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VOL. 74 (3), 379-386, 2008 COMMON MECHANISM OF RECOGNITION...

recognition between complementary molecules, lectin-carbohydrate,
which are present on both the host and the mycoparasite, is similar to
those described in many other parasitic and symbiotic fungi (6-9).

On the other hand, P. ostreatus (Jacq.: Fries) Kumm fruit bodies
(oyster mushrooms) have also been described presenting the «dry
bubble» disease in their commercial cultures (10). For this reason,
parallel studies were carried out on in order to purify and
characterize another similar lectin in this fungus (11, 12). So the
aim of the present work is to confirm that the same mechanism of
recognition and binding of carbohydrate-lectin is the previous step
to the mycosis symptoms development in both mushrooms, and to
establish a common molecular basis between the complementary
molecules, glucogalactomannan-lectin, in this verticillium disease.

MATERIALS AND METHODS

Organisms and culture conditions

Fruit bodies of Agaricus bisporus (commercial strain Fungisem
H 25) and Pleurotus ostreatus (commercial strain Amycel 3000)
were grown in the CIES (Centro de Investigación, Experimentación
y Servicios del Champiñón, Quintanar del Rey, Cuenca, Spain).
Verticillium fungicola var. fungicola (CBS 992.69) was grown on
Raper medium (13).

Preparation of V. fungicola cell wall glucogalactomannan

The preparation of V. fungicola cell walls and the fractionation
and purification procedure for obtaining the glucogalactomannan
were performed as reported in earlier studies (14).

Purification, characterization and carbohydrate specificity
of A. bisporus and P. ostreatus lectins

The purification of A. bisporus and P. ostreatus lectins from their
corresponding mushrooms were carried out by ammonium sulfate

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