Melatonin improves drought tolerance in cowpea through growth modulation, antioxidant response, and ionic homeostasis, supporting sustainable agriculture
Cowpeas are highly nutritious legumes renowned for their protein-rich seeds and remarkable ability to withstand moderate drought. To explore the role of melatonin (MT) in enhancing drought tolerance and its potential application through MT-enriched organic fertilizers for sustainable agriculture, co...
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| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2025-01-01
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| Series: | Environmental Research Communications |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/2515-7620/add85f |
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| Summary: | Cowpeas are highly nutritious legumes renowned for their protein-rich seeds and remarkable ability to withstand moderate drought. To explore the role of melatonin (MT) in enhancing drought tolerance and its potential application through MT-enriched organic fertilizers for sustainable agriculture, cowpea plants were subjected to two levels of drought stress: moderate drought (MD) and severe drought (SD) and the amelioration effects of MT were evaluated by measuring various growth metrics and biochemical indicators. The results revealed that MT influenced multiple mechanisms in cowpeas that modulate drought tolerance, which varied depending on drought severity. Under severe drought, MT enhanced growth and stress tolerance by significantly improving the plant biomass, pigments, and photosynthetic parameters, such as internal CO _2 concentration ( Ci ), stomatal conductance ( Gs ), transpiration rate ( E ), and net photosynthesis rate ( A ). MT application increased sodium (Na ^+ ), and reduced potassium (K ^+ ) accumulation but maintained the Na ^+ /K ^+ ratio at the normal level. Still, it did not affect the leaves’ proline or soluble sugar concentrations compared to plants growing under severe drought without MT treatment. Under the same conditions, MT application enhanced antioxidant responses by reducing hydrogen peroxide (H _2 O _2 ) levels, thereby mitigating electrolyte leakage (EL), and increasing catalase (CAT) activity but decreasing superoxide dismutase (SOD) activity. Under moderate drought, MT’s enhancement effect is less pronounced than in severe drought, as cowpeas can naturally sustain moderate drought stress. The results obtained from this study suggest that MT applications in cowpeas under severe drought primarily led to ionic adjustments and oxidative stress reduction and management by shifting the antioxidant response from superoxide detoxification to H _2 O _2 breakdown, thereby promoting stress tolerance through improved redox balance and reduced oxidative damage. The novelty of this study lies in revealing, for the first time, how foliar-applied MT enhances drought tolerance in cowpeas while highlighting its potential to support sustainable agricultural practices. |
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| ISSN: | 2515-7620 |