Pre-penetration events in fungal parasitism of nematode eggs

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Pre-penetration events in fungal parasitism of nematode eggs. / Lopez-Llorcz, LV; Olivares-Bernabeu, C; Salinas, J; Jansson, Hans-Börje; Kolattukudy, PE.

In: Mycological Research, Vol. 106, 2002, p. 499-506.

Research output: Contribution to journalArticle

Harvard

Lopez-Llorcz, LV, Olivares-Bernabeu, C, Salinas, J, Jansson, H-B & Kolattukudy, PE 2002, 'Pre-penetration events in fungal parasitism of nematode eggs', Mycological Research, vol. 106, pp. 499-506. https://doi.org/10.1017/S0953756202005798

APA

Lopez-Llorcz, LV., Olivares-Bernabeu, C., Salinas, J., Jansson, H-B., & Kolattukudy, PE. (2002). Pre-penetration events in fungal parasitism of nematode eggs. Mycological Research, 106, 499-506. https://doi.org/10.1017/S0953756202005798

CBE

Lopez-Llorcz LV, Olivares-Bernabeu C, Salinas J, Jansson H-B, Kolattukudy PE. 2002. Pre-penetration events in fungal parasitism of nematode eggs. Mycological Research. 106:499-506. https://doi.org/10.1017/S0953756202005798

MLA

Vancouver

Lopez-Llorcz LV, Olivares-Bernabeu C, Salinas J, Jansson H-B, Kolattukudy PE. Pre-penetration events in fungal parasitism of nematode eggs. Mycological Research. 2002;106:499-506. https://doi.org/10.1017/S0953756202005798

Author

Lopez-Llorcz, LV ; Olivares-Bernabeu, C ; Salinas, J ; Jansson, Hans-Börje ; Kolattukudy, PE. / Pre-penetration events in fungal parasitism of nematode eggs. In: Mycological Research. 2002 ; Vol. 106. pp. 499-506.

RIS

TY - JOUR

T1 - Pre-penetration events in fungal parasitism of nematode eggs

AU - Lopez-Llorcz, LV

AU - Olivares-Bernabeu, C

AU - Salinas, J

AU - Jansson, Hans-Börje

AU - Kolattukudy, PE

PY - 2002

Y1 - 2002

N2 - The present investigation deals with the main factors involved in early infection of nematode eggs by fungal parasites. We studied the effect of hydrophobicity on appressorium formation by germlings of Pochonia rubescens (syn. Verticillium suchlasporium), P. chlamydosporia (syn. V. chlamydosporium) and Lecanicillium lecanii (syn. V. lecanii). Appressoria were frequently formed on hydrophobic surfaces such as polyvinyl chloride or polystyrene and were infrequently formed on hydrophilic materials such as glass or aluminium. Infected eggs probed with the FITC-labelled lectin Concanavalin-A showed intense labelling corresponding to appressoria formed by fungal parasites on the eggshell surface. Proteolytic activity was found in extracts from conidia and germlings of fungal parasites (especially P. chlamydosporia) in the absence of nematode eggs. Addition of the serine proteinase inhibitors phenylmetylsulphonyl fluoride (PMSF) or diisopropyl fluorophosphonate (DFP) to the extracts reduced their proteolytic activity. PMSF was the most effective inhibitor. Zymography also revealed proteolytic activity in extracts from the three fungi tested. This activity mostly corresponded to bands of Rf's of substrate degradation similar to that Of purified main protease (P32) from P. rubescens. Other bands with molecular weight higher than P32 (low Rf) were found especially for P. chlamydosporia extracts. For L. lecanii only bands of low Rf were found. Serum anti-P32 partially inhibited proteolytic activity of extracts from conidia and germlings. Application of PMSF and DFP to the inoculum, reduced egg penetration for the three species studied. PMSF caused the highest reduction in eggs infected by L. lecanii, while DFP significantly reduced egg infection by both P. chlamydosporia and L. lecanii. Our results therefore show hydrophobicity, appresorium formation and protease production as factors involved in early parasitism of nematode eggs.

AB - The present investigation deals with the main factors involved in early infection of nematode eggs by fungal parasites. We studied the effect of hydrophobicity on appressorium formation by germlings of Pochonia rubescens (syn. Verticillium suchlasporium), P. chlamydosporia (syn. V. chlamydosporium) and Lecanicillium lecanii (syn. V. lecanii). Appressoria were frequently formed on hydrophobic surfaces such as polyvinyl chloride or polystyrene and were infrequently formed on hydrophilic materials such as glass or aluminium. Infected eggs probed with the FITC-labelled lectin Concanavalin-A showed intense labelling corresponding to appressoria formed by fungal parasites on the eggshell surface. Proteolytic activity was found in extracts from conidia and germlings of fungal parasites (especially P. chlamydosporia) in the absence of nematode eggs. Addition of the serine proteinase inhibitors phenylmetylsulphonyl fluoride (PMSF) or diisopropyl fluorophosphonate (DFP) to the extracts reduced their proteolytic activity. PMSF was the most effective inhibitor. Zymography also revealed proteolytic activity in extracts from the three fungi tested. This activity mostly corresponded to bands of Rf's of substrate degradation similar to that Of purified main protease (P32) from P. rubescens. Other bands with molecular weight higher than P32 (low Rf) were found especially for P. chlamydosporia extracts. For L. lecanii only bands of low Rf were found. Serum anti-P32 partially inhibited proteolytic activity of extracts from conidia and germlings. Application of PMSF and DFP to the inoculum, reduced egg penetration for the three species studied. PMSF caused the highest reduction in eggs infected by L. lecanii, while DFP significantly reduced egg infection by both P. chlamydosporia and L. lecanii. Our results therefore show hydrophobicity, appresorium formation and protease production as factors involved in early parasitism of nematode eggs.

U2 - 10.1017/S0953756202005798

DO - 10.1017/S0953756202005798

M3 - Article

VL - 106

SP - 499

EP - 506

JO - Fungal Biology

JF - Fungal Biology

SN - 1878-6146

ER -