Table 1.
Summary of some recent examples of melatonin-mediated temperature stress tolerance in different plants.
| Plant specie | Stress condition | Dose | Protective role | References |
|---|---|---|---|---|
| Cold stress | ||||
| Barley (Hordeum vulgare L.) | 2 ± 0.5°C | 1 mM | Exogenous MET application increased the drought priming-induced cold tolerance (DPICT) by modulating subcellular antioxidant systems and ABA levels | 50 |
| Maize (Zea mays L.) | 5°C, 14 d | 50 and 500 μM | MET pretreatment-induced modifications improve the respiratory/energetic metabolism of the conditioned seeds, and these changes could be crucial for efficient stress amelioration | 51 |
| Cucumber (Cucumis sativus L.) | 10°C, 7 d | 50 and 500 μM | MET pretreatment improved the antioxidant defense, especially SOD and GSSG-R, stimulating glutathione’s de novo synthesis and augmenting other antioxidants’ activities (GSH/GSSG ratio) | 52 |
| Elymus nutans | 4°C | 0, 1, 10, 50, 100, 300 μM | MET application improved ABA production and up-regulated the CS-responsive genes expression in an ABA-independent manner | 53 |
| Rice (Oryza sativa L.) | 12°C | 20 or 100 μM | MET pretreatment relieved the stress-induced inhibitions to photosynthesis, and PSII activities and also increased the antioxidant enzyme activities and non-enzymatic antioxidant levels | 54 |
| Watermelon (Citrullus lanatus L.) | 4°C | 50, 150, 300, 500, or 800 μM | MET induced cold tolerance via long-distance signaling, and such induction was associated with an enhanced antioxidant capacity and optimized defense gene expression | 55 |
| Cucumber (Cucumis sativus L.) | 15/8°C day/night | 200 μM | MET alleviated chilling stress in cucumber seedlings by up-regulation of CsZat12 and modulation of polyamine and abscisic acid metabolism | 56 |
| Tea (Camellia sinensis L.) | −5°C, 3 h | 100 µM | MET treatment mitigated the CS-induced reductions in photosynthetic capacity by reducing oxidative stress through enhanced antioxidant potential and redox homeostasis | 57 |
| Tea (Camellia sinensis L.) | 4°C | 100 µM | MET pretreatment alleviated the ROS burst, decreased MDA levels, maintained high photosynthetic efficiency, and increased the activities of SOD, POD, APX, and CAT | 58 |
| Rice (Oryza sativa L.) | 15/15°C | 150 μM | MET alleviated low-temperature stress through AB15-mediated signals during seed germination. | 59 |
| Alfalfa (Medicago truncatula L.) | 4°C | 75 μM | MET pretreatment enhanced the antioxidative ability by improving the activities of POD, SOD, CAT and APX, helping the plants counteract CS-mediated damage by strengthening the non-enzymatic antioxidant system | 48 |
| Barley (Hordeum vulgare L.) | 5°C | 1 μM | MET pretreatment improved the activities of SOD and CAT and also helped plants sustain stable redox homeostasis | 60 |
| Pepper (Capsicum annuum L.) | 5/10 ± 0.5°C, 72 h | 5 µM | MET treatment improved water relations, photosynthetic parameters, and antioxidant enzymes’ activities while lowered MDA and H2O2 contents and membrane permeability | 61 |
| Strawberry (Fragaria × ananassa L.) | 0/−4 ◦C (16/8 h), 2 d | 100 μM | MET pretreatment protected plants from the cold damages induced through enhanced antioxidant defense potential and modulated the DREB/CBF – COR pathway. | 62 |
| Pepper (Capsicum annuum L.) | 15°C/5°C | 200 µmol L−1 | MET alleviated low temperature-induced stress by GA3, IAA, and ZT accumulation while decreased ABA level | 63 |
| Eggplant (Solanum melongena L.) | 5°C/10°C (night/day), 3 d | 1, 5 or 25 μM | MET alleviated adverse effects of chilling stress, and increased the APOX, POX, CAT, and photosynthetic activities | 64 |
| Banana (Musa spp.) | 4°C | 50, 100, 150 and 200 μM | MET improved the electron transfer rate, total antioxidant capacity, CAT and SOD activities and proline and soluble sugar contents and significantly reduced the accumulations of MDA, superoxide anion and H2O2 | 65 |
| Heat stress | ||||
| Perennial ryegrass (Lolium perenne L.) | 38/33°C | 20 μM | MET treatment alleviated growth inhibition and leaf senescence, increasing the melatonin and CK content’s endogenous content and decreasing ABA content. It also up-regulated the CK biosynthesis genes expression, while the biosynthesis and signaling genes involved in ABA were down-regulated | 66 |
| Kiwifruit (Actinidia deliciosa) | 45 ◦C | 200 µM | MET alleviated heat-induced oxidative harm through reducing H2O2 content and increasing proline content, raised ascorbic acid levels, and the activity of antioxidant enzymes, including SOD, CAT, and POD | 67 |
| Tall fescue (Festuca arundinacea) | 42°C | 1 mM and 50 mM | MET treatment decreased ROS, electrolyte leakage, and MDA but increased Chl, total protein, and antioxidant enzyme activities | 68 |
| Tomato (Solanum lycopersicum L.) | 28 ± 1°C, 36 h | 100 μM | MET pretreatment reduced the oxidative stress by controlling the over-accumulation of O2•− and H2O2, lowering the lipid peroxidation content and less membrane injury index | 69 |
| Tomato (Solanum lycopersicum L.) | 40°C, 9 h | 10 μM | Endogenous MET alleviated the heat-induced oxidative stress by maintaining an efficient enzymatic antioxidant system and redox homeostasis. | 70 |
| Radish (Raphanus sativus L.) | 35°C/30°C day/night | 0, 11.6, 17.4, 29.0, 34.8 and 67.0 mg L−1 | MET treatment increased the antioxidant enzyme activity, APX, Chl a, and carotenoid contents compared with the control. The auxin and ABA contents were also increased significantly | 71 |
| Wheat (Triticum aestivum L.) | 42 ◦C | 100 µM | MET treatment reduced oxidative stress by preventing the over-accumulation of H2O2, lowering lipid peroxidation, MDA, and increasing proline biosynthesis. It also increased the activities of antioxidant enzymes, such as SOD, CAT, and POD | 72 |
| Pinellia ternata | 35°C day/30°C | 100 μM | MET treatment increased Chl content and relative water content and decreased MDA and electrolyte leakage. Also, activated HSPs, ribosomal proteins, and ROS-scavenging enzymes | 73 |
| Tall fescue (Festuca arundinacea) | 42°C | 20 µM | MET reduced the heat-caused damaging effects on Chl a, Chl b, carotenoid, and protein synthesis machinery. It also enhanced the activities of antioxidant enzymes, protein, and lipid molecules and favored the lower production of H2O2 and MDA | 74 |
| Strawberry (Fragaria × ananassa Duch.) | 35°C and 40°C | 0, 50, and 100 μM | MET treatment decreased heat injury symptoms and induced antioxidant mechanisms, also up-regulated the expression of defense HSF (FaTHsfA2a, FaTHSFB1a) and HSP (HSP90) genes | 75 |
| Rice (Oryza sativa L.) | 38 ◦C | 0, 20, 100, 500 µM | MET treatment improved the heat tolerance of rice seeds by enhancing the activity of the antioxidant enzymes and significantly reducing the MDA content | 76 |
| Tomato (Solanum lycopersicum L.) | 40°C, 7 d | 50 mM | MET alleviated the oxidative damage of PSII by balancing the electron transfer of the donor side, reaction center, and receptor side | 77 |
| Rice (Oryza sativa L.) | 38°C/28°C | 250 mL of 200 μmol L−1 | MET improved the stress resistance by enhancing the scavenging efficiency of ROS and improved the leaf photosynthetic and heat-resistance properties. | 78 |
Abbreviations: Abscisic acid (ABA); ascorbate peroxidase (APX); cold stress (CS); cytokinin (CK); chlorophyll (Chl); catalase (CAT); glutathione reductase (GSSG-R); gibberellic acid (GA3); heat stress (HS); hydrogen peroxide (H2O2); heat shock proteins (HSPs); indole-3-acetic acid (IAA); malondialdehyde (MDA); melatonin (MET); peroxidase (POD); reactive oxygen species (ROS); superoxide dismutase (SOD); zeatin (ZT).