Influence of exogenous spermidine on carbon-nitrogen metabolism under Ca(NO3)2 stress in cucumber root
Influence of exogenous spermidine on carbon-nitrogen metabolism under Ca(NO3)2 stress in cucumber root
复制标题
外源亚精胺对Ca(NO3)(2)胁迫下黄瓜根碳氮代谢的影响
DOI：
10.1007/s10725-016-0193-8
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发表时间：
2017-01-01
影响因子：
4.2
通讯作者：
Sun, Jin
中科院分区：
文献类型：
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作者：
Du, Jing;Shu, Sheng;Sun, Jin
研究了外源亚精胺(Spd)对黄瓜(Cucumis sativus L.cv.)80 mM Ca(NO3)(2)胁迫下的生长和碳氮平衡。结果表明，叶施Spd(1 MM)处理通过调节黄瓜幼苗的碳氮平衡，缓解了Ca(NO3)(2)胁迫对黄瓜幼苗生长的抑制作用。外源Spd的应用有效地调控了主要碳氮代谢酶的转录水平和活性，显著降低了Ca(NO3)(2)胁迫下的NO3(-)和NH4(+)含量。此外，Spd处理显著增加了蔗糖、果糖和葡萄糖等可溶性碳水化合物的积累，从而保护了与N代谢有关的酶活性，并有效地促进了Ca(NO3)(2)胁迫下NO3(-)的同化。外源Spd还增加了作为蛋白质组成成分的氨基酸总量，促进了可溶性蛋白质的生物合成。在Spd的存在下，总C含量和C/N比显著增加，而全N含量则显著降低。结果表明，外源Spd能有效地促进硝酸盐向氨基酸的转化，促进碳同化产物的积累，从而增强植物维持C-N平衡的能力，最终提高黄瓜对Ca(NO3)(2)的耐逆性。
The present study aimed to investigate the effect of exogenous spermidine (Spd) on cucumber (Cucumis sativus L. cv. Jinyou No. 4) growth and carbon-nitrogen balance under 80 mM Ca(NO3)(2) stress. The result showed that leaf-applied Spd (1 mM) treatment alleviated the growth inhibition caused by Ca(NO3)(2) stress by regulating the carbon-nitrogen balance in cucumber seedlings. The application of exogenous Spd effectively regulated the transcription levels and activities of major carbon-nitrogen metabolism enzymes, resulting in a significant decrease of NO3 (-) and NH4 (+) contents under Ca(NO3)(2) stress. In addition, Spd treatment remarkably increased the accumulation of soluble carbohydrates (sucrose, fructose and glucose), thus protected enzyme activities related N metabolism and effectively promoted NO3 (-) assimilation under Ca(NO3)(2) stress. Exogenous Spd also enhanced total amino acids, which serve as the building blocks of protein, and promoted the biosynthesis of soluble protein. In the presence of Spd, total C content and the C/N ratio increased significantly, while total N content decreased in response to Ca(NO3)(2) stress. Based on our results, we suggested that exogenous Spd could effectively accelerate nitrate transformation into amino acids and improve the accumulation of carbon assimilation production, thereby enhancing the ability of the plants to maintain their C-N balance, and eventually promote the cucumber Ca(NO3)(2) stress tolerance.