Treatment of Licorice Seeds with Colchicine: Changes in Seedling DNA Levels and Anthocyanin and Glycyrrhizic Acid Contents of Derived Callus Cultures

Abstract

The use of colchicine to induce polyploids increases secondary metabolite production potential and has been used for many years for the production of valuable compounds in plants. This project took advantage of this method to increase the production of secondary metabolites in licorice. For this purpose, seeds of licorice, Glycyrrhiza glabra var. glandulifera, were treated with different concentrations of colchicine for 24 hours and then cultivated in vitro. After a month, the effect of colchicine on the cellular DNA level of cotyledons was analyzed by spectrophotometry and flow cytometry. For callus induction, root explants of one month old plantlets derived from colchicine treated seeds were transferred to MS medium containing growth regulators and the anthocyanin and glycyrrhizic acid levels of the callus tissues were measured after two months of growth. The total DNA content of plantlets derived from seeds treated with 0.05%, 0.08% and 0.1% of colchicine for 24 hours was increased significantly. Treated plants had increased numbers of larger stomata, significantly in those treated with 0.1% of colchicine for 24 hours. After colchicine treatment, the root, shoot and leaf thickness was found to be increased, while their length was decreased. Results of flow cytometry showed changes in ploidy level in plantlets obtained from treatment with 0.08% (mixoploids) and 0.1% (tetraploids) of colchicine. Anthocyanin level was significantly increased in callus obtained from plantlets treated with 0.08% of colchicine. The amount of glycyrrhizic acid in all treatments increased, especially in the 0.1 and 0.03% colchicine treatments and this seems to prove an increased production of metabolites in polyploid licorice tissues.

Transcriptome analysis reveals in vitro cultured Withania somnifera leaf and root tissues as a promising source for targeted withanolide biosynthesis

“…To meet the growing demand of the herbal industry, in vitro cultures could be an alternative to field-grown plants for consistent production of secondary metabolites within a short period [ 15 ]. Several reports indicate the potential of manipulating in vitro tissues to produce bioactive terpenoids, phenolics, saponins and anthocyanins [ 16 - 18 ], but any attempt to engineer efficient production of secondary metabolites requires understanding of their biosynthetic pathway(s), and our present knowledge of withanolide biosynthesis is limited to only a few genes involved in the pathway [ 10 , 19 , 20 ].…”

Is a plant’s ploidy status reflected in its metabolome?

“…Triploid progeny population obtained from diploid and tetraploid of Camellia tea species indicated that the catechin and caffeine levels of the triploid progenies were higher than their diploid parent and showed heterosis for caffeine and EGCG, thus allowing quantitative enhancement of some of the quality-related parameters in tea (Das et al, 2013). The ploidy level in licorice plantlets obtained from treatment with 0.08% (to induce mixoploidy [defined as presence of both diploids and polyploids in a population]) and 0.1% ( to induce tetraploidy) of colchicine demonstrated that the anthocyanin level was significantly increased in callus obtained from mixoploid plantlets whereas the amount of glycyrrhizic acid increased upon induction of polyploidization, proving an increased production of metabolites in polyploid licorice tissues (Bernard et al, 2012). In copperexposed diploid and tetraploid chamomile (Matricaria chamomilla) roots, it was demonstrated that flavonoids and phenolic acids did not differ with respect to ploidy ( al., 2010).…”

Effect of pre-sowing treatments with chemical mutagens on seed germination and growth performance of jamun (Syzygium cuminiL. Skeels) under different potting substrates

“…The amount of chlorophyll produced per gram leaf tissue is also affected by environmental conditions and the genetic composition of the plant [48]. Since T 4 is known to increase the total DNA content in plant cells [49], it might have enhanced synthesis of photosynthetic pigments as well.…”

“…Warner and Gerald [50] suggested that the photosynthetic rate per unit leaf area is related to the number of photosynthetic cells per unit area. As a matter of fact, the photosynthetic rate per cell is correlated with the amount of DNA per cell, which is increased in colchicinetreated plants [49].…”

“…Changing the metabolic profile in colchicine-treated plants can be interpreted as the cause of an alteration in the mechanism(s) which regulates the biosynthesis of several compounds [55]. As colchicine affects the cellular DNA level [49], it also affects protein metabolism and thus alters the plant metabolism, leading to the generation of reactive oxygen species. Plants protect themselves from this harmful radiation by synthesizing phenolic compounds, which act as a screen inside the epidermal cell layer, and by adjusting the antioxidant systems at both cell and whole organism levels [56].…”