Effects of Culture Conditions, Carbon Source and Regulators on Saffron Callus Growth and Crocin Accumulation in the Callus

IntroductionSaffron is a precious herbal medicine.In recentyears,scientists have found that the mostimportant secondary metabolites in saffron pistils,such as crocetin,crocin,safranal and picrocrocin,have anticancer effects,especially on leukemia,papilloma,squamous cell carcinoma and softtissuesarcoma1,2 ] .Saffron inhibits the gene expressionand DNA and RNA synthesis of cancer cells at themolecular level and is also a potent inhibitor oftumor promotion induced by 1 2 - o-tetradecanoylphorb…

Effects of Culture Conditions, Carbon Source and Regulators on Saffron Callus Growth and Crocin Accumulation in the Callus

There are many factors influencing the growth and secondary metabolites of callus and saffron callus. In this paper, the effects of culture conditions, including culture temperatures, light levels, the carbon source and its concentration, and the preserve of regulators (mainly hormones), are studied for callus cultures. All the experiments used Murashige and Skoog (MS) solid medium as the basic medium with 10 g/L agar, pH 5.75.8. Saffron callus was cultured at 20℃ in the dark, with a sucrose concentration of 45 g/L (or starchy hydrolysate concentration of 40 g/L), but 30 g/L sucrose was best for the synthesis of crocin (for starchy hydrolysate the concentration can range from 20 to 40 g/L). To promote callus growth, the best auxin was α-naphthaleneacetic acid (NAA) and the optimum ratio of NAA (mg/L) to benzylaminopurine (BA) (mg/L) was and uniconazole (S-07) (1.25 mg/L) increased the crocin content remarkably as analyzed by high performance liquid chromatography (HPLC). NAA (2 mg/L) promoted the growth of saffron callus but had no benefit and may inhibit crocin synthesis while S-07 (1.25 mg/L) had the opposite effect. GA3 promoted both growth and synthesis.