Plant Growth Regulators and Their Interaction with Abiotic Stress Factors

Abstract

In order to reduce the negative impacts on crop production worldwide, plants adapted various hormonal response pathways to resolve the environmental stressful conditions. Endogenous plant hormones play an important role in stressful environmental conditions by facilitating development, allocation of nutrients, and transitions from source to sink. Additionally, due to hormonal interactions, plant design and canopy shade can fine-tune the adaptive mechanism against diverse stress conditions. Abscisic acid (ABA), ethylene, salicylic acid, brassinosteroids, and jasmonic acid play a vital role in plant reaction to abiotic stresses among plants growth regulators. In addition, plants can detect favorable environmental conditions through other hormones including auxins, gibberellins, cytokinins, and strigolactones. The ABA is 116the main biomolecule created by drought and salinity in response to stress. Ethylene helps the plants in cold, drought with salinity, and overwatering. Jasmonic acid helps plants to recover from mechanical injuries and drought stress. The content of salicylic acid increases in response to different abiotic stresses such as drought salinity freezing and heavy metal toxicity. Brassinosteroids control the antioxidant activity of carbohydrate metabolism chlorophyll content to enhance plants growth under stress. In this chapter, an overview of plant hormones, their signaling, and perception is discussed in detail. In addition, a detailed account on phytohormones and their crucial role in tolerating environmental constraints is also deliberated.