ABSTRACT
Probiotics, a group of naturally-occurring living microbes, have shown different capabilities to promote soil health, stimulate plant growth, control plant pathogens, and enhance plant tolerance against various abiotic and biotic stresses. This group combines diverse living microbes, including bacteria, archaea, fungi, etc. they have evolved over time to adopt diverse mechanisms and develop their ability to produce a plethora of macro and micro molecules to secure their survival and increase their fitness among a diverse population of competitive soil microorganism. As a result, their existence around plants has led to noticeable benefits and became advantageous additives for plant health. In this book chapter, we will introduce plant probiotics and present their types, biology, natural interactions with the surrounding environmental components and conditions, and the mechanisms they are employing to improve plant health (direct and indirect). In addition, we will try to cover the most important applications of these bacteria in the agriculture field. Moreover, we will present some of the challenges that encounter the extended use of this promising group of microorganisms for sustainable agriculture practices. And finally, we will discuss some of the challenges which are associated with the expansion of their use at larger scales, including technical, social awareness, as well as legal issues.
