Endophytic Actinobacteria from Native Plants of Algerian Sahara

Abstract Actinobacteria are widely represented in soils, and play various beneficial roles. They can occur in the plant rhizosphere soil and inhibit soil-borne pathogens. Some actinobacteria are also known to form close associations with plants, colonize their internal tissues without causing disease symptoms, induce systemic resistance, and promote their growth. In the aim of discovering new biocontrol and/or plant growth-promoting agents, researchers have turned their attention to rhizospheric and endophytic actinobacteria isolated from different ecological niches. In the Algerian Sahara, several native plants have successfully adapted to the drought of arid climate and the poor sandy soil. The regeneration from seeds and the vigorous growth without human intervention suggests a contribution of beneficial actinobacteria, both to the biological protection of seedlings against soil-borne phytopathogens and to promote their growth. Recent knowledge in the field of isolation and selection of promising actinobacteria associated with roots of Saharan native plants, their biocontrol and plant growth-promoting attributes, their efficacy in the in vivo biocontrol of soil-borne phytopathogens and in the growth promotion of crop plants, and proposals of formulated biofungicides for sustainable agriculture are explored in this chapter.