Spermine: Its Emerging Role in Regulating Drought Stress Responses in Plants

Abstract

In recent years, research on spermine (Spm) has turned up a lot of new information about this essential polyamine, especially as it is able to counteract damage from abiotic stresses. Spm has been shown to protect plants from a variety of environmental insults, but whether it can prevent the adverse effects of drought has not yet been reported. Drought stress increases endogenous Spm in plants and exogenous application of Spm improves the plants’ ability to tolerate drought stress. Spm’s role in enhancing antioxidant defense mechanisms, glyoxalase systems, methylglyoxal (MG) detoxification, and creating tolerance for drought-induced oxidative stress is well documented in plants. However, the influences of enzyme activity and osmoregulation on Spm biosynthesis and metabolism are variable. Spm interacts with other molecules like nitric oxide (NO) and phytohormones such as abscisic acid, salicylic acid, brassinosteroids, and ethylene, to coordinate the reactions necessary for developing drought tolerance. This review focuses on the role of Spm in plants under severe drought stress. We have proposed models to explain how Spm interacts with existing defense mechanisms in plants to improve drought tolerance.

Green Synthesized Metal Oxide Nanoparticles Mediate Growth Regulation and Physiology of Crop Plants under Drought Stress

“…However, decreasing fertile area, water scarcity, the effects of global warming, and the low efficacy of present fertilizers and pesticides exacerbate abiotic stresses on crops, lowering their yields. Drought, for example, costs billions of dollars in crop yield loss each year [ 3 , 4 ]. As a result, decreasing food production is a serious concern.…”

“…As a result, decreasing food production is a serious concern. Drought-tolerant crop varieties have taken a long time to develop, yet there are still few economically feasible vigorous drought-tolerant species [ 3 , 4 , 5 , 6 ]. Simultaneously, public anxiety about the safety of the transgenic crop is high [ 7 ].…”

Alleviation of copper phytotoxicity by acetylsalicylic acid and nitric oxide application in mung bean involves the up-regulation of antioxidants, osmolytes and glyoxalase system

“…Compatible osmolytes contribute to the regulation of plant growth by maintaining tissue water content and protecting the proper function of the enzyme (Elkelish et al 2019a), providing protection to major macromolecules and helping in stress signalling (Hasan et al 2019b;Hasan et al 2020b). Phytohormones play a crucial role in regulating the metabolism of osmolytes by integrating beneficial responses to the stress factor (Sharma et al 2019;Hasan et al 2021a;Hasan et al 2021b) and it was evident in this study that exogenous application not only increased the content of osmolytes but also finely regulated their metabolism. For example, proline synthesizing enzyme (γ-GK) up-regulated while catabolizing (PROX) one was down-regulated to result in greater accumulation of proline.…”

Polyamine Metabolism in Scots Pine Embryogenic Cells under Potassium Deficiency

“…In proliferating embryogenic cells, only Spm/t-Spm content increased under polyethylene glycol (PEG)-induced osmotic stress [ 63 ]. In plants, Spm is known to improve photosynthesis and osmoregulation and enhance antioxidant defense under drought stress [ 65 ]. Furthermore, PA metabolism is also associated with somatic embryogenesis (SE) [ 64 ], and in vitro rooting in Pinus species [ 25 ].…”