title: Arabidopsis root-abundant cytosolic methionine sulfoxide reductase B genes MsrB7 and MsrB8 are involved in tolerance to oxidative stress.
abstract: Excess reactive oxygen species (ROS) accumulation under various environmental stresses can damage intracellular polysaccharides, DNA, lipids and proteins. Methionine sulfoxide reductase (MSR) participates in a protein repair system that is one of the defensive mechanisms that diminishes oxidative destruction. In Arabidopsis, cytosolic MsrB7 and MsrB8 are oxidative stress-inducible protein repair enzymes that are abundant in the root. Here methyl viologen (MV) treatment was demonstrated to increase greatly the accumulation of H(2)O(2) in MsrB7-knockdown, MsrB8-knockdown and wild-type Arabidopsis, but not in transgenic plants overexpressing MsrB7 or MsrB8. The reduction in H(2)O(2) level under MV treatment in these overexpressing plants coincided with increased activity of glutathione S-transferase (GST), a herbicide-detoxifying enzyme. MsrB7 and MsrB8 are suggested to play an important role in defense against oxidative stress. Transgenic plants overexpressing MsrB7 or MsrB8 were viable and survived after MV and H(2)O(2) treatment. Ectopic expression of specific cytosolic MsrB genes may be useful for application in crop improvement.
authors.affiliation: Academia Sinica Biotechnology Center in Southern Taiwan, Tainan 741, Taiwan.
authors.forename: Chia-Wen
authors.initials: CW
authors.lastname: Li
authors.forename: Shu-Hong
authors.initials: SH
authors.lastname: Lee
authors.forename: Pei-Shan
authors.initials: PS
authors.lastname: Chieh
authors.forename: Choun-Sea
authors.initials: CS
authors.lastname: Lin
authors.forename: Yu-Chie
authors.initials: YC
authors.lastname: Wang
authors.forename: Ming-Tsair
authors.initials: MT
authors.lastname: Chan
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D003600:Cytosol / Q000201:enzymology*; D018506:Gene Expression Regulation, Plant; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism / Q000494:pharmacology; D018551:Solanum lycopersicum / Q000187:drug effects / Q000235:genetics; D051150:Methionine Sulfoxide Reductases / Q000235:genetics* / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D018384:Oxidative Stress / Q000235:genetics*; D010269:Paraquat; D018517:Plant Roots / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D030821:Plants, Genetically Modified / Q000201:enzymology; D013312:Stress, Physiological
chemical_list: D029681:Arabidopsis Proteins; D006861:Hydrogen Peroxide; D051150:Methionine Sulfoxide Reductases; C580622:MsrB7 protein, Arabidopsis; C580623:MsrB8 protein, Arabidopsis; D005982:Glutathione Transferase; D010269:Paraquat