Sun Chengliang, Lu Lingli, Liu Lijuan, Liu Wenjing, Yu Yan, Liu Xiaoxia, Hu Yan, Jin Chongwei, Lin Xianyong
MOE Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource & Environmental Sciences, Zhejiang University, Hangzhou, 310058, China.
Key Laboratory of Subtropical Soil Science and Plant Nutrition of Zhejiang Province, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China.
New Phytol. 2014 Mar;201(4):1240-1250. doi: 10.1111/nph.12597. Epub 2013 Nov 15.
• Nitric oxide (NO) is an important signaling molecule involved in the physiological processes of plants. The role of NO release in the tolerance strategies of roots of wheat (Triticum aestivum) under aluminum (Al) stress was investigated using two genotypes with different Al resistances. • An early NO burst at 3 h was observed in the root tips of the Al-tolerant genotype Jian-864, whereas the Al-sensitive genotype Yang-5 showed no NO accumulation at 3 h but an extremely high NO concentration after 12 h. Stimulating NO production at 3 h in the root tips of Yang-5 with the NO donor relieved Al-induced root inhibition and callose production, as well as oxidative damage and ROS accumulation, while elimination of the early NO burst by NO scavenger aggravated root inhibition in Jian-864. • Synthesis of early NO in roots of Jian-864 was mediated through nitrate reductase (NR) but not through NO synthase. Elevated antioxidant enzyme activities were induced by Al stress in both wheat genotypes and significantly enhanced by NO donor, but suppressed by NO scavenger or NR inhibitor. • These results suggest that an NR-mediated early NO burst plays an important role in Al resistance of wheat through modulating enhanced antioxidant defense to adapt to Al stress.
• 一氧化氮（NO）是参与植物生理过程的重要信号分子。利用两种具有不同铝抗性的基因型小麦，研究了铝（Al）胁迫下NO释放在小麦（Triticum aestivum）根系耐受策略中的作用。• 在耐铝基因型剑864的根尖中，在3小时时观察到早期NO爆发，而铝敏感基因型扬5在3小时时未显示NO积累，但在12小时后NO浓度极高。用NO供体刺激扬5根尖在3小时时的NO产生，可缓解铝诱导的根抑制和胼胝质产生，以及氧化损伤和ROS积累，而用NO清除剂消除早期NO爆发则加重了剑864的根抑制。• 剑864根系中早期NO的合成是通过硝酸还原酶（NR）介导的，而不是通过一氧化氮合酶。铝胁迫在两种小麦基因型中均诱导了抗氧化酶活性升高，NO供体显著增强了该活性，但NO清除剂或NR抑制剂则抑制了该活性。• 这些结果表明，NR介导的早期NO爆发通过调节增强的抗氧化防御来适应铝胁迫，在小麦的耐铝性中起重要作用。
