Changes in growth, oxidative metabolism and essential oil composition of lemon balm (Melissa officinalis L.) subjected to salt stress

Abstract

Agricultural crops are severely affected by salinity. Recent studies have shown that salt stress signaling components affect plant metabolism and stimulate the accumulation of organic osmolytes and antioxidant substances. This work aimed at assessing the growth and development of lemon balm, Melissa officinalis L., subjected to salt stress, as well as its antioxidant response, essential oil composition, and essential oil yield (%). A completely randomized experimental design was conducted under greenhouse conditions, where 30-days-old lemon balm plants were treated with different NaCl concentrations (0, 50, 100, 150 and 200 mM) for sixty days. The highest concentrations (150 mM and 200 mM NaCl) caused significant reductions in shoot height, shoot fresh mass, relative water content, water activity and chlorophyll production due to changes in osmotic activity. The activities of superoxide dismutase (SOD) and catalase (CAT) increased in plants subjected to salinity. In addition, membrane damage (DM) increased with increase in NaCl concentration. The yield of the essential oils decreased but the number of compounds increased in all the NaCl treatments. The compounds neryl-acetate and geranyl-acetate were detected at 100, 150 and 200mM NaCl, suggesting that under salt stress, lemon balm plants activate the metabolic pathways for the production of terpenoids, consequently producing monoterpenes. Salinity negatively affected most of the parameters evaluated in lemon balm plants. Our results show that lemon balm plants are tolerant to low concentrations of salinity (up to 50mM) as proved by their distinct metabolic responses.

Effect of Saline Irrigation Water, Gibberellic Acid(GA3) and Biofertilizers on Growth, Flowers Yield and Oil Production of Matricaria Chamomilla, L.plants

“…Charles et al(1990) stated the stimulation of essential oil production under salinity could be due to a higher oil gland density and an increase in the absolute number of glands produced prior to leaf emergence. These findings are in consistent with those of Bonacina et al(2017) on Melissa officinalis.…”

Relationships of irrigation water and soil physical and chemical characteristics with yield, chemical composition and antimicrobial activity of Damask rose essential oil

“…Assessment of irrigation water characteristics showed higher concentrations of all cations and anions, water-soluble salts and consequently higher EC, sodium adsorption ratio (SAR) and soluble sodium percentage (SSP) at the Noushabad site, which could be among the reasons for its higher EO yield. However, [61][62][63] showed that higher soil salinity significantly reduced EO yield in Cuminum cyminum L., Mentha canadensis L., and Melissa officinalis L., respectively. These conflicting results regarding the effect of salinity on EO yield of various species in previous research might be due to genotype differences (sensitivity to salinity and halophilism), growing conditions and cultivation techniques [64,65].…”

“…Production of monoterpenes is catalyzed by terpene synthesis, which is guided by stressrelated programs. [62,63,65] determined the effects of higher salinity on the synthesis of the major compounds in the EO, especially monoterpenes, in Mentha canadensis L., Melissa officinalis L., and Mentha spicata, respectively. Their results contradict the findings of the present study.…”

Growth, Enzymatic Activity, and Antioxidant Activity of Sweet Basil Grown in Vitro

“…The enzymatic extract was obtained by maceration of 200 mg of fresh leaf tissue in liquid nitrogen, with the addition of 1.5 mL of 400 mM potassium phosphate extraction buffer (pH 7.8), 1.0 mM EDTA, and 200 mM ascorbic acid. The suspension was centrifuged at 12.000 rpm for 15 min at 40 °C and the supernatant collected (BONACINA et al, 2017).…”