|Gobelman Werner, Karin|
Submitted to: Journal of Heredity
Publication Type: Review Article
Publication Acceptance Date: 11/1/1998
Publication Date: N/A
Technical Abstract: Cytoplasmic male sterility (CMS) systems have been useful in the production of hybrid seed in a number of crops. The Texas or T-cytoplasmic male- sterile (cms-T) system was used extensively in the 1960s to eliminate the need for hand detasseling in hybrid maize production. As a consequence of the 1970 epidemic of southern corn leaf blight, cms-T is no longer widely used commercially. However, it has been developed as a model system to study the genetic and molecular mechanisms underlying male sterility and fertility restoration. Male sterility in T-cytoplasm maize results from the action of a T-cytoplasm specific mitochondrial gene, T-urf13. Full or partial fertility restoration of T-cytoplasm maize is mediated by the Rf2 nuclear restorer, in combination with one of three other restorers: Rf1, Rf8, or Rf*. Rf2 encodes a protein highly similar to mitochondrial aldehyde dehydrogenases; Rf1, Rf8, and Rf* each mediate discrete T-urf13 mitochondrial transcript processing events. To test the functionality of Rf1, Rf8, or Rf*, a T-cytoplasm transformation system is under development. AFLP bulk-segregant analysis has been used to identify DNA markers flanking the Rf8 locus. These tools will provide a foundation for determining mechanisms of nuclear-directed mitochondrial RNA processing and fertility restoration.