Premium
The intercellular biotrophic leaf pathogen Cymadothea trifolii locally degrades pectins, but not cellulose or xyloglucan in cell walls of Trifolium repens
Author(s) -
Simon Uwe K.,
Bauer Robert,
Rioux Danny,
Simard Marie,
Oberwinkler Franz
Publication year - 2005
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2004.01233.x
Subject(s) - xyloglucan , cell wall , pectinase , biology , chitin , apoplast , callose , pectin , haustorium , hypha , cellulose , botany , biophysics , biochemistry , host (biology) , enzyme , ecology , chitosan
Summary• The intercellular ascomycetous pathogen Cymadothea trifolii , causing sooty blotch of clover, proliferates within leaves of Trifolium spp. and produces a complex structure called interaction apparatus (IA) in its own hyphae. Opposite the IA the plant plasmalemma invaginates to form a bubble. Both structures are connected by a tube with an electron‐dense sheath. • Using immunocytochemistry on high‐pressure frozen and freeze‐substituted samples, we examined several plant and fungal cell wall components, including those in new host wall appositions at the interaction site, as well as a fungal polygalacturonase. • Within the tube linking IA and host bubble, labelling was obtained for cellulose and xyloglucan but not for rhamnogalacturonan‐I and homogalacturonans. The IA labelled for chitin and β‐1,3‐glucans, and for a fungal polygalacturonase. Plant wall appositions reacted with antibodies against callose, xyloglucans and rhamnogalacturonan‐I. • Cymadothea trifolii partly degrades the host cell wall. Structural elements remain intact, but the pectin matrix is dissolved. A fungal polygalacturonase detected in the IA is probably a key factor in this process. Owing to the presence of chitin and β‐1,3‐glucans, the IA itself is considered an apoplastic compartment.