β-Glucuronidase activity during development of the male gametophyte from transgenic and non-transgenic plants

Abstract

Beta-glucuronidase (GUS) was histochemically analyzed in anthers and pollen of potato, tobacco and tomato. GUS activity was determined in transgenic plants containing a chimaeric GUS gene and in untransformed plants. In anthers of transgenic plants at premeiotic and meiotic stages of sporogenous development, indigogenic precipitation indicative of GUS activity was consistently manifest in cells of the vascular cylinder, the connectivum and the stomium while no activity was found in the tapetal and sporogenous tissues. At similar stages, anther sections of untransformed plants did not show any indigo blue staining. At later stages of microspore and pollen development, anthers of both transgenic and untransformed plants demonstrated consistently high levels of GUS activity in tapetal and sporogenic cells. In anthers of transgenic plants, GUS was also present in the vascular cylinder, the connectivum and the stomium. These results indicate that in anthers of transgenic potato, tobacco and tomato the chimaeric GUS gene product was localized tissue specifically. They also show that an endogenous GUS gene was expressed in a temporal- and spatial-specific manner in the tapetum and pollen of both transformed and untransformed plants.