Hybrid Development Flowers with Arabidopsis

Managing the reproductive lives of crop plants can be a major challenge. Because many plants, such as corn, benefit from hybrid vigor, growers try to avoid inbreeding , and try instead to have plants exchange pollen with others. However, many flowers are built so that the male anthers are so close to the female pistils that it is hard to avoid self-fertilization. Since the demand for hybrids is so great, many growers make exceptional efforts to avoid inbreeding. For example, for many years, the producers of hybrid seed corn detasseled millions of acres of corn plants by hand - a costly and time-consuming procedure.

Because hybrids are so desirable and the techniques for making them can be so difficult, researchers have long sought an easier way to breed hybrids. One strategy is to breed plants to have a trait known as cytoplasmic male sterility, where plants are unable to make pollen and, therefore, must be fertilized by pollen from other plants. This type of male sterility has the unusual characteristic of being determined by genes found on the mitochondria in the cytoplasm, instead of genes found in the nucleus.

George Pelletier, of the Institut National de Recherche Agronomique in Versailles, France, began his search for new ways of using cytoplasmic male sterility by studying plants such as tobacco and oilseed rape. A major achievement was the development of new techniques for manipulating the cells of such crop plants to gain a better understanding of the role of the genome in male sterility.

In 1992, however, Pelletier expanded his research to include work with Arabidopsis. "Arabidopsis thaliana appeared to us as an excellent material for studying specific functions of the male gametophytes [sex cells] due to the possibility of recovering mutants very easily [and] specific genes involved in pollen formation and plant reproduction," he says. "The information obtained from A. thaliana will be of high interest to crop improvement. It is already true for genes involved in lipid metabolism, and we believe it will be confirmed in plant development."

Concerning plant reproduction and the challenge of growing hybrids with greater ease, Pelletier adds, "We think that new systems of pollination control could be produced from promoters, and genes isolated from A. thaliana."

Such systems borrowed from Arabidopsis may accelerate the production of hybrids - and thereby enhance worldwide agricultural production.

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