Recently, Dr. Guo Zhiying’s co-first authored paper titled Profiling of Phytohormone-Specific MicroRNAs and Characterization of the MiR160-ARF Module Involved in Glandular Trichome Development and Artemisinin Biosynthesis in Artemisia Annua was published in a leading journal in the field of Plant Science, Plant Biotechnology Journal (IF=13.263, top-listed in Chinese Academy of Sciences’ Journal Ranking).
Upon high-throughput sequencing and bioinformatic analysis on miRNAs from 10 A. annua libraries and the degradome, this paper, in its selection of key responsive miRNAs for the induction of specific phytohormone, has discovered that miR160 can respond to the specific induction of SA and MeJA and that overexpressing MIR160 can suppress the density of glandular trichome in Arabidopsis and A. annua. Applying Short tandem target mimic (STTM）in A. annua. to mediate MIR160 for silence expression significantly increases A. annua.’s glandular trichome density and artemisinin content, while adopting RNA-Seq to analyze silencing and overexpressing MIR160 transgenic Artemisia annua plants influences the expression levels of enzyme genes in the biosynthetic pathway of artemisinin. The conducting of degradome sequencing, RLM-RACE mapping, transient transformation, and other experiments shows that ARF1 is the main target gene for miR160. Also, it is indicated that utilizing the mutation technique to mutate ARF1 into a mutant that is miR160 degradation proof brings a marked increase of A. annua.’s glandular trichome density and artemisinin content. Furthermore, the performance of Y1H, EMSA, and Dual-Luc verifies the fact that the combination of AaARF1 and AaDBR2 promoter’s GAGACA box activates the expression of AaADBR2. To conclude, this study reveals the biological function of miR160-ARF1 module in regulating artemisinin synthesis and glandular trichome development, providing a new idea for the engineering of artemisinin’s secondary metabolites.
This study was supported by National Natural Science Foundation of China (Grant NO.82003903) and the Natural Science Foundation of Fujian Province (Grant NO.2020J05243).
