نوع مقاله : مقاله پژوهشی

نویسندگان

• مهشید طبری فرد ¹
• منیره چنیانی ²
• علی گنجعلی ¹

¹ گروه زیست‌شناسی، دانشکده‌علوم، دانشگاه‌فردوسی‌مشهد، مشهد، ایران

² گروه زیست شناسی، دانشکده علوم، دانشگاه فردوسی مشهد، مشهد، ایران

چکیده

کلیدواژه‌ها

• آنتیاکسیدان
• الیسیتور
• فلاونوئید
• رزمارینیکاسید
• کلپوره

موضوعات

• علوم گیاهان دارویی

عنوان مقاله [English]

Induction of Secondary Metabolites Contents and Antioxidant Capacity of Teucrium polium Callus under Treatment with Naphthalene Acetic Acid, Benzylaminopurine, and Methyl Jasmonate

نویسندگان [English]

• Mahshid Tabarifard ¹
• Monireh Cheniany ²
• Ali Ganjeali ¹

کلیدواژه‌ها [English]

• Antioxidant
• Elicitor
• Flavonoid
• Rosmarinic acid
• Teucrium polium

Extended Abstract

Introduction

    One of the most important factors for the preservation of plants, in particular medicinal ones, is the use of biotechnological methods for increasing the production of secondary metabolites. The main medicinal compounds of Teucrium polium are divided into several groups based on their origin, among which phenolic compounds, flavonoids and phenolic acids have a major contribution. It has been reported that any factor affecting the gene expression level and activity of phenylalanine ammonia-lyase can affect the synthesis of phenolic compounds. Methyl jasmonate is one of the most important abiotic elicitors, which plays a key role to induce a large number of genes related to the defense pathway. It has been reported that these esters can promote the biosynthesis of several kinds of secondary metabolites including indole alkaloids, sesquiterpenes and phenolic compounds. The present study was conducted with the aim of investigating the effect of exogenous application of benzylaminopurine (BAP) and naphthalene acetic acid (NAA) on callus induction of Teucrium polium leaf explants, and the effect of methyl jasmonate elicitation on the phenolic compounds and antioxidant activity in calli under the same conditions

Material and Methods

   Immature leaf of the T. polium grown under hydroponic condition were cultured on MS medium supplied with various concentrations of BAP (0, 0.5, 1, and 1.5 mg/L) in combination with NAA (0, 0.5, and 1 mg/L). Regarding the highest callus induction frequency and mean weight of dry calli, the selected cultures were treated with different concentrations of methyl jasmonate (50, 100, and 200 μM). Explants without methyl jasmonate treatment were considered as controls. The methyl jasmonate treated calli were collected, air dried and extracted at room temperature. The content of phenolic compounds, flavonoids, flavones, O-diphenol, phenolic acids, and rosmarinic acid as well as antioxidant capacity (measured by both DPPH Free Radical Inhibition and Ferric Reducing Antioxidant Power assays) were evaluated.

Results

   The highest percentage of callus induction (100%) from the leaf explants was achieved from the medium supplemented by BAP individually as well as in combination with NAA. The maximum fresh and dry weights of calli were achieved in three combinations of growth regulators, i.e., (i) 1.5 mg/L BAP + 0.5 mg/L NAA, (ii) 1.5 mg/L BAP, and (iii) 1 mg/L BAP. The maximum contents of phenolic compounds, flavonoids, flavones, O-diphenol, phenolic acids, and rosmarinic acid were measured at pretreatment of the callus with 50 μM methyl jasmonate, with statistically significant differences with other methyl jasmonate concentrations. The highest antioxidant activity with an IC50 of 2.066 ± 0.24 µg/mL using DPPH assay, and 383.79 ± 33.61 mg Fe+ 100g-1 DW using FRAP was in 50 μM methyl jasmonate and 1.5 mg/L BAP + 0.5 mg/L NAA treatment.

Discussion

   It has been confirmed that jasmonates increase the expression of genes and transcription factors related to secondary metabolite biosynthesis in cell culture. The increase in the activity of phenylpropanoid pathway-related enzymes (PAL, C4H, 4CL, CAD, POD, and PPO) and their gene expression is a result of this class of elicitors, which are important factors in the synthesis of phenolic compounds. The results of the present study also showed the role of jasmonate in increasing most of the studied metabolites. However, high concentrations of methyl-jasmonate with excessive accumulation of reactive oxygen species lead to oxidation of macromolecules such as nucleic acids, proteins, and lipids, which ultimately leads to cell death.

Conclusion

   The results of the present research showed that the application of methyl jasmonate in optimal concentration can play an effective role in increasing the active pharmacological compounds of T. polium. Also, the use of methyl jasmonate in combination with growth regulators had positive effects on the synthesis of phenolic compounds and further increase of the antioxidant power in calli.