Molecular basis of nuclear and cytoplasmic male sterility in higher plants

Two major types of male sterility, Mendelian sterility (MST) and cytoplasmic male sterility (CMS) can be distinguished according to their genetic control. Molecular advances concerning MST arose initially from the isolation and the characterization of genes expressed specifically in anther and pollen. These genes were manipulated to induce pollen failure. MST was induced by tapetal-specific expression of different genes such as an RNase gene, a modified glucanase gene, the Agrobacterium rhizogenes rolC gene or an unedited atp9 mitochondrial gene in tobacco transformants, and by antisense inhibition of flavonoid biosynthesis in anthers of petunia transformants. Other recent data on MST molecular genetics were obtained from the analysis of three categories of mutants