Lambertellin system, the mechanism for fungal replacement of Monilinia fructigena with Lambertella corni-maris without competitive inhibition on agar media.

ABSTRACT

The 'Lambertellin system' was disclosed which rationally explains the fungal replacement (mycoparasitism) of Monilinia fructigena (M. f., the host) with Lambertella corni-maris (L. corni-maris, the parasite) without competitive inhibition in the simultaneous incubations on agar media. The 'Lambertellin system' involves; (a) L. corni-maris secretes nontoxic lambertellols (1, 2) as the diffusible precursors of the authentic responsible substance 3 regardless of existence of the host M. f.; (b) In the absence of the host, the environment around the parasite is kept under neutral condition, and both 1 and 2 are readily transformed into 3; (c) Lambertellin (3) inhibits not only the host but also the parasite. The parasite degrades 3 for detoxification; and (d) Upon the host M. f. approaching closely to the area where the parasite inhabits, the environment around the parasite becomes acidic to stabilize 1 and 2, which gives them a chance to diffuse into the host area. Then these are gradually transformed into 3 to inhibit the host without damaging the parasite. This mechanism also accords with the progress of 'Natsu-Nenju' disease on apple fruits, which is known to be a mysterious phyto-disease because of two unique stages of its lifecycle, anamorphic (asexual) and teleomorphic (sexual). The 'Lambertellin system' would be categorized as a novel class of alleropathies.