Contrary, suspension of N. calcicola HN9 in log phase only raised content of ascorbic acid, and induced activity of SOD and APX, however, its accumulated level was lower than that in death phase. Lack of convinced evidences discribed how strain N. calcicola HN9 in log phase affected to biosynthesis of total phenolics and activity of CAT and PPO. | Journal of Science and Technology 54 (2) (2016) 238-248 DOI: EFFECT OF CYANOBACTERIA Nostoc calcicola ON ANTIOXIDANT SYSTEM OF SOYBEAN Mai Van Chung1, *, Mai Thi Thanh Huyen2, Dinh Thi Truong Giang2 1 2 Faculty of Biology, Vinh University, 182 Le Duan str., Vinh city, Nghe An province Faculty of Chemistry, Vinh University, 182 Le Duan str., Vinh city, Nghe An province * Email: chungmv@ Received: 2 June 2015; Accepted for publication: 24 September 2015 ABSTRACT Strain Nostoc calcicola HN9 of Cyanobacteria, which was in the static culture, was collected biomass in death and log phases to exam its effect on the antioxidant system of soybean [Glycine max (L.) Merr. “Nam Dan”] in the vegetative stages. Suspension of N. calcicola HN9 in death phase caused to oxidative stress in soybean leaves with a burst of superoxide anion radical (O2•-) in stage V1 and hydrogen peroxide (H2O2) in stage V3. In N. calcicola HN9-treated plants, whereas generation of ascorbic acid was inhibited, total phenolics was early accumulated to high content; parallel, activity of enzymes such as superoxide dismutases (SOD), catalase (CAT), ascorbate peroxidases (APX) and polyphenol oxidase (PPO) were enhanced during the vegetative stages. An enhancement of SOD, CAT, and APX firmly regulated ROS products to reduce cellular damages, and allowed them to play crucial function in enhancement soybean tolerance, whereas, the defensive role of PPO should be more clarified in the prospective studies. Contrary, suspension of N. calcicola HN9 in log phase only raised content of ascorbic acid, and induced activity of SOD and APX, however, its accumulated level was lower than that in death phase. Lack of convinced evidences discribed how strain N. calcicola HN9 in log phase affected to biosynthesis of total phenolics and activity of CAT and PPO. Keywords: soybean “Nam Dan”, cyanobacteria, Nostoc calcicola HN9, enzymatic antioxidant; non-enzymatic antioxidant. 1.
