Plant’s defense and survival strategies versus pathogen’s anti-defense and infection capabilities: The hormone-based mechanisms

Abstract

Plants are constantly exposed to various biotic stresses caused by diverse species of pathogens such as bacteria, fungi, insects, oomycetes, and viruses. A plant-pathogen interaction depicts a continuous process of gaining a competitive advantage over each other in a natural environment. For the counter-defense, plants have evolved an array of resistance strategies that help in diminishing the effect of pathogen and pest attack (Panstruga et al. 2009; Denancé et al. 2013). Plants have been equipped with a molecular defense system to sense pathogen and pest attack. They have specialized proteins to recognize pathogens, which are known as plant recognition receptors (PRRs). These molecules are responsible for the identification of comparatively conserved components of the pathogen termed as pathogen-associated molecular patterns (PAMPs). In counteraction, a pathogen exudes effector proteins to normalize the plant specific PAMP-triggered immunity (PTI). This battle continues, as the plant starts secreting specialized proteins to recognize these effectors. Plants are equipped with resistance (R) proteins that play a significant role in the identification of these pathogen-derived effector proteins. This process is known as effector-triggered immunity (ETI; Dodds and Rathjen, 2010).