The Induction of Embryogenesis in Nicotiana Immature Pollen in Culture

Summary

Immature pollen grains consitute unique experimental material for the study of embryogenic processes because they are uniform in size and shape in a given species and can easily be isolated. They are also useful in the production of haploid and homozygotic plants for breeding and studies on genetics. However, basic information on pollen embryogenesis is limited and the mechanism of the acquisition of embryogenic capacity is still unclear. This is mainly due to the fact that the number of immature pollen grains which undergo the process of embryogenesis is not high enough to allow physiological and biochemical analysis.

Therefore, with the aim of increasing the frequency of embryogenesis, we conducted a series of experiments by both anther and isolated pollen culture on various factors that affect Nicotiana pollen embryogenesis. The results enabled us to increase significantly the rate of embryogenesis and to direct the development of immature pollen grains to either normal maturation or embryogenesis.

We also attempted to define any biochemical changes which may be related to the induction of pollen embryogenesis by applying this experimental system. We found some significant changes in protein phosphorylation which seem to be related to the initial stage of pollen embryogenesis.