In vitro callus induction for determination of lectin activity in pea (Pisum sativum L.) variety (AP-1)

From 8-10 days old seedlings of Pisum sativum L. (variety AP-1), various parts root, cotyledon as well as leaf were separated to use as explants. Root and cotyledonary explants did not show any response on MS (Murashige & Skoog) media supplemented with 2, 4-D at a concentration of 5 ppm. However, leaf explants showed callus formation on this media. The callus so formed was subcultured on MS media supplemented with 2, 4-D, IAA, and kinetin. After eight weeks, callus (green and friable) was harvested and used for extraction of lectin protein, known for a wide variety of biological activities in plants, animals and microbes. Seeds were also used to extract lectin protein. Seed extract showed haemagglutination activity of 800 HU/ml, where as callus extract showed 100HU/ml. In seed extract, specific haemagglutination activity was 4 times more than callus extract. Moreover, lectin from seed extract was found to be more thermostable than that of callus extract. In pH range of 6.0-8.0, no loss of lectin activity was observed in seed as well as callus extract. Above and below this pH range, lectin activity showed reduction. Among the various tested sugars, seed as well as callus extract showed specificity for fructose, glucose, maltose, mannose, N- acetyl glucosamine and sucrose.