Background Tartary buckwheat (Fagopyrum tataricum) is predominantly cultivated in arid and semi-arid mountainous regions. However, existing studies predominantly focus on describing the natural metabolic changes and the regulation of stress resistance during the germination of Tartary buckwheat. In contrast, research on the systematic influence of calcium ions on the germination physiology and metabolic networks of plants has yet to be reported. In this study, we elucidated the physiological mechanisms underlying calcium-mediated effects on Tartary buckwheat seed germination using six concentrations of CaCl₂ (0, 1, 2, 3, 4, and 5 g·L⁻¹). Results Exogenous calcium application exhibited a concentration-dependent effect on seed germination, characterized by low-dose promotion and high-dose inhibition. An appropriate calcium supply significantly promoted the accumulation of osmoregulatory substances, including total sugars, reducing sugars, and free amino acids, by enhancing the decomposition of starch and soluble proteins. Furthermore, it facilitated the accumulation of active compounds, such as total phenols, flavonoids, and γ-aminobutyric acid, and enhanced the activities of key enzymes including phenylalanine ammonia-lyase, glutamate decarboxylase, and α-amylase, thereby improving seed antioxidant capacity. Metabolomic analysis revealed that linoleic acid metabolism, D-amino acid metabolism, and phenylalanine metabolism are the core pathways involved in calcium-regulated seed germination. Furthermore, exogenous calcium systematically improved stress resistance and germination capacity by modulating the levels of key metabolites in these pathways, thereby influencing lipid remodeling, nitrogen metabolism, and secondary metabolite synthesis. Conclusions Exogenous calcium effectively promoted the germination of Tartary buckwheat seeds by mediating amino acid and lipid metabolism, thus regulating osmotic balance and the antioxidant defense system. The optimal treatment concentration identified was 3 g·L⁻¹ CaCl₂. This study elucidates the multiple mechanisms through which calcium regulates the germination of Tartary buckwheat seeds at both physiological and metabolic levels, providing a theoretical basis and practical guidance for the rational application of calcium fertilizers in Tartary buckwheat cultivation. Graphical Abstract

Calcium supply promotes seed germination in Tartary buckwheat (Fagopyrum tataricum) by mediating amino acid and lipid metabolism to drive osmotic regulation and antioxidant responses

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2026年3月12日

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Qiang Wang,
Jinyang Deng,
Qingchen Zeng,
Zhiyan Wang,
Mingda Yin,
Chao Zhan,
Yu Wang,
Xiaotian Liang,
Dabing Xiang,
Xiaoqin Zheng,
Jingwei Huang,
Chengang Liang,
Linsen Mei,
Yu Fan,
Liang Zou,
Yan Wan

摘要

Background

Tartary buckwheat (Fagopyrum tataricum) is predominantly cultivated in arid and semi-arid mountainous regions. However, existing studies predominantly focus on describing the natural metabolic changes and the regulation of stress resistance during the germination of Tartary buckwheat. In contrast, research on the systematic influence of calcium ions on the germination physiology and metabolic networks of plants has yet to be reported. In this study, we elucidated the physiological mechanisms underlying calcium-mediated effects on Tartary buckwheat seed germination using six concentrations of CaCl₂ (0, 1, 2, 3, 4, and 5 g·L⁻¹).

Results

Exogenous calcium application exhibited a concentration-dependent effect on seed germination, characterized by low-dose promotion and high-dose inhibition. An appropriate calcium supply significantly promoted the accumulation of osmoregulatory substances, including total sugars, reducing sugars, and free amino acids, by enhancing the decomposition of starch and soluble proteins. Furthermore, it facilitated the accumulation of active compounds, such as total phenols, flavonoids, and γ-aminobutyric acid, and enhanced the activities of key enzymes including phenylalanine ammonia-lyase, glutamate decarboxylase, and α-amylase, thereby improving seed antioxidant capacity. Metabolomic analysis revealed that linoleic acid metabolism, D-amino acid metabolism, and phenylalanine metabolism are the core pathways involved in calcium-regulated seed germination. Furthermore, exogenous calcium systematically improved stress resistance and germination capacity by modulating the levels of key metabolites in these pathways, thereby influencing lipid remodeling, nitrogen metabolism, and secondary metabolite synthesis.

Conclusions

Exogenous calcium effectively promoted the germination of Tartary buckwheat seeds by mediating amino acid and lipid metabolism, thus regulating osmotic balance and the antioxidant defense system. The optimal treatment concentration identified was 3 g·L⁻¹ CaCl₂. This study elucidates the multiple mechanisms through which calcium regulates the germination of Tartary buckwheat seeds at both physiological and metabolic levels, providing a theoretical basis and practical guidance for the rational application of calcium fertilizers in Tartary buckwheat cultivation.

Graphical Abstract