1). With regard to fungal adhesion at 0 hpi, most of the germlings were easily removed from the substrate,
irrespective of whether appressoria formed (Fig. 1). The enzyme treatments at 1 hpi on the spores attached via the STM restored the frequency of appressorium formation. According to the increase in the appressorium formation rate, the rate of the remaining infection structures also increased after treatment with β-1,3-glucanase, α-glucosidase, α-mannosidase, protease, or lipase (>65%; Fig. 1). The relatively lower percentages of both appressorium PCI-32765 price formation (<44%) and adhesion (<27%) at 1 hpi were observed after treatment with α-chymotrypsin, trypsin, or collagenases (crude, type I type 4, and type V; Fig. 1). Treatment with pepsin did not affect the retention of the germlings (66.8%) despite low appressorium formation (0.8%; Fig. 1). β-Mannosidase, collagenases type N-2 and type S-1, and gelatinase B affected the adhesion (<50%) despite having little effect on appressorium formation (>75%; Fig. 1). Furthermore, at 6 hpi,
during which appressoria begin to form, the removal effect was confirmed in the treatments with MMPs (<50%); crude collagenase, collagenase S-1, and gelatinase B were the most effective (Fig. 1). Typical blast lesions were observed 4 days after inoculation with the M. oryzae spore suspension. Similar symptoms were observed with mixtures of the spore suspension and each of the following enzymes: β-1,3-glucanase, α-glucosidase, α-mannosidase, and protease (Fig. 2). α-Mannosidase, α-chymotrypsin, selleck inhibitor pepsin, lipase, collagenase type I, collagenase 4, collagenase type V, and collagenase N-2 moderately suppressed lesion formation. When Bay 11-7085 treated with trypsin, pronase E, crude collagenase, collagenase type X, collagenase N-2, collagenase S-1, or gelatinase
B, the lesions on the leaves were remarkably suppressed (Fig. 2). It was difficult to ascertain whether the absence of spores was the result of the enzyme treatments or the lack of spores at the beginning of the experiment. Magnaporthe grisea reportedly produced cutinases (Sweigard et al., 1992; Skamnioti & Gurr, 2007). Therefore, this pathogen can degrade the wax of plant surfaces. The detached infection structure would be recognizable as vestiges of the degraded wax on the wheat surface. In this regard, it was important to maintain the wax layer on the plant surfaces as near to natural conditions as possible. Samples were fixed with osmium tetroxide vapor without dehydration for SEM, which showed that the M. oryzae germlings incubated with distilled water had ECM and merged tightly with the wax to withstand the water flow sufficiently. In the treatment with cellulase or protease, the infection structures tightly adhered to the surface (97.7% and 95.6%, respectively) as in the distilled water treatment (98.3%; Fig. 3, Table 1). Conversely, treatment with crude collagenase or gelatinase B resulted in detachment of the germlings (12.3% and 10.