Hydrogen Peroxide Acts on Sensitive Mitochondrial Proteins to Induce Death of a Fungal Pathogen Revealed by Proteomic Analysis

Abstract

How the host cells of plants and animals protect themselves against fungal invasion is a biologically interesting and economically important problem. Here we investigate the mechanistic process that leads to death of Penicillium expansum, a widespread phytopathogenic fungus, by identifying the cellular compounds affected by hydrogen peroxide (H2O2) that is frequently produced as a response of the host cells. We show that plasma membrane damage was not the main reason for H2O2-induced death of the fungal pathogen. Proteomic analysis of the changes of total cellular proteins in P. expansum showed that a large proportion of the differentially expressed proteins appeared to be of mitochondrial origin, implying that mitochondria may be involved in this process. We then performed mitochondrial sub-proteomic analysis to seek the H2O2-sensitive proteins in P. expansum. A set of mitochondrial proteins were identified, including respiratory chain complexes I and III, F1F0 ATP synthase, and mitochondrial phosphate carrier protein. The functions of several proteins were further investigated to determine their effects on the H2O2-induced fungal death. Through fluorescent co-localization and the use of specific inhibitor, we provide evidence that complex III of the mitochondrial respiratory chain contributes to ROS generation in fungal mitochondria under H2O2 stress. The undesirable accumulation of ROS caused oxidative damage of mitochondrial proteins and led to the collapse of mitochondrial membrane potential. Meanwhile, we demonstrate that ATP synthase is involved in the response of fungal pathogen to oxidative stress, because inhibition of ATP synthase by oligomycin decreases survival. Our data suggest that mitochondrial impairment due to functional alteration of oxidative stress-sensitive proteins is associated with fungal death caused by H2O2.

Thiol switches in mitochondria: operation and physiological relevance

“…The addition of H 2 O 2 to cells was reported to preferentially damage (or modify) mitochondrial proteins (Garcia et al, 2010;Perluigi et al, 2010;Qin et al, 2011;Martinez-Acedo et al, 2012;Stauch et al, 2014). In several investigations H 2 O 2 addition reduced respiratory activity and mitochondrial membrane potential.…”

Proteomic responses of fruits to environmental stresses

“…Proteomic analysis of the changes of total cellular proteins in P. expansum showed that a large proportion of the differentially expressed proteins appeared to be of mitochondrial origin, implying that mitochondria may be involved in this process. Further mitochondrial sub-proteomic analysis characterized a set of mitochondrial proteins, including respiratory chain complexes I and III, F 1 F 0 ATP synthase, and mitochondrial phosphate carrier protein which might be associated with fungal death caused by H 2 O 2 (Qin et al, 2011). The pH value, as one of the most important environmental parameters, has critical influence on spore germination of P. expansum .…”

Hydrogen Peroxide for Insect and Algae Control in a Lettuce Hydroponic Environment

“…These insects are commonly present in the phenolic foams used as substrate for germination of lettuce seeds. Possible future problems can also be addressed with routine use of H 2 O 2 , since flies are horizontal transmitters of plant pathogens (El-Hamalawi, 2008) and by the fact that investigations demonstrated the antifungal action of hydrogen peroxide (Qin et al, 2011).…”

“…The objective of this work was to evaluate the efficiency of hydrogen peroxide (H 2 O 2 ) as a sanitizing agent (for algae control) and insecticide (for fly control) in a hydroponic commercial system. H 2 O 2 has a recognized potential for causing oxidative stress in living organisms (Vännin & Koskula, 1998;Qin et al, 2011;Wojtyla et al, 2016) and is widely used as a disinfectant and sterilant (Watt et al, 2004). The evaluation of entomopathogenic fungi to replace synthetic insecticides, in the control of fungus gnats and shore fly, was also explored as a more sustainable form of fly control (Stanghellini & El-Hamalawi, 2005) and other vector insects (Tiago et al, 2014), in a hydroponic system.…”