Plant metabolites and signaling pathways in response to biotic and abiotic stresses: Exploring bio stimulant applications

Plants are constantly exposed to a wide array of complex interactions involving various environmental factors, leading to disruptions in their metabolic processes and incurring physiological costs when faced with biotic and abiotic stress. In response to these stimuli, plants have developed diverse signaling mechanisms to adapt to the prevailing conditions. Plants equipped with different signaling pathways undergo changes at the transcriptomic and metabolic level to survive stress stimuli. The signaling pathways are divided into four major subsections: signal perception, signal transduction, regulation of gene expression and physiological responses. Transcription factors (TFs) play a crucial role in the organization of defense mechanisms by regulating downstream gene expression. Primary metabolites (PMs) and Secondary metabolites (SMs) represent fundamental compounds involved in these plant response mechanisms. These plant extracts are a promising method of increasing the tolerance of plants to environmental stresses and can be used as biostimulants. This review aimed to elucidate the contributions of PMs and SMs in plant reactions, as well as their biosynthesis pathways. Additionally, the interplay between these compounds was discussed. The molecular physiology of plant responses to environmental stimuli via signaling pathway was described in this research. Ultimately, plant metabolites were introduced as bio stimulants that can mitigate the adverse effects of various biotic and abiotic stresses.