Karnal bunt (KB) disease incited by Tillelia indica is widely
distributed and an economically important disease of wheat. The present
study, attempts were made to find out the physiological, biochemical and
molecular basis of resistant and stage specific immunity, against KB.The
enzymes of phenylpropanoid pathway were expressed and remained higher in
resistant genotype. Phenylpropanoid metabolism is involved in synthesis
of carotenoid, act as precursor of ABA synthesis. The low carotenoid
levels in resistant than susceptible genotype due to its more conversion
in to ABA pool, induced downstream jasmonic acid mediated pathway and
caused induction of PR- proteins (b-1,3 glucanase, protease and protease
inhibitors) in wheat spikes. Stoichiometric balance of protease and
protease inhibitor play key role in controlling the resistance by
intervention of programmed cell death (PCD). The results of present
study clearly demonstrated that resistant is due to involvement of multi
component signaling leading to genotype to genotype dependent and stages
dependent immunity against KB and cystatin-proteinase interaction is key
factors in triggering plant defence against pathogenic fungi.