Light quality on growth and phenolic compounds accumulation in Moringa oleifera L. grown in vitro

Abstract

All plant parts of the Moringa oleifera can contain relevant concentrations of phytochemicals with health benefits. Plants grown in vitro allow pathogen-free plant material production and rapid propagation, and this technique is widely used to obtain secondary metabolites. This study analyzed how light spectrum quality affects growth, chlorophyll, and total phenolic content in M. oleifera plants grown in vitro. M. oleifera seeds were inoculated in MS medium supplemented with 3% sucrose and 0.7% agar and were stored under a controlled temperature, humidity and photoperiod. The light conditions tested were white fluorescent lamps (WFL) and light-emitting diodes (LED: 70% red + 30% blue), both standardized with a photon flux density of 58 μmol m-2s-1. Radiation emitted by WFL and LED did not influence stem germination, height, or diameter. However, WFL provided higher total chlorophyll levels. All plant parts germinated in vitro were analyzed via high-performance liquid chromatography with a diode-array detector (HPLC-DAD), and preliminary analyses revealed preferential synthesis of gallic acid derivatives in the leaves under LED radiation. For the total phenolic content, leaves under the LED and WFL irradiations showed 3.524 ± 0.054 and 3.805 ± 0.304 micrograms, respectively, of gallic acid equivalents per milligram of dry matter (μg GAE mg-1 DM). Light quality did not interfere with phenolic compound accumulation; however, it stimulated the preferential synthesis of gallic acid derivatives in leaves grown under LED radiation, and the evidence indicated that all evaluated organs synthesized nonpolar substances.

The influence of different wavelengths of LED light on the production of glucosinolates and phenolic compounds and the antioxidant potential in in vitro cultures of Nasturtium officinale (watercress)

“…There are other known studies in which the production of phenolic compounds did not increase by stimulation with different lighting conditions. Da Silva et al (da Silva et al 2020) had tested the influence of red and blue LED light (70:30%) on the total phenolic content in Moringa oleifera shoots cultures. In vitro cultures grown under white light (control) accumulated more phenolic compounds than under the red and blue light (70:30%) conditions.…”

Probing the Phytochemical Composition and Antioxidant Activity of Moringa oleifera under Ideal Germination Conditions

“…The polyphenols, flavonoids, MDA, and antioxidant capacity in moringa seed at 4 °C, 20 °C, and 30 °C showed that maximum phenolic compounds were observed at 20 °C and 30 °C [ 33 ]. da Silva et al [ 34 ] investigated the phenolic composition of different organs of Moringa oleifera , such as leaves, hypocotyls, and roots, and reported values ranging between 2.185 ± 0.089 mg GAE/g and 3.805 ± 0.304 mg GAE/g. Similar results were seen in faba beans, where polyphenolics were synthesized and accumulated at approximately the same time as seed priming throughout the germination process [ 35 ].…”

Crescimento inicial de Moringa oleifera em substrato arenoso com adição de vermicomposto em duas luminosidades

“…Os frutos verdes possuem todos os aminoácidos necessários à espécie humana e representam um alimento básico à população, além da espécie produzir compostos fenólicos e flavonoides, entre outros metabólitos secundários 4 , indicando seu potencial medicinal. De acordo revisão realizada por Silva et al (2020) 5 , a espécie possui uma série de atividades biológicas, com atividade anti-inflamatória, anticancerígena, antioxidante e antimicrobiana.…”