Systemic resistance: Plant responses to interaction with fungal bio-control agents

Abstract

Systemic resistance in plant against phytopathogens is mainly associated with systemic acquired resistance (SAR) and induced systemic resistance (ISR). SAR and ISR are mechanisms of induced defense that confers long-lasting protection against a broad spectrum of phytopathogens. SAR requires the signal molecule salicylic acid (SA) while ISR signal molecules are jasmonic acid (JA) and ethylene. These are associated with accumulation of pathogenesis-related proteins (PRP) which contribute resistance inside plant. Bio-control fungi (BCF) such as Trichoderma spp. and Pseudomonas spp. are agents that control plant diseases. They have the ability to control numerous soil-borne as well as many foliar and fruit pathogens. BCF also augments nutrient uptake and increase nitrogen use efficiency in crop plants. Some strains also have abilities to improve photosynthetic efficiency of plants. Furthermore, PcPCL1606 has displayed additional traits regarding its fitness in soil and plant root environments such as soil survival, efficient plant root colonization, promotion of plant growth. The present review highlights systemic resistance in plant concerns with SAR and ISR-mediated functional traits, such as enhancement of plant growth and bio-control of phytopathogens.