Experimental Paper. In vitro synthesis of mucilage in Plantago ovata Forsk affected by genotypes and culture media

Abstract

Summary Introduction: Psyllium (Plantago ovata Forsk) is medicinally used mainly for its mucilage content. Objective: In the present study, an attempt was made to improve mucilage yield under in vitro callus culture using different genotypes, explants and culture media. Methods: The effects of a range of concentrations of plant growth regulators including 2,4-dichlorophenoxyacetic acid (2,4-D) and kinetin (Kin) were evaluated on mucilage synthesis under in vitro culture using cotyledon, hypocotyl and seed explants. Fourteen genotypes originating from different geographical regions of Iran were used to evaluate their response to in vitro mucilage synthesis. Results: The highest rate of callus induction (76%) and callus growth rate CGR (0.38 mm/day) were induced on MS medium supplemented with 0.5 mg/l 2,4-D and 1 mg/l Kin and the hypocotyl explant. The results of analysis of variance showed significant genotypic differences for callus induction, CGR and mucilage content of callus and seeds. The mucilage content ranged from 0.38 to 0.08 (g/g DW) and 0.13 to 0.042 (g/g DW) for callus and seed, respectively. The superior callus induction (73%), CGR (0.45 mm/day) and mucilage content of callus (0.38 g/g DW) was denoted to Po1 genotype. The callus produced nearly three times more mucilage than the seeds using superior genotype (Po1). Conclusion: The results of this study revealed that high efficiency of callus culture of P. ovata using hypocotyl explant accompanied by the exploration of genetic diversity are important to improve the yield of mucilage synthesis by in vitro callus culture.

Examining the Physiological Traits of Callus Tissues from Endosperm- Supported Mature Embryos in Common Wheat (Triticum aestivum L.) under In Vitro Salt Stress Conditions

“…Our results indicated a negative effect of salinity on callus growth in terms of fresh and dry matter as the concentration increases in the culture medium especially at 9 g/l NaCl. Golkar et al 19 stated in their nding that the 200 mM NaCl salt concentration had the highest inhibitory effect on callus formation for all genotypes studied. According to Arzani and Ashraf 20 this nding can be explained by the osmotic effect of NaCl, which results in a decrease in the water content of the cytosol in turn causing a decrease in callus growth.…”

Cellular debris, not mucilage polysaccharides, dominate extracts ofPlantago ovataandPlantago lanceolatacalli grownin vitro

“…The same treatment (0.5 mg/L 2,4-D with 1.0 mg/L KIN) had also been reported to produce very high callus induction rate, growth rate and mucilage yield from P. ovata hypocotyls 11 and leaves 10 . Previous studies of mucilage production from Plantago-derived calli reported that the largest calli yielded the most mucilage 9,11 , so T2 calli from both species and explant types were used for mucilage compositional analysis.…”

“…It has been reported that mucilage produced from mucilaginous calli can be easily extracted to yield quantities significantly higher than seedderived mucilage. Recent work reported that calli derived from Plantago lanceolata 9 , P. ovata 10,11 , P. major 12 , Lepidium sativum 13,14 , Linum usitatissimum 15 and several Alyssum species 16 could produce significantly (up to 10) more mucilage than their respective…”

“…Freeze-dried 8 week old calli were lightly ground using a mortar and pestle prior to mucilage extraction. In line with previous publications10,11,16 , mucilage was extracted from calli and seeds following the method of Sharma and Koul 24 with some modifications described by Cowley et al,25 .…”