Researchers Target Expressed Genes in Vascular Tissues of Switchgrass

The Science

Using a laser-based technique for microdissecting plant tissues, BESC researchers have targeted and analyzed DNA that is actively expressed in switchgrass vascular tissues where secondary cell walls are synthesized and reinforced with lignin. A total of 2,766 unique genes were identified from 5,734 expressed DNA segments (known as expressed sequence tags or ESTs). A significant number of these expressed sequences are novel with no significant hits to existing EST data. A small subset of the identified genes was targeted with labeled probes to visualize the expression of these genes in live plant tissue, and researchers found that several genes have much higher expression in the vascular bundles. The gene list generated from this study provides an important genomic resource for narrowing the range of molecular targets that could play key roles in modifying the lignin content of switchgrass and other related bioenergy crops.


Switchgrass is a perennial C4 grass that thrives in a wide range of North American habitats and is an emerging crop for the production of lignocellulosic biofuels. Lignin is an integral component of secondary plant cell walls that provides structural rigidity to the cell wall but it interferes with the conversion of cellulose to fermentable sugars by preventing chemical access to cellulose. Thus, one strategy for improving production of cellulosic ethanol is the down-regulation of lignin in plants. To achieve this goal, it is important to understand the molecular processes involved in vascular tissue development, lignification and secondary wall synthesis. Since active lignification occurs in the vascular system of the plant, researchers refined a protocol for isolating vascular tissues using laser-capture microdissection (LCM) in an effort to identify transcripts of switchgrass involved in lignification and secondary cell wall synthesis.

BER Program Manager

Dawn Adin

U.S. Department of Energy, Biological and Environmental Research (SC-33)
Biological Systems Science Division
[email protected]


Srivastava, A. C., K. Palanichelvam, J. Ma, J. Steele, E. B. Blancaflor, and Y. Tang. 2010. “Collection and Analysis of Expressed Sequence Tags Derived from Laser Capture Microdissected Switchgrass (Panicum virgatum L. Alamo) Vascular Tissues,” BioEnergy Research, DOI: 10.1007/