Mitochondrial transcript processing and restoration of male fertility in T-cytoplasm maize

• Published in: The Journal of heredity 1999-05, Vol.90 (3), p.380-385
• Main Authors: Wise, R.P, Gobelman-Werner, K, Pei, D, Dill, C.L, Schnable, P.S
• Format: Article
• Language: English
• Subjects: Alleles; Base Sequence; Corn; DNA Transposable Elements; DNA, Complementary; DNA, Mitochondrial - genetics; Fertility; Flowers & plants; Genetics; Genome, Plant; Molecular biology; Mutation; RNA Processing, Post-Transcriptional; RNA, Messenger - genetics; RNA, Messenger - metabolism; Sequence Homology, Nucleic Acid; Zea mays; Zea mays - genetics; Zea mays - physiology
• ISSN: 0022-1503; 1465-7333
• DOI: 10.1093/jhered/90.3.380

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 closely linked to the Rf8 locus. These tools will provide a foundation for determining mechanisms of nuclear-directed mitochondrial RNA processing and fertility restoration.