Authors : Meraj-ul-Haque and P. B. Nandkar
Page Nos : 76-78
Description :
Abstract:
Plants are known to respond to pathogen attack in various ways. As soon as the pathogen penetrates the host cell, a defense response cascade of the host cell operates and, as a result, different physical and chemical changes occur in the host cells. This hypersensitive response (HR) is characterized by strengthening of host cell walls due to the synthesis of wall bound phenolics, activation of cell death program and induction of a host of other biochemical responses which include accumulation of defense related proteins and antimicrobial compounds. All these responses, directly or indirectly, play a role in restricting the growth/entry of pathogen in the host.
In our result biocontrol treated seeds elicit induced resistance in tomato plants by induction of host defense related enzymes before inoculation with pathogen. However, there was a further increase in the enzymatic activity after challenged inoculation, indicating that increase enzymatic activity is a natural response of susceptible infected plants to pathogen attack. The enzymatic activities increased further 24-72 HAC and reduced slightly towards 72-96 HAC. Tr4-(T. viride + T. virens) + Fusarium sp. recorded maximum enzymatic activity followed by Tr2-Trichoderma virens + Fusarium sp. than Tr3-Trichoderma viride + Fusarium sp. after 48 HAC. Lower enzymatic activities were consistently detected in non-challenged control throughout the study and were lower than biocontrol treated seedlings.
