title: Abnormal chloroplast development and growth inhibition in rice thioredoxin m knock-down plants.
abstract: Plant cells contain several thioredoxin isoforms that are characterized by subcellular localization and substrate specificity. Here, we describe the functional characterization of a rice (Oryza sativa) thioredoxin m isoform (Ostrxm) using a reverse genetics technique. Ostrxm showed green tissue-specific and light-responsive mRNA expression. Ostrxm was localized in chloroplasts of rice mesophyll cells, and the recombinant protein showed dithiothreitol-dependent insulin beta-chain reduction activity in vitro. RNA interference (RNAi) of Ostrxm resulted in rice plants with developmental defects, including semidwarfism, pale-green leaves, abnormal chloroplast structure, and reduced carotenoid and chlorophyll content. Ostrxm RNAi plants showed remarkably decreased F(v)/F(m) values under high irradiance conditions (1,000 micromol m(-2) s(-1)) with delayed recovery. Two-dimensional electrophoresis and matrix-assisted laser-desorption/ionization time-of-flight analysis showed that the levels of several chloroplast proteins critical for photosynthesis and biogenesis were significantly decreased in Ostrxm RNAi plants. Furthermore, 2-Cys peroxiredoxin, a known target of thioredoxin, was present in oxidized forms, and hydrogen peroxide levels were increased in Ostrxm RNAi plants. The pleiotropic effects of Ostrxm RNAi suggest that Ostrxm plays an important role in the redox regulation of chloroplast target proteins involved in diverse physiological functions.
authors: Division of Applied Life Science (BK21 Program), EB-NCRC and Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Korea.
authors: Yong Hun
authors: YH
authors: Chi
authors: Jeong Chan
authors: JC
authors: Moon
authors: Jin Ho
authors: JH
authors: Park
authors: Ho-Seung
authors: HS
authors: Kim
authors: Ismayil S
authors: IS
authors: Zulfugarov
authors: Wahyu Indra
authors: WI
authors: Fanata
authors: Ho Hee
authors: HH
authors: Jang
authors: Jung Ro
authors: JR
authors: Lee
authors: Young Mee
authors: YM
authors: Lee
authors: Sun Tae
authors: ST
authors: Kim
authors: Yong-Yoon
authors: YY
authors: Chung
authors: Chae Oh
authors: CO
authors: Lim
authors: Jae-Yean
authors: JY
authors: Kim
authors: Dae-Jin
authors: DJ
authors: Yun
authors: Choon-Hwan
authors: CH
authors: Lee
authors: Kyun Oh
authors: KO
authors: Lee
authors: Sang Yeol
authors: SY
authors: Lee
mesh_terms: D002338:Carotenoids / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D054479:Chloroplast Thioredoxins / Q000235:genetics / Q000378:metabolism*; D002736:Chloroplasts / Q000378:metabolism* / Q000648:ultrastructure; D004229:Dithiothreitol / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D017343:Genes, Plant; D006861:Hydrogen Peroxide / Q000378:metabolism; D012275:Oryza / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D054464:Peroxiredoxins / Q000378:metabolism; D010641:Phenotype; D010788:Photosynthesis; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D011972:Receptor, Insulin / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013379:Substrate Specificity
chemical_list: D054479:Chloroplast Thioredoxins; D010940:Plant Proteins; D020033:Protein Isoforms; D012333:RNA, Messenger; D018749:RNA, Plant; D011994:Recombinant Proteins; D002734:Chlorophyll; D002338:Carotenoids; D006861:Hydrogen Peroxide; D054464:Peroxiredoxins; D011972:Receptor, Insulin; D004229:Dithiothreitol