These
compounds have antibacterial and antifungal potential, which has
great importance in plant cell protection. Cinnamic acid is a key
product of phenyl propanoid pathway, synthesized from precursor
molecule phenylalanine through catalysis by the PAL activity. This
enzyme plays a key role in host resistance to biotic stress (Singh
and Prithiviraj, 1997). The product of PAL and cinnamic acid is
directly linked to cell lignifications process and the maximum PAL
activity usually occur about 24e48 h after pathogen infection. In
the experiments, the PAL activity was average in all treatments with
little elevation in vh32 and vh8 against R. solani compared to plant