Mechanisms of Cell Wall Degrading Enzymes from Bacillus methylotrophicus and Bacillus subtilis in Suppressing Foliar Blight Pathogens

Abstract

Bacillus strains are potent Biocontrol agents (BCAs) and have been identified as an effective way to control the growth of phytopathogens of wheat. Through a direct inhibition mechanism which involves the production of cell wall degrading enzymes (proteases, glucanase, and chitinases) and siderophores they suppress the foliar blight disease. Both the strains of Bacillus P10 and UP11 shows growth inhibition Alternaria triticina (77.56%, 67.83%) and Bipolaris sorokiniana (73.97%, 62.16%) through a dual culture assay. These strains were subsequently examined for their ability to produce cell wall-degrading enzymes i.e., chitinase, protease, and β-1,3-glucanases and antifungal metabolites i.e., siderophores. It was found that when the antagonist’s bacteria were Co-cultured with fungal pathogens then maximum production of hydrolytic enzymes and siderophore was achieved at 96 hrs, but when both strains P10 and UP11 were alone maximum production was found at 48 hrs i.e., the exponential phase. The current study determined that Bacillus methylotrophicus (P10) and Bacillus subtilis (UP11) are highly effective strain for controlling Foliar Blight disease. Direct or Antibiosis is the main mechanism involved in this study. Further research on the interaction mechanisms between Bacillus-derived compounds and host plants is necessary.