Plants are constantly challenged by diverse pathogens and have evolved sophisticated defense reactions to survive these attacks. Treatment of diverse biotic and abiotic agents can strengthen pathogen infection resistance in plants. Recently, abiotic resistance inducers proved to be important components of the integrated disease management programs. Natural inducers among others include polysaccharides and their derived oligosaccharides, representing eco-friendly compounds that promote plant growth beside a concurrent stimulation of pathogen-induced resistance. Alginates (ALG) are gaining interest by virtue of their eco-friendliness and dual roles as a plant stimulant for defense mechanisms and growth promotions. Alginate and its degradation products initiate defense responses by eliciting plant immunity, as it acts as a pathogen-associated molecular pattern. Moreover, ALG regulates the biosynthesis and metabolism of abscisic acid, which helps maintain fruit quality and prolong shelf life. Alginate and its biological activity in plants, effectiveness of alginates against pathogen infestation. Identifying of the mechanisms under biotic and abiotic stress will assist in developing research and additional application practices of alginate-derived oligosaccharides (AOS) providing sustainable and economical plant protection methods in the future.