Coordinated and independent functions of velvet-complex genes in fungal development and virulence of the fungal cereal pathogen Cochliobolus sativus. Issue 8 (August 2016)

• Record Type: Journal Article
• Authors: Wang, Rui; Leng, Yueqiang; Shrestha, Subidhya; Zhong, Shaobin
• Is Part Of: Fungal biology. Volume 120:Issue 8(2016:Aug.)
• Page Start: 948
• Page End: 960
• Publication Date: 2016-08
• Subjects: Conidiogenesis -- Regulatory factors -- Secondary metabolites; Mycology -- Periodicals; Fungi -- Periodicals; 579.505
• DOI: 10.1016/j.funbio.2016.05.004
• Languages: English
• ISSNs: 1878-6146

Abstract

Abstract: LaeA and velvet proteins regulate fungal development and secondary metabolism through formation of multimeric complexes in many fungal species, but their functions in the cereal fungal pathogen Cochliobolus sativus are not well understood. In this study, four velvet complex genes ( CsLaeA, CsVeA, CsVelB, and CsVelC ) in C. sativus were identified and characterized using knockout mutants generated for each of the genes. Both Δ CsVeA and Δ CsVelB showed significant reduction in aerial mycelia growth. Δ CsVelB also exhibited a hypermorphic conidiation phenotype with indeterminate growth of the conidial tip cells and premature germination of conidia. Δ CsLaeA, Δ CsVeA, and Δ CsVelB produced more conidia under constant dark conditions than under constant light conditions whereas no differences were observed under the two conditions for the wild type. These three mutants also showed significantly reduced conidiation under constant light conditions, but produced more small sized conidia under constant dark conditions compared to the wild type. All knockout mutants (Δ CsLaeA, Δ CsVeA, Δ CsVelB and Δ CsVelC ) showed some extent of reduction in virulence on susceptible barley plants compared to the wild type strain. The results revealed the conserved and unique roles of velvet -complex proteins as regulators in mediating fungal development and secondary metabolism in C. sativus . Highlights: CsLaeA, CsVeA, CsVelB, and CsVelC were first characterized in C. sativus. CsVeA and CsVelB plays opposing roles under different light conditions. CsVelB affects conidiogenesis pattern like CsVosA. All the velvet proteins are involved in regulating virulence. The velvet genes regulate non-ribosomal peptide synthetases required for virulence.