Biochemical characterization of micropropagated Ceratonia siliqua L. under effect of growth regulators and light quality

Background Carob ( Ceratonia siliqua L.) is one of the important crops in terms of nutritional and medicinal value in the countries of Western Asia and North Africa. Despite the fact that some countries have used Carob in traditional medicines, the modern food industry began to discover the great potential of this plant which differentiates with antioxidant capacity as well as other important medicinal activities. Some of very few studies that have been reported on this important plant were published. Methodology In the present study, micropropagation behavior and biochemical constituents of Ceratonia siliqua L. cultured on MS medium supplemented with different types and concentrations of cytokinins (0.0, 0.5, 1.0, or 1.5 mg/l BA, Kin, or TDZ and 0.2 mg/l NAA) under various light qualities ((white, green, blue, red, and yellow) were examined. Results MS culture medium supplemented with BA produced the highest shootlets number/explants. For light quality, the data showed that green light increased shootlet number/explants, fresh and dry weights. However, yellow light increased shootlet length and leaves number and also caused significant increase in total phenols, flavonoids, and antioxidant capacity (DPPH) as compared to other lights. HPLC analysis showed that yellow light caused the highest accumulation of total phenolic and catechin that were the highest accumulated compounds (509 μg/ml) followed by that were accumulated under green light (412.68 μg/ml). Shootlets grown under white light (control) gave the highest accumulation of p-coumaric acid, rosmarinic acid, and cinnamic acid. Shootlets grown under blue light gave the highest accumulation of gentisic acid and syringic acid. Red light caused the highest accumulation of vanillic acid. However, white light accumulated the highest amount of flavonoid compounds comparing with other light qualities. Conclusion This study had reached to optimize a suitable micropropagation protocol of Ceratonia siliqua L. and characterization of biochemical constituents that can be beneficial for increasing its medical value which will help in food industries for commercial purposes.