Mitochondrial atp6 transcript editing during microgametogenesis in male-sterile sorghum.
A marked reduction of mitochondrial atp6 transcript-editing capability in sorghum anthers and pollen has been invoked as a factor in the loss of viability of male gametophytes in lines carrying the IS1112C male-sterile cytoplasm. We initiated a systematic examination of transcript editing of sorghum atp6 during microgametogenesis, from microspores through pollen, in two sets of male-fertile and near-isogenic, male-sterile lines. Transcript editing in cDNA populations from fertile lines indicated an average of about 90% editing among 15 sites examined. Parallel samples from sterile lines demonstrated a detectable reduction in editing efficiency, most evident in late pollen samples. However, editing efficiency in these cells averaged 80%, substantially higher than the 20% previously observed. Thus male-sterile lines retain substantial atp6-editing efficiency in an environment where the sterility and fertility restoration traits are stably expressed. Drastically reduced editing of atp6 transcripts in anthers and pollen of male-sterile sorghum is not demonstrable in a field environment; and thus it is not a factor in the loss of microgametophyte viability in this system.
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USDA-ARS, Department of Plant Pathology, University of Florida, Gainesville 32611, USA. drpg@gnv.ifas.ufl.edu
Van Tang
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D001483:Base Sequence; D002523:Edible Grain / Q000235:genetics* / Q000502:physiology; D008928:Mitochondria / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics*; D006180:Proton-Translocating ATPases; D017393:RNA Editing
D010940:Plant Proteins; D006180:Proton-Translocating ATPases