Immunolocalization of arabinogalactan proteins (AGPs) in reproductive structures of an early-divergent angiosperm, Trithuria (Hydatellaceae)

Abstract

Background and Aims Trithuria is the sole genus of Hydatellaceae, a family of the early-divergent angiosperm lineage Nymphaeales (water-lilies). In this study different arabinogalactan protein (AGP) epitopes in T. submersa were evaluated in order to understand the diversity of these proteins and their functions in flowering plants. Methods Immunolabelling of different AGPs and pectin epitopes in reproductive structures of T. submersa at the stage of early seed development was achieved by immunofluorescence of specific antibodies. Key Results AGPs in Trithuria pistil tissues could be important as structural proteins and also as possible signalling molecules. Intense labelling was obtained with anti-AGP antibodies both in the anthers and in the intine wall, the latter associated with pollen tube emergence. Conclusions AGPs could play a significant role in Trithuria reproduction, due to their specific presence in the pollen tube pathway. The results agree with labellings obtained for Arabidopsis and confirms the importance of AGPs in angiosperm reproductive structures as essential structural components and probably important signalling molecules. © The Author 2012.