Molecular Mechanism of Plant–Bacteria Interactions

Over the past few decades, significant progress has been made in understanding the impact of microbes on plant cellular functions and how plants react to microbial invasion, affecting numerous interactions between phytopathogens, symbiotic microorganisms, and plant microbiota. Root exudates are valuable suppliers of nutrients and energy for soil microorganisms, which develop complex communication networks with plants. Bacteria and plants interact in various mechanisms, and this association may be positive, negative, or neutral for the plant. Sometimes a bacterium’s effects change depending on the environmental conditions. Mutualistic and pathogenic rhizobia can penetrate and create persistent infections in their host plant. The effectiveness of plant–bacteria interaction requires the perturbation of plant immunity by either avoiding detection or dampening host defenses. There is a considerable need to boost efforts in this crucial field of research to achieve a systems-level understanding of host–microbe interactions. Although significant efforts have been made in recent years to unravel the molecular aspects of plant–bacterial interactions, many critical issues about these mechanisms still need to be answered. This chapter summarizes current advances in understanding the molecular mechanisms underlying interactions between plants and bacteria and the signaling molecules involved and their function in the rhizosphere.