Response of Resistant and Susceptible Bayberry Cultivars to Infection of Twig Blight Pathogen by Histological Observation and Gibberellin Related Genes Expression.

Haiying Ren,Temoor Ahmed,Bin Li,Yangchun Wu,Xingjiang Qi

doi:10.3390/pathogens10040402

Haiying Ren, Temoor Ahmed + Show 3 more

Open Access

https://doi.org/10.3390/pathogens10040402

Copy DOI

Journal: Pathogens	Publication Date: Mar 29, 2021
Citations: 8	License type: CC BY 4.0

Affiliation: Zhejiang University, Zhejiang Normal University

Abstract

Bayberry is an important fruit tree native to the subtropical regions of China. However, a systematic twig blight disease caused by Pestalotiopsis versicolor and P. microspora, resulted in the death of the whole tree of bayberry. The main variety Dongkui is highly sensitive to the twig blight disease, but the variety Zaojia is very highly resistant to the disease. Therefore, it is very necessary to clear the difference between resistant and susceptible varieties in response to the fungal infection. In this paper, we investigated the response of resistant and susceptible bayberry cultivars to infection of twig blight pathogen by histological observation and gibberellin signaling pathway-related genes expression. Microscopic observation revealed the difference in the infection process between resistant and susceptible varieties. The results of frozen scanning electron microscopy showed that the Pestalotiopsis conidia were shrunk, the mycelium was shriveled and did not extend into the cells of resistant cultivars, while the conidia were full and the top was extended, the mycelia was normal and continued to extend to the cells of a susceptible cultivar. Indeed, the medulla cells were almost intact in resistant cultivar, but obviously damaged in susceptible cultivar after inoculation of the main fungal pathogen P. versicolor conidia, which is earlier germinated on sterile glass slide than that of a hard plastic slide. The quantitative real-time PCR results showed a significant difference between resistant and susceptible cultivars in the expression of gibberellin signaling pathway-related genes in leaves and stems of bayberry, which is closely related to infection time, the type of genes and varieties. Overall, this study provides a clue for our understanding of the resistance mechanism of bayberry against the twig blight disease.

Highlights

Bayberry (Myrica rubra) is an important subtropical fruit in China with unique flavor, high nutritional value and economic benefits, and enjoys a high reputation at home and abroad [1,2]
The aim of this study was to analyze the infecting process of this pathogen in bayberry, the response of resistant and susceptible cultivars to infection of twig blight pathogen was investigated by histological observation of the phloem, xylem and medulla cells as well as P. versicolor conidia and mycelial
The conidia began to germinate after 8 h of incubation, the penultimate cell at the base started to expand, and the germ tube grew from the side of the cell

Summary

Introduction

Bayberry (Myrica rubra) is an important subtropical fruit in China with unique flavor, high nutritional value and economic benefits, and enjoys a high reputation at home and abroad [1,2]. The planting area of Myrica rubra in China is 333,300 hectares large and in Zhejiang Province is as high as 86,700 hectares, ranking the first in China. Because of its remarkable economic and ecological benefits, it has become the main fruit in Zhejiang Province, and its output value has steadily ranked the first in all kinds of fruits in Zhejiang Province. In 2004, a systematic twig blight disease was first found in Xianju County, Zhejiang Province. The disease has been found in the main producing areas (such as Ruian, Huangyan, Linhai, Qingtian) of bayberry in Zhejiang Province and many other provinces, including Fujian, Jiangxi, Guangxi, Guangdong and other places [3,4]. The outbreak of twig blight seriously restricted the development of the bayberry industry [5]

Objectives

Methods

Results

Conclusion