Plant secondary metabolites as defenses: A review

Plant secondary metabolites have a variety of functions, including mediating relationships between organisms, responding to environmental challenges, and protecting plants against infections, pests, and herbivores. In a similar way, through controlling plant metabolism, plant microbiomes take part in many of the aforementioned processes indirectly or directly. Researchers have discovered that plants may affect their microbiome by secreting a variety of metabolites, and that the microbiome could likewise affect the metabolome of the host plant. Pesticides are agrochemicals that are employed to safeguard humans and plants from numerous illnesses in urban green zones, public health initiatives, and agricultural fields. The careless use of chemical pesticides is destroying our ecology. As a result, it is necessary to investigate environmentally benign alternatives to pathogen management, such as plant-based metabolites. According to literature, plant metabolites have been shown to have the ability to battle plant pathogens. Phenolics, flavonoids, and alkaloids are a few of the secondary metabolites of plants that have been covered in this study.