Transcriptomic characterization of candidate genes responsive to salt tolerance of Miscanthus energy crops

Given the growing need for biofuel production but the lack of suitable land for producing biomass feedstock, development of stress-tolerant energy crops will be increasingly important. We used comparative transcriptomics to reveal differential responses to long-term salt stress among five populations of Miscanthus lutarioriparius grown in the natural habitats and salinity experimental site. A total of 59 genes were found to be potentially responsive to the high-salinity conditions shared by the five populations, including those involved in detoxification, plant defense, photosynthesis, and signal transduction. Of these genes, about 70% were related to abiotic stress response. Among five populations, the most contrasting performance between relatively high survival rates and the relatively weak growing traits was in accordance with the down-regulation of genes involved in growth and up-regulation of genes related to plant stress tolerance in one of the populations. These results might reveal a potential tolerance-productivity trade-off, where resources were allocated from growth to stress resistance. The comparative transcriptomics of different populations among different environments will provide a basis for breeding and domestication of energy crops.