Morphological and biochemical analysis of the CNTs-induced in-vitro culture of Moringa oleifera

Abstract The current research work was designed to study the effects of carbon nanotubes (CNTs) on morphological and phytochemical profile of in vitro culture of Moringa oleifera. The surface sterilized Moringa seeds were cultured on MS basal medium containing different concentrations of carbon nanotubes (0, 20, 50, 80 and 100 mg/l) and incubated at 25 ± 1°C for germination, and/or callus induction and regeneration. Similarly, the germinated in vitro plants were analysed for biochemical analysis and phytohormones level. The results showed that earlier germination (after 3 days) was recorded on CNTs-fortified medium and the highest used concentration (100 mg/l) of CNTs resulted in 100% germination of the explants. Similarly, in case of callogenesis, we found that as we increased the CNTs concentrations from lower to higher, we obtained higher percentage in callus formation and highest fresh (3.081 ± 0.005 g) and dry weight (1.64 ± 0.0012 g) were recorded on the media with 100 mg/l of CNTs. The induced calli were subjected to regeneration and the best results in the highest number of shoot (5 ± 0.57), shoot length (11 ± 0.57 cm), highest number of leaves (24), highest root number (12 ± 0.57), and root length (9.8 ± 0.35) were all observed on 100 mg/l CNTs-media. The spectrophotometric analysis of the total soluble sugars, proline, flavonoids, and phenolic contents revealed that the highest flavonoids were found on 50 mg/l concentration of CNTs, while the highest sugars, proline, and phenolics were observed on 100 mg/l of CNTs. The phytohormones, indole acetic acid (IAA, salicyclic acid, and gibberellic acid) were quantified. CNTs affected the level of IAA, however SA and GA were not significantly affected by the use of CNTs in the MS media. To the best of our knowledge, this is the first trial in determining the impact of CNTs on the morphological and biochemical characteristics of the medicinally important plant, M. oleifera, where the application of CNTs caused a growth promoting effect on moringa plant and triggered the biosynthesis of essential plant metabolites.