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Ontogenetic changes in vitamin C in selected rice varieties

Permanent URL:
http://handle.nal.usda.gov/10113/58005
Abstract:
Vitamin C (L-ascorbic acid) is a key antioxidant for both plants and animals. In plants, ascorbate is involved in several key physiological processes including photosynthesis, cell expansion and division, growth, flowering, and senescence. In addition, ascorbate is an enzyme cofactor and a regulator of gene expression. During exposure to abiotic stresses, ascorbate counteracts excessive reactive oxygen species within the cell and protects key molecules, including lipids, proteins, and nucleic acids, from irreversible damage. In this study we focus on understanding how ascorbate levels are controlled in rice (Oryza sativa) during plant development and in response to light intensity and photoperiod. Our results indicate that in rice ascorbate metabolism follows a different pattern compared to other species. In the rice accessions we analyzed, total foliar ascorbate content increases during development and peaks at the vegetative 2e4 and the reproductive 4 stages, whereas other research has shown that in Arabidopsis thaliana and other dicots, ascorbate content declines with plant age. The pattern in rice does not seem to change when plants were grown under increasing light intensity: 150, 400 or 1200e1500 mmol m2 s1. We observed little diurnal variation in AsA content in rice and did not see a steady decline during the dark period as has been reported in other species such as Arabidopsis and tomato. The total foliar ascorbate content of twenty-three rice accessions from four major rice subgroups was compared. These genotypes differed as much as eight-fold in ascorbate content at the V2 stage indicating the potential to enhance vitamin C levels in genotypes of global interest via breeding approaches.
Author(s):
Katherine A. Lisko , John F. Hubstenberger , Gregory C. Phillps , Helen Belefant-Miller , Anna McClung , Argelia Lorence
Subject(s):
Arabidopsis thaliana , Oryza sativa , animals , ascorbic acid , chemical constituents of plants , diurnal variation , flowering , gene expression , genotype , light intensity , lipids , nucleic acids , photosynthesis , plant age , proteins , reactive oxygen species , regulator genes , rice , scotophase , senescence , tomatoes , varieties
Source:
Plant physiology and biochemistry 2013 v.66
Language:
English
Year:
2013
Collection:
Journal Articles, USDA Authors, Peer-Reviewed
File:
Download [PDF File]
Rights:
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.