Extreme environmental factors, including heat, UV-B radiation, heavy metals, salt and drought, substantially impact bioactive components and the content of essential oils (EOs) in medicinal and aromatic plants (MAPs). Rooted plants cannot avoid undesirable traumas but are equipped well to survive and produce, which imposes serious injury regarding arrested growth, metabolism, and ultimately productivity. The production of EOs in plants is primarily influenced by several biotic and abiotic factors, which in turn impact the yield and bioactive constituents of the oil. The EOs are used for various physiological, ecological, and defensive purposes. The EOs are accumulated in specialized secretory tissues such as glandular hairs/secretory ducts/cavities/oil cells of the plant and are responsible for producing aroma in aromatic plants. They have long been prized for medical, culinary, and aromatic properties and biological purposes. The changing environment influences the ability of a plant to generate volatile organic molecules. In response to environmental stresses, plants evolve various tolerance mechanisms, including modifications to their membrane systems, preservation of the structure of their cell walls, creation of secondary metabolites (SMs) and antioxidants, phytohormones, and accumulation of osmolytes. Secondary metabolites serve a crucial role in maintaining to provide tolerance against stress conditions. Understanding how stress affects the quantity and quality of EOs may have a significant positive impact on EO growers and the processing sector. However, it is crucial to increase yield while retaining oil quality from a business standpoint. Thus, improving EO productivity and quality is a huge task. Taking the aspects (environmental changes) into consideration, the critical issue regarding the cultivation of EO-bearing plants is the variation in quantitative and qualitative production of the EO. The review article comprises EO biosynthesis, the impact of environmental factors, and scientific strategies employed to facilitate the EO production in aromatic plants under unfavourable conditions. All rights reserved, Elsevier.
