File(s) under permanent embargo

In situ localization associates biologically active plant natriuretic peptide immuno-analogues with conductive tissue and stomata

journal contribution
posted on 2003-06-01, 00:00 authored by M Maryani, M Morse, G Bradley, H Irving, David CahillDavid Cahill, Christoph Gehring
Plant natriuretic peptide immuno-analogues (irPNP) have previously been shown to affect a number of biological processes including stomatal guard cell movements, ion fluxes and osmoticum-dependent water transport. Tissue printing and immunofluorescent labelling techniques have been used here to study the tissue and cellular localization of irPNP in ivy (Hedera helix L.) and potato (Solanum tuberosum L.). Polyclonal antibodies active against human atrial natriuretic peptide (anti-hANP) and antibodies against irPNP from potato (anti-StPNP) were used for immunolabelling. Tissue prints revealed that immunoreactants are concentrated in vascular tissues of leaves, petioles and stems. Phloem-associated cells, xylem cells and parenchymatic xylem cells showed the strongest immunoreaction. Immunofluorescent microscopy with fluorescein isothiocyanate (FITC)-conjugated goat anti-rabbit IgG supported this finding and, furthermore, revealed strong labelling to stomatal guard cells and the adjacent apoplastic space as well. Biologically active immunoreactants were also detected in xylem exudates of a soft South African perennial forest sage (Plectranthus ciliatus E. Mey ex Benth.) thus strengthening the evidence for a systemic role of the protein. In summary, in situ cellular localization is consistent with physiological responses elicited by irPNPs reported previously and is indicative of a systemic role in plant homeostasis.

History

Journal

Journal of experimental botany

Volume

54

Issue

387

Pagination

1553 - 1564

Publisher

Oxford University Press

Location

London, England

ISSN

0022-0957

Language

eng

Publication classification

C1 Refereed article in a scholarly journal

Copyright notice

2003, Society for Experimental Biology