Bulked Segregant RNA-Seq Reveals Distinct Expression Profiling in Chinese Wheat Cultivar Jimai 23 Responding to Powdery Mildew.

Tong Zhu,Liancheng Liu,Mengshu Jia,Xiaolu Wang,Haosheng Li,Cheng Liu,Xu Zhang,Wenrui Wang,Hongxing Xu,Xiao Liang,Jiancheng Song,Liping Niu,Jianjun Liu,Huagang He,Liru Wu,Pengtao Ma,Ran Han,Wenxiao Du

doi:10.3389/fgene.2020.00474

Abstract

Wheat powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is one of the most destructive fungal diseases threatening global wheat production. Host resistance is well known to be the most efficient method to control this disease. However, the molecular mechanism of wheat powdery mildew resistance (Pm) is still unclear. To analyze the molecular mechanism of Pm, we used the resistant wheat cultivar Jimai 23 to investigate its potential resistance components and profiled its expression in response to powdery mildew infection using bulked segregant RNA-Seq (BSR-Seq). We showed that the Pm of Jimai 23 was provided by a single dominant gene, tentatively designated PmJM23, and assigned it to the documented Pm2 region of chromosome 5DS. 3,816 consistently different SNPs were called between resistant and susceptible parents and the bulked pools derived from the combinations between the resistant parent Jimai23 and the susceptible parent Tainong18. 58 of the SNPs were assigned to the candidate region of PmJM23. Subsequently, 3,803 differentially expressed genes (DEGs) between parents and bulks were analyzed by GO, COG and KEGG pathway enrichment. The temporal expression patterns of associated genes following Bgt inoculation were further determined by RT-qPCR. Expression of six disease-related genes was investigated during Bgt infection and might serve as valuable genetic resources for the improvement of durable resistance to Bgt.

Highlights

Bread wheat (Triticum aestivum L.) is one of the most important and widely planted crops worldwide
When inoculated with Blumeria graminis f. sp. tritici (Bgt) isolate YT01, Jimai 23 showed no visible symptoms on the first leaf (IT 0), while Tainong 18 showed abundant sporulation with more than 80% of the leaf area covered with aerial hyphae
Jimai 23 is an elite wheat cultivar released in the Shandong Province of China that is highly resistant to powdery mildew

Summary

Introduction

Bread wheat (Triticum aestivum L.) is one of the most important and widely planted crops worldwide. Infection by powdery mildew will lead to a 10–15% yield reduction in general, but which sometimes can be as high as 62% in severely infected fields (Singh et al, 2016). In China, the epidemic area of wheat powdery mildew has been around six million hectares for the last 10 years.. In China, the epidemic area of wheat powdery mildew has been around six million hectares for the last 10 years.1 To control this disease and prevent epidemics, fungicides are often used, but drug resistance of Bgt is increasingly serious due to pathogenic variation (Manoharachary and Kunwar, 2014). Compared to the use of fungicides, the breeding and use of resistant cultivars is considered to be the most effective and environmentally friendly means of preventing disease epidemics (Selter et al, 2014)

Methods

Results

Conclusion