Factors underlying a latitudinal gradient in the S/G lignin monomer ratio in natural poplar variants
Abstract
The chemical composition of wood plays a pivotal role in the adaptability and structural integrity of trees. However, few studies have investigated the environmental factors that determine lignin composition and its biological significance in plants. Here, we examined the lignin syringyl-to-guaiacyl (S/G) ratio in members of a Populus trichocarpa population sourced from their native habitat and conducted a genome wide association study to identify genes linked to lignin formation. Our results revealed many significant associations, suggesting that lignin biosynthesis is a complex polygenic trait. Additionally, we found an increase in the S/G ratio from northern to southern geographic origin of the trees sampled, along with a corresponding metabolic and transcriptional reprogramming of xylem cell wall biosynthesis. Further molecular analysis identified a mutation in a cell wall laccase genetically associated with higher S/G ratios that predominate in trees from warmer lower latitudes. Collectively, our findings suggest that lignin heterogeneity arises from an evolutionary process enabling poplar adaptation to different climatic challenges.
Article Details
Journal Info
Proceedings of the National Academy of Sciences
National Academy of Sciences
Authors (18)
Weiwei Zhu
Division of Plant Science and Technology, University of Missouri
Jin Zhang
Pradeep Kumar Prabhakar
Complex Carbohydrate Research Center, University of Georgia
Yen On Chan
Institute for Data Science and Informatics, Department of Biomedical Informatics, Biostatistics, and Medical Epidemiology, University of Missouri
Rachel A. Weber
Division of Plant Science and Technology, University of Missouri
Mengjun Shu
Biosciences Division, Oak Ridge National Laboratory
Ganesh Panzade
Institute for Data Science and Informatics, Department of Biomedical Informatics, Biostatistics, and Medical Epidemiology, University of Missouri
Connor J. Cooper
Independent Researcher
Russell B. Davidson
Biosciences Division, Oak Ridge National Laboratory
Jin-Gui Chen
Center for Bioenergy Innovation, Oak Ridge National Laboratory
Sara S. Jawdy
Center for Bioenergy Innovation, Oak Ridge National Laboratory
Jerry M. Parks
Breeanna R. Urbanowicz
Complex Carbohydrate Research Center, University of Georgia
Gerald A. Tuskan
Center for Bioenergy Innovation, Oak Ridge National Laboratory
Trupti Joshi
Institute for Data Science and Informatics, Department of Biomedical Informatics, Biostatistics, and Medical Epidemiology, University of Missouri
Richard A. Dixon
Center for Bioenergy Innovation, Oak Ridge National Laboratory
Wellington Muchero
Center for Bioenergy Innovation, Oak Ridge National Laboratory
Jaime Barros
Division of Plant Science and Technology, University of Missouri