Role of Phenolic compounds in plant defense mechanism: An updated review
Pratiksha Salunke and *Dipak Koche
Department of Botany, Shri Shivaji College of Arts, Commerce, and Science, Akola-444003 (India) *Corresponding author: kochedeepak77@gmail.com
ABSTRACT
Being immovable, plants have to face all types of abiotic and biotic stress conditions. In response to various stress conditions, different plants accumulate different phenolic compounds. The phenolic compounds accumulated to counter various stresses depend on the type of stress conditions. In general, light stress induce the synthesis of phenolics and flavonoids; temperature extremes inducethe accumulation of osmoprotectant compounds which eventually stimulate the synthesis of antioxidants such as flavonoids, tannins, and phenolics in plants. In nearly all types of stress conditions plants increase the production of reactive oxygen species (ROS) and also to counter this, the plant produces phenolic acids, polyphenols, flavonoids, anthocyanins, and other compounds with similar properties to counter ROS such as (H2O2). In case of biological stresses, the plants accumulate phenolics at the infection site to restrict microbes’ growth. Sometimes, they also induce the synthesis and accumulation of Salicylic acid (SA) and H2O2 at the site of infection. It’s important for plants as they develop systemic acquired resistance (SAR). The synthesis and accumulation of phenolic compounds were also recorded immediately after postinfection; indicating their crucial role in plant defense mechanisms against various types of stresses. The present review focuses on current updates on the role of phenolics and their physiological functions as a response to stress conditions and their probable applications in stress counter.