Functional Annotation of circRNAs of Tea Leaves During Infection by the Tea Leaf Spot Pathogen Didymella segeticola

Abstract

Didymella segeticola (Q. Chen) Q. Chen, Crous & L. Cai (syn. Phoma segeticola) is an important phytopathogen that causes leaf spot on tea, Camellia sinensis [L.] O. Kuntze, which results in huge tea production losses. The functional annotation and analysis of circular RNAs (circRNAs) of tea leaves during D. segeticola infection may reveal the host–pathogen interaction mechanisms. In this study, a model of tea (C. sinensis ‘Fuding-dabaicha’) leaves infected by D. segeticola was constructed, and then circRNAs of tea leaves were sequenced on the Illumina HiSeq 4000 platform. In total, 231 and 118 differentially expressed circRNAs from tea leaves were significantly up- and down-regulated, respectively, by the D. segeticola infection. A Kyoto Encyclopedia of Genes and Genomes analysis indicated that the differentially expressed circRNA-hosting-genes were significantly enriched in the plant–pathogen interaction pathway. As the differentially expressed circRNA-hosting-gene of circRNA in the pathway, the U-box domain-containing protein 35 gene was enriched in response to stress according to a Gene Ontology analysis. The expression profiling of circRNAs and the annotation of circRNA-hosting-genes of tea leaves during D. segeticola infection will provide a resource for future research on host–pathogen interactions.