Galactinol and Raffinose Constitute a Novel Function to Protect Plants from Oxidative Damage1[W][OA]

By A. Nishizawa, Y. Yabuta, S. Shigeoka. Plant Physiology, 2008

1,016 citations recorded by the source corpus.

Galactinol synthase (GolS) is a key enzyme in the synthesis of raffinose family oligosaccharides that function as osmoprotectants in plant cells. In leaves of Arabidopsis (Arabidopsis thaliana) plants overexpressing heat shock transcription factor A2 (HsfA2), the transcription of GolS1, -2, and -4 and raffinose synthase 2 (RS2) was highly induced; thus, levels of galactinol and raffinose increased compared with those in wild-type plants under control growth conditions. In leaves of the wild-type plants, treatment with 50 μm methylviologen (MV) increased the transcript levels of not only HsfA2, but also GolS1, -2, -3, -4, and -8 and RS2, -4, -5, and -6, the total activities of GolS isoenzymes, and the levels of galactinol and raffinose. GolS1- or GolS2-overexpressing Arabidopsis plants (Ox-GolS1-11, Ox-GolS2-8, and Ox-GolS2-29) had increased levels of galactinol and raffinose in the leaves compared with wild-type plants under control growth conditions. High intracellular levels of galactinol and raffinose in the transgenic plants were correlated with increased tolerance to MV treatment and salinity or chilling stress. Galactinol and raffinose effectively protected salicylate from attack by hydroxyl radicals in vitro. These findings suggest the possibility that galactinol and raffinose scavenge hydroxyl radicals as a novel function to protect plant cells from oxidative damage caused by MV treatment, salinity, or chilling.

Subfields: Molecular Biology, Plant Science

View Paper: https://www.semanticscholar.org/paper/1a69192a72c903724a698047d37a1ddd66d07205

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Citations in the corpus

Understanding Oxidative Stress and Antioxidant Functions to Enhance Photosynthesis1 (2010, background): “…plants overexpressing galactinol synthases (GolS1 and GolS2), key enzymes in the synthesis of galactinol and raffinose, had increased levels of these oligosaccharides and enhanced tolerance to enhanced oxidation caused by exposure to paraquat, chilling, and osmotic stress (Nishizawa et al., 2008).”
Ethylene regulation of sugar metabolism in climacteric and non-climacteric plums (2018, methodology): “and their high antioxidant capacities (Nishizawa et al., 2008; Sun et al., 2013; Taji et al., 2002; Valluru and Van den Ende, 2011; Xue et al., 2007).”
The use of metabolomics to dissect plant responses to abiotic stresses (2012, background): “Raffinose is also shown to function to protect plants from oxidative damage [135], making the observation reasonable since oxidative damage likely underlies most stress conditions.”
ROS-mediated abiotic stress-induced programmed cell death in plants (2015, background): “Furthermore, both galactinol and raffinose can scavenge HO• in vitro (Nishizawa et al., 2008).”
Sucrose signaling pathways leading to fructan and anthocyanin accumulation: A dual function in abiotic and biotic stress responses? (2014, background): “Also, it has been 21 suggested that galactinol, RFOs and fructans might be essential in scavenging hydroxyl 22 radicals in the vicinity of membranes in vivo since such reactions could be demonstrated 23 in vitro (Nishizawa et al., 2008; Peshev et al., 2013).”
Drought, salt, and temperature stress-induced metabolic rearrangements and regulatory networks (2012, neutral): “Over expression of HsFA2 led to the constitutive accumulation of galactinol and raffinose and improved the tolerance of Arabidopsis plants to different environmental stresses (Nishizawa et al., 2006, 2008; Ogawa et al., 2007).”
Cold stress and acclimation - what is important for metabolic adjustment? (2010, background): “Nishizawa et al. (2008) have also suggested the possibility that both galactinol and raffinose are ROS scavengers.”