Evaluation of Switchgrass Overexpressing PvMYB4 Transcription Factor Gene

Switchgrass (Panicum virgatum L.) is a leading candidate as biofuels feedstock. However, large-scale production from it is limited by recalcitrance, the difficulty to deconstruct plant cell walls. The team led by C. Neal Stewart Jr. of the University of Tenessee and the Oak Ridge National Laboratory aim to assess the field performance of switchgrass overexpressing the transcription factor gene PvMYB4, which can result in reduced lignin in switchgrass.

One transgenic event, which had relatively low ectopic overexpression of PvMYB4, had significant gains in both biofuel (32% more) and biomass (63% more) compared to the control plants. However, five other transgenic events planted did not survive the first field winter and were all high-overexpressing events.

These results demonstrate the potential of modifying the expression of a transcription factor to improve feedstock qualities. Further research is needed to develop strategies for transgene expression in feedstocks to optimize desired phenotypes.