Effects of short-term salt stress on photosynthetic characteristics, physiological metabolism, and ion homeostasis in soybean seedlings.
4 affiliations
- 1College of Agriculture, Northeast Agricultural University, Harbin, 150030, China.
- 2Hulunbuir Agricultural Technology Extension Center, Hulunbuir, Inner Mongolia, 021008, China.
- 3College of Agriculture, Northeast Agricultural University, Harbin, 150030, China. [email protected].
- 4College of Agriculture, Heilongjiang Agricultural Engineering Vocational and Technical University, Harbin, 150025, China. [email protected].
Abstract
Background
Salt stress is a major abiotic stress limiting soybean production, with the seedling stage being the most salt-sensitive period. Elucidating the growth, photosynthetic, and physiological response mechanisms of soybean seedlings to salt stress holds significant theoretical value for breeding salt-tolerant cultivars.Methods
In this study, we systematically investigated the effects of varying NaCl stress intensities (0-160 mmol⋅kg⁻¹) on plant growth, photosynthetic gas exchange, chlorophyll fluorescence, antioxidant physiology, and ion homeostasis using a salt-tolerant cultivar (Zhonglongdou 136, ZLD136) and a salt-sensitive cultivar (Henong 85, HN85).Results
The results demonstrated that increasing salt concentrations significantly inhibited plant growth and photosynthetic carbon assimilation. However, ZLD136 exhibited superior phenotypic stability and photoprotective mechanisms, evidenced by a significant increase in non-photochemical quenching (NPQt). Salt stress triggered a substantial rise in malondialdehyde (MDA) content and relative electrical conductivity (REC); notably, ZLD136 effectively mitigated membrane lipid peroxidation by maintaining higher antioxidant enzyme (superoxide dismutase SOD, peroxidase POD, and catalase CAT) activities and accumulating more osmolytes, including proline (Pro) and soluble sugars (SS). Furthermore, the salt-tolerant cultivar more efficiently coordinated the mitochondrial respiratory electron transport chain (cytochrome c oxidase COX and alternative oxidase AOX pathways) to dissipate excess reducing power and maintain cellular energy homeostasis. ZLD136 also possessed a stronger capacity for ion regulation, significantly outperforming HN85 in maintaining higher leaf K⁺/Na⁺ and Ca²⁺/Na⁺ ratios.Conclusions
Salt tolerance in soybean seedlings involves a comprehensive synergistic network, and the salt tolerance advantage of ZLD136 primarily stems from its superior ability to maintain ion balance, highly efficient photoprotective mechanisms, and a robust antioxidant defense system. Comprehensive analysis revealed that with intensifying salt stress, the physiological responses of soybean gradually transitioned from relying on the antioxidant enzyme system to the synthesis of osmolytes. Moreover, maintaining ion homeostasis (particularly a high leaf K⁺/Na⁺ ratio) is the core prerequisite for alleviating physiological and metabolic disorders, safeguarding photosynthetic functions, and ensuring short-term plant growth.
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BibTeX
@article{zhou2026effects,
title = {{Effects of short-term salt stress on photosynthetic characteristics, physiological metabolism, and ion homeostasis in soybean seedlings.}},
author = {Xinyu Zhou and Jiaqi Zhen and Xiyue Wang and Zhipeng Qu and Yuanqi Ma and Wei Zhao and Xinhe Wei and Shoukun Dong and Xiaomei Li},
journal = {BMC plant biology},
year = {2026},
month = jul,
doi = {10.1186/s12870-026-09567-7},
url = {https://europepmc.org/article/MED/42902149},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Effects of short-term salt stress on photosynthetic characteristics, physiological metabolism, and ion homeostasis in soybean seedlings.
AU - Xinyu Zhou
AU - Jiaqi Zhen
AU - Xiyue Wang
AU - Zhipeng Qu
AU - Yuanqi Ma
AU - Wei Zhao
AU - Xinhe Wei
AU - Shoukun Dong
AU - Xiaomei Li
PY - 2026
DA - 2026/07/01
JO - BMC plant biology
DO - 10.1186/s12870-026-09567-7
UR - https://europepmc.org/article/MED/42902149
AB - Background Salt stress is a major abiotic stress limiting soybean production, with the seedling stage being the most salt-sensitive period. Elucidating the growth, photosynthetic, and physiological response mechanisms of soybean seedlings to salt stress holds significant theoretical value for breeding salt-tolerant cultivars.Methods In this study, we systematically investigated the effects of varying NaCl stress intensities (0-160 mmol⋅kg⁻¹) on plant growth, photosynthetic gas exchange, chlorophyll fluorescence, antioxidant physiology, and ion homeostasis using a salt-tolerant cultivar (Zhonglongdou 136, ZLD136) and a salt-sensitive cultivar (Henong 85, HN85).Results The results demonstrated that increasing salt concentrations significantly inhibited plant growth and photosynthetic carbon assimilation. However, ZLD136 exhibited superior phenotypic stability and photoprotective mechanisms, evidenced by a significant increase in non-photochemical quenching (NPQt). Salt stress triggered a substantial rise in malondialdehyde (MDA) content and relative electrical conductivity (REC); notably, ZLD136 effectively mitigated membrane lipid peroxidation by maintaining higher antioxidant enzyme (superoxide dismutase SOD, peroxidase POD, and catalase CAT) activities and accumulating more osmolytes, including proline (Pro) and soluble sugars (SS). Furthermore, the salt-tolerant cultivar more efficiently coordinated the mitochondrial respiratory electron transport chain (cytochrome c oxidase COX and alternative oxidase AOX pathways) to dissipate excess reducing power and maintain cellular energy homeostasis. ZLD136 also possessed a stronger capacity for ion regulation, significantly outperforming HN85 in maintaining higher leaf K⁺/Na⁺ and Ca²⁺/Na⁺ ratios.Conclusions Salt tolerance in soybean seedlings involves a comprehensive synergistic network, and the salt tolerance advantage of ZLD136 primarily stems from its superior ability to maintain ion balance, highly efficient photoprotective mechanisms, and a robust antioxidant defense system. Comprehensive analysis revealed that with intensifying salt stress, the physiological responses of soybean gradually transitioned from relying on the antioxidant enzyme system to the synthesis of osmolytes. Moreover, maintaining ion homeostasis (particularly a high leaf K⁺/Na⁺ ratio) is the core prerequisite for alleviating physiological and metabolic disorders, safeguarding photosynthetic functions, and ensuring short-term plant growth.
SN - 1471-2229
ER -