Effects of biocontrol agents on lipid and protein composition of Indian mustard seeds from plants infected with Alternaria species

Field experiments were carried out with Indian mustard (Brassica juncea L. Cv RLM 1359) to investigate the influence of biocontrol agents on seeds from plants infected with Alternaria blight. The biocontrol agents viz, Trichoderma harzianum, Pseudomonas fluorescens and Bacillus subtilis were applied as seed treatment/seed treatment coupled with spray on 30 and 60 days after sowing of seeds in experimental fields. The plants treated with different biocontrol agents were more developed than non-treated plants throughout the experiment. Biochemical analysis revealed that application of biocontrol agents resulted in increase in lipid and protein content in seeds from treated plants. The proportion of various lipidic fractions i.e. phospholipids, glycolipids and sterol content in seeds increased with a corresponding decrease in total glycerides. The proportion of 18:3, 20:1 and 22:1 fatty acids increased while that of 18:1 and 18:2 fatty acids decreased in seeds with application of biocontrol agents. There were both qualitative and quantitative differences in the banding patterns of albumin and globulin proteins after application of biocontrol agents. The data suggested that biochemical alterations in the host induced by treatment with biocontrol agents could be associated with defence mechanisms and enhanced growth of the plant.