College of Life Sciences, Shihezi University, Shihezi, 832003, China.
Key Laboratory of Xinjiang Phytomedicine Resource and Utilization, Pharmacy School, Ministry of Education, Shihezi University, Shihezi, 832003, China.
Sci Rep. 2022 Mar 24;12(1):5089. doi: 10.1038/s41598-022-09061-8.
Silicon (Si) effectively alleviates the effects of salt stress in plants and can enhance salt tolerance in liquorice. However, the mechanisms by which Si improved salt tolerance in liquorice and the effects of foliar application of Si on different liquorice species under salt stress are not fully understood. We investigated the effects of foliar application of Si on the growth, physiological and biochemical characteristics, and ion balance of two liquorice species, Glycyrrhiza uralensis and G. inflata. High salt stress resulted in the accumulation of a large amount of Na, decreased photosynthetic pigment concentrations, perturbed ion homeostasis, and eventually inhibited both liquorice species growth. These effects were more pronounced in G. uralensis, as G. inflata is more salt tolerant than G. uralensis. Foliar application of Si effectively reduced the decomposition of photosynthetic pigments and improved gas exchange parameters, thereby promoting photosynthesis. It also effectively inhibited lipid peroxidation and leaf electrolyte leakage and enhanced osmotic adjustment of the plants. Furthermore, Si application increased the K concentration and reduced Na absorption, transport, and accumulation in the plants. The protective effects of Si were more pronounced in G. uralensis than in G. inflata. In conclusion, Si reduces Na absorption, improves ion balance, and alleviates the negative effects of salt stress in the two liquorice species studied, but the effect is species dependent. These findings may help to develop novel strategies for protecting liquorice plants against salt stress and provide a theoretical basis for the evaluation of salt tolerance and the scientific cultivation of liquorice.
硅（Si）能有效缓解植物盐胁迫的影响，并能增强甘草的耐盐性。然而，硅提高甘草耐盐性的机制以及硅对不同甘草品种在盐胁迫下的叶面喷施效果尚不完全清楚。我们研究了叶面喷施硅对两种甘草（甘草和胀果甘草）生长、生理生化特性和离子平衡的影响。高盐胁迫导致大量 Na 的积累，降低了光合色素浓度，破坏了离子稳态，最终抑制了两种甘草的生长。在甘草中这些影响更为明显，因为胀果甘草比甘草更耐盐。叶面喷施硅能有效减少光合色素的分解，改善气体交换参数，从而促进光合作用。它还能有效抑制脂质过氧化和叶片电解质渗漏，增强植物的渗透调节。此外，硅的应用增加了 K 的浓度，减少了 Na 的吸收、运输和积累。硅在甘草中的保护作用比在胀果甘草中更为明显。总之，硅减少了 Na 的吸收，改善了离子平衡，缓解了研究的两种甘草品种的盐胁迫的负面影响，但这种作用是依赖于物种的。这些发现可能有助于开发保护甘草植物免受盐胁迫的新策略，并为甘草耐盐性评价和科学栽培提供理论依据。
