University of Isfahan Journal of Plant Biological Sciences 3041-9603 16 3 2024 09 22 Effect of culture filtrate and Serendipita indica cell homogenate on content and chemical composition of essential oil and some physiological traits of lemon balm (Melissa officinalis L.) Effect of culture filtrate and Serendipita indica cell homogenate on content and chemical composition of essential oil and some physiological traits of lemon balm (Melissa officinalis L.) 95 120 29876 10.22108/ijpb.2025.145810.1413 FA Maryam Kiani Department of Plant Production and Genetics, Faculty of Agriculture, Malayer University, Malayer, Iran Mohammad Abdoli Department of Plant Production and Genetics, Faculty of Agriculture, Malayer University, Malayer, Iran Mehdi Ghabooli Department of Plant Production and Genetics, Faculty of Agriculture, Malayer University, Malayer, Iran Journal Article 2025 07 01 Lemon balm (Melissa officinalis L.) is a perennial herb that has antioxidant, anti-bacterial, anti-inflammatory, antifungal, and antitumor activities. The present study aimed to investigate the effect of foliar application of culture filtrate (0 and ½ v/v), Serendipita indica cell homogenate (20, 40, 80, and 160 mg/L), and their combined effect on the content and chemical composition of essential oil and some physiological traits of lemon balm in a completely randomized design with three replications. A total of 38 compounds were identified in M. officinalis essential oils, with the major constituents being citronellal, γ-3-carene, trans-carveol, citral, and linalool (total 25.77 to 40.20%), respectively. The results showed that the effect of treatments on the content of major components of lemon balm essential oil was highly significant at the 1% probability level. The highest essential oil content (0.28%) and major compounds, including citronellal, trans-carveol, citral, and linalool (32, 56, 58, 74, and 63% higher than those in the control plants, respectively) were obtained by ½ culture filtrate plus 160 mg/l cell homogenate treatment. The lowest amount was received in the control treatment (without elicitor). The results showed that the type and amount of these elicitors significantly affected the amount of chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, soluble sugar, malondialdehyde content, proline, and flavonoids compared to the control. Citral showed a positive and significant correlation with citronellal, trans-carveol, and linalool (p ≤ 0.01). The heatmap for the studied traits showed a distinct clustering between the control and the treatments of these elicitors. Overall, foliar application of S. indica culture filtrate and cell homogenate is suggested as a biotic elicitor to improve the production of M. officinalis essential oil and its major compounds. Introduction Lemon balm (Melissa officinalis L.) is a perennial herb that has antioxidant, anti-bacterial, anti-inflammatory, antifungal, and antitumor activities. Unlike other plants of the Lamiaceae family, the essential oil content of lemon balm is relatively low; therefore, it has become one of the most valuable types of essential oils. The use of elicitors can be a suitable approach to increase the production of valuable secondary metabolites in medicinal and aromatic plants. The endophytic fungus, Serendipita indica stimulates the growth of many plant species and also increases the production of secondary metabolites. The present study aimed to investigate the effect of foliar application of culture filtrate and S. indica cell homogenate and their combined impact on the content and chemical composition of essential oil and some physiological traits of M. officinalis. Materials and Methods The present study was conducted in a completely randomized design with 10 treatments and three replications in the research greenhouse of Malayer University. The experimental treatments included foliar application with culture filtrate (0 and ½ v/v), S. indica cell homogenate (20, 40, 80, and 160 mg/L), and the combined effect of ½ culture filtrate with 20, 40, 80, and 160 mg/L of S. indica cell homogenate. Autoclaved S. indica culture medium was used as culture filtrate, and powdered mycelium sediment dissolved in distilled water was used as cell homogenate. The control treatment (0 v/v culture filtrate) was sprayed with distilled water. Foliar application of the biotic elicitors on M. officinalis aerial parts was performed at the 40% flowering stage. Five days after elicitation with culture filtrate and S. indica cell homogenate, aerial parts of treated and control plants were sampled to determine biochemical and physiological traits. The content and chemical composition of essential oil, as well as some physiological traits including chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, proline, malondialdehyde content, soluble sugars, total phenols, and flavonoids were measured. The composition of the essential oils was determined by gas chromatography-mass spectroscopy (GC/MS). The correlation coefficient (r) between measured traits was estimated using the Pearson method. Results and Discussion A total of 38 compounds were identified in M. officinalis essential oils, with citronellal, γ-3-carene, trans-carveol, citral, and linalool being the major constituents (total 25.77 to 40.20%). The results of analysis of variance (ANOVA) showed that the effects of treatments consisting of different concentrations of culture filtrate, S. indica cell homogenate, and their combined effects on the content of major components of lemon balm essential oil were highly significant at the 1% probability level. The highest essential oil content (0.28%) and major compounds, including citronellal, trans-carveol, citral, and linalool (32, 56, 58, 74, and 63% higher than those in the control plants, respectively) were obtained by ½ culture filtrate plus 160 mg/l cell homogenate treatment. The lowest amount was obtained in the control treatment (without elicitor). The results showed that the type and amount of these elicitors significantly affected the amount of chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, soluble sugar, malondialdehyde content, proline, and flavonoids compared to the control. The results of correlation between different traits showed that the amount of essential oil had a positive and significant correlation at the 1% probability level with the major essential oil compounds including citronellal (r=0.986**), trans-carveol (r=0.976**), linalool (r=0.971**), and citral (r=0.962**) and a negative and significant correlation with γ-3-carene (r=-0.976**). Also, citral showed a positive and significant correlation with citronellal, trans-carveol, and linalool (P≤0.01). The heatmap results show that for the essential oil content and the major compounds, including citronellal, trans-carveol, citral, and linalool, the best result was obtained by the treatment of ½ culture filtrate+160 mg/L cell homogenate. Conclusion The current study provided evidence that M. officinalis is a medicinal plant that is well responsive to foliar application of culture filtrate and S. indica cell homogenate applied either alone or together. The results of the heatmap for the studied traits showed that the treated plants could be grouped into three distinct clusters and showed a clear separation between the control and the treatments of these elicitors. Overall, the results indicated that foliar application of S. indica culture filtrate and cell homogenate is suggested as a biotic elicitor to improve the production of M. officinalis essential oil and its major compounds, including linalool, trans-carveol, citronellal, and citral. Lemon balm (Melissa officinalis L.) is a perennial herb that has antioxidant, anti-bacterial, anti-inflammatory, antifungal, and antitumor activities. The present study aimed to investigate the effect of foliar application of culture filtrate (0 and ½ v/v), Serendipita indica cell homogenate (20, 40, 80, and 160 mg/L), and their combined effect on the content and chemical composition of essential oil and some physiological traits of lemon balm in a completely randomized design with three replications. A total of 38 compounds were identified in M. officinalis essential oils, with the major constituents being citronellal, γ-3-carene, trans-carveol, citral, and linalool (total 25.77 to 40.20%), respectively. The results showed that the effect of treatments on the content of major components of lemon balm essential oil was highly significant at the 1% probability level. The highest essential oil content (0.28%) and major compounds, including citronellal, trans-carveol, citral, and linalool (32, 56, 58, 74, and 63% higher than those in the control plants, respectively) were obtained by ½ culture filtrate plus 160 mg/l cell homogenate treatment. The lowest amount was received in the control treatment (without elicitor). The results showed that the type and amount of these elicitors significantly affected the amount of chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, soluble sugar, malondialdehyde content, proline, and flavonoids compared to the control. Citral showed a positive and significant correlation with citronellal, trans-carveol, and linalool (p ≤ 0.01). The heatmap for the studied traits showed a distinct clustering between the control and the treatments of these elicitors. Overall, foliar application of S. indica culture filtrate and cell homogenate is suggested as a biotic elicitor to improve the production of M. officinalis essential oil and its major compounds. Introduction Lemon balm (Melissa officinalis L.) is a perennial herb that has antioxidant, anti-bacterial, anti-inflammatory, antifungal, and antitumor activities. Unlike other plants of the Lamiaceae family, the essential oil content of lemon balm is relatively low; therefore, it has become one of the most valuable types of essential oils. The use of elicitors can be a suitable approach to increase the production of valuable secondary metabolites in medicinal and aromatic plants. The endophytic fungus, Serendipita indica stimulates the growth of many plant species and also increases the production of secondary metabolites. The present study aimed to investigate the effect of foliar application of culture filtrate and S. indica cell homogenate and their combined impact on the content and chemical composition of essential oil and some physiological traits of M. officinalis. Materials and Methods The present study was conducted in a completely randomized design with 10 treatments and three replications in the research greenhouse of Malayer University. The experimental treatments included foliar application with culture filtrate (0 and ½ v/v), S. indica cell homogenate (20, 40, 80, and 160 mg/L), and the combined effect of ½ culture filtrate with 20, 40, 80, and 160 mg/L of S. indica cell homogenate. Autoclaved S. indica culture medium was used as culture filtrate, and powdered mycelium sediment dissolved in distilled water was used as cell homogenate. The control treatment (0 v/v culture filtrate) was sprayed with distilled water. Foliar application of the biotic elicitors on M. officinalis aerial parts was performed at the 40% flowering stage. Five days after elicitation with culture filtrate and S. indica cell homogenate, aerial parts of treated and control plants were sampled to determine biochemical and physiological traits. The content and chemical composition of essential oil, as well as some physiological traits including chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, proline, malondialdehyde content, soluble sugars, total phenols, and flavonoids were measured. The composition of the essential oils was determined by gas chromatography-mass spectroscopy (GC/MS). The correlation coefficient (r) between measured traits was estimated using the Pearson method. Results and Discussion A total of 38 compounds were identified in M. officinalis essential oils, with citronellal, γ-3-carene, trans-carveol, citral, and linalool being the major constituents (total 25.77 to 40.20%). The results of analysis of variance (ANOVA) showed that the effects of treatments consisting of different concentrations of culture filtrate, S. indica cell homogenate, and their combined effects on the content of major components of lemon balm essential oil were highly significant at the 1% probability level. The highest essential oil content (0.28%) and major compounds, including citronellal, trans-carveol, citral, and linalool (32, 56, 58, 74, and 63% higher than those in the control plants, respectively) were obtained by ½ culture filtrate plus 160 mg/l cell homogenate treatment. The lowest amount was obtained in the control treatment (without elicitor). The results showed that the type and amount of these elicitors significantly affected the amount of chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, soluble sugar, malondialdehyde content, proline, and flavonoids compared to the control. The results of correlation between different traits showed that the amount of essential oil had a positive and significant correlation at the 1% probability level with the major essential oil compounds including citronellal (r=0.986**), trans-carveol (r=0.976**), linalool (r=0.971**), and citral (r=0.962**) and a negative and significant correlation with γ-3-carene (r=-0.976**). Also, citral showed a positive and significant correlation with citronellal, trans-carveol, and linalool (P≤0.01). The heatmap results show that for the essential oil content and the major compounds, including citronellal, trans-carveol, citral, and linalool, the best result was obtained by the treatment of ½ culture filtrate+160 mg/L cell homogenate. Conclusion The current study provided evidence that M. officinalis is a medicinal plant that is well responsive to foliar application of culture filtrate and S. indica cell homogenate applied either alone or together. The results of the heatmap for the studied traits showed that the treated plants could be grouped into three distinct clusters and showed a clear separation between the control and the treatments of these elicitors. Overall, the results indicated that foliar application of S. indica culture filtrate and cell homogenate is suggested as a biotic elicitor to improve the production of M. officinalis essential oil and its major compounds, including linalool, trans-carveol, citronellal, and citral.

https://ijpb.ui.ac.ir/article_29876_5698f08b03800abc2eb0f9b0897b9d70.pdf