Methyl Jasmonate Induces Genes Involved in Linalool Accumulation and Increases the Content of Phenolics in Two Iranian Coriander (Coriandrum sativum L.) Ecotypes

Abstract

The medicinal herb coriander (Coriandrum sativum L.), with a high linalool (LIN) content, is widely recognized for its therapeutic benefits. As a novel report, the goals of this study were to determine how methyl jasmonate (MeJA) affects total phenolic content (TPC), LIN content, flavonoid content (TFC), and changes in gene expression involved in the linalool biosynthesis pathway (CsγTRPS and CsLINS). Our findings showed that, in comparison to the control samples, MeJA treatment substantially enhanced the TPC, LIN, and TFC content in both ecotypes. Additionally, for both Iranian coriander ecotypes, treatment-induced increases in CsγTRPS and CsLINS expression were connected to LIN accumulation in all treatments. A 24 h treatment with 150 µM MeJA substantially increased the LIN content in the Mashhad and Zanjan ecotypes, which was between 1.48 and 1.69 times greater than that in untreated plants, according to gas chromatography-mass spectrometry (GC-MS) analysis. Our findings demonstrated that MeJA significantly affects the accumulation of LIN, TPC, and TFC in Iranian C. sativum treated with MeJA, which is likely the consequence of gene activation from the monoterpene biosynthesis pathway. Our discoveries have improved the understanding of the molecular mechanisms behind LIN synthesis in coriander plants.

Keywords: coriander; gene expression; linalool; methyl jasmonate; total flavonoid content; total phenolic.

Figure 1

Conversion of geranyl diphosphate to (S)-linalool by LINS, and to other monoterpene products by TRPS.

Figure 2

Linalool content of Iranian coriander ecotype leaves after various MeJA treatments. According to Duncan’s test, bars with different lettering indicate significance at a 1% level of probability. Error bar are shown in percent of standard deviation.

Figure 3

The impact of various MeJA concentrations on the TPC (A) and TFC (B) of leaf extracts from two Iranian coriander ecotypes. The data are shown as mean standard deviations (n = 3). According to Duncan’s test, distinct letters in each column indicate significance at a 1% level of probability. Error bars are shown in percent of standard deviation.

Figure 4

Linalool biosynthetic pathway genes CsγTRPS (A) and CsLINS (B) are expressed in the leaves of control (untreated) and MeJA-treated coriander plants, respectively. The Ct values formed the basis of qRT-PCR. The reference gene actin was used to standardize the Ct value for each sample. According to Duncan’s test, bars with different letters are substantially (p ≤ 0.01) different. Standard error values are shown by error bars.