Light spectra affect the morphoanatomical and chemical features of clonal Phyllanthus tenellus Roxb. grown in vitro

Abstract

Phyllanthus tenellus Roxb. is a widely distributed tropical medicinal plant and highly valued for its therapeutic properties. Since variable light conditions can significantly alter phenolic compounds that are the main therapeutic constituents of P. tenellus, including tannins and flavonoids, the development of this plant and its chemical metabolism in response to different light spectra were investigated. To accomplish this, P. tenellus was cultured in modified Murashige and Skoog (MS) medium for 60 days, and its development, leaf anatomy and phytochemistry were analyzed after exposure to white, red, green, yellow and blue light, as well as darkness. Compared to white light, the best in vitro morphogenic responses, including rooting percentage, shoot height, number of leaves, and number and length of branches, occurred under exposure to blue and yellow light. Plantlets developed under white and blue lights presented the greatest thickness of palisade and spongy parenchymas. Under dark condition, plantlets showed fragile aspect and the lowest thickness of leaf tissues. In contrast to other light treatments, chlorophyll and carotenoid contents were significantly lower in plants maintained under green light, whereas yellow light improved the production of phenolic compounds. These results highlight the influence of different light spectra on morphoanatomical features and suggest how different light spectra affect secondary metabolite production in the context of preserving this plant's therapeutic integrity.

Histochemical Screening of Leaves Compared to in situ and in vitro Calluses of Solanum aculeatissimum Jacq.

“…In Piper aduncum L. cultivation, the most important compounds were influenced by the environment, indicating that the variations in the production and components of the essential oils of this species depend on the light conditions and may be related to phenotypic characteristics and genetic factors (Pacheco et al, 2016). Victório (2015) emphasizes that light has the capacity to influence the entire secondary metabolism and plant growth. Abiotic elicitors, such as the absence or presence of light, have been used for induction of biosynthesis pathways (Oliveira et al, 2009) and for accumulation and distribution of organic compounds.…”

Biotic and Abiotic Elicitors Induce Biosynthesis and Accumulation of Some Withanolide Compounds in the Callus Culture of Withania somnifera L.

“…According to Twaij & Taha (2017), sequential light periods led to an enhanced fresh and dry weight of callus tissue compared to constant light or dark conditions in Ricinus communis culture. An increase in different phytochemicals was recorded in various cultures of plants (Victório et al, 2015).…”