Transcriptome analysis reveals gene responses to herbicide, tribenuron methyl, in Brassica napus L. during seed germination

Liuyan Wang,Hongsong Shi,Ruili Wang,Chenyang Li,Fang Yuan,Qingyuan Zhou,Jiayi Wu,Cui Cui,Wei Lei,Lijiao Meng

doi:10.1186/s12864-021-07614-1

Abstract

BackgroundTribenuron methyl (TBM) is an herbicide that inhibits sulfonylurea acetolactate synthase (ALS) and is one of the most widely used broad-leaved herbicides for crop production. However, soil residues or drifting of the herbicide spray might affect the germination and growth of rapeseed, Brassica napus, so it is imperative to understand the response mechanism of rape to TBM during germination. The aim of this study was to use transcriptome analysis to reveal the gene responses in herbicide-tolerant rapeseed to TBM stress during seed germination.Results2414, 2286, and 1068 differentially expressed genes (DEGs) were identified in TBM-treated resistant vs sensitive lines, treated vs. control sensitive lines, treated vs. control resistant lines, respectively. GO analysis showed that most DEGs were annotated to the oxidation-reduction pathways and catalytic activity. KEGG enrichment was mainly involved in plant-pathogen interactions, α-linolenic acid metabolism, glucosinolate biosynthesis, and phenylpropanoid biosynthesis. Based on GO and KEGG enrichment, a total of 137 target genes were identified, including genes involved in biotransferase activity, response to antioxidant stress and lipid metabolism. Biotransferase genes, CYP450, ABC and GST, detoxify herbicide molecules through physical or biochemical processes. Antioxidant genes, RBOH, WRKY, CDPK, MAPK, CAT, and POD regulate plant tolerance by transmitting ROS signals and triggering antioxidant enzyme expression. Lipid-related genes and hormone-related genes were also found, such as LOX3, ADH1, JAZ6, BIN2 and ERF, and they also played an important role in herbicide resistance.ConclusionsThis study provides insights for selecting TBM-tolerant rapeseed germplasm and exploring the molecular mechanism of TBM tolerance during germination.

Highlights

Tribenuron methyl (TBM) is an herbicide that inhibits sulfonylurea acetolactate synthase (ALS) and is one of the most widely used broad-leaved herbicides for crop production
Tribenuron methyl (TBM) is an herbicide that acts by inhibiting sulfonylurea acetolactate synthase (ALS), which reduces isoleucine, leucine and valine biosynthesis [2]
RNA-seq has facilitated the identification of differently expressed genes (DEGs) in rapeseed under abiotic stresses such as drought [5], freezing [6] and salinity [7], as well as some candidate genes related to sclerotinia [8], seed aging [9], seed coat color [10], and flowering time [11]

Summary

Introduction

Tribenuron methyl (TBM) is an herbicide that inhibits sulfonylurea acetolactate synthase (ALS) and is one of the most widely used broad-leaved herbicides for crop production. Soil residues or drifting of the herbicide spray might affect the germination and growth of rapeseed, Brassica napus, so it is imperative to understand the response mechanism of rape to TBM during germination. The aim of this study was to use transcriptome analysis to reveal the gene responses in herbicide-tolerant rapeseed to TBM stress during seed germination. Rapeseed is a broad-leaved crop and more sensitive to TBM, so TBM is rarely used directly for weed control in rapeseed production Planting methods such as rotation or intercropping can leave TBM residues in soil and herbicide spray can drift onto other areas [2, 3], which might cause physiological and biochemical changes that inhibit germination or reduce seedling quality and crop growth and development. There were few studies on the effect of TBM on rapeseed germination

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