Role of MYB305 in the Function of the Floral Nectary

Iowa State University, Ames IA

Investigators

Abstract

In many species of flowering plants, a floral nectary gland secretes rich nectar that attracts visiting pollinators such as honeybees to the flower. These visiting pollinators then transfer pollen from flower to flower which not only increases the number of seeds set in the fruit, but also increases the diversity of plants by increasing the degree of 'genetic-outcrossing' for the plant. This project involves the study of the floral nectary gland and specifically a transcription factor, MYB305, that mediates the development of this important floral organ. The investigators have previously developed knockout mutants of MYB305 in a tobacco model system. The knockout mutants fail to properly develop and they do not produce nectar. This project will focus on a comparison between the knockout mutant plants with wildtype plants that do produce nectar. Initially the investigators will evaluate the genes that are expressed in the developing nectary gland of both wildtype and mutant plants to identify targets of MYB305 action. The project will also examine nectaries from a number of additional species of solanaceous plants to evaluate the degree to which the tobacco model system can serve to predict the biochemistry and genetics of this very important plant family. Identifying and understanding the molecules that regulate nectary development could lead to novel and dramatic improvements in both nectar quantity and quality that could enhance pollinator visitation, cross-pollination, and ultimately increase plant productivity (yield). Broader Impacts Various aspects of this proposal are directed towards graduate and undergraduate education and training. Information is disseminated via the Nectary Gene Expression website (www.bb.iastate.edu/necgex/). This website is popular with gardeners, students and laymen. Site hits and resulting emails suggest it is a truly successful outreach to the general population and has been a fruitful educational extension for this project. Further, by enhancing the function of nectaries, increased cross-pollination of insect pollinated fruits, vegetables, nuts, berries, oilseed and other crops will result.