The entomopathogen Metarhizium anisopliae can modulate the secretion of lipolytic enzymes in response to different substrates including components of arthropod cuticle

Secretome of the Biocontrol AgentMetarhizium anisopliaeInduced by the Cuticle of the Cotton PestDysdercus peruvianusReveals New Insights into Infection

“…The strategy of applying synthetic media to induce the activation of the infection systems has been applied with success, revealing genes and proteins involved in different stages of Metarhizium anisopliae ’s infection process. 7,12,43,44 Several articles have been reporting poor correlation between mRNA and protein levels. 45−47 Most of the work in M. anisopliae has analyzed gene expression, which makes the identification of secreted proteins difficult.…”

“…13 Spores (10 7 mL –1 ) were inoculated in 70 mL of basal medium (BM; 0.6% NaNO 3 , 0.2% glucose, 0.2% peptone, 0.05% yeast extract) containing 0.05% cholesteryl stearate and 0.7% D. peruvianus (DP) cuticle (as infection condition) or 1% glucose (G) for the control condition to mimic infection conditions. 7 The flasks were incubated at 28 °C with shaking (150 rpm) for 48 or 96 h. The choice for this culture medium and culture times and conditions was made based on our previous work, 7 where we detected infection enzymes, lipases, and proteases differentially in the presence of host cuticle components compared with different controls, where one of them was 1% glucose. Also, in this previous work, we have proved that glucose had no influence on the secretion of these enzymes.…”

The Na+/H+ antiporter Nhx1 controls vacuolar fusion indispensible for life cycles in vitro and in vivo in a fungal insect pathogen

“…In the dying host, the blastospores turn back into hyphae and penetrate again the host cuticle for outgrowth and conidiation on the surface of the host cadaver. In the infection cycle, it is critical for the fungus to make use of limited nutrition on the insect cuticle for conidial germination, hyphal growth, and secretion of extracellular proteolytic, chitinolytic and lipolytic enzymes for cuticular penetration (St. Leger et al ., ; Gupta et al ., ; da Silva et al ., ; Kim et al ., ). Such cellular events are inevitably relevant to vacuolar structure and function.…”

Relationship between virulence and enzymatic profiles in the cuticle of Tenebrio molitor by 2-deoxy-d-glucose-resistant mutants of Beauveria bassiana (Bals.) Vuill

“…The letters distinguish the groups which resulted from the median test on each line (P \ 0.05) . Although proteases initiate degradation, these enzymes act synergistically with chitinases in the solubilization of the cuticle (Smith et al 1981;St Leger et al 1986a, b;Beys da Silva et al 2010). This could be related to mutant 884.5, which presented Pr1 activity 49% superior relative to the WT strain, but significantly lower levels of chitinases (33%) and exochitinasas (60%), affecting the virulence against T. molitor larvae.…”

“…During the cuticle penetration by EF, the importance of the extracellular proteolytic, chitinolytic and lipolytic enzymes has been showed. In these sense, Beauveria bassiana produce such enzymes in vivo playing a key role in the cuticle hydrolysis (St Leger et al 1986a;Gupta et al 1994;Kim et al 2010;Beys da Silva et al 2010). The importance of these enzymes is evidenced by a correlation with disease onset (Gupta et al 1994), in fact, the cuticledegrading enzymes are present even in ungerminated conidia (Shah et al 2005;Safavi et al 2007); also a protease-defective mutant of B. bassiana was found to have decreased virulence against migratory grasshoppers (Bidochka and Khachatourians 1990).…”