Physiological changes in wheat during development of loose smut

This study was planned to determine the dynamics of total phenolic content, polyphenol oxidase and peroxidase activities in wheat (var. Inqlab-91) infected with Ustilago tritici with the objective to investigate the role of phenolics and related enzymes in host pathogen interaction. The biochemical analysis was carried out twice, once at grain filling stage when disease emerges and second at crop maturity. Roots were found most sensitive as considerable increase in both phenolic content and enzymes activity was recorded in early and later stage of disease development. Conversely in case of infected stem and leaves the enzyme activities were found lower at early disease stage in comparison to the control. However, the enzyme activities increased in both parts when checked again at crop maturity with an exception of no increment in peroxidase and cresolase activities in leaves.