Cardosin A, an abundant aspartic proteinase, accumulates in protein storage vacuoles in the stigmatic papillae of Cynara cardunculus L.

• Type: Article in International Scientific Journal
• Date: 1997

Authors

RamalhoSantos, M (Author) Other; Pissarra, J (Author) FCUP; Verissimo, P (Author) Other; Pereira, S (Author) FCUP; Salema, R (Author) FCUP; Pires, E (Author) Other; Faro, CJ (Author) Other

Journal

Title: Planta

Vol. 203

Pages: 204-212

ISSN: 0032-0935

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 62 Citations

Scopus - 68 Citations

Scientific classification

FOS: Natural sciences > Biological sciences

Other information

Authenticus ID: P-001-AMW

DOI: 10.1007/s004250050183

Abstract (EN): The function of aspartic proteinases (EC 3.4.23) present in flowers of Cynara species is still unknown. Cardosin Al as a highly abundant aspartic proteinase from Cynara cardunculus L.. a relative of the artichoke, is synthesised as a zymogen and subsequently undergoes proteolytic processing, yielding the mature and active enzyme. Here we report the study of the expression and localization of cardosin A-as a first approach to address the question of its physiological relevance. A polyclonal antibody specific for cardosin A was raised against a synthetic peptide corresponding to an amino acid sequence of the enzyme. This antibody was used to study the organ-specific, tissue specific and subcellular localization of cardosin A by immunoblotting, tissue printing and immunogold electron microscopy. The results showed that expression of cardosin A is highly restricted to the pistils, and that the enzyme accumulates mainly in protein storage vacuoles of the stigmatic papillae. Cardosin A is also present, although much less abundantly, in the vacuoles of the cells of the epidermis of the style. In view of these results, the possible physiological roles of cardosin A are discussed, namely an involvement in defense mechanisms or pollen-pistil interaction, as well as in flower senescence.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9