Saline–alkaline stress is one of the most serious global problems affecting agriculture, causing enormous economic and yield losses in agricultural production. Wheat, one of the most important crops worldwide, is often subjected to saline–alkaline stress. In this study, two wheat cultivars with different saline–alkaline tolerance, XC-12 (non-tolerance) and XC-45 (tolerance), were used to investigate the influence of saline–alkaline stress on photosynthesis and nitrogen (N) metabolism through hydroponic experiment with aim of elucidating the mechanism of resistance to salt-alkali. These results showed that saline–alkaline stress significantly reduced biomass accumulation, chlorophyll content, photosynthetic ability and N absorption but increased N utilization efficiency. There was no significant difference in photosynthesis between XC-12 and XC-45 under saline–alkaline stress. In addition, XC-45 had lower ratio of Na⁺/K⁺ in leaves and Na⁺-K⁺ selection rate and higher N absorption ability than XC-12, thereby improving physiological metabolism. Moreover, the roots exhibited greater growth performance in response to saline–alkaline stress as a result of increasing glutamine synthetase activity in roots, thus promoting N metabolism in roots. By coordinating the synergistic effect of increasing soluble protein in root, XC-45 exhibited greater tolerance to saline–alkaline stress. All data pinpoint that the root physiological function was more responsible for resistance to saline–alkaline stress in wheat.

中文翻译：

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小麦对盐碱胁迫的耐受性取决于根系。


盐碱胁迫是影响农业的最严重的全球性问题之一，造成农业生产巨大的经济和产量损失。小麦是世界上最重要的作物之一，经常遭受盐碱胁迫。本研究以两个不同耐盐碱小麦品种XC-12（不耐盐）和XC-45（耐盐碱）为材料，通过研究盐碱胁迫对光合作用和氮（N）代谢的影响。水培实验旨在阐明其抗盐碱机制。结果表明，盐碱胁迫显着降低了生物量积累、叶绿素含量、光合能力和氮素吸收，但提高了氮素利用效率。盐碱胁迫下XC-12和XC-45的光合作用没有显着差异。此外，XC-45比XC-12具有更低的叶片Na ⁺ /K ⁺比值和Na ⁺ -K ⁺选择率以及更高的N吸收能力，从而改善了生理代谢。此外，由于根部谷氨酰胺合成酶活性增加，根部在应对盐碱胁迫时表现出更好的生长性能，从而促进根部的氮代谢。通过协调根部可溶性蛋白增加的协同效应，XC-45表现出更强的盐碱胁迫耐受性。所有数据都表明，根系生理功能对小麦抵抗盐碱胁迫负有更大的责任。