Bulked Segregant RNA-Seq Provides Distinctive Expression Profile Against Powdery Mildew in the Wheat Genotype YD588.

Pengtao Ma,Yufei Xu,Hongxing Xu,Xu Zhang,Bo Wang,Cheng Liu,Liru Wu,Wenrui Wang

doi:10.3389/fpls.2021.764978

Abstract

Wheat powdery mildew, caused by the fungal pathogen Blumeria graminis f. sp. tritici (Bgt), is a destructive disease leading to huge yield losses in production. Host resistance can greatly contribute to the control of the disease. To explore potential genes related to the powdery mildew (Pm) resistance, in this study, we used a resistant genotype YD588 to investigate the potential resistance components and profiled its expression in response to powdery mildew infection. Genetic analysis showed that a single dominant gene, tentatively designated PmYD588, conferred resistance to powdery mildew in YD588. Using bulked segregant RNA-Seq (BSR-Seq) and single nucleotide polymorphism (SNP) association analysis, two high-confidence candidate regions were detected in the chromosome arm 2B, spanning 453,752,054-506,356,791 and 584,117,809-664,221,850 bp, respectively. To confirm the candidate region, molecular markers were developed using the BSR-Seq data and mapped PmYD588 to an interval of 4.2 cM by using the markers YTU588-004 and YTU588-008. The physical position was subsequently locked into the interval of 647.1–656.0 Mb, which was different from those of Pm6, Pm33, Pm51, Pm52, Pm63, Pm64, PmQ, PmKN0816, MlZec1, and MlAB10 on the same chromosome arm in its position, suggesting that it is most likely a new Pm gene. To explore the potential regulatory genes of the R gene, 2,973 differentially expressed genes (DEGs) between the parents and bulks were analyzed using gene ontology (GO), clusters of orthologous group (COG), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Based on the data, we selected 23 potential regulated genes in the enriched pathway of plant-pathogen interaction and detected their temporal expression patterns using an additional set of wheat samples and time-course analysis postinoculation with Bgt. As a result, six disease-related genes showed distinctive expression profiles after Bgt invasion and can serve as key candidates for the dissection of resistance mechanisms and improvement of durable resistance to wheat powdery mildew.

Highlights

Common wheat (Triticum aestivum L.) is one of the most important cereal crops worldwide (Hoisington et al, 1999)
The wheat breeding line YD588 was used as the resistant parent against powdery mildew and the susceptible cultivar Yannong 21 (YN21) was used as susceptible to be crossed with YD588 in order to produce F1
Compared with the documented powdery mildew (Pm) genes, especially the Pm2 and Pm4 that were mainly used in the production in China, YD588 showed a higher potential in resistance breeding

Summary

Introduction

Common wheat (Triticum aestivum L.) is one of the most important cereal crops worldwide (Hoisington et al, 1999). Tritici, (Bgt), can lead to huge yield losses (Everts et al, 2001; Singh et al, 2016; Tsai et al, 2020). Powdery mildew, caused by Blumeria graminis f. To control this disease, farmers traditionally relied on fungicide. Environmental pollution along with the use of pesticides become increasingly prominent (Felsenstein et al, 2010). Speaking, host resistance is generally considered to be the most economical, sustainable, and environmentally friendly approach to control wheat powdery mildew (Johansson et al, 2020; Li Y. et al, 2021)

Methods

Results

Conclusion