Transcriptome analysis reveals the mechanism of anthocyanin accumulation induced by leaf breakage in foxtail millet

Anthocyanin is a class of water-soluble pigments with antioxidant activity which enhances the stress tolerance of plants. The destruction of vascular bundles may lead to the accumulation of anthocyanin; however, the response mechanism on this phenomenon in foxtail millet is not well understood. In this study, a foxtail millet variety Hong Miao Qi Tou Hong (HMQTH) which displayed increasing anthocyanin accumulation after leaf breakage was investigated. Through transcriptome analysis the gene expression pattern induced by leaf breakage in HMQTH was identified. Differentially expressed genes (DEGs) were mainly enriched in processes such as stimulus response, antioxidant function and flavonoid biosynthesis. Both the results of RNA-seq and qRT-PCR showed a total of 18 differential genes related to stress response and anthocyanin biosynthesis pathways were identified, including 7 genes involved in flavonoid and anthocyanin synthesis, 6 genes which were related to stress response and 5 genes regulating phytohormone synthesis and ABA signaling. This study uncovered the relationship between plant response to wounding and anthocyanin accumulation in foxtail millet, and provided genetic resources for the molecular breeding of crops with high anthocyanin content.