Antifungal Activity and Possible Mode of Action of Ningnanmycin Against Tea Gray Blight Disease Pathogen Pseudopestalotiopsis camelliae-sinensis.

Gray blight is a serious disease of tea (Camellia sinensis) for which there is currently no effective control or preventive measure apart from fungicides. Screening for effectiveness of a natural antimicrobial against this pathogen and identifying its mode of action could contribute to the management of this disease. Antifungal activity of the antimicrobial ningnanmycin (NNM) from Streptomyces noursei var. xichangensis against the pathogen causing gray blight disease, Pseudopestalotiopsis camelliae-sinensis strain GZHS-2017-010, was confirmed in vitro by the mycelial growth rate method. Optical microscopy, scanning electron microscopy, and transmission electron microscopy were used to observe morphological changes in hyphae of P. camelliae-sinensis treated with NNM. RNA sequencing, bioinformatics, and quantitative real-time PCR were used to identify genes in the hyphae that were differentially expressed in response to treatment with NNM. Thirty-eight genes from 16 pathways, known as targets of antifungal agents, were used to investigate gene expression in hyphae at the half-maximal effective concentration (EC50), EC30, and EC70 for 1, 7, or 14 h. The results indicated that NNM can inhibit the growth of hyphae in vitro, with an EC50 of 75.92 U/ml, inducing morphological changes in organelles, septa, and extracellular polysaccharides, targeting ribosomes to disturb translation in protein synthesis and influencing some biosynthetic functions of the hyphae.

Integrated mRNA and Small RNA Sequencing for Analyzing Leaf Spot Pathogen Didymella segeticola and Its Host, Tea (Camellia sinensis), During Infection.

Leaf spot on tea plants (Camellia sinensis [L.] Kuntze), caused by the fungus Didymella segeticola (Q. Chen) Q. Chen, Crous & L. Cai (syn. Phoma segeticola), negatively affects the productivity and quality of tea leaves in Guizhou Province, China. Although the genome sequence of D. segeticola has been published, no data on the transcriptome or microRNAs (miRNAs) of the pathogen or host during infection are available. Here, we report on the high-quality transcriptome and miRNA sequences of both D. segeticola and tea during infection, using the Illumina HiSeq 4000 or HiSeq 2500 platforms. Comprehensive expression profiling of the fungal pathogen and its host will provide a resource for future research into trait-specific genes of the pathogen and the host as well as on host-pathogen interactions and on disease resistance mechanisms.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Whole Genome Sequence and Gene Annotation Resource for Didymella bellidis Associated with Tea Leaf Spot.

Didymella bellidis is a phytopathogenic fungus that causes leaf spot on tea plants (Camellia sinensis), which negatively affects the productivity and quality of tea leaves in Guizhou Province, China. D. bellidis isolate GZYQYQX2B was sequenced using Pacific Biosciences and Illumina technologies, and assembled into a whole genome of 35.5 Mbp. Transcripts of D. bellidis isolate GZYQYQX2B were predicted from the assembled genome and were further validated by RNA sequence data. In total, 10,731 genes were predicted by integrating three approaches, namely ab initio and homology-based gene prediction, as well as transcriptomics data. The whole-genome sequence of D. bellidis will provide a resource for future research on trait-specific genes of the pathogen and host-pathogen interactions.

Integrated mRNA and Small RNA Sequencing for Analyzing Tea Leaf Spot Pathogen Lasiodiplodia theobromae, Under In Vitro Conditions and the Course of Infection.

Lasiodiplodia theobromae is a phytopathogenic fungus, which can cause many different diseases on different crops. The pathogen can cause leaf spot on tea plants (Camellia sinensis), which negatively affects the productivity and quality of tea leaves in tea plantations in Guizhou Province, China. Although the genome sequence of L. theobromae has been published, no data on the transcriptome or small RNA sequences of L. theobromae under in vitro conditions and the course of infection of tea leaf are available. Here, we report the high-quality transcriptome and small RNA sequences of L. theobromae in vitro conditions and the course of infection of tea leaf using the platform of Illumina HiSeq. This comprehensive expression profiling of the fungal pathogen will provide a valuable resource for future research on trait-specific genes of the pathogen, host-pathogen interactions, and disease resistance in the host.