Advanced Research Journal of Biochemistry Vol.1 (3), pp. 057-061, November, 2013.© Advanced Scholars Journals

Full Length Research Paper

Changes of some phenolic compounds and enzyme activities on infected pearl millet caused by Sclerospora graminicola

Kumar Arun*, P. C. Mali and V. K. Manga

 Central Arid Zone Research Institute,Jodhpur-342003, India.

*Corresponding author. E-mail: [email protected]. 

Accepted 12 October, 2013

 Abstract

Downy mildew or green ear disease of pearl millet caused by Sclerospora graminicola is the most destructive disease. Affected plants produce green ear with various types of proliferations and malformation of the panicle. Deranged physiology of susceptible and resistant varieties is governed by genetic base, pathogen virulence and induced resistance. Phenolic compounds have been noticed most influential secondary products in determination of resistance in pearl millet plants. In relation to this, activities of polyphenol oxidase (PPO), peroxidase (POX), catalase (CAT) and IAA oxidase (IAAO) have also been found deranged considerably in the downy mildew affected plants of susceptible and resistant cultivars. The study suggests that accumulation of total phenols and OD-phenols caused the hyperphenolicity in infected resistant host tissues despite increased activities of POX and PPO. Total amino acids and free proline contents were increased manifold (1222.2 and 942.6%, respectively) in diseased tissues, particularly in resistant cv. HHB 67 than in susceptible one (Eknath), indicating biotic stress caused by S. graminicola. The role of enzyme activities and their related compounds have been discussed in the present paper.

Key words: Pearl millet, downy mildew, Sclerospora graminicola, metabolites, oxidative enzymes, hyperphenolicity.