Agarwood,a kind of highly valued non-timber product across Asia,Middle East,and Europe,is formed only when its resource trees--the genus Aquilaria are wounded or infected by some microbes.Now the populations of agarwood-producing species are facing the threats of overharvest and habitat loss.To promote the efficiency of agarwood production and protect the wild resource of Aquilaria species,we urgently need to reveal the regulation mechanism of agarwood formation.MicroRNAs (miRNAs) are a group of gene expression regulators with overwhelming effects on a large spectrum of biological processes especially in plant stress responses.