Transcriptome and degradome sequencing reveals changes in Populus x euramericana 'Neva' caused by its allelopathic response to p-hydroxybenzoic acid

Plant species produce different types of allelopathic chemicals in nature; however, little is known about the differential regulation of plant allelopathy. Because allelopathy caused by p-hydroxybenzoic acid (pHBA) is one of the main obstacles to continuous cropping of Populus x euramericana 'Neva', we examined gene expression dynamics in Neva leaves induced by pHBA. The expression of genes related to photosynthesis and respiration changed, while mRNA involved in regulating gene expression during allelopathy was degraded. Some miRNAs that are involved in plant allelopathy target crucial genes for regulating reactive oxygen species. Moreover, coexpression regulatory networks were constructed based on profiles of the identified miRNA-target interactions and the differentially expressed miRNA-target pairs. These findings provide a mechanistic framework for understanding allelopathy in plants.