title: Pollen developmental defects in ZD-CMS rice line explored by cytological, molecular and proteomic approaches.
abstract: Cytoplasmic male sterility (CMS) is a widely observed phenomenon, which is especially useful in hybrid seed production. Meixiang A (MxA) is a new rice CMS line derived from a pollen-free sterile line named Yunnan ZidaoA (ZD-CMS). In this study, a homologous WA352 gene with variation in two nucleotides was identified in MxA. Cytological analysis revealed that MxA was aborted in the early uninucleate stage. The protein expression profiles of MxA and its maintainer line MeixiangB (MxB) were systematically compared using iTRAQ-based quantitative proteomics technology using young florets at the early uninucleate stage. A total of 688 proteins were quantified in both rice lines, and 45 of these proteins were found to be differentially expressed. Bioinformatics analysis indicated a large number of the proteins involved in carbohydrate metabolism or the stress response were downregulated in MxA, suggesting that these metabolic processes had been hindered during pollen development in MxA. The ROS (reactive oxygen species) level was increased in the mitochondrion of MxA, and further ultrastructural analysis showed the mitochondria with disrupted cristae in the rice CMS line MxA. These findings substantially contribute to our knowledge of pollen developmental defects in ZD-CMS rice line.
  
  
  CONCLUSIONS
  MeixiangA (MxA) is a new type of rice CMS line, which is derived from pollen-free sterile line Yunnan ZidaoA. In this study, the cytological, molecular and proteomic approaches were used to study the characteristics of this new CMS line. Cytological study indicates the CMS line is aborted at the early uninucleate stage. A potential sterile gene ZD352 is identified in MxA, the protein product of which is mainly accumulated at the MMC/Meiotic stage. iTRAQ based proteomic analysis is performed to study the relevant proteins involved in the CMS occurance, 45 proteins are found to be significant differentially expressed and these proteins are involved in many cellular processes such as carbohydrate metabolism, stress response, protein synthesis. To our knowledge, this is the first report using the iTRAQ-labeled quantitative proteomic to study the protein expression variation during the abortion processes between a CMS line and its maintainer line. These results provide new insights on the CMS mechanisms of ZD-CMS rice line.
authors.affiliation: State Key Laboratory of Hybrid Rice, Department of Genetics, College of Life Sciences, Wuhan University, Wuhan 430072, P.R. China.
authors.forename: Junjie
authors.initials: J
authors.lastname: Yan
authors.affiliation: State Key Laboratory of Virology, Department of Biochemistry, College of Life Sciences, Wuhan University, Wuhan 430072, P.R. China.
authors.forename: Han
authors.initials: H
authors.lastname: Tian
authors.affiliation: State Key Laboratory of Hybrid Rice, Department of Genetics, College of Life Sciences, Wuhan University, Wuhan 430072, P.R. China.
authors.forename: Shuzhen
authors.initials: S
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Hybrid Rice, Department of Genetics, College of Life Sciences, Wuhan University, Wuhan 430072, P.R. China.
authors.forename: Jinzhen
authors.initials: J
authors.lastname: Shao
authors.affiliation: State Key Laboratory of Hybrid Rice, Department of Genetics, College of Life Sciences, Wuhan University, Wuhan 430072, P.R. China.
authors.forename: Yinzhen
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Hybrid Rice, Department of Genetics, College of Life Sciences, Wuhan University, Wuhan 430072, P.R. China.
authors.forename: Hongyuan
authors.initials: H
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Virology, Department of Biochemistry, College of Life Sciences, Wuhan University, Wuhan 430072, P.R. China.
authors.forename: Lin
authors.initials: L
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Hybrid Rice, Department of Genetics, College of Life Sciences, Wuhan University, Wuhan 430072, P.R. China. Electronic address: yiding@whu.edu.cn.
authors.forename: Yi
authors.initials: Y
authors.lastname: Ding
mesh_terms: D018506:Gene Expression Regulation, Plant; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D012275:Oryza / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D051479:Plant Infertility / Q000235:genetics*; D010940:Plant Proteins / Q000096:biosynthesis / Q000235:genetics; D011058:Pollen / Q000235:genetics / Q000378:metabolism; D040901:Proteomics
chemical_list: D010940:Plant Proteins
keywords: Abortive gene; Mitochondrion; Proteomics; Rice CMS; iTRAQ