title: A pepper MSRB2 gene confers drought tolerance in rice through the protection of chloroplast-targeted genes.
abstract: BACKGROUND
  The perturbation of the steady state of reactive oxygen species (ROS) due to biotic and abiotic stresses in a plant could lead to protein denaturation through the modification of amino acid residues, including the oxidation of methionine residues. Methionine sulfoxide reductases (MSRs) catalyze the reduction of methionine sulfoxide back to the methionine residue. To assess the role of this enzyme, we generated transgenic rice using a pepper CaMSRB2 gene under the control of the rice Rab21 (responsive to ABA protein 21) promoter with/without a selection marker, the bar gene.
  
  
  RESULTS
  A drought resistance test on transgenic plants showed that CaMSRB2 confers drought tolerance to rice, as evidenced by less oxidative stress symptoms and a strengthened PSII quantum yield under stress conditions, and increased survival rate and chlorophyll index after the re-watering. The results from immunoblotting using a methionine sulfoxide antibody and nano-LC-MS/MS spectrometry suggest that porphobilinogen deaminase (PBGD), which is involved in chlorophyll synthesis, is a putative target of CaMSRB2. The oxidized methionine content of PBGD expressed in E. coli increased in the presence of H2O2, and the Met-95 and Met-227 residues of PBGD were reduced by CaMSRB2 in the presence of dithiothreitol (DTT). An expression profiling analysis of the overexpression lines also suggested that photosystems are less severely affected by drought stress.
  
  
  CONCLUSIONS
  Our results indicate that CaMSRB2 might play an important functional role in chloroplasts for conferring drought stress tolerance in rice.
authors.affiliation: Division of Bioscience and Bioinformatics, Myong Ji University, Yongin, Kyonggido, Korea.
authors.forename: Joung Sug
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Rice research division, National Institute of Crop Science, Suwon, Korea.
authors.forename: Hyang-Mi
authors.initials: HM
authors.lastname: Park
authors.affiliation: Genomics Genetics Institute, GreenGene BioTech Inc., Yongin, Kyonggido, Korea.
authors.forename: Songhwa
authors.initials: S
authors.lastname: Chae
authors.affiliation: Genomics Genetics Institute, GreenGene BioTech Inc., Yongin, Kyonggido, Korea.
authors.forename: Tae-Ho
authors.initials: TH
authors.lastname: Lee
authors.affiliation: National Academy of Agricultural Science, Rural Development Administration, Suwon, Korea.
authors.forename: Duk-Ju
authors.initials: DJ
authors.lastname: Hwang
authors.affiliation: National Academy of Agricultural Science, Rural Development Administration, Suwon, Korea.
authors.forename: Sung-Dug
authors.initials: SD
authors.lastname: Oh
authors.affiliation: National Academy of Agricultural Science, Rural Development Administration, Suwon, Korea.
authors.forename: Jong-Sug
authors.initials: JS
authors.lastname: Park
authors.affiliation: Functional Food Center, Korea Institute of Science and Technology (KIST), Gangneung, Gangwon-do, Korea.
authors.forename: Dae-Geun
authors.initials: DG
authors.lastname: Song
authors.affiliation: Functional Food Center, Korea Institute of Science and Technology (KIST), Gangneung, Gangwon-do, Korea.
authors.forename: Cheol-Ho
authors.initials: CH
authors.lastname: Pan
authors.affiliation: College of Agriculture and Life Sciences and Plant Genomics & Breeding Institute, Seoul National University, Seoul, Korea.
authors.forename: Doil
authors.initials: D
authors.lastname: Choi
authors.affiliation: Rice research division, National Institute of Crop Science, Suwon, Korea.
authors.forename: Yul-Ho
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Division of Bioscience and Bioinformatics, Myong Ji University, Yongin, Kyonggido, Korea; Genomics Genetics Institute, GreenGene BioTech Inc., Yongin, Kyonggido, Korea.
authors.forename: Baek Hie
authors.initials: BH
authors.lastname: Nahm
authors.affiliation: Genomics Genetics Institute, GreenGene BioTech Inc., Yongin, Kyonggido, Korea.
authors.forename: Yeon-Ki
authors.initials: YK
authors.lastname: Kim
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D000595:Amino Acid Sequence; D002212:Capsicum / Q000235:genetics*; D002734:Chlorophyll / Q000378:metabolism; D015536:Down-Regulation / Q000235:genetics; D055864:Droughts; D005453:Fluorescence; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D061125:Genes, Chloroplast; D017343:Genes, Plant; D011163:Hydroxymethylbilane Synthase / Q000378:metabolism; D008715:Methionine / Q000031:analogs & derivatives / Q000378:metabolism; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics* / Q000502:physiology; D018384:Oxidative Stress; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics; D030821:Plants, Genetically Modified; D021381:Protein Transport; D011994:Recombinant Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013347:Subcellular Fractions / Q000378:metabolism; D014170:Transformation, Genetic; D015854:Up-Regulation / Q000235:genetics
chemical_list: D010940:Plant Proteins; D011994:Recombinant Proteins; D002734:Chlorophyll; D008715:Methionine; D011163:Hydroxymethylbilane Synthase; C013111:methionine sulfoxide