Identification of catalase as an early up-regulated gene in Beauveria bassiana and its role in entomopathogenic fungal virulence

Stress response signaling and virulence: insights from entomopathogenic fungi

“…In B. bassiana, five catalases, catA (spore-specific), catB (secreted), catC (cytoplasmic), catD (secreted catalase/peroxidase), and catP (peroxisomal), have been characterized, knockout mutants of which showed discrete phenotypes in susceptibility to oxidative, heat, and Uv-B stress (wang et al 2013). early up-regulation of a catalase was noted in B. bassiana during stress and infection, and overexpression of the enzyme resulted in increased virulence (Ali et al 2012;Chantasingh et al 2013). However, the contributions of catalases to virulence in entomopathogenic fungi likely extend beyond stress response, as these enzymes have also been linked to the ability to degrade hydrocarbons found on host (insect) cuticles (Pedrini et al 2006).…”

“…These cells are able to evade immune cells and/ or survive within phagocytic cells, a phenomenon paralleling several microbial animal pathogens that are capable of surviving within host macrophages (Bidochka et al 2010;Kurtti and Keyhani 2008). Programs of gene expression in response to cuticle and cuticular components ultimately lead to production of the factors needed for successful mycosis to occur (Chantasingh et al 2013;Cho et al 2006aCho et al , 2006bMantilla et al 2012). And, although more of these genes are being identified, additional research is needed to better understand the temporal expression of these factors that undoubtedly contribute to different stages of the infection process.…”

Improving mycoinsecticides for insect biological control

“…Overexpression (essentially constitutive 1 ) of an endogenous superoxide dismutase, enzymes involved in scavenging and detoxification of reactive oxygen species (ROS) by converting superoxide ions to molecular oxygen and peroxide, in B. bassiana, resulted in enhanced tolerance to oxidative stress (menadione) and increased virulence (Xie et al 2010). Similarly, overexpression of catalase activity in B. bassiana increased stress resistance and virulence (Chantasingh et al 2013). Direct attempts at addressing temperature variation tolerances have been achieved via overexpression of a M. roberstsii heat shock factor (Hsp25), resulting in increased fungal growth as compared to the wild-type parent at temperatures as high as 35°C in both media as well as on locust wings, and conferred greater tolerance to osmotic stress (1 M mannitol) (Liao et al 2013b).…”

A review of progress toward field application of transgenic mosquitocidal entomopathogenic fungi

“…Additional important achievements have been made in the engineering of Beauveria spp. and Metarhizium spp., including improved resistance to all of the field‐relevant, environmental abiotic stresses ( e.g ., UV and temperature extremes) that have limited application of these fungi in the past . The state of knowledge and technology for modifying entomopathogenic fungi reveals a field ripe for tailored development and application for sustainable large‐scale depletion of a target pest.…”

“…and Metarhizium spp., including improved resistance to all of the field-relevant, environmental abiotic stresses (e.g., UV and temperature extremes) that have limited application of these fungi in the past. 58,79,85 The state of knowledge and technology for modifying entomopathogenic fungi reveals a field ripe for tailored development and application for sustainable large-scale depletion of a target pest. Scientifically, the development of transgenic entomopathogenic fungi for vector control has progressed sufficiently for field application; however, this technology needs an informed community ready to usher in a new era of transgenic microbial control.…”