Salicylic Acid: Molecular Basis of Stress Resistance in Plants

Plants and their casual pathogens are in a continuous evolutionary battle and combat with each other in order to overwhelm their counter mechanisms. Beyond physical barriers and natural openings in plants, all pathogens retain a plethora of various strategies to overcome plant defense mechanisms. Conversely, plants employ mainly two-tiered immune system to resist pathogen attacks, on molecular basis, basal and durable immune response, both which stem from highly complicated and genetically controlled pathways including the incorporation of major gene(s) and multiple genes with minor effects, respectively. Plant immune response and following pathogen resistance are accomplished through perception of pathogen-derived effectors, elicitors, and conserved specific pathogen molecules. Recent advances in biotechnology, bioinformatics, next-generation sequencing, and all omics platforms provide useful and novel insights over tremendous examples of persistent plant-pathogen combat such as the discovery of new resistance genes, miRNAs, siRNAs, transcription factors, and such. Rising environmental and ecological disarrangements, however, further affect pathogen populations remarkably, mostly encouraging the development of highly aggressive or novel pathogens, pointing to recurrent struggling between pathogen and plants.