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Elucidating the effect of γ‐aminobutyric acid (GABA) on seed germination and seedling growth of Medicago ruthenica under low‐temperature could provide a reference for alleviating the harmful effects of low temperatures on legumes in alpine meadows. We set up different temperatures to screen three low temperatures that inhibit seed germination of Medicago ruthenica, and six aqueous concentrations of GABA (0, 0.1, 0.5, 1, 5, 10 mM) were set up to screen out the best GABA seed soaking concentration that can promote the seed germination at low‐temperature. The three temperatures of 10 °C, 20/5 °C and 15/5 °C inhibited seed germination of Medicago ruthenica. Soaking seeds with 1 mM GABA could significantly increase seed germination rate of Medicago ruthenica at low‐temperature (10 °C). Soaking seeds only with 0.1 mM GABA could promote germination of Medicago ruthenica at 20/5 °C, but there is no significant difference compared with distilled water soaking. Whereas, all GABA seed soaking concentrations delayed seed germination time and inhibited seed germination at 15/5 °C. Pre‐spraying seedlings with 1 mM GABA at 10 °C reduced the production of superoxide anion, hydrogen peroxide and malondialdehyde content, and increased the activities of catalase, peroxidase, superoxide dismutase and ascorbate peroxidase in leaves of Medicago ruthenica on days 7. Simultaneously, Pre‐spraying seedlings with 1 mM GABA at 10 °C significantly increased the net photosynthetic rate and decreased intercellular CO2 concentration. These data suggest that GABA could enhance the cold tolerance of Medicago ruthenica by promoting seed germination, regulating the antioxidant system, and increasing photosynthetic efficiency. However, the mitigation effect of GABA on low‐temperature is only applicable to a certain temperature. The mitigation effect of GABA on low temperature will be weakened as the low temperature of plants is less than 10 °C [ABSTRACT FROM AUTHOR]

Introduction: Grazing management is essential to maintain the stability of grassland ecosystems., Methods: To determine the optimal rest-grazing period of alpine meadow, five rest-grazing periods were set based on soil thawing and plant re-greening in this study. The niche, interspecific relationships, and stability of plant communities at different rest-grazing periods were investigated., Results: Rest-grazing during soil thawing resulted in a small niche width and niche overlap of plants, overall positive interspecific associations, and a high stability of plant communities. Delayed rest-grazing time to plant re-greening resulted in a large niche width and niche overlap of plants, overall negative interspecific associations, and a low stability of plant communities., Discussion: Rest-grazing in alpine meadows should begin as soon as possible to promote healthy and sustainable utilization of grasslands., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Ma, Hou, Xu, Chen, Yang, Xu and Yu.)