Oxidative stress in entomopathogenic fungi and its potential role on mycoinsecticide enhancement.

M. C. MANNINO; C. HUARTE-BONNET; N. PEDRINI

Microbes for Sustainable lnsect Pest Management, Sustainability in Plant and Crop Protection

Springer Nature

Año: 2019; p. 201 - 209

Entomopathogenic fungi (EF) are used worldwide as environmentallyfriendly mycoinsecticides. A successful invasion process depends on the fungalability to cope with several stress factors, such as osmotic stress, temperature, UVradiation, and oxidative stress. Reactive oxygen species (ROS) can appear due toeither previous environmental stresses or endogenous metabolic changes. Moreover,ROS may be either part of the host defense against fungi or the fungus itself canrelease ROS in the hemolymph to overcome insect defenses. Regardless of itssource, fungi must mitigate ROS damage in their cells. Antioxidant response infungi involves the action of enzymes as well as non-enzymatic compounds.Oxidative stress and antioxidant responses are known to have several direct and/orindirect consequences in fungal adaptation. Nutritive stress produced by non-preferredcarbohydrate sources in conidia production can increase ROS scavengersconsequently enhancing UV tolerance. Additionally, growth in long chain cuticularhydrocarbons triggers ROS production and antioxidant gene induction, leading tomore virulent conidia. Also, ROS can act as signaling molecules for cell differentiationinto new propagules such as microsclerotia and mycelial pellets that toleratedesiccation and produce new infective conidia in the field. In this chapter we willsummarize ROS sources and antioxidant scavengers during conidial production andfungal invasion into their hosts, and the beneficial consequences for stress tolerance,virulence and cell differentiation that can arise from these initial drawbacks.