Rhizospheric Pseudomonas fluorescens enhances piperine production in Piper nigrum, a possible means of biochemical defence against Phytophthora capsici

Abstract

Black pepper is an important export-oriented spice crop. Foot rot caused by P. capsici is a very serious disease, which cause serious economic loss to the farmers. Biological control is the viable strategy for sustainable disease management. Efficient strains of P. fluorescens reduced the foliar infection caused by P. capsici significantly. It has been observed that the level of piperine, the pungent principle in black pepper, is increased to significant levels upon root bacterization of the black pepper vines. In addition to it, piperine (Sigma) inhibited the mycelial growth of P. capsici, in vitro, demonstrating the direct fungicidal activity of this alkaloid. An increase in the quantity of piperine is supposed to contribute to the overall host defence mechanism of the plant. The paper describes for the first time, the rhizobacteria-mediated induction of piperine in black pepper.