Nuclear genes from Tx CMS maintainer lines are unable to maintain atp6 RNA editing in any anther cell-type in the sorghum bicolor A3 cytoplasm.
RNA editing and cytoplasmic male sterility are two important phenomena associated with higher plant mitochondria. We recently have shown a potential function of RNA editing in CMS development. The frequency of atp6 RNA editing was specifically reduced in anthers of male-sterile Sorghum bicolor, which increased in frequency in partially restored progeny. Here we present data that show that the loss of RNA editing capability also occurs in a second nuclear background that allows the expression of male sterility. Loss of RNA editing thus appears to be associated with unique combinations of male-sterile cytoplasm and non-restoring nuclear backgrounds. In addition, the reduction of RNA editing affects both gametophytic and sporophytic anther cell-types but not other floral tissues. An analysis of F(2) plants exhibiting different levels of fertility indicates a co-segregation of fertility restoration and atp6 RNA editing. The atp6 transcript abundance is similar in seedlings and anthers of male-sterile, partially restored, and male-fertile lines and thus is not associated with loss of atp6 RNA editing in anthers. A model for RNA editing and male sterility based on the data available is presented. Functional correlations with other CMS systems are also discussed.
Howad
W
W
Lehrstuhl für Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, D-44780 Bochum, Germany.
Tang
H V
HV
Pring
D R
DR
Kempken
F
F
D002467:Cell Nucleus / Q000235:genetics*; D003433:Crosses, Genetic; D003593:Cytoplasm / Q000235:genetics*; D004171:Diploidy; D005298:Fertility; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics*; D006238:Haploidy; D019684:Magnoliopsida / Q000166:cytology / Q000235:genetics* / Q000502:physiology; D008957:Models, Genetic; D009928:Organ Specificity; D010940:Plant Proteins / Q000235:genetics*; D018514:Plant Structures / Q000166:cytology / Q000235:genetics / Q000502:physiology; D011058:Pollen / Q000166:cytology / Q000235:genetics / Q000502:physiology; D006180:Proton-Translocating ATPases; D012313:RNA / Q000235:genetics / Q000378:metabolism; D017393:RNA Editing; D000077278:RNA, Mitochondrial; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D014158:Transcription, Genetic / Q000235:genetics
D010940:Plant Proteins; D000077278:RNA, Mitochondrial; D018749:RNA, Plant; D012313:RNA; D006180:Proton-Translocating ATPases