SmJAZ8 acts as a core repressor regulating JA-induced biosynthesis of salvianolic acids and tanshinones in Salvia miltiorrhiza hairy roots

Abstract

Jasmonates (JAs) are important plant hormones that regulate a variety of plant development and defense processes, including biosynthesis of secondary metabolites. The JASMONATE ZIM DOMAIN (JAZ) proteins act as negative regulators in the JA signaling pathways of plants. We first verified that methyl jasmonate (MeJA) enhanced the accumulation of both salvianolic acids and tanshinones in Salvia miltiorrhiza (Danshen) hairy roots by inducing the expression of their biosynthetic pathway genes. Nine JAZ genes were cloned from Danshen and their expression levels in hairy roots were all increased by treatment with MeJA. When analyzed in detail, however, SmJAZ8 showed the strongest expression in the induced hairy roots. Overexpression or RNAi of SmJAZ8 deregulated or up-regulated the yields of salvianolic acids and tanshinones in the MeJA-induced transgenic hairy roots, respectively, and transcription factors and biosynthetic pathway genes showed an expression pattern that mirrored the production of the compounds. Genetic transformation of SmJAZ8 altered the expression of other SmJAZ genes, suggesting evidence of crosstalk occurring in JAZ-regulated secondary metabolism. Furthermore, the transcriptome analysis revealed a primary-secondary metabolism balance regulated by SmJAZ8. Altogether, we propose a novel role for SmJAZ8 as a negative feedback loop controller in the JA-induced biosynthesis of salvianolic acids and tanshinones.

Identification, molecular characterization and expression of JAZ genes in Lycoris aurea

“…Further studies should be conducted to verify the network of interactions of LaJAZ proteins in vivo for figuring out potentials of LaJAZ formation in the jasmonate signaling. Much evidence suggests that JAZ proteins were involved in mediating the biosynthesis of specific secondary metabolites [56][57][58][59][60]. For example, JA enhances the accumulation of anthocyanin [61], and JAZ proteins interact with transcription factors or energy sensor SNF1-RELATED KINASE 1 (SnRK1) to affect anthocyanin accumulation [56,57].…”

“…For example, JA enhances the accumulation of anthocyanin [61], and JAZ proteins interact with transcription factors or energy sensor SNF1-RELATED KINASE 1 (SnRK1) to affect anthocyanin accumulation [56,57]. In Salvia miltiorrhiza hairy roots, JA-induced tanshinone biosynthesis is mediated by JAZ proteins and SmJAZ8 acts as a core repressor [59,60]. Also, it has been reported that the enhanced accumulation of Amaryllidaceae alkaloids can be elicited by addition of exogenous JAs treatment in Amaryllidaceae plants [37,38,62,63], but the exact molecular regulation mechanisms, including those related with JAZs, are still obscure in this plant family.…”

Transcriptome analysis reveals the GRAS family in Salvia miltiorrhiza hairy roots in response to gibberellin

“…Total phenolics and total flavonoids were detected as previously described with some modifications [5,32]. The absorbance of the samples for the total phenolics and total flavonoids analyses was measured at 765 nm and 506 nm, respectively.…”

“…More than 40 tanshinones and 20 hydrophilic phenolic acids have been isolated and identified from S. miltiorrhiza [3]. Tanshinones including dihydrotanshinone I (DT-I), cryptotanshinone (CT), tanshinone I (T-I) and tanshinone IIA (T-IIA) in S. miltiorrhiza are biosynthesized through the mevalonic acid (MVA) and 2-C-methyl-D-erythritol-4-phosphate (MEP) pathways [4,5]. Phenolic acids including salvianolic acid B (Sal B) and rosmarinic acid (RA) in S. miltiorrhiza are biosynthesized via the phenylpropanoid and the tyrosine-derived pathways [6,7].…”

Physiological and transcriptome analysis reveal molecular mechanism in Salvia miltiorrhiza leaves of near-isogenic male fertile lines and male sterile lines

“…Male sterility plays an extremely important role in heterosis utilization and hybrid seed yield of crops and its use has successfully increased crop yield [11][12][13]. S. miltiorrhiza is generally used as a medicinal plant and has been widely used to treat cardiovascular and cerebrovascular diseases, hyperlipidemia, and acute ischemic stroke [14][15][16][17][18]. There are many traditional Chinese medicines such as Fufang Danshen Tablets and Danshen injections, etc., which contain active ingredients extracted from S. miltiorrhiza [19].…”