Protective mechanisms of exogenous melatonin on chlorophyll metabolism and photosynthesis in tomato seedlings under heat stress
Elevated temperatures severely affect plant growth, reducing yield and quality. Melatonin (MT), a plant biomolecule, is known to enhance stress tolerance, but its role in heat resistance and underlying mechanisms require further exploration. This study investigates MT’s regulatory effects on chlorop...
Saved in:
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2025-02-01
|
| Series: | Frontiers in Plant Science |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/articles/10.3389/fpls.2025.1519950/full |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1832540930397175808 |
|---|---|
| author | Wangwang An Guangzheng Wang Jianhua Dou Yonghai Zhang Qing Yang Yongmei He Zhongqi Tang Jihua Yu Jihua Yu |
| author_facet | Wangwang An Guangzheng Wang Jianhua Dou Yonghai Zhang Qing Yang Yongmei He Zhongqi Tang Jihua Yu Jihua Yu |
| author_sort | Wangwang An |
| collection | DOAJ |
| description | Elevated temperatures severely affect plant growth, reducing yield and quality. Melatonin (MT), a plant biomolecule, is known to enhance stress tolerance, but its role in heat resistance and underlying mechanisms require further exploration. This study investigates MT’s regulatory effects on chlorophyll metabolism and photosynthesis in tomato seedlings under high-temperature stress (40°C). Tomato seedlings treated with 100 μmol MT showed improved physiological and photosynthetic performance under heat stress. MT application increased osmolytes (proline and soluble sugar), enhanced antioxidant enzyme activities [catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX)], and reduced oxidative damage markers (H2O2, O2−, malondialdehyde, and conductivity). Photosynthetic parameters, including key enzyme activities [sedoheptulose-1,7-bisphosphatase (SBPase), ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), and NADP-dependent glyceraldehyde-3-phosphate dehydrogenase (NADP-GAPDH)], photochemical efficiency [Fv/Fm and Y(II)], and photochemical quenching (Qp), were significantly improved, restoring the OJIP curve and enhancing photosynthesis. MT also regulated chlorophyll metabolism by promoting synthesis [increasing chlorophyll a and b, 5-aminolevulinic acid (ALA), Mg-protoporphyrin (Mg Proto), and protochlorophyllide (Pchlide) levels] and upregulating synthesis genes (SlHEMA1, SlPORB, SlPORC, and SlCHLI) while inhibiting degradation genes (SlCLH1, SlCLH2, SlPAO, SlPPH, and SlRCCR). These findings demonstrate that MT enhances tomato heat tolerance by protecting chlorophyll metabolism and photosynthesis, offering a theoretical basis for improving crop resilience to heat stress. |
| format | Article |
| id | doaj-art-1dd2b11f69e24dc19f05420c952b209f |
| institution | Kabale University |
| issn | 1664-462X |
| language | English |
| publishDate | 2025-02-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Plant Science |
| spelling | doaj-art-1dd2b11f69e24dc19f05420c952b209f2025-02-04T11:59:26ZengFrontiers Media S.A.Frontiers in Plant Science1664-462X2025-02-011610.3389/fpls.2025.15199501519950Protective mechanisms of exogenous melatonin on chlorophyll metabolism and photosynthesis in tomato seedlings under heat stressWangwang An0Guangzheng Wang1Jianhua Dou2Yonghai Zhang3Qing Yang4Yongmei He5Zhongqi Tang6Jihua Yu7Jihua Yu8College of Horticulture, Gansu Agricultural University, Lanzhou, ChinaCollege of Horticulture, Gansu Agricultural University, Lanzhou, ChinaCollege of Horticulture, Gansu Agricultural University, Lanzhou, ChinaCollege of Horticulture, Gansu Agricultural University, Lanzhou, ChinaCollege of Horticulture, Gansu Agricultural University, Lanzhou, ChinaCollege of Horticulture, Gansu Agricultural University, Lanzhou, ChinaCollege of Horticulture, Gansu Agricultural University, Lanzhou, ChinaCollege of Horticulture, Gansu Agricultural University, Lanzhou, ChinaState Key Laboratory of Aridland Crop Science (Gansu Agricultural University), Lanzhou, ChinaElevated temperatures severely affect plant growth, reducing yield and quality. Melatonin (MT), a plant biomolecule, is known to enhance stress tolerance, but its role in heat resistance and underlying mechanisms require further exploration. This study investigates MT’s regulatory effects on chlorophyll metabolism and photosynthesis in tomato seedlings under high-temperature stress (40°C). Tomato seedlings treated with 100 μmol MT showed improved physiological and photosynthetic performance under heat stress. MT application increased osmolytes (proline and soluble sugar), enhanced antioxidant enzyme activities [catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX)], and reduced oxidative damage markers (H2O2, O2−, malondialdehyde, and conductivity). Photosynthetic parameters, including key enzyme activities [sedoheptulose-1,7-bisphosphatase (SBPase), ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), and NADP-dependent glyceraldehyde-3-phosphate dehydrogenase (NADP-GAPDH)], photochemical efficiency [Fv/Fm and Y(II)], and photochemical quenching (Qp), were significantly improved, restoring the OJIP curve and enhancing photosynthesis. MT also regulated chlorophyll metabolism by promoting synthesis [increasing chlorophyll a and b, 5-aminolevulinic acid (ALA), Mg-protoporphyrin (Mg Proto), and protochlorophyllide (Pchlide) levels] and upregulating synthesis genes (SlHEMA1, SlPORB, SlPORC, and SlCHLI) while inhibiting degradation genes (SlCLH1, SlCLH2, SlPAO, SlPPH, and SlRCCR). These findings demonstrate that MT enhances tomato heat tolerance by protecting chlorophyll metabolism and photosynthesis, offering a theoretical basis for improving crop resilience to heat stress.https://www.frontiersin.org/articles/10.3389/fpls.2025.1519950/fulltomatomelatoninhigh temperaturephotosynthesischlorophyll metabolism |
| spellingShingle | Wangwang An Guangzheng Wang Jianhua Dou Yonghai Zhang Qing Yang Yongmei He Zhongqi Tang Jihua Yu Jihua Yu Protective mechanisms of exogenous melatonin on chlorophyll metabolism and photosynthesis in tomato seedlings under heat stress Frontiers in Plant Science tomato melatonin high temperature photosynthesis chlorophyll metabolism |
| title | Protective mechanisms of exogenous melatonin on chlorophyll metabolism and photosynthesis in tomato seedlings under heat stress |
| title_full | Protective mechanisms of exogenous melatonin on chlorophyll metabolism and photosynthesis in tomato seedlings under heat stress |
| title_fullStr | Protective mechanisms of exogenous melatonin on chlorophyll metabolism and photosynthesis in tomato seedlings under heat stress |
| title_full_unstemmed | Protective mechanisms of exogenous melatonin on chlorophyll metabolism and photosynthesis in tomato seedlings under heat stress |
| title_short | Protective mechanisms of exogenous melatonin on chlorophyll metabolism and photosynthesis in tomato seedlings under heat stress |
| title_sort | protective mechanisms of exogenous melatonin on chlorophyll metabolism and photosynthesis in tomato seedlings under heat stress |
| topic | tomato melatonin high temperature photosynthesis chlorophyll metabolism |
| url | https://www.frontiersin.org/articles/10.3389/fpls.2025.1519950/full |
| work_keys_str_mv | AT wangwangan protectivemechanismsofexogenousmelatoninonchlorophyllmetabolismandphotosynthesisintomatoseedlingsunderheatstress AT guangzhengwang protectivemechanismsofexogenousmelatoninonchlorophyllmetabolismandphotosynthesisintomatoseedlingsunderheatstress AT jianhuadou protectivemechanismsofexogenousmelatoninonchlorophyllmetabolismandphotosynthesisintomatoseedlingsunderheatstress AT yonghaizhang protectivemechanismsofexogenousmelatoninonchlorophyllmetabolismandphotosynthesisintomatoseedlingsunderheatstress AT qingyang protectivemechanismsofexogenousmelatoninonchlorophyllmetabolismandphotosynthesisintomatoseedlingsunderheatstress AT yongmeihe protectivemechanismsofexogenousmelatoninonchlorophyllmetabolismandphotosynthesisintomatoseedlingsunderheatstress AT zhongqitang protectivemechanismsofexogenousmelatoninonchlorophyllmetabolismandphotosynthesisintomatoseedlingsunderheatstress AT jihuayu protectivemechanismsofexogenousmelatoninonchlorophyllmetabolismandphotosynthesisintomatoseedlingsunderheatstress AT jihuayu protectivemechanismsofexogenousmelatoninonchlorophyllmetabolismandphotosynthesisintomatoseedlingsunderheatstress |