Bio-priming with a hypovirulent phytopathogenic fungus enhances the connection and strength of microbial interaction network in rapeseed

Zheng Qu,Jiatao Xie,Huizhang Zhao,Yanping Fu,Qianqian Wang,Yang Lin,Yao Yao,Daohong Jiang,Jiasen Cheng,Hongxiang Zhang

doi:10.1038/s41522-020-00157-5

Abstract

Plant disease is one of the most important causes of crop losses worldwide. The effective control of plant disease is related to food security. Sclerotinia stem rot (SSR) caused by Sclerotinia sclerotiorum leads to serious yield losses in rapeseed (Brassica napus) production. Hypovirulent strain DT-8 of S. sclerotiorum, infected with Sclerotinia sclerotiorum hypovirulence-associated DNA virus 1 (SsHADV-1), has the potential to control SSR. In this study, we found rapeseed bio-priming with strain DT-8 could significantly decrease the disease severity of SSR and increase yield in the field. After bio-priming, strain DT-8 could be detected on the aerial part of the rapeseed plant. By 16S rRNA gene and internal transcribed spacer (ITS) sequencing technique, the microbiome on different parts of the SSR lesion on bioprimed and non-bioprimed rapeseed stem was determined. The results indicated that SSR and bio-priming treatment could influence the structure and composition of fungal and bacterial communities. Bio-priming treatment could reduce the total abundance of possible plant pathogens and enhance the connectivity and robustness of the interaction network at the genus level. This might be one of the mechanisms that rapeseed bioprimed with strain DT-8 had excellent tolerance on SSR. It might be another possible mechanism of biocontrol and will provide a theoretical guide for agricultural practical production.

Highlights

Based on the estimate of the United Nations, the global population will reach 9.7 billion by mid-century and 10.8 billion by the end of this century[1]
It’s a worldwide problem to prevent the economic losses caused by plant diseases
By 16S rRNA gene and internal transcribed spacer (ITS)-sequencing techniques, we found bio-priming and Sclerotinia stem rot (SSR) could impact the composition and structure of microbial communities

Summary

Introduction

Based on the estimate of the United Nations, the global population will reach 9.7 billion by mid-century and 10.8 billion by the end of this century[1]. On one hand, we should improve the yield and creating efficient cultivation techniques; on the other hand, we should protect plants from pests and diseases[3]. Sclerotinia stem rot (SSR) caused by the necrotrophic fungal pathogen Sclerotinia sclerotiorum (Lib.) de Bary is a major threat of rapeseed[5] and always causes devastating yield losses[6]. When a rapeseed plant is infected, as the necrotic lesions girdle the stem and cause the stem to lose its rigidity, the major cause of SSR-induced yield loss, lodging, may occur[7]. Considering the development of the fungicide-resistant population of S. sclerotiorum and environmental problems, it is important to explore novel and environmentally friendly alternatives or to reduce the amount of chemical fungicides used[8]

Methods

Results

Conclusion