Suman Preet Singh Khanuja

Medicinal and aromatic plants: A case example of evolving secondary metabolome and biochemical pathway diversity

The unique capability of plants, in spite of being immobile in strict sense, to defend and respond precisely to environmental stresses whether biotic or abiotic is relatable to their ability to synthesize an array of phytochemicals as metabolites. We find these plants compounds useful for health care as nutraceuticals, drugs and medicines and even most attractive fragrances and flavors. This huge diversity of low molecular weight compounds is represented by secondary metabolites that confer the power of responding to stimuli in plants. Hence, the network of metabolic pathways in plant species represents the pool of functions and chemical diversity leading to biomolecules such as alkaloids, flavanoids, terpenoids, glycosides, etc. Although the structures of approximately 50,000 such metabolites have already been elucidated, there are probably hundreds of thousands of such compounds which we are not able to detect or decipher within the existing limitation of detection. Only a few of these are part of ‘primary’ metabolic pathways (those common to all organisms). The rest are termed ‘secondary’ metabolites; this term is historical and was initially associated with inessentiality but we know today their necessity in defence to signals and stimuli.