Transcriptome of alfalfa plants under animal grazing. Medicago sativa

By comparing transcriptomes of tolerant and intolerant plants of sickle alfalfa subject to intensive animal grazing, we identified pathways involved in nutrient-responsive signaling, light and wound response, cell wall formation, and energy metabolism. In these pathways, grazing suppressed 39 genes, but less severe in the tolerant plant, and activated 5 genes all carrying polymorphisms in their homologous transcripts between the tolerant and intolerant plants. These genes and pathways - responsive to grazing and differentially expressed between the tolerant and intolerant plants – underline a defense mechanism in alfalfa against grazing stresses. Overall design: We examined transcriptomes of 3 alfalfa plants: grazing tolerant and grazed, grazing tolerant and not grazed, grazing intolerant and grazed, all at single replicate each.