Integrative omic analysis reveals the dynamic change of phenylpropanoid metabolism in Morus alba under different stress

Phenylpropanoid metabolism is one of the most important pathways in Morus alba to response the stress. From the general phenylpropanoid pathway, there are two metabolic branches in M. alba including flavonoid and lignin biosynthesis which also play the roles in response to stress. However, the dynamic changes between flavonoid and lignin biosynthesis under biotic and abiotic stress in M. alba were unclear. To explore the different response mechanism related to phenylproanoid metabolism under stresses in M. alba, a combined proteomic and metabolomic study of M. alba leaves under UV-B stress and Botrytis cinerea infection was performed. Results showed that most of proteins involved in lignin and flavonoid biosynthesis pathway was increased under either UV-B stress or B. cinerea infection in M. alba. It was also confirmed by enzyme assays and metabolomics analysis. Additionally, abundance of proteins involved in biosynthesis of jasmonic acid were increased after B. cinerea infection. These results suggests that both flavonoid and lignin biosynthesis participates in the responses to abiotic and biotic stress in M. alba, but they might be regulated by different hormone signaling.