Extracellular localization of napin in the embryogenic tissues of Brassica napus spp. oleifera

Abstract

Napin, a storage protein, has been reported to be transcribed abundantly during the pre-embryogenic stage and associated with the induction of Brassica napus secondary embryogenesis. In this study, we studied the distribution pattern of napin in the winter oilseed rape embryogenic tissue in comparison to that of the nonembryogenic tissue using the indirect immunofluorescence localisation coupled with the ultrastructural immunogold labelling techniques. Immunolocalisation studies revealed that the extracellular matrix layer outside the outer epidermal cell wall of B. napus embryogenic tissues contained napin. This is the first study to report the extracellular localisation of napin. In addition, we have also further characterised the expression pattern of Eg1 that encodes for napin in the B. napus embryogenic tissue.

Hydroxyproline Rich Proteins in Salt Adapted Embryogenic Suspension Cultures ofDactylis GlomerataL.

“…JiM13 epitopes are known to be expressed in pro-embryogenic cells but not in mature or later stage embryos. no such distribution was established for JiM8 labeling as stated by namasivayam et al (27) but in previous studies JiM8 epitopes were considered to be characteristic for embryogenic potential of the culture as a whole and not for particular cells, destined to form embryos (44). JiM8 and JiM13 epitopes are diversely expressed in different cell types in D. glomerata suspension cultures in agreement with the understanding that different AGP epitopes are associated with different plant cell types and stages of development.…”

“…hRGPs are considered important structural components of the cell wall and are involved in almost every substantial process during plant growth and development (10). their role in plant stress response and embryogenesis is extensively investigated (13,21,27,45) but still many aspects of their functions remain contradictory and unclear. the main classes of hRGPs include the superfamily of highly glycosylated arabinogalactan proteins (AGPs), the moderately glycosylated extensins and the proline-rich proteins (PRPs) (41).…”