Melatonin Enhances Tomato Salt Tolerance by Improving Water Use Efficiency, Photosynthesis, and Redox Homeostasis
Salinity stress is a primary abiotic constraint limiting global crop productivity, with progressive soil salinization inducing growth inhibition and physiological dysfunction in plants. Although melatonin (MT) has been extensively documented to enhance stress adaptation, the underlying mechanisms th...
Saved in:
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-07-01
|
| Series: | Agronomy |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4395/15/7/1746 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1839616722276974592 |
|---|---|
| author | Chen Ru Yuxuan Liu Xingjiao Yu Chuanliu Xie Xiaotao Hu |
| author_facet | Chen Ru Yuxuan Liu Xingjiao Yu Chuanliu Xie Xiaotao Hu |
| author_sort | Chen Ru |
| collection | DOAJ |
| description | Salinity stress is a primary abiotic constraint limiting global crop productivity, with progressive soil salinization inducing growth inhibition and physiological dysfunction in plants. Although melatonin (MT) has been extensively documented to enhance stress adaptation, the underlying mechanisms through which it mediates salt tolerance by integrating physiological processes remain unclear. This study investigated the effects of varying MT concentrations on photosynthetic performance, plant water relations, water-use efficiency, and stress-responsive physiological parameters in tomatoes, aiming to identify the key physiological pathways for MT-mediated salt stress mitigation. The results showed that salt stress significantly reduced the leaf relative water content and root hydraulic conductivity, suppressed the photosynthetic rate, and ultimately caused significant reductions in the aboveground and root biomass. MT spraying effectively improved leaf water status and root water uptake capacity, enhancing the photosynthetic rate and water-use efficiency, thereby providing material and energy support for plant growth. Furthermore, MT spraying increased the total antioxidant capacity in leaves and promoted the synthesis of phenolic and flavonoid compounds, thereby reducing oxidative damage. Simultaneously, it stimulated the accumulation of osmolytes to enhance cellular osmotic adjustment capacity and optimized ion uptake to maintain cellular ion homeostasis. Among the tested concentrations, 100 μM MT showed the most significant alleviative effects. This concentration comprehensively enhanced the salt tolerance and growth performance of tomato plants by synergistically optimizing water use, photosynthetic function, antioxidant defense, and ion balance. In conclusion, these findings provide experimental evidence for elucidating the physiological mechanisms underlying MT-mediated salt tolerance in tomatoes and offer theoretical references for the rational application of MT in crop production under saline conditions. |
| format | Article |
| id | doaj-art-a0c93be7bcfd4020924d17878ea96e3a |
| institution | Matheson Library |
| issn | 2073-4395 |
| language | English |
| publishDate | 2025-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Agronomy |
| spelling | doaj-art-a0c93be7bcfd4020924d17878ea96e3a2025-07-25T13:10:19ZengMDPI AGAgronomy2073-43952025-07-01157174610.3390/agronomy15071746Melatonin Enhances Tomato Salt Tolerance by Improving Water Use Efficiency, Photosynthesis, and Redox HomeostasisChen Ru0Yuxuan Liu1Xingjiao Yu2Chuanliu Xie3Xiaotao Hu4School of Engineering, Anhui Agricultural University, Hefei 230036, ChinaSchool of Engineering, Anhui Agricultural University, Hefei 230036, ChinaCollege of Water Resources and Architectural Engineering, Northwest A&F University, Yangling 712100, ChinaSchool of Engineering, Anhui Agricultural University, Hefei 230036, ChinaKey Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest A&F University, Yangling 712100, ChinaSalinity stress is a primary abiotic constraint limiting global crop productivity, with progressive soil salinization inducing growth inhibition and physiological dysfunction in plants. Although melatonin (MT) has been extensively documented to enhance stress adaptation, the underlying mechanisms through which it mediates salt tolerance by integrating physiological processes remain unclear. This study investigated the effects of varying MT concentrations on photosynthetic performance, plant water relations, water-use efficiency, and stress-responsive physiological parameters in tomatoes, aiming to identify the key physiological pathways for MT-mediated salt stress mitigation. The results showed that salt stress significantly reduced the leaf relative water content and root hydraulic conductivity, suppressed the photosynthetic rate, and ultimately caused significant reductions in the aboveground and root biomass. MT spraying effectively improved leaf water status and root water uptake capacity, enhancing the photosynthetic rate and water-use efficiency, thereby providing material and energy support for plant growth. Furthermore, MT spraying increased the total antioxidant capacity in leaves and promoted the synthesis of phenolic and flavonoid compounds, thereby reducing oxidative damage. Simultaneously, it stimulated the accumulation of osmolytes to enhance cellular osmotic adjustment capacity and optimized ion uptake to maintain cellular ion homeostasis. Among the tested concentrations, 100 μM MT showed the most significant alleviative effects. This concentration comprehensively enhanced the salt tolerance and growth performance of tomato plants by synergistically optimizing water use, photosynthetic function, antioxidant defense, and ion balance. In conclusion, these findings provide experimental evidence for elucidating the physiological mechanisms underlying MT-mediated salt tolerance in tomatoes and offer theoretical references for the rational application of MT in crop production under saline conditions.https://www.mdpi.com/2073-4395/15/7/1746melatoninsalt stresswater use efficiencyion homeostasisantioxidant defenseosmoregulation |
| spellingShingle | Chen Ru Yuxuan Liu Xingjiao Yu Chuanliu Xie Xiaotao Hu Melatonin Enhances Tomato Salt Tolerance by Improving Water Use Efficiency, Photosynthesis, and Redox Homeostasis Agronomy melatonin salt stress water use efficiency ion homeostasis antioxidant defense osmoregulation |
| title | Melatonin Enhances Tomato Salt Tolerance by Improving Water Use Efficiency, Photosynthesis, and Redox Homeostasis |
| title_full | Melatonin Enhances Tomato Salt Tolerance by Improving Water Use Efficiency, Photosynthesis, and Redox Homeostasis |
| title_fullStr | Melatonin Enhances Tomato Salt Tolerance by Improving Water Use Efficiency, Photosynthesis, and Redox Homeostasis |
| title_full_unstemmed | Melatonin Enhances Tomato Salt Tolerance by Improving Water Use Efficiency, Photosynthesis, and Redox Homeostasis |
| title_short | Melatonin Enhances Tomato Salt Tolerance by Improving Water Use Efficiency, Photosynthesis, and Redox Homeostasis |
| title_sort | melatonin enhances tomato salt tolerance by improving water use efficiency photosynthesis and redox homeostasis |
| topic | melatonin salt stress water use efficiency ion homeostasis antioxidant defense osmoregulation |
| url | https://www.mdpi.com/2073-4395/15/7/1746 |
| work_keys_str_mv | AT chenru melatoninenhancestomatosalttolerancebyimprovingwateruseefficiencyphotosynthesisandredoxhomeostasis AT yuxuanliu melatoninenhancestomatosalttolerancebyimprovingwateruseefficiencyphotosynthesisandredoxhomeostasis AT xingjiaoyu melatoninenhancestomatosalttolerancebyimprovingwateruseefficiencyphotosynthesisandredoxhomeostasis AT chuanliuxie melatoninenhancestomatosalttolerancebyimprovingwateruseefficiencyphotosynthesisandredoxhomeostasis AT xiaotaohu melatoninenhancestomatosalttolerancebyimprovingwateruseefficiencyphotosynthesisandredoxhomeostasis |