in the Ecuadorian Littoral

“…The most important non-enzymatic antioxidants are: ascorbic acid (vitamin C), α-tocopherol (vitamin E), glutathione and β-carotenes (Scandalios, 2005). Some compounds related to oxidative and anti-oxidative responses caused by stress factors, such as ascorbic acid, have been found to be involved in tolerance responses to biotic and abiotic stress and optimal development (Shen and Yeh, 2010). Ascorbic acid is present in chloroplasts, cytosol, vacuoles, and apoplastic space; constituting perhaps the most important non-enzymatic antioxidant in plants, which participates in the defense against biotic and abiotic oxidative stress (Smirnoff, 1996).…”