Phytochemical, antioxidant, enzyme activity and antifungal properties of Satureja khuzistanica in vitro and in vivo explants stimulated by some chemical elicitors

Context:Satureja khuzistanica Jamzad. (Lamiaceae), is known for its antifungal and antioxidant compounds, especially rosmarinic acid (RA). Objective: The study examines the effect of elicitors on RA production and phytochemical properties of S. khuzistanica. Materials and methods:In vitro plants were treated with methyl jasmonate (MeJA) and multi-walled carbon nanotubes (MWCNTs). In vivo plants were treated with MWCNTs and salicylic acid (SA). RA was measured by HPLC. Catalase (CAT), guaiacol peroxidase (POD) and ascorbate peroxidase (APX) were quantified. DPPH and β-carotene were assayed in in vivo extracts. The antifungal effects of extracts were evaluated against Fusarium solani K (FsK). Results: The highest RA contents of in vitro plants were 50 mg/L MeJA (140.99 mg/g DW) and 250 mg/L MWCNTs (140.49 mg/g DW). The highest in vivo were 24 h MWCNTs (7.13 mg/g DW) and 72 h SA (9.12 mg/g DW). The maximum POD and APX activities were at 100 mg/L MeJA (5 and 4 mg protein, respectively). CAT had the highest activities at 50 mg/L MeJA (2 mg protein). DPPH and β-carotene showed 50% and 80% inhibition, respectively. The FsK aggregation was the lowest for in vitro extract in number of conidia [1.82 × 1010], fresh weight (6.51 g) and dry weight (0.21 g) that proved RA inhibitory effects. The callus reduces FsK growth diameter to 2.75 on the 5th day. Discussion and conclusions: Application of MeJA, SA, and MWCNTSs could increase RA in S. khuzistanica and highlighted potential characteristics in pharmaceutical and antifungal effects. © 2020, © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group

Identification and expression profiling of rosmarinic acid biosynthetic genes from Satureja khuzistanica under carbon nanotubes and methyl jasmonate elicitation

Satureja khuzistanica is a medicinal herb endemic to Iran which can serve as a source of rosmarinic acid (RA). In the present study, the effect of different concentrations of methyl jasmonate (MeJA) and multi-walled carbon nanotubes (MWCNTs) on the rosmarinic acid accumulation and the expression of genes involved in its biosynthetic pathway was evaluated in nodal segment cultures of S. khuzistanica. The concentration of RA varied in plant extracts derived from the field, plants obtained under in vitro solid media, calli, suspension cultures and nodal segment cultures in liquid medium, with the highest amount recorded in nodal segment cultures. Phenylalanine ammonia-lyase (PAL), tyrosine aminotransferase (TAT), 4-hydroxyphenylpyruvate reductase (HPPR) and RA synthase (RAS) cDNA clones as key biosynthetic genes of RA production were identified and expression patterns were assayed in response to MeJA and MWCNTs, exogenously applied at a range of 0, 50, 100, 250 mg L −1 . The expression levels of HPPR, PAL and TAT were up-regulated at 100 mg L −1 MWCNTs, whereas down-regulated levels were observed at 250 mg L −1 . RAS was up-regulated in all MWCNTs treatments. HPPR, PAL and TAT expression increased sharply at 250 mg L −1 MeJA. The highest levels of RAS transcripts were observed at 100 mg L −1 MeJA. The highest HPPR, PAL and TAT expression levels were observed at 250 mg L −1 MeJA. In accordance, HPLC analysis showed a high amount of RA under MeJA and MWCNT elicitors. Our results provide helpful information on the expression profiles of biosynthetic genes in connection with RA accumulation. © 2018, Springer Nature B.V