Title

A laccase exclusively expressed by Metarhizium anisopliae during isotropic growth is involved in pigmentation, tolerance to abiotic stresses and virulence

Document Type

Article

Journal/Book Title/Conference

Fungal Genetic Biology

Volume

47

Issue

7

Publication Date

7-1-2010

First Page

602

Last Page

607

DOI

10.1016/j.fgb.2010.03.011

Abstract

Insect pathogenic fungi including Metarhizium anisopliae offer an environmentally friendly alternative to chemical pesticides. However, their use has been limited by their relatively slow killing speed compared to chemicals and low tolerance to abiotic stresses. We report here on a class 1 laccase (MLAC1) that is involved in both virulence and tolerance to environmental stresses. Mlac1 is expressed during isotropic growth (swelling) but not during polarized growth (e.g., germ tubes and hyphae); Mlac1 is therefore expressed exclusively in the later stages of conidiation and in blastospores when M. anisopliae is living as a saprophyte. During infection processes, Mlac1 is also expressed by appressoria (infection structures) on the cuticle surface and hyphal bodies inside the insect haemocoel. Disrupting Mlac1 reduced virulence to caterpillars because of impaired appressoria and delayed post-infection events. It also produced a yellow-conidia phenotype with increased conidial susceptibility to heat shock (45 degrees C for 2h) and UV-B stress. The relationship between M. anisopliae's pigment-synthesis pathway and its adaptation to diverse natural habitats is discussed.

This document is currently not available here.

Share

COinS