Role of Plant Metabolites in Abiotic Stress Tolerance Under Changing Climatic Conditions with Special Reference to Secondary Compounds

Abstract

Plants produce diverse secondary plant products that are triggered by a wide range of abiotic factors, such as drought, salinity, UV light, temperature, and cold stress, to cope with environmental changes. Global changes in environmental conditions due to human activities result in elevated carbon dioxide (CO 2 ). Alterations in ozone, UV light, and temperature, and so on, appear to influence endogenous plant metabolites for adaptation. Moreover, plants have adapted to produce several metabolites that are species-specific and dependent on environmental factors. Various plant metabolites, such as polyamines, flavonoids, jasmonic acid, methyljasmonate, glycine betaine, and so on, have a protective role during abiotic stress. In order to cope with various stresses, plants execute various mechanisms, including scavenging of reactive oxygen species (ROS), production of antioxidants, maintenance of membrane stability, and accumulation or adjustment of compatible solutes. This chapter focuses on the role of plant metabolites for their adaptation with special reference to secondary compounds on major global change factors, such as elevated CO 2 , ozone, UV light, temperature, and cold. Introduction: Plant Secondary MetabolitesSecondary metabolites produced by higher plants play an important role in many complex biotic and abiotic interactions [1,2]. Most secondary metabolites are synthesized from the intermediates of primary carbon metabolism via phenylpropanoid, shikimate, mevalonate, or methyl-erythritol phosphate pathways [3]. Several plant secondary metabolites are used for the production of medicines, dyes, insecticides, flavors, fragrances, and food quality (taste, color, and smell) [4-6]. Accumulation of plant secondary metabolites often occurs in plants under stresses, including various elicitors or signal molecules, altogether playing a crucial role in the adaptation of plants to the environment and in overcoming stress conditions [7][8][9]. Abiotic stresses have an effect on different cellular processes, such as growth, 705

Responses of Lotus corniculatus to environmental change 3: The sensitivity of phenolic accumulation to growth temperature and light intensity and effects on tissue digestibility

“…It is well established that the accumulation of secondary metabolites can be affected by external abiotic factors (Dixon and Paiva 1995;Ramakrishna and Ravishankar 2013), as well as by biotic stress such as fungal attack and herbivore predation (Swain 1977;Bennett and Wallsgrove 1994;Mithöfer and Bola 2012). Response to climate change could include both increases in plant secondary metabolites to deleterious levels, or decreases in levels resulting Communicated by Dorothea Bartels.…”

Unraveling the Modulation of Controlled Salinity Stress on Morphometric Traits, Mineral Profile, and Bioactive Metabolome Equilibrium in Hydroponic Basil

“…It is long established that salinity and other suboptimal environmental conditions (e.g., temperature, light intensity, nutrients, and water) have a strong impact on the accumulation of secondary compounds in plants [6][7][8]. The array of diverse molecules probably represents the most important functional feature of medicinal and aromatic plant (MAP) species [9].…”

Responses of Lotus corniculatus to environmental change. 4: Root carbohydrate levels at defoliation and regrowth climatic conditions are major drivers of phenolic content and forage quality

“…Stress-induced accumulation of plant secondary metabolites by both abiotic and biotic factors is well documented, as is the role of secondary metabolites in general herbivory and plant survival fitness (Swain 1977;Rosenthal and Berenbaum 1992;Bennett and Wallsgrove 1994;Dixon and Paiva 1995;Wink 2003;Iason 2005;Mithöfer and Boland 2012;Ramakrishna and Ravishankar 2013). Consequently, there is the potential for climate change to modify the levels of plant secondary metabolites resulting in either deleterious levels appearing in food or feed, or reduced levels compromising plant pathogen defence responses.…”