Abstract
In contrast to acute stresses like drought, chilling, or pest infestation, salt stress causes progressive and long-term damage to plants. NaCl is the most important salt in nature and an important factor causing salt stress. Exogenous hormone regulation is one of the most influential and environmentally friendly methods recognized in recent years, Melatonin (MT) is an important plant defense component, and it has low cost and large income compared with traditional saline-alkali land improvement. To explore the effects of exogenous MT on the salt tolerance of alfalfa seedlings and the physiological response mechanism, in order to provide new ideas for salt-resistant cultivation of alfalfa, which is very important for sustainable agriculture. This study aimed to elucidate the effects of MT on alfalfa under salt stress conditions. Two types of alfalfa with different salt tolerances under normal growth (0 mmol·L-1 NaCl) and salt stress (150 mmol·L-1 NaCl) conditions were treated with 0, 50, 100, 150, and 200 µmol·L-1MT. MT treatment increased plant height, leaf area, and root morphology and repaired chloroplast damage. Osmoregulatory substances such as proline, soluble sugars, and soluble proteins were significantly elevated by NaCl treatment and continued to increase after MT treatment. MT inhibited lipid peroxidation, cellular membrane defects, and reactive oxygen species accumulation induced by NaCl stress. The NaCl stress decreased the K+ concentration and increased the Na+ concentration. However, MT treatment reversed these levels and increased antioxidant enzyme activities and antioxidant nonenzymatic substances to scavenge excess ROS, inhibited the degradation of leaf SPAD values, and promoted photosynthetic gas exchange and chlorophyll fluorescence parameters. The most effective treatment for inhibiting salt stress was 150 µmol·L-1 MT. These results indicate that salt-tolerant and salt-sensitive alfalfa can be sprayed with MT to improve NaCl tolerance.
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Claims 13
Claim · model-written summary
MT treatment increased plant height, leaf area and root morphology of alfalfa.
- Taxon
- alfalfa
Medicago sativat0 - Treatment
- MT treatmente1
- Outcome
- plant height, leaf area, and root morphologye1
- Direction
- increasede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“alfalfa (Medicago sativa L.)”
e1“MT treatment increased plant height, leaf area, and root morphology and repaired chloroplast damage”
Claim · model-written summary
MT treatment repaired chloroplast damage in alfalfa.
- Taxon
- alfalfaMedicago sativat0
- Treatment
- MT treatmente1
- Outcome
- chloroplast damagee1
- Direction
- repairede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“alfalfa (Medicago sativa L.)”
e1“MT treatment increased plant height, leaf area, and root morphology and repaired chloroplast damage”
Claim · model-written summary
NaCl treatment significantly elevated proline, soluble sugars and soluble proteins in alfalfa compared with normal growth.
- Taxon
- alfalfaMedicago sativat0
- Treatment
- NaCl treatmente1
- Outcome
- proline, soluble sugars, and soluble proteinse1
- Direction
- elevatede1
- Comparator
- normal growthe2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“alfalfa (Medicago sativa L.)”
e1“Osmoregulatory substances such as proline, soluble sugars, and soluble proteins were significantly elevated by NaCl treatment”
e2“Two types of alfalfa with different salt tolerances under normal growth (0 mmol·L-1 NaCl)”
Claim · model-written summary
MT treatment further increased proline, soluble sugars and soluble proteins after NaCl stress.
- Taxon
- alfalfaMedicago sativat0
- Treatment
- MT treatmente2
- Outcome
- proline, soluble sugars, and soluble proteinse1
- Direction
- continued to increasee2
- Comparator
- NaCl treatmente1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“alfalfa (Medicago sativa L.)”
e1“Osmoregulatory substances such as proline, soluble sugars, and soluble proteins were significantly elevated by NaCl treatment”
e2“continued to increase after MT treatment”
Claim · model-written summary
MT inhibited lipid peroxidation, membrane defects and ROS accumulation induced by NaCl stress.
- Taxon
- alfalfaMedicago sativat0
- Treatment
- MTe1
- Outcome
- lipid peroxidation, cellular membrane defects, and reactive oxygen species accumulatione1
- Direction
- inhibitede1
- Comparator
- NaCl stresse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“alfalfa (Medicago sativa L.)”
e1“MT inhibited lipid peroxidation, cellular membrane defects, and reactive oxygen species accumulation induced by NaCl stress”
Claim · model-written summary
NaCl stress decreased the K+ concentration in alfalfa.
- Taxon
- alfalfaMedicago sativat0
- Treatment
- NaCl stresse1
- Outcome
- K+ concentratione1
- Direction
- decreasede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“alfalfa (Medicago sativa L.)”
e1“The NaCl stress decreased the K+ concentration and increased the Na+ concentration”
Claim · model-written summary
NaCl stress increased the Na+ concentration in alfalfa.
- Taxon
- alfalfaMedicago sativat0
- Treatment
- NaCl stresse1
- Outcome
- Na+ concentratione1
- Direction
- increasede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“alfalfa (Medicago sativa L.)”
e1“The NaCl stress decreased the K+ concentration and increased the Na+ concentration”
Claim · model-written summary
MT treatment reversed the NaCl-induced changes in K+ and Na+ levels.
- Taxon
- alfalfaMedicago sativat0
- Treatment
- MT treatmente2
- Outcome
- these levelse2
- Direction
- reversede2
- Comparator
- NaCl stresse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“alfalfa (Medicago sativa L.)”
e1“The NaCl stress decreased the K+ concentration and increased the Na+ concentration”
e2“MT treatment reversed these levels”
Claim · model-written summary
MT treatment increased antioxidant enzyme activities and antioxidant nonenzymatic substances.
- Taxon
- alfalfaMedicago sativat0
- Treatment
- MT treatmente1
- Outcome
- antioxidant enzyme activitiese1
- Direction
- increasede1
- Qualifier
- antioxidant nonenzymatic substancese1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“alfalfa (Medicago sativa L.)”
e1“MT treatment reversed these levels and increased antioxidant enzyme activities and antioxidant nonenzymatic substances”
Claim · model-written summary
MT treatment inhibited the degradation of leaf SPAD values in alfalfa.
- Taxon
- alfalfaMedicago sativat0
- Organ / stage
- leafe2
- Treatment
- MT treatmente1
- Outcome
- leaf SPAD valuese2
- Direction
- inhibited the degradatione2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“alfalfa (Medicago sativa L.)”
e1“MT treatment reversed these levels”
e2“inhibited the degradation of leaf SPAD values”
Claim · model-written summary
MT treatment promoted photosynthetic gas exchange and chlorophyll fluorescence parameters.
- Taxon
- alfalfaMedicago sativat0
- Treatment
- MT treatmente1
- Outcome
- photosynthetic gas exchangee2
- Direction
- promotede2
- Qualifier
- chlorophyll fluorescence parameterse2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“alfalfa (Medicago sativa L.)”
e1“MT treatment reversed these levels”
e2“promoted photosynthetic gas exchange and chlorophyll fluorescence parameters”
Claim · model-written summary
150 µmol·L-1 MT was the most effective treatment for inhibiting salt stress among the tested MT concentrations.
- Taxon
- alfalfaMedicago sativat0
- Treatment
- 150 µmol·L-1 MTe1
- Outcome
- inhibiting salt stresse1
- Direction
- most effectivee1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“alfalfa (Medicago sativa L.)”
e1“The most effective treatment for inhibiting salt stress was 150 µmol·L-1 MT”
Claim · model-written summary
Salt-tolerant and salt-sensitive alfalfa can be sprayed with MT to improve NaCl tolerance (recommendation).
Verbatim
e1“These results indicate that salt-tolerant and salt-sensitive alfalfa can be sprayed with MT to improve NaCl tolerance”
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See all 14 papers →8 of 9 groups shown: named compounds and organisms first, then groups whose results differ (checked claim by claim), then those with positive and negative results, then the smaller groups.
Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.