|
1
|
Chen X, Han H, Cong Y, Li X, Zhang W, Cui J, Xu W, Pang S, Liu H. Ascorbic Acid Improves Tomato Salt Tolerance by Regulating Ion Homeostasis and Proline Synthesis. PLANTS (BASEL, SWITZERLAND) 2024; 13:1672. [PMID: 38931104 PMCID: PMC11207900 DOI: 10.3390/plants13121672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 06/12/2024] [Accepted: 06/13/2024] [Indexed: 06/28/2024]
Abstract
In this study, processing tomato (Solanum lycopersicum L.) 'Ligeer 87-5' was hydroponically cultivated under 100 mM NaCl to simulate salt stress. To investigate the impacts on ion homeostasis, osmotic regulation, and redox status in tomato seedlings, different endogenous levels of ascorbic acid (AsA) were established through the foliar application of 0.5 mM AsA (NA treatment), 0.25 mM lycorine (LYC, an inhibitor of AsA synthesis; NL treatment), and a combination of LYC and AsA (NLA treatment). The results demonstrated that exogenous AsA significantly increased the activities and gene expressions of key enzymes (L-galactono-1,4-lactone dehydrogenase (GalLDH) and L-galactose dehydrogenase (GalDH)) involved in AsA synthesis in tomato seedling leaves under NaCl stress and NL treatment, thereby increasing cellular AsA content to maintain its redox status in a reduced state. Additionally, exogenous AsA regulated multiple ion transporters via the SOS pathway and increased the selective absorption of K+, Ca2+, and Mg2+ in the aerial parts, reconstructing ion homeostasis in cells, thereby alleviating ion imbalance caused by salt stress. Exogenous AsA also increased proline dehydrogenase (ProDH) activity and gene expression, while inhibiting the activity and transcription levels of Δ1-pyrroline-5-carboxylate synthetase (P5CS) and ornithine-δ-aminotransferase (OAT), thereby reducing excessive proline content in the leaves and alleviating osmotic stress. LYC exacerbated ion imbalance and osmotic stress caused by salt stress, which could be significantly reversed by AsA application. Therefore, exogenous AsA application increased endogenous AsA levels, reestablished ion homeostasis, maintained osmotic balance, effectively alleviated the inhibitory effect of salt stress on tomato seedling growth, and enhanced their salt tolerance.
Collapse
Affiliation(s)
- Xianjun Chen
- Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization of Xinjiang Production and Contruction Crops, Department of Horticulture, Agricultural College, Shihezi University, Shihezi 832003, China; (X.C.); (H.H.); (Y.C.); (X.L.); (W.Z.); (J.C.); (W.X.)
- Key Laboratory of Molecular Breeding and Variety Creation of Horticultural Plants for Mountain Features in Guizhou Province, School of Life and Health Science, Kaili University, Kaili 556011, China
| | - Hongwei Han
- Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization of Xinjiang Production and Contruction Crops, Department of Horticulture, Agricultural College, Shihezi University, Shihezi 832003, China; (X.C.); (H.H.); (Y.C.); (X.L.); (W.Z.); (J.C.); (W.X.)
- Key Laboratory of Horticulture Crop Genomics and Genetic Improvement in Xinjiang, Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830000, China
| | - Yundan Cong
- Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization of Xinjiang Production and Contruction Crops, Department of Horticulture, Agricultural College, Shihezi University, Shihezi 832003, China; (X.C.); (H.H.); (Y.C.); (X.L.); (W.Z.); (J.C.); (W.X.)
| | - Xuezhen Li
- Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization of Xinjiang Production and Contruction Crops, Department of Horticulture, Agricultural College, Shihezi University, Shihezi 832003, China; (X.C.); (H.H.); (Y.C.); (X.L.); (W.Z.); (J.C.); (W.X.)
| | - Wenbo Zhang
- Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization of Xinjiang Production and Contruction Crops, Department of Horticulture, Agricultural College, Shihezi University, Shihezi 832003, China; (X.C.); (H.H.); (Y.C.); (X.L.); (W.Z.); (J.C.); (W.X.)
| | - Jinxia Cui
- Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization of Xinjiang Production and Contruction Crops, Department of Horticulture, Agricultural College, Shihezi University, Shihezi 832003, China; (X.C.); (H.H.); (Y.C.); (X.L.); (W.Z.); (J.C.); (W.X.)
| | - Wei Xu
- Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization of Xinjiang Production and Contruction Crops, Department of Horticulture, Agricultural College, Shihezi University, Shihezi 832003, China; (X.C.); (H.H.); (Y.C.); (X.L.); (W.Z.); (J.C.); (W.X.)
| | - Shengqun Pang
- Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization of Xinjiang Production and Contruction Crops, Department of Horticulture, Agricultural College, Shihezi University, Shihezi 832003, China; (X.C.); (H.H.); (Y.C.); (X.L.); (W.Z.); (J.C.); (W.X.)
| | - Huiying Liu
- Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization of Xinjiang Production and Contruction Crops, Department of Horticulture, Agricultural College, Shihezi University, Shihezi 832003, China; (X.C.); (H.H.); (Y.C.); (X.L.); (W.Z.); (J.C.); (W.X.)
| |
Collapse
|
|
2
|
Xu J, Wang T, Sun C, Liu P, Chen J, Hou X, Yu T, Gao Y, Liu Z, Yang L, Zhang L. Eugenol improves salt tolerance via enhancing antioxidant capacity and regulating ionic balance in tobacco seedlings. FRONTIERS IN PLANT SCIENCE 2024; 14:1284480. [PMID: 38293630 PMCID: PMC10825873 DOI: 10.3389/fpls.2023.1284480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 12/29/2023] [Indexed: 02/01/2024]
Abstract
Salt stress inhibits plant growth by disturbing plant intrinsic physiology. The application of exogenous plant growth regulators to improve the plant tolerance against salt stress has become one of the promising approaches to promote plant growth in saline environment. Eugenol (4-allyl-2- methoxyphenol) is the main ingredient in clove oil and it is known for its strong antioxidant and anti-microbial activities. Eugenol also has the ability of inhibiting several plant pathogens, implying the potential use of eugenol as an environmental friendly agrichemical. However, little is known about the possible role of eugenol in the regulation of plant tolerance against abiotic stress. Therefore, here we investigated the effectiveness of phytochemical eugenol in promoting salt tolerance in tobacco seedlings through physiological, histochemical, and biochemical method. The seedling roots were exposed to NaCl solution in the presence or absence of eugenol. Salt stress inhibited seedling growth, but eugenol supplementation effectively attenuated its effects in a dose-dependent manner, with an optimal effect at 20 µM. ROS (reactive oxygen species) accumulation was found in seedlings upon salt stress which was further resulted in the amelioration of lipid peroxidation, loss of membrane integrity, and cell death in salt-treated seedlings. Addition of eugenol highly suppressed ROS accumulation and reduced lipid peroxidation generation. Both enzymatic and non-enzymatic antioxidative systems were activated by eugenol treatment. AsA/DHA and GSH/GSSG were also enhanced upon eugenol treatment, which helped maintain redox homeostasis upon salinity. Eugenol treatment resulted in an increase in the content of osmoprotectants (e.g. proline, soluble sugar and starch) in salt-treated seedlings. Na+ levels decreased significantly in seedlings upon eugenol exposure. This may result from the upregulation of the expression of two ionic transporter genes, SOS1 (salt-hypersensitive 1) and NHX1 (Na+/H+ anti-transporter 1). Hierarchical cluster combined correlation analysis uncovered that eugenol induced salt tolerance was mediated by redox homeostasis and maintaining ionic balance in tobacco seedlings. This work reveals that eugenol plays a crucial role in regulating plant resistant physiology. This may extend its biological function as a novel biostimulant and opens up new possibilities for improving crop productivity in the saline agricultural environment.
Collapse
Affiliation(s)
- Jiaxin Xu
- College of Plant Protection, Shandong Agricultural University, Taian, China
| | - Tingting Wang
- College of Plant Protection, Shandong Agricultural University, Taian, China
| | - Changwei Sun
- College of Horticulture, Nanjing Agricultural University, Nanjing, China
| | - Peng Liu
- College of Plant Protection, Shandong Agricultural University, Taian, China
| | - Jian Chen
- Institute of Food Quality and Safety, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Xin Hou
- College of Plant Protection, Shandong Agricultural University, Taian, China
| | - Tao Yu
- College of Plant Protection, Shandong Agricultural University, Taian, China
| | - Yun Gao
- College of Plant Protection, Shandong Agricultural University, Taian, China
| | - Zhiguo Liu
- College of Plant Protection, Shandong Agricultural University, Taian, China
| | - Long Yang
- College of Plant Protection, Shandong Agricultural University, Taian, China
| | - Li Zhang
- College of Plant Protection, Shandong Agricultural University, Taian, China
| |
Collapse
|