Trivalent aluminum ions (Al3+) in acidic soils are a major constraint for crop productivity inhibiting root elongation and promoting cell death. Al3+-toxicity has adverse biochemical and physiological effects on plant root growth. Sulfur is an essential macronutrient assimilated from the soil in the form of sulfate. However, the implication of sulfate nutritional status in the modulation of short-term Al3+-tolerance mechanisms in plant roots has not been previously reported. Here, we evaluated the effects of increased sulfate supply on short-term Al3+-toxicity in roots of Lolium perenne, measuring Al, Ca, Mg and S uptake, lipid peroxidation, total SOD activity, and transcriptional levels of Cu/Zn and Fe-SOD genes. First, the nitrogen sulfur ratio (N/S) in the TF nutrient solutions used in this study were computed to confirm that L. perenne plants were grown in sulfate deficiency (120 μM), optimal supply (240 μM), or overdoses conditions (360 μM), without affecting dry root biomass. Sulfate supplementation (>240 μM, and N/S ratio < 16) played a significant protection to Al3+-stress that prevents morphological changes in root tips, inhibits lipid peroxidation and differentially up-regulates total SOD activity, due changes in SOD gene expression. The results support the importance of sulfate nutritional status, on plant tissue homeostasis, enhancing the physiological tolerance mechanisms modulating lipid peroxidation damage induced by short-term Al3+-toxicity.

中文翻译：

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硫酸盐营养改善了多年生黑麦草根部的短期Al3 +胁迫耐受性。

酸性土壤中的三价铝离子（Al3 +）是作物生产力抑制根伸长并促进细胞死亡的主要限制因素。Al3 +毒性对植物根系的生长具有不利的生化和生理作用。硫是从土壤中以硫酸盐形式吸收的重要常量营养素。但是，以前尚未报道过硫酸盐营养状况对植物根部短期Al3 +耐受机制的调节作用。在这里，我们评估了硫酸盐供应的增加对黑麦草根部短期Al3 +毒性的影响，测量了Al，Ca，Mg和S的吸收，脂质过氧化，总SOD活性以及Cu / Zn和Fe-的转录水平SOD基因。首先，计算本研究中使用的TF营养液中的氮硫比（N / S），以确认L。perenne植物生长在硫酸盐缺乏（120μM），最佳供应量（240μM）或过量的条件下（360μM），而不会影响干燥的根生物量。补充硫酸盐（> 240μM，N / S比<16）对Al3 +胁迫起到了重要的保护作用，可防止根尖形态发生变化，抑制脂质过氧化并差异性上调总SOD活性，这是SOD基因表达的变化。结果支持硫酸盐营养状态对植物组织稳态的重要性，增强了调节短期Al3 +毒性引起的脂质过氧化损伤的生理耐受机制。16）对Al3 +胁迫起到了重要的保护作用，可防止根尖形态发生变化，抑制脂质过氧化并差异性上调总SOD活性（由于SOD基因表达的变化）。结果支持硫酸盐营养状态对植物组织稳态的重要性，增强了调节短期Al3 +毒性引起的脂质过氧化损伤的生理耐受机制。16）对Al3 +胁迫起到了重要的保护作用，可防止根尖形态发生变化，抑制脂质过氧化并差异性上调总SOD活性（由于SOD基因表达的变化）。结果支持硫酸盐营养状态对植物组织稳态的重要性，增强了调节短期Al3 +毒性引起的脂质过氧化损伤的生理耐受机制。