Immunohistochemical localisation of ubiquitin and the proteasome in sunflower ( Helianthus annuus cv. Giganteus)

• DOI: 10.1007/s004250000511
• Publication Date: 2003-02-13T04:21:55Z
• Authors: Christina Ingvardsen; Bjarke Veierskov; Priyavadan A. Joshi
• Keywords: 0301 basic medicine; Proteasome Endopeptidase Complex; 0303 health sciences; Indoleacetic Acids; Ubiquitin; Meristem; Gene Expression Regulation, Developmental; Cell Differentiation; Immunohistochemistry; Cysteine Endopeptidases; 03 medical and health sciences; Multienzyme Complexes; Helianthus; Plant Shoots; Signal Transduction

This study provides an immunohistochemical demonstration of the involvement of the ubiquitin- and proteasome-dependent pathway during differentiation and organogenesis in plants. The localisation of ubiquitin and the proteasome was studied in meristems, leaves, stems and roots of sunflower (Helianthus annuus L. cv. Giganteus). By using a new technique that enhances very low antigen signals, we obtained information on the structural distribution of the ubiquitin- and proteasome-dependent pathway, and of the importance of this pathway during organogenesis and plant development. Ubiquitin and the proteasome showed overall similarities in their cellular localisation. The highest antigenic signal was observed in the root and shoot apical meristems, in leaf primordia and vascular tissue. The cambium showed less expression than the apical meristems. During adventitious root formation in cuttings, no sign of increased expression was observed within dedifferentiating tissue, but as organogenesis progressed, the antigenic signal of ubiquitin and the proteasome gradually increased in the developing roots. Comparison of immunochemical results and Western blots demonstrated that important changes in the cellular antigen signal could only be detected by immunochemistry.