Analysis Of Jerusalem Artichoke Petal Phenolic In Cell Suspension Cultures

Jerusalem artichoke (Helianthus tuberosus L.) is native to North America, which belongs to the sunflower plants group in Asteraceae family, now widely cultured around the world. It has a number of advantage over traditionally agricultural crops, including high growth rate, strong resistance to pests and plant diseases, good tolerance to frost, drought and poor soil, and so on. To the best of our knowledge, the chemical components analysis of Jeruasalem artichoke petal has not been reported previously. An in vitro culture of Jerusalem artichoke petal was established in our research. Total phenolic and flavonoids was detected in the suspension cultures, callus culture, petal, flower disc and the antioxidant activity was evaluated by FRAP, DPPH, ABTS methods respectively.(1) Using the Jerusalem artichoke petal as explant, an in vitro culture system was established. Callus cultures were obtained by inoculating petal explants on Murashige and Skoog(MS) medium supplemented with naphthalene acetic acid (NAA,1.0 mg/L) and 6-Benzylaminopurine (6-BA,2.0 mg/L). The callus was subcultured on the same medium to investigate its biomass accumulation on weekly. We found that the log phase was achieved on 2-5 weeks and decline phase was observed after 6 weeks. For suspension culture, loosen callus were cultured on the same MS media and selected 30 g/L sucrose as carbon source, glutamic acid 0.5 mg/L + glutamine 1 mg/L as nitrogen source. The corresponding cells growth curve is that the log phase was achieved on 6-24 days, stationary phase was achieved on 24-33 days, and then decline phase was observed.(2)The total phenolic and total flavonoid of different growth phase of callus and suspension culture was determined. Highest total phenolic 15.02 mg GAE/g DW and total flavonoid 8.03 mg QE/g D W was detected in the stable growth period of suspension culture. The total phenolic and flavonoid of the petal and flower disk were also determined, which was lower than the suspension culture. Additionally, the method for phenolic components analysis and quantitative determination in suspension cultures, callus, petal and flower disk was established by applying ultra performance liquid chromatography (UPLC) with fourteen phenolic standard products. All of the fourteen phenolic components were detected in suspension cultures, callus, petal and eleven phenolic components were found in the flower disk. Among the phenolic compounds, maximum levels of catechin, caffieic acid, salicylic acid,3-hydroxycinnamic acid, ferulic acid, sinapic acid,4-hydroxicumarin were detected in suspension cultures, maximum levels of gallic acid, protocatechuic acid, chlorogenic acid, epicatechin were detected in callus, and 4-hydroxybenzoic acid was higest in petal and quercetin was higest in flower disk.(3)The antioxidant activity of the extraction from suspension cultures, callus, petal and flower disk was determined by FRAP, DPPH and ABTS methods respectively. The results showed that the highest antioxidant activity was detected in the stable growth period of callus and suspension culture with all three methods. The petal and flower disk were used as control, maximum levels of FRAP antioxidant activity 9.07 mg TE/g DW (petal; 5.64 mg TE/g DW), DPPH antioxidant activity 89.41%(petal; 65.23%), ABTS antioxidant activity 93.92%(petal; 43.97%) was displayed by suspension cultures.