CgGCS, Encoding a Glucosylceramide Synthase, Is Required for Growth, Conidiation and Pathogenicity in Colletotrichum gloeosporioides.

Yimei Huang,Bin Li,Jian Yin,Chunhua Hu,Ou Sheng,Ganjun Yi,Fangcheng Bi,Huijun Gao,Chunyu Li,Qiaosong Yang,Guiming Deng,Tao Dong,Tongxin Dou

doi:10.3389/fmicb.2019.01016

Abstract

Fungal glucosylceramide plays important role in cell division, hyphal formation and growth, spore germination and the modulation of virulence and has recently been considered as target for small molecule inhibitors. In this study, we characterized CgGCS, a protein encoding a glucosylceramide synthase (GCS) in Colletotrichum gloeosporioides. Disruption of CgGCS resulted in a severe reduction of mycelial growth and defects in conidiogenesis. Sphingolipid profile analysis revealed large decreases in glucosylceramide production in the mutant strains. Pathogenicity assays indicated that the ability of the ΔCgGCS mutants to invade both tomato and mango hosts was almost lost. In addition, the expression levels of many genes, especially those related to metabolism, were shown to be affected by the mutation of CgGCS via transcriptome analysis. Overall, our results demonstrate that C. gloeosporioides glucosylceramide is an important regulatory factor in fungal growth, conidiation, and pathogenesis in hosts.

Highlights

Colletotrichum gloeosporioides is a pathogen that causes anthracnose in a broad range of plant hosts, including mango, avocado, yam cassava and strawberry, and is one of the most important postharvest pathogenic fungi in fruit (Perfect et al, 1999; Cannon et al, 2000; Hyde et al, 2009)
We presented a characterization of CgGCS in the postharvest pathogen C. gloeosporioides, with the goal of determining its importance for virulence
We revealed the nature of glucosylceramide generated by Glucosylceramide synthase (GCS) in C. gloeosporioides

Summary

Introduction

Colletotrichum gloeosporioides is a pathogen that causes anthracnose in a broad range of plant hosts, including mango, avocado, yam cassava and strawberry, and is one of the most important postharvest pathogenic fungi in fruit (Perfect et al, 1999; Cannon et al, 2000; Hyde et al, 2009). Except functioning as a membrane component, GlcCer is involved in spore germination, hyphal growth, morphogenesis, virulence, and differentiation in fungi via its regulation of the physical properties. Glucosylceramie Affects Pathogenicity of C. gloeosporioides of membranes in several human and plant pathogens (Levery et al, 2002; Warnecke and Heinz, 2003; da Silva et al, 2004; Rittershaus et al, 2006; Ramamoorthy et al, 2007; Rittenour et al, 2011; Zhu et al, 2014). In Aspergillus nidulans and Aspergillus fumigatus, inhibition of GlcCer synthesis using a GCS inhibitor strongly affected spore germination and hyphal growth (Levery et al, 2002). In Fusarium graminearum, GCS1 is not required for pathogenicity, but it does affect conidial morphology and hyphae growth (Ramamoorthy et al, 2007), suggesting that it plays different roles in different fungi

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Conclusion