title: TSV, a putative plastidic oxidoreductase, protects rice chloroplasts from cold stress during development by interacting with plastidic thioredoxin Z.
abstract: Rice is vulnerable to cold stress. Seedlings are very sensitive to cold stress and this harms global rice production. The effects of cold on chloroplast development are well known, but little is known about the underlying molecular mechanisms. Here, we isolated a temperature-sensitive virescent (tsv) mutant that is extremely sensitive to cold stress. It displayed defective chloroplasts, decreased chlorophyll and zero survivorship under cold stress. We isolated and identified TSV by map-based cloning and rescue experiments, combined with genetic, cytological and molecular biological analyses. We found that TSV, a putative plastidic oxidoreductase, is a new type of virescent protein. A mutation in tsv causes premature termination of the gene product. The activity of plastid-encoded RNA polymerase (PEP) and the expression of genes participating in chlorophyll synthesis were severely reduced in the tsv mutant under cold stress, but not at normal temperatures. TSV expression was induced by low temperatures. Strikingly, TSV interacted with OsTrxZ (a subunit of PEP in chloroplasts) and enhanced OsTrxZ stability under low temperatures. We demonstrated that TSV protects rice chloroplasts from cold stress by interacting with OsTrxZ. These results provide novel insights into ways in which rice chloroplast development and chlorophyll synthesis are protected by TSV under cold stress.
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Tianhui
authors.initials: T
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Xinhua
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Gaoming
authors.initials: G
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Yunlu
authors.initials: Y
authors.lastname: Tian
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Yihua
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Biology, Wilkes University, Wilkes-Barre, PA, 18766, USA.
authors.forename: William
authors.initials: W
authors.lastname: Terzaghi
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China.|Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing, 210095, China.
authors.forename: Chunming
authors.initials: C
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China.|National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop, Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors.forename: Jianmin
authors.initials: J
authors.lastname: Wan
mesh_terms: D002734:Chlorophyll / Q000378:metabolism; D054479:Chloroplast Thioredoxins / Q000378:metabolism*; D002736:Chloroplasts / Q000378:metabolism / Q000502:physiology / Q000648:ultrastructure; D003001:Cloning, Molecular; D058639:Cold-Shock Response; D004252:DNA Mutational Analysis; D012275:Oryza / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D010940:Plant Proteins / Q000378:metabolism*; D013696:Temperature
chemical_list: D054479:Chloroplast Thioredoxins; D010940:Plant Proteins; D002734:Chlorophyll
keywords: 
  Oryza sativa
  ; 
  OsTrxZ
  ; TEMPERATURE-SENSITIVE VIRESCENT (TSV); chlorophyll synthesis; chloroplast development; cold stress