High temperature enhances the ability of Trichoderma asperellum to infect Pleurotus ostreatus mycelia

Abstract

Trichoderma asperellum is one of the species which can be isolated from contaminated Pleurotus ostreatus cultivation substrate with green mold disease. This study focused on the relationship between high temperature and infectivity of T. asperellum to P. ostreatus. Antagonism experiments between T. asperellum and P. ostreatus mycelia revealed that high temperature-treated P. ostreatus mycelia were more easily infected by T. asperellum and covered by conidia. Microscopic observation also showed that P. ostreatus mycelia treated with high temperature could adsorb more T. asperellum conidia. Furthermore, conidia obtained from T. asperellum mycelia grown at 36°C featured higher germination rate compared with that incubated at 28°C. High temperature-treated T. asperellum mycelia can produce conidia in shorter periods, and T. asperellum mycelia were less sensitive to high temperature than P. ostreatus. Deactivated P. ostreatus mycelia can induce T. asperellum cell wall-degrading enzymes (CWDEs) and P. ostreatus mycelia subjected to high temperature showed induced CWDEs more effective than those incubated at 28°C. Moreover, T. asperellum showed higher CWDEs activity at high temperature. In dual cultures, hydrogen peroxide (H2O2) increased after 36°C, and high concentration of H2O2 could significantly inhibit the growth of P. ostreatus mycelia. In summary, our findings indicated for the first time that high temperature can induce a series of mechanisms to enhance infection abilities of T. asperellum to P. ostreatus mycelia and to cause Pleurotus green mold disease.

Phylogenetic Diversity of Trichoderma Strains and Their Antagonistic Potential against Soil-Borne Pathogens under Stress Conditions

“…They can easily be attacked by the highly efficient phosphate solubilizing T. harzianum. Several studies [20,82] reported that high temperature could induce T. asperellum mycelia to form a massive number of conidia in a short time and speed up the spread of conidia, forming a sizeable infected area with Trichoderma.…”

Metabolic Response of Pleurotus ostreatus to Continuous Heat Stress

“…Thus, high temperature is the most adverse stress in the cultivation of P. ostreatus. After high-temperature stress, mycelial growth is inhibited, mycelia are susceptible to infection by pathogens, such as Trichoderma asperellum, and apoptotic-like cell death can occur (Song et al, 2014;Qiu et al, 2017). These adverse effects cause enormous economic losses, which urgently call for studies on the mechanism of P. ostreatus resistance to heat stress.…”

Hsp40 Protein LeDnaJ07 Enhances the Thermotolerance of Lentinula edodes and Regulates IAA Biosynthesis by Interacting LetrpE

“…High temperature not only inhibits mycelial growth and fruiting body formation, but also enhances Trichoderma sp. infection and cell membrane fluidity in edible fungi (Lu et al, 2014;Liu et al, 2017;Qiu et al, 2017). Previous studies have reported that Para-aminobenzoic acid (PABA) synthase and nitric oxide reduced ROS (reactive oxygen species) accumulation to alleviate oxidative damage induced by heat stress (Kong et al, 2012a;Lu et al, 2014); catalase, trehalose, HSP and calcium-calmodulin play an important role in regulating the response of the edible fungi to heat stress (Kong et al, 2012b;Deng et al, 2014;Wang et al, 2017;Liu et al, 2018).…”