Profiling of phytohormone‐specific microRNAs and characterization of the miR160‐ARF1 module involved in glandular trichome development and artemisinin biosynthesis in Artemisia annua

Abstract

Summary MicroRNAs (miRNAs) play crucial roles in plant development and secondary metabolism through different modes of sequence‐specific interaction with their targets. Artemisinin biosynthesis is extensively regulated by phytohormones. However, the function of phytohormone‐responsive miRNAs in artemisinin biosynthesis remains enigmatic. Thus, we combined the analysis of transcriptomics, small RNAs, and the degradome to generate a comprehensive resource for identifying key miRNA‐target circuits involved in the phytohormone‐induced process of artemisinin biosynthesis in Artemisia annua. In total, 151 conserved and 52 novel miRNAs and their 4132 targets were determined. Based on the differential expression analysis, miR160 was selected as a potential miRNA involved in artemisinin synthesis. Overexpressing MIR160 significantly impaired glandular trichome formation and suppressed artemisinin biosynthesis in A. annua, while repressing its expression resulted in the opposite effect, indicating that miR160 negatively regulates glandular trichome development and artemisinin biosynthesis. RNA ligase‐mediated 5′ RACE and transient transformation assays showed that miR160 mediates the RNA cleavage of Auxin Response Factor 1 (ARF1) in A. annua. Furthermore, ARF1 was shown to increase artemisinin synthesis by activating AaDBR2 expression. Taken together, our results reveal the intrinsic link between the miR160‐ARF1 module and artemisinin biosynthesis, and may expedite the innovation of metabolic engineering approaches for high and stable production of artemisinin in the future.

Graphene enhances artemisinin production in the traditional medicinal plant Artemisia annua via dynamic physiological processes and miRNA regulation

“…However, few studies have addressed the relationship between miRNAs and GSTs. In A. annua , a single study reported that miR160 reduces the formation of GSTs by targeting and cleaving AaARF1 ( Guo et al., 2022 ).…”

A non-canonical Aux/IAA gene MsIAA32 regulates peltate glandular trichome development in spearmint

“…SlARF4 was shown to mediate trichome development through MYBs and cyclin genes ( Yuan et al., 2021 ). Recently ARF1 was characterized from Artemisia annua as positive regulator of glandular trichome formation and artemisinin biosynthesis ( Guo et al., 2023 ). But no information is available on the role of non-canonical Aux/IAAs in trichome development.…”

Iron oxide nanoparticles (Fe3O4-NPs) elicited Artemisia annua L. in vitro, toward enhancing artemisinin production through overexpression of key genes in the terpenoids biosynthetic pathway and induction of oxidative stress

“…Over the previous three decades, three primary approaches to metabolic engineering have been extended to improve artemisinin production in A. annua: (i) Increased expression of artemisinin biosynthetic pathway genes (including ADS, CYP71AV1, DBR2, and ALDH1); (ii) increasing the expression of TF genes that are involved in its biosynthesis and formation of glandular trichomes; and (iii) utilizing exogenous phytohormones (Guo et al 2022). The selection of genotypes with high artemisinin content and useful agronomic traits as well as the transcriptional regulation of the sesquiterpenoid pathway have been studied (De Paolis et al 2020;Wetzstein et al 2019).…”