title: The mitochondrial gene orfH79 plays a critical role in impairing both male gametophyte development and root growth in CMS-Honglian rice.
abstract: BACKGROUND
  Cytoplasmic male sterility (CMS) has often been associated with abnormal mitochondrial open reading frames. The mitochondrial gene orfH79 is a candidate gene for causing the CMS trait in CMS-Honglian (CMS-HL) rice. However, whether the orfH79 expression can actually induce CMS in rice remains unclear.
  
  
  RESULTS
  Western blot analysis revealed that the ORFH79 protein is mainly present in mitochondria of CMS-HL rice and is absent in the fertile line. To investigate the function of ORFH79 protein in mitochondria, this gene was fused to a mitochondrial transit peptide sequence and used to transform wild type rice, where its expression induced the gametophytic male sterile phenotype. In addition, excessive accumulation of reactive oxygen species (ROS) in the microspore, a reduced ATP/ADP ratio, decreased mitochondrial membrane potential and a lower respiration rate in the transgenic plants were found to be similar to those in CMS-HL rice. Moreover, retarded growth of primary and lateral roots accompanied by abnormal accumulation of ROS in the root tip was observed in both transgenic rice and CMS-HL rice (YTA).
  
  
  CONCLUSIONS
  These results suggest that the expression of orfH79 in mitochondria impairs mitochondrial function, which affects the development of both male gametophytes and the roots of CMS-HL rice.
authors.affiliation: Key Laboratory of MOE for Plant Developmental Biology, College of Life Science, Wuhan University, Wuhan, PR China. shaoqingli@whu.edu.cn
authors.forename: Xiaojue
authors.initials: X
authors.lastname: Peng
authors.forename: Kun
authors.initials: K
authors.lastname: Wang
authors.forename: Chaofeng
authors.initials: C
authors.lastname: Hu
authors.forename: Youlin
authors.initials: Y
authors.lastname: Zhu
authors.forename: Ting
authors.initials: T
authors.lastname: Wang
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.forename: Jiping
authors.initials: J
authors.lastname: Tong
authors.forename: Shaoqing
authors.initials: S
authors.lastname: Li
authors.forename: Yingguo
authors.initials: Y
authors.lastname: Zhu
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D050259:Genes, Mitochondrial / Q000502:physiology*; D053078:Membrane Potential, Mitochondrial; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism; D012275:Oryza / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D018517:Plant Roots / Q000254:growth & development* / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D011058:Pollen / Q000254:growth & development* / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D017382:Reactive Oxygen Species; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate