Enhanced bioactive compounds composition in Lavandula officinalis in-vitro plantlets using NaCl and Moringa oleifera, Aloe vera and Spirulina platensis extracts

Biotic and abiotic elicitors have been reported to promote growth or multiplication as well as alter bioactive compositions of different plant species. Lavandula officinalis is a perennial plant, which produces fragrant flowers that are utilized to prepare the lavender oil. Lavender oil is rich in beta-linalool, cineol, camphor and many other bioactive compounds, which together contributes to its pain relieving, antimicrobial and cicatrizing activities. Micropmpagation is a good alternative to propagate lavender as it reduces the time required to achieve the production of essential oil and eliminates the exposures of the lavender plants to environmental pollutants, thus ensuring a better quality of the oil produced. In this study, we have investigated the effects of 3 biotic elicitors Moringa oleifera leaf extract (MLE), Aloe vera leaf extract (ALE), Spirulina platensis aqueous extract (SAE) and an abiotic elicitor - Sodium chloride (NaCl) on the growth, multiplication and phytochemical compositions of Lavandula officinalis in-vitro plantlets. All tested biotic elicitors (MLE, ALE, SAE) negatively affected the plantlets fresh weight and shoots height. However, these elicitors were found to enhance the number of leaves per explant. On the other hand, the effect of abiotic elicitor (NaC1) were opposite to that of the biotic elicitors. In contrast to the negative growth effects, SAE and high ALE concentration (40 ml/L) were found to enhance number of shoots per explant. Interestingly, we found that all tested biotic and abiotic elicitors were able to increase the betalinalool contents in the L. officinalis in-vitro plantlets. We observed that SAE is the best elicitor among the 4 tested elicitors because both 0.5 and 1.0 g/L SAE were able to increase linalool production and enhanced shoots proliferation.