Melatonin as a key regulator in seed germination under abiotic stress

Abstract

Seed germination (SG) is the first stage in a plant's life and has an immense importance in sustaining crop production. Abiotic stresses reduce SG by increasing the deterioration of seed quality, and reducing germination potential, and seed vigor. Thus, to achieve a sustainable level of crop yield, it is important to improve SG under abiotic stress conditions. Melatonin (MEL) is an important biomolecule that interplays in developmental processes and regulates many adaptive responses in plants, especially under abiotic stresses. Thus, this review specifically summarizes and discusses the mechanistic basis of MEL‐mediated SG under abiotic stresses. MEL regulates SG by regulating some stress‐specific responses and some common responses. For instance, MEL induced stress specific responses include the regulation of ionic homeostasis, and hydrolysis of storage proteins under salinity stress, regulation of C‐repeat binding factors signaling under cold stress, starch metabolism under high temperature and heavy metal stress, and activation of aquaporins and accumulation of osmolytes under drought stress. On other hand, MEL mediated regulation of gibberellins biosynthesis and abscisic acid catabolism, redox homeostasis, and Ca2+ signaling are amongst the common responses. Nonetheless factors such as endogenous MEL contents, plant species, and growth conditions also influence above‐mentioned responses. In conclusion, MEL regulates SG under abiotic stress conditions by interacting with different physiological mechanisms.

Mass Spectrometry-Imaging Analysis of Active Ingredients in the Leaves of Taxus cuspidata

“…33 Melatonine is an important indole heterocyclic compound that is involved in various adaptive responses in plants. 34 Interestingly, aurantiamide and melatonine specifically accumulated in the upper epidermal cells (>90%), indicating that they are at the front line of plant defense. The active flavonoid compound, corylin, was first detected in the medicinal plant Psoralea fructus ( Psoralea corylifolia L.).…”

“…Aurantiamide and its acetylation product (aurantiamide acetate) are peptides exhibiting significant cytotoxic activity on the HL-60 leukemia human cancer cell line . Melatonine is an important indole heterocyclic compound that is involved in various adaptive responses in plants . Interestingly, aurantiamide and melatonine specifically accumulated in the upper epidermal cells (>90%), indicating that they are at the front line of plant defense.…”

Have All of the Phytohormonal Properties of Melatonin Been Verified?

“…Interestingly, melatonin increases the concentration of itself [ 65 ]. All of melatonin’s effects concerning abiotic stress [ 5 , 6 , 66 , 67 , 68 , 69 , 70 ], biotic stress [ 6 , 7 , 8 , 71 , 72 ], and growth and development [ 5 , 66 , 69 , 70 ] have been extensively reviewed in recent years.…”

“…Melatonin is biosynthesized and catabolized like other phytohormones, and its metabolic pathways consist of a regulatory network together with other phytohormones [ 64 ]. Melatonin is synthesized in plants from tryptophan (Trp) mainly via trypamine, serotonin, and N -acetylserotonin [ 66 , 73 ]. However, under some environmental stresses, melatonin is produced via alternative pathways using 5-hydroxytryptophan or 5-methoxytryptophan or both as intermediates.…”

Oil Palm AP2 Subfamily Gene EgAP2.25 Improves Salt Stress Tolerance in Transgenic Tobacco Plants

“…Oil palm ( Elaeis guineensis ) is mainly used for palm oil production and is one of the main woody economic crops in tropical regions [ 27 ]. Nevertheless, palm oil productivity is significantly affected by environmental factors, such as extreme weather, salinity, and drought [ 28 , 29 , 30 ]. Previously, we finished the identification and characterization of oil palm AP2/ERF family genes and analyzed the expression of some oil palm AP2/ERF genes under abiotic stress conditions with real-time quantitative PCR (qPCR) [ 14 ].…”