Journal of Plant Biochemistry & Physiology
Open Access

Abstract

β-Amino Butyric Acid – Resistance Inducing Agent in Pearl Millet.

Sekhar Shailasree and Prasad Melvin

β-amino butyric acid (BABA), applied as inducer of resistance to the seeds of susceptible cultivar of pearl millet [Pennisetum glaucum (L) R Br] against downy mildew [Sclerospora graminicola (Sacc) Schroet]. Infection offered protection to the host operative through vegetative and reproductive growth. Biochemical studies identified a close association between BABA-treatment and accumulation of defence-related proteins like phenylalanine ammonia lyase, peroxidise and β-1,3-glucanase. Studies on phenotypic host defence identified modifications in host cell wall leading to papillae formation with hydroxyproline-rich glycoproteins (HRGPs) as its major constituent. The HRGPs were identified as extensions by use of MAC 265 monoclonal antibodies. PgMPK4 (mitogen-activated protein kinase) was identified as the crucial signal transduction module signalling of pathogen cues. This increased accumulation of PgMPK4 mRNA and kinase activity in BABA-treated samples and further kinase inhibitor treatments providing critical evidence of PgMPK4 involvement in the JA- and SA mediated expression of defence genes, it may be assumed that BABA-induced resistance could be a JA/SA mediated phenomenon.