Jasmonic acid‐responsive AabHLH1 positively regulates artemisinin biosynthesis in Artemisia annua

Abstract

Artemisia annua is the only natural source of the sesquiterpenoid artemisinin, which is widely used to treat malaria. The phytohormone jasmonic acid (JA) can significantly promote artemisinin biosynthesis in A. annua. AabHLH1 can bind and activate artemisinin biosynthetic genes, such as AaADS and AaCYP71AV1. In this study, we proved that AabHLH1 was responsive to MeJA treatment and highly expressed in glandular trichome-enriched tissues, and that its expression profile was similar to that of AaADS. Yeast two-hybrid assays showed that AabHLH1 interacted with all nine AaJAZ proteins in A. annua. Functional analysis with transgenic plants showed that several artemisinin biosynthetic genes were upregulated in AabHLH1-OE transgenic A. annua lines and downregulated in AabHLH1-EAR lines; furthermore, the artemisinin content was increased in the AabHLH1-OE lines and decreased in the AabHLH1-EAR lines. These results demonstrate that the JA-induced AabHLH1 positively regulates artemisinin biosynthesis by regulating the biosynthetic genes, and thus provide new insight into the regulatory mechanism of JA-induced artemisinin biosynthesis in

Integration of Metabolite Profiling and Transcriptome Analysis Reveals Genes Related to Volatile Terpenoid Metabolism in Finger Citron (C. medica var. sarcodactylis)

“…The transcript levels of TPS genes were regulated by a number of different TFs. So far, six TF families in plants associated with terpenoid metabolism have been identified, including AP2/ERF [25,26,32,33], bHLH [31], MYB [27], NAC [28], WRKY [29], and bZIP [30]. Their gene IDs are summarized in Table S3.…”

“…Hong et al found that AtMYC2 combines multiple plant hormone signals in the transcriptional regulation of sesquiterpene biosynthesis and activates the production of ( E )-β-caryophyllene [31]. AaERF1 and AaERF2 positively regulate the expression level of ADS and CYP71AV1 , leading to the accumulation of artemisinin [32,33].…”

Enhancing artemisinin content in and delivery from Artemisia annua: a review of alternative, classical, and transgenic approaches

“…JA also promotes degradation of the AaJAZ8 repressor, a negative regulator of TCP14-ORA complex formation. Li et al ( 2019 ) showed that JA has a positive impact on artemisinin biosynthesis due to its stimulatory effect on AaBHLH , which in turn induces artemisinin biosynthetic genes, such as ADS and CYP71AV1. These results suggest that JA biosynthetic genes such as AaAOC and AaOPR3 and JA responsive transcription factors such as AaBHLH, ERF1 and ORA have potential for creating transgenic varieties with increased artemisinin content.…”

Regulatory Mechanisms of bHLH Transcription Factors in Plant Adaptive Responses to Various Abiotic Stresses

“…Using transient assays in both Nicotiana tabacum leaves or Actinidia arguta fruits and stable transformation in Arabidopsis, Wang et al (2019) demonstrated that co-expression of AcMYB123 and AcbHLH42 is a prerequisite for anthocyanin production by activating transcription of AcF3GT1 and AcANS or their homologous genes. Li L. et al (2019) found that AabHLH1 interacted with AaMYB3 to regulate the accumulation of procyanidine. In addition, DhMYB2 interacted with DhbHLH1 to regulate anthocyanin production in Dendrobium hybrid petals .…”