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Genetic and transcriptomic analyses of lignin- and lodging-related traits in Brassica napus

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Abstract

Key message

Candidate genes associated with lignin and lodging traits were identified by combining phenotypic, genotypic, and gene expression data in B. napus.

Abstract

Brassica napus is one of the world’s most important oilseed crops, but its yield can be dramatically reduced by lodging, bending, and falling of its vertical stems. Lignin has been shown to contribute to stem mechanical strength. In this study, we found that the syringyl/guaiacyl (S/G) monolignol ratio exhibits a significant negative correlation with disease and lodging resistance. A total of 92 and 50 SNP and SSR loci, respectively, were found to be significantly associated with five traits, breaking force, breaking strength, lodging coefficient, acid detergent lignin content, and the S/G monolignol ratio using GWAS. To identify novel genes involved in lignin biosynthesis, transcriptome sequencing of high- (H) and low (L)-ADL content accessions was performed. The up-regulated genes were mainly involved in glycoside catabolic processes (especially glucosinolate catabolism) and cell wall biogenesis, while down-regulated genes were involved in glucosinolate biosynthesis, indicating that crosstalk exists between glucosinolate metabolic processes and lignin biosynthesis. Integrating this differential expression with the GWAS analysis, we identified four candidate genes regulating lignin, including glycosyl hydrolase (BnaA01g00480D), CYT1 (BnaA04g22820D), and two encoding transcription factors, SHINE1 (ERF family) and DAR6 (LIM family). This study provides insight into the genetic control of lodging and lignin in B. napus.

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Acknowledgments

This work was supported by the National Science and Technology (2013BAD01B03-12) and the National High Technology Research and Development Plan (2016YFD0101007), 863 project (2011AA10A104 and 2013AA102602), the National Natural Science Foundation of China (31171619, 31371655, and 31571701 and U1302266), the Earmarked Fund for Modern Agro-industry Technology Research System (CARS-13), the “111″ Project (B12006), and the postdoctoral programme (BX201700201). Thanks to the China Scholarship Council (CSC) for its support.

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  1. Chongqing Engineering Research Center for Rapeseed, College of Agronomy and Biotechnology, Southwest University, Chongqing, 400716, China

    Lijuan Wei, Hongju Jian, Kun Lu, Nengwen Yin, Jia Wang, Xiujian Duan, Wei Li, Liezhao Liu, Xinfu Xu, Rui Wang & Jiana Li

  2. Plant Genome Mapping Laboratory, University of Georgia, Athens, 30605, GA, USA

    Lijuan Wei & Andrew H. Paterson

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  1. Lijuan Wei
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Wei, L., Jian, H., Lu, K. et al. Genetic and transcriptomic analyses of lignin- and lodging-related traits in Brassica napus . Theor Appl Genet 130, 1961–1973 (2017). https://doi.org/10.1007/s00122-017-2937-x

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