Understanding Mineral Transport in Switchgrass

Genetic insights into nutrient movement will enhance bioenergy feedstock’s sustainability.

Image courtesy of the Great Lakes Bioenergy Research Center via a Creative Commons license.
To better understand how switchgrass acquires and mobilizes minerals, researchers have conducted the first molecular study of transporter genes in this bioenergy feedstock.

The Science

A viable bioenergy industry will depend on the development of sustainably grown feedstocks (i.e., bioenergy crops that yield high amounts of biomass with minimal inputs of water, fertilizer, and other chemicals). The efficient acquisition and mobilization of mineral nutrients by feedstocks are critical to sustainability. Additionally, biomass minerals influence the platform (e.g., pyrolysis, thermochemistry) used to produce biofuels from plant feedstocks. For example, high levels of silicon in ash decrease conversion efficiency. In perennial bioenergy plants such as switchgrass, certain minerals are recycled or mobilized from senescing tissues in the autumn to perennial crowns, rhizomes, and roots for winter storage and then remobilized and translocated to growing stem and leaf tissues in the spring. This seasonal storage and recycling of minerals depend on specific transporters for movement into and out of cells, a poorly understood process. To better understand this movement, researchers have conducted the first molecular study of mineral transporter genes in switchgrass.

The Impact

This study will facilitate functional characterization of genes critical for efficient nutrient transport and use and will lead to the development of sustainable, high-yielding switchgrass cultivars.


With funding from the Plant Feedstocks Genomics for Bioenergy activity—jointly supported by the U.S. Department of Agriculture (USDA) and the U.S. Department of Energy (DOE)—researchers combined bioinformatics and real-time reverse-transcription polymerase chain reaction (qRT-PCR) approaches to classify mineral transporter genes and gene families in switchgrass and to discern differential expression of these genes during the growing season. The team identified 520 genes in 40 different switchgrass families and observed both tissue and temporal specificity of expression. These results provide the foundation for correlating expression of specific genes with mineral translocation.


Brian M. Waters
University of Nebraska, Lincoln


This work was supported in part by the USDA National Institute of Food and Agriculture (grant number 2011-67009-30096), the Office of Biological and Environmental Research within DOE’s Office of Science (grant number DE-AI02-09ER64829), and the Current Research Information System project of USDA’s Agricultural Research Service (5440-21000-030-00D).


Palmer, N. A., et al. “Global changes in mineral transporters in tetraploid switchgrasses (Panicum virgatum L.).” Front. Plant Sci. 4, 549 (2014). [DOI: 10.3389/fpls.2013.00549].

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