Xylem systems genetics analysis reveals a key regulator of lignin biosynthesis in Populus deltoides
- Kelly M. Balmant1,
- Jerald D. Noble2,
- Filipe C. Alves3,
- Christopher Dervinis1,
- Daniel Conde1,
- Henry W. Schmidt1,
- Ana I. Vazquez3,
- William B. Barbazuk2,4,5,
- Gustavo de los Campos3,6,
- Marcio F.R. Resende Jr.2,7 and
- Matias Kirst1,2,5
- 1School of Forest Resources and Conservation, University of Florida, Gainesville, Florida 32611, USA;
- 2Plant Molecular and Cellular Biology Graduate Program, University of Florida, Gainesville, Florida 32611, USA;
- 3Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, Michigan 48824, USA;
- 4Department of Biology, University of Florida, Gainesville, Florida 32611, USA;
- 5Genetics Institute, University of Florida, Gainesville, Florida 32611, USA;
- 6Statistics Department, Michigan State University, East Lansing, Michigan 48824, USA;
- 7Horticulture Sciences Department, University of Florida, Gainesville, Florida 32611, USA
Abstract
Despite the growing resources and tools for high-throughput characterization and analysis of genomic information, the discovery of the genetic elements that regulate complex traits remains a challenge. Systems genetics is an emerging field that aims to understand the flow of biological information that underlies complex traits from genotype to phenotype. In this study, we used a systems genetics approach to identify and evaluate regulators of the lignin biosynthesis pathway in Populus deltoides by combining genome, transcriptome, and phenotype data from a population of 268 unrelated individuals of P. deltoides. The discovery of lignin regulators began with the quantitative genetic analysis of the xylem transcriptome and resulted in the detection of 6706 and 4628 significant local- and distant-eQTL associations, respectively. Among the locally regulated genes, we identified the R2R3-MYB transcription factor MYB125 (Potri.003G114100) as a putative trans-regulator of the majority of genes in the lignin biosynthesis pathway. The expression of MYB125 in a diverse population positively correlated with lignin content. Furthermore, overexpression of MYB125 in transgenic poplar resulted in increased lignin content, as well as altered expression of genes in the lignin biosynthesis pathway. Altogether, our findings indicate that MYB125 is involved in the control of a transcriptional coexpression network of lignin biosynthesis genes during secondary cell wall formation in P. deltoides.
Footnotes
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[Supplemental material is available for this article.]
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Article published online before print. Article, supplemental material, and publication date are at http://www.genome.org/cgi/doi/10.1101/gr.261438.120.
- Received January 20, 2020.
- Accepted July 13, 2020.
This article is distributed exclusively by Cold Spring Harbor Laboratory Press for the first six months after the full-issue publication date (see http://genome.cshlp.org/site/misc/terms.xhtml). After six months, it is available under a Creative Commons License (Attribution-NonCommercial 4.0 International), as described at http://creativecommons.org/licenses/by-nc/4.0/.
