Host Transcriptional Response of Sclerotinia sclerotiorum Induced by the Mycoparasite Coniothyrium minitans

Abstract

Mycoparasite Coniothyrium minitans parasitizes specifically the mycelia or sclerotia of Sclerotinia sclerotiorum, a worldwidely spread plant fungal pathogen causing serious diseases on crops. The interaction of C. minitans with S. sclerotiorum remains reciprocal and complex and little is known, especially on the side of the host (S. sclerotiorum). In this study, the early transcriptional response of S. sclerotiorum to the mycoparasitism by C. minitans was explored and the differentially expressed genes (DEGs) were analyzed. Based on GO ontology, KEGG pathway and fungal categories database, 887 upregulated DEGs were enriched in the growth related function (i.e., rRNA processing, ribosome biogenesis, binding and transport), while the 546 down-regulated DEGs were enriched in the stress-related functions (i.e., oxidoreductase, response to stress and heat and the chorismate biosynthetic process). The expression of shikimate pathway and the biosynthesis of phenylalanine involving genes was significantly suppressed. Furthermore, 581 unenriched DEGs were explored in the parasitizing process and were mapped on the Pfam domains of redox enzymes, Alpha/Beta hydrolase, haloacid dehalogenase, and other universal conserved domain containing proteins. Thirty-two DEGs encoding candidate effectors, with 16 up-regulated and 16 down-regulated, were observed with diverse function. SS1G_11912 (encoding SsNEP2) was significantly upregulated and may function in the parasitism. The involving of the shikimate pathway of phenylalanine biosynthesis and effector candidates were discussed. The results provide a basal understand on the interaction of S. sclerotiorum and C. minitans.

Research Progress on Phytopathogenic Fungi and Their Role as Biocontrol Agents

“…in Chinese cabbage petioles and significantly increase the fresh weight of the ground and root system and the root-to-shoot ratio, resulting in a growth-promoting effect. Mechanisms in Trichoderma that are antagonistic to plant pathogens include heavy parasitism, antibiosis, and competition (Costa et al, 2019;Zhao et al, 2020). The application of phytopathogenic fungi in the field of biological control has shown great developmental prospects, but if they are to become an important disease management tool for crops, a large number of reliable and efficient biological agents must be produced (Antweiler et al, 2017;Garrigues et al, 2018;Loc et al, 2019;Vitorino et al, 2020).…”

Antifungal Mechanism and Efficacy of Kojic Acid for the Control of Sclerotinia sclerotiorum in Soybean

“…In order to develop efficient methods for the management of Sclerotinia stem rot, several research groups have developed biocontrol strategies using Bacillus spp., and have achieved generally low–moderate control efficacies (46–76% inhibition rate; Radhakrishnan et al, 2017 ; Lopes et al, 2018 ; Massawe et al, 2018 ). Among the biocontrol strains Coniothyrium minitans CON/M/91–08, Streptomyces lydicus WYEC 108, Trichoderma harzianum T-22, and Bacillus subtilis QST 713 screened for the control of Sclerotinia stem rot, the highest biocontrol efficacy was obtained when using C. minitans (68.5% disease severity inhibition; Zeng et al, 2012 ; Zhao et al, 2020 ). Similarly, Clonostachys rosea , Stachybotrys levispora , Trichoderma asperelloides , and Sporidesmiun sclerotivorum have also been evaluated for the management of S. sclerotiorum in soybean, and in this case, S. sclerotivorum reduced Sclerotinia stem rot by 56–100% in commercial fields ( Del Rio et al, 2002 ; Rodriguez et al, 2011 ; Ribeiro et al, 2018 ; Sumida et al, 2018 ).…”

Combining Desirable Traits for a Good Biocontrol Strategy against Sclerotinia sclerotiorum

“…Hydrolytic enzymes produced by C. minitans, such as chitinases, have been shown to play an active role in this crucial stage of mycoparasitism, in addition to playing a role in remodeling its cell membrane as it grows inside the phytopathogen [37,103]. Zhao et al assembled and analyzed the genome and transcriptome of the C. minitans strain ZS-1 during its early interaction with S. sclerotiorum to better understand parasitism [104]. Expressed genes involved in host defense responses were detected, including CWDEs, transporters, secretory proteins, and secondary metabolite productions.…”

“…Expressed genes involved in host defense responses were detected, including CWDEs, transporters, secretory proteins, and secondary metabolite productions. Seventeen DEGs of fungal CWDEs were up-regulated during parasitism [104]. Shared and unique characteristics of the major facilitator superfamily (MFS), ABC transporter proteins, secretory proteins, and secondary metabolite biosynthesis gene clusters were identified as being involved [104].…”