The microRNA analysis of sesquiterpenoids biosynthesis by Atractylodes lancea (Thunb.) DC. with early stem growth mutation

Atractylodes lancea (Thunb.) DC. is a traditional Chinese medicinal plant with high medicinal value, and its active ingredients are a variety of sesquiterpenoids. In recent years, due to blind exploitation and environmental degradation, the wild resources are gradually exhausting, and the quality of artificially cultivated A. lancea is declining, so it is urgent to seek excellent quality resources of A. lancea. We obtained a mutant of A. lancea with early stem growth under high temperature and hormone stress. Compared with the wild-type, the mutant grows better and contains higher sesquiterpenoid content, so the stem development in advance is considered as the superior shape feature of A. lancea. Although the mechanism of high yield sesquiterpenoids of the mutant was preliminarily explained from the perspective of physiology and biochemistry, its molecular regulation mechanism is still unclear. The formation of superior shape features in medicinal plants is regulated by epigenetic regulatory factors, so this study intends to further explore the mechanism of efficient synthesis of sesquiterpenoids from the perspective of microRNAs of the stem early development mutant of A. lancea. MicroRNA sequencing of wild-type and mutant A. lancea showed that 105 differentially expressed microRNAs were identified. Further Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation analysis of target genes showed that these differentially expressed microRNAs regulated key genes of hormone signal transduction pathway, circadian rhythm, terpene synthesis and carbon metabolism pathway, as well as a large number of transcription factors, thus promoting the growth and development of A. lancea and the accumulation of active sesquiterpenoids, and enhancing the ability to resist adverse environments. This study revealed the molecular mechanism of microRNAs regulating the growth and development of mutant A. lancea and efficiently synthesizing sesquiterpenoids from the perspective of epigenetics, and provided a theoretical basis for the breeding of excellent varieties of A. lancea.