University of Hohenheim, Institute of Crop Science, Quality of Plant Products 340e, Schloss Westflügel, Stuttgart, 70599, Germany.
Department of Safety and Quality of Fruit and Vegetables, Max Rubner-Institut, Haid-und-Neu-Straße 9, Karlsruhe, 76131, Germany.
BMC Plant Biol. 2024 Oct 29;24(1):1022. doi: 10.1186/s12870-024-05719-9.
Exploring the adaptive responses of onions (Allium cepa L.) to salinity reveals a critical challenge for this salt-sensitive crop. While previous studies have concentrated on the effects of sodium (Na), this research highlights the substantial yet less-explored impact of chloride (Cl) accumulation. Two onion varieties were subjected to treatments with different sodium and chloride containing salts to observe early metabolic responses without causing toxicity.
The initial effects of salinity on onions showed increased concentrations of both ions, with Cl having a more pronounced impact on metabolic profiles than Na. Onions initially adapt to salinity by first altering their organic acid concentrations, which are critical for essential functions such as energy production and stress response. The landrace Birnförmige exhibited more effective regulation of its Na/K balance and a milder response to Cl compared to the hybrid Hytech. Metabolic alterations were analyzed using advanced techniques, revealing specific responses in leaves and bulbs to Cl accumulation, with significant changes observed in organic acids involved in the TCA cycle, such as fumaric acid, and succinic acid, in both varieties. Additionally, there was a variety-specific increase in ethanolamine in Birnförmige and lysine in Hytech in response to Cl accumulation.
This comprehensive study offers new insights into onion ion regulation and stress adaptation during the initial stages of salinity exposure, emphasizing the importance of considering both Na and Cl when assessing plant responses to salinity.
探索洋葱对盐度的适应反应揭示了这个对盐敏感的作物面临的一个关键挑战。虽然之前的研究集中在钠离子（Na）的影响上，但这项研究强调了氯离子（Cl）积累的大量但研究较少的影响。本研究用不同含钠和氯盐的溶液处理两种洋葱品种，在不造成毒性的情况下观察早期的代谢反应。
盐度对洋葱的最初影响表现为两种离子浓度的增加，Cl 对代谢谱的影响比 Na 更为显著。洋葱最初通过改变其有机酸浓度来适应盐度，这些有机酸对能量产生和应激反应等基本功能至关重要。与杂种 Hytech 相比，地方品种 Birnförmige 对其 Na/K 平衡的调节更为有效，对 Cl 的反应也更为温和。使用先进技术分析代谢变化，揭示了 Cl 积累对叶片和鳞茎的特定影响，在参与 TCA 循环的有机酸中观察到显著变化，如富马酸和琥珀酸，在两个品种中均有变化。此外，Birnförmige 中乙醇胺和 Hytech 中赖氨酸的含量在 Cl 积累时均有品种特异性增加。
这项全面的研究提供了洋葱在盐度暴露初期离子调节和应激适应的新见解，强调在评估植物对盐度的反应时，同时考虑 Na 和 Cl 的重要性。
