Abstract
Saline-alkali stress is a major abiotic stress factor that adversely affects the growth, development, and yield of crops by disrupting ion homeostasis, osmotic balance, and metabolic processes. This study was designed to explore the alleviating effect of melatonin on the growth and development of tomato plants under saline-alkali stress conditions and to screen for optimal concentrations to alleviate the stress. Tomato variety ‘Condine Red’ was used as the test material, and a total of six treatments were designed including no saline-alkali stress and no melatonin spray as control (CK), and foliar spraying of 0, 50, 100, 150, and 200 µmol·L − 1 melatonin under saline-alkali stress (75 mmol·L − 1 ), which were used to determine the growth and photosynthetic characteristics of tomato plants. The results showed that saline-alkali stress significantly inhibited plant height, stem diameter, root activity and biomass accumulation, significantly reduced the chlorophyll content of tomato leaves and the efficiency of photosynthetic electron transfer from primary quinone receptor QA to secondary quinone receptor QB, and caused significant deformation of the fast chlorophyll fluorescence induced kinetic curve (OJIP), inhibiting photosynthesis. Exogenous melatonin could improve tomato tolerance to saline-alkali stress, and the effect depended on the concentration. In this experiment, treatment with 100 µmol·L − 1 melatonin showed the strongest positive effect on the growth of tomato plants under saline-alkali stress according to the comprehensive evaluation of principal components. In addition, changes in photosynthetic chlorophyll fluorescence parameters and chlorophyll fluorescence induction curves after melatonin treatment highlighted that melatonin could improve the response of the photosynthetic system to saline-alkali stress by enhancing quenching of excess excitation energy and protecting the photosynthetic electron transport system. Collectively, exogenous melatonin pretreatment increased root activity, chlorophyll content and improved photosystem processes, thereby alleviating tomato growth under saline-alkali stress. The results of this study lay the foundation for the practical application of melatonin in saline-alkali stress.
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Claims 7
Claim · model-written summary
Saline-alkali stress significantly inhibited plant height, stem diameter, root activity and biomass accumulation.
- Taxon
- tomato
Solanum lycopersicumt0 - Treatment
- saline-alkali stresse0
- Outcome
- plant height, stem diameter, root activity and biomass accumulatione0
- Direction
- inhibitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“saline-alkali stress significantly inhibited plant height, stem diameter, root activity and biomass accumulation”
t0“tomato seedlings under saline-alkali stress”
Claim · model-written summary
Saline-alkali stress significantly reduced tomato leaf chlorophyll content and electron transfer efficiency from QA to QB.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- saline-alkali stresst0
- Outcome
- chlorophyll content of tomato leaves and the efficiency of photosynthetic electron transfere0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“significantly reduced the chlorophyll content of tomato leaves and the efficiency of photosynthetic electron transfer from primary quinone receptor QA to secondary quinone receptor QB”
t0“tomato seedlings under saline-alkali stress”
Claim · model-written summary
Saline-alkali stress significantly deformed the OJIP curve and inhibited photosynthesis.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- saline-alkali stresst0
- Outcome
- fast chlorophyll fluorescence induced kinetic curve (OJIP), inhibiting photosynthesise0
- Direction
- inhibitinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“caused significant deformation of the fast chlorophyll fluorescence induced kinetic curve (OJIP), inhibiting photosynthesis”
t0“tomato seedlings under saline-alkali stress”
Claim · model-written summary
Melatonin improved tomato tolerance to saline-alkali stress in a concentration-dependent manner.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- Exogenous melatonine0
- Outcome
- tomato tolerance to saline-alkali stresse0
- Direction
- improvee0
- Qualifier
- depended on the concentratione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Exogenous melatonin could improve tomato tolerance to saline-alkali stress, and the effect depended on the concentration.”
t0“tomato seedlings under saline-alkali stress”
Claim · model-written summary
Among tested concentrations, 100 µmol·L − 1 melatonin gave the strongest positive growth response under saline-alkali stress.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- 100 µmol·L − 1 melatonine0
- Outcome
- growth of tomato plantse0
- Direction
- strongest positive effecte0
- Qualifier
- under saline-alkali stresse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“treatment with 100 µmol·L − 1 melatonin showed the strongest positive effect on the growth of tomato plants under saline-alkali stress according to the comprehensive evaluation of principal components.”
t0“tomato seedlings under saline-alkali stress”
Claim · model-written summary
Melatonin enhanced quenching of excess excitation energy and protected photosynthetic electron transport under saline-alkali stress.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- melatonine0
- Outcome
- quenching of excess excitation energy and protecting the photosynthetic electron transport systeme0
- Direction
- enhancinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“melatonin could improve the response of the photosynthetic system to saline-alkali stress by enhancing quenching of excess excitation energy and protecting the photosynthetic electron transport system.”
t0“tomato seedlings under saline-alkali stress”
Claim · model-written summary
Melatonin pretreatment increased root activity and chlorophyll content and improved photosystem processes.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- exogenous melatonin pretreatmente0
- Outcome
- root activity, chlorophyll content and improved photosystem processese0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“exogenous melatonin pretreatment increased root activity, chlorophyll content and improved photosystem processes”
t0“tomato seedlings under saline-alkali stress”
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