Cardosins in postembryonic development of cardoon: towards an elucidation of the biological function of plant aspartic proteinases

• Type: Article in International Scientific Journal
• Date: 2008

Authors

Claudia Sofia Pereira (Author) Other; Diana Soares da Costa (Author) Other; Susana Pereira (Author) FCUP; de Moura Nogueira (Author) Other; Albuquerque, PM (Author) Other; Teixeira, J (Author) FCUP; Faro, C (Author) Other; Pissarra, J (Author) FCUP

Journal

Title: Protoplasma

Vol. 232

Pages: 203-213

ISSN: 0033-183X

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 25 Citations

Scopus - 25 Citations

Scientific classification

FOS: Natural sciences > Biological sciences

Other information

Authenticus ID: P-004-4P6

DOI: 10.1007/s00709-008-0288-9

Abstract (EN): Following on from previous work, the temporal and spatial accumulation of the aspartic proteinases (EC 3.4.23) cardosin A and cardosin B during postembryonic seed development of cardoon (Cynara cardunculus) was studied. mRNA and protein analyses of both cardosins suggested that the proteins accumulate during seed maturation, and that cardosin A is later synthesised de novo at the time of radicle emergence. Immunocytochemistry revealed that the precursor form of cardosin A accumulates in protein bodies and cell walls. This localisation in seeds is different from that previously described for cardoon flowers, suggesting a tissue-dependent targeting of the protein. It is known that procardosins are active and may have a role in proteolysis and processing of storage proteins. However, the presence of procardosin A in seeds could be related to the proposed role of the plant-specific insert in membrane lipid conversion during water uptake and solute leakage in actively growing tissues. This is in accordance with the recently proposed bifunctional role of aspartic proteinase precursor molecules that possess a membrane-destabilising domain in addition to a protease domain. Mature cardosin B, but not its mRNA, was detected in the first hours after seed imbibition and disappeared at the time of radicle emergence. This extracellular aspartic protease has already been implicated in cell wall loosening and remodelling, and its role in seed germination could be related to loosening tissue constraints for radicle protusion. The described pattern of cardosin A and B expression suggests a finely tuned developmental regulation and prompts an analysis of their possible roles in the physiology of postembryonic development.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11