Miscanthus and sorghum, both C4 plant species, occupy a distinct niche of the leaf economics spectrum (LES), with higher photosynthetic rates and nitrogen use efficiency than more common C3 plants. A study led by researchers at the Center for Advanced Bioenergy and Bioproducts Innovation (CABBI) improves understanding of leaf functional relationships and provides valuable new information for scientists modeling the productivity of C4 bioenergy crops.
The research team found that miscanthus and sorghum — both C4 plant species — occupy a distinct niche of the leaf economics spectrum (LES), with greater photosynthetic rates and nitrogen use efficiency than more common C3 plants.
The study, published in Plant, Cell & Environment, was led by Postdoctoral Researcher Shuai Li of CABBI, a U.S. Department of Energy-funded Bioenergy Research Center. Li works with Lisa Ainsworth, a Plant Physiologist with the U.S. Department of Agriculture’s Agricultural Research Service (USDA-ARS) Global Change and Photosynthesis Research Unit and Adjunct Professor of Plant Biology and the Carl R. Woese Institute of Genomic Biology (IGB) at the University of Illinois Urbana-Champaign.
This study used diverse miscanthus plantings in Illinois and Mississippi to test how leaf properties vary in different lines and in different environments. We investigated the investments that different miscanthus lines make in leaf structure and nutrient content – information that is critical for modeling bioenergy crop productivity and where it can be grown.
Shuai Li
LES describes the relationships between leaf traits that reflect fundamental trade-offs that underpin key ecological strategies for resource acquisition and utilization in plants. It is largely based on data from C3 species in natural environments and has received little attention from C4 crops, which use a different carbon-fixation process: C4 plants convert sunlight energy into 4-carbon molecules, whereas C3 plants produce a 3-carbon molecule as their first photosynthesis product. C4 plants account for approximately 3% of all land plant species but include major sources of food and biofuels around the world, such as maize, sorghum, and miscanthus.
The CABBI researchers showed that C4 bioenergy crops occupy a distinct range of the LES, with higher photosynthetic rates and greater nitrogen use efficiency. Additionally, Miscanthus × giganteus genotypes with different ploidy levels (or number of chromosome pairs) exhibit leaf trait divergence and distinct leaf functional relationships compared to C3 plants.
The study improves understanding of overall global patterns in leaf functional relationships and offers insight into the potential for ploidy to improve resource use efficiency by expanding the trait relationships described in the LES to include C4 crops in agricultural conditions, according to Ainsworth.
“This study used diverse miscanthus plantings in Illinois and Mississippi to test how leaf properties vary in different lines and in different environments,” Ainsworth explained. “We investigated the investments that different miscanthus lines make in leaf structure and nutrient content – information that is critical for modeling bioenergy crop productivity and where it can be grown.”
