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ARTICLE

Characterization and Pathogenicity of Pseudopestalotiopsis vietnamensis Causing Gray Blight of Wuyi Rock Tea (Camellia sinensis) in China and Specific Mechanisms of Disease Infection

by Guangheng Wu^1,#,*, Lu Rui^2,3,#, Xiang Lu⁴, Libo Han², Gan Lv¹, Xianyu Fu⁵, Jinxian Liu⁵, Nong Zhou³, Chuanhai Zhang¹

1 Fujian Provincial Key Laboratory of Eco-Industrial Green Technology, College of Ecology and Resources Engineering, Wuyi University, Wuyishan, 354300, China
2 Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Plant Immunity Center, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
3 Chongqing Engineering Laboratory of Green Planting and Deep Processing of Famous-Region Drug in the Three Gorges Reservoir Region, College of Biology and Food Engineering, Chongqing Three Gorges University, Chongqing, 404120, China
4 State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China
5 College of Tea and Food Science, Wuyi University, Wuyishan, 354300, China

* Corresponding Author: Guangheng Wu. Email:
# These authors contributed equally to this work

(This article belongs to the Special Issue: Plant–Environment Interactions)

Phyton-International Journal of Experimental Botany 2023, 92(1), 131-147. https://doi.org/10.32604/phyton.2022.021919

Received 19 February 2022; Accepted 11 May 2022; Issue published 06 September 2022

Abstract

Gray blight disease (GBD) causes significant losses in tea production in China. Although genes and biological processes involved in resistance to fungal disease in tea plants have been identified, specific mechanisms of the GBD infection process remain unknown. In this study, morphological and multi-gene (TEF-TUB-ITS) phylogenetic characteristics were used to identify isolate CLBB1 of Pseudopestalotiopsis vietnamensis. Pathogenicity tests confirmed that isolate CLBB1 from tea leaves caused GBD in the susceptible tea cultivar Wuyi Rock (Camellia sinensis var. sinensis cv. Shuixian). Spores began to germinate 24 h after infection (hai), and after 48 h, elongated fungal hyphae formed from a single conidium. Transcriptome analysis revealed that 482, 517, and 369 genes were differentially expressed at 24, 48, and 72 hai, respectively, in Wuyi Rock tea leaves. Isolate CLBB1 infection elicited phenotype-related responses and activated defense-related pathways, including plant–pathogen interaction, MAPK signaling, and plant hormone signal transduction, suggesting a possible mechanism underlying phenotype-based susceptibility to CLBB1. Thus, a new Ps. vietnamensis strain causing GBD in the tea cultivar ‘Shuixian’ was discovered in this study. Transcriptome analysis indicated that pathogen invasion activated chitin-related MAPK pathways and that tea plants required a hormone to restrict CLBB1.

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