Application of silicon (Si) and salicylic acid (SA) mitigates plant stress; however, this effect is not known under nitrogen (N) deficiency conditions in rice plants. The objective of the present study was to determine whether foliar application with a soluble form of Si and SA, individually or in combination, could mitigate N deficiency stress in rice plants. The treatments consisted of application of 3.45 g L⁻¹ Si only (sprayed on the leaves), 4.5 mM SA only, a combination of both, and no application as control. Net CO₂ assimilation rate, transpiration, lignin and carbon contents, C:N:P:Si stoichiometric ratio and grain yield were evaluated. Foliar application of Si combined with SA or isolated application of SA did not mitigate N deficiency stress in rice plants. However, silicon application increased rice yield by 18.6% in N-deficient conditions. Our results show that the beneficial effects of Si under nitrogen deficient conditions are related to the stoichiometry change in C with Si and increases of lignin synthesis.

中文翻译：

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硅和水杨酸在缓解水稻氮缺乏胁迫中的作用

硅（Si）和水杨酸（SA）的应用减轻了植物的压力。但是，在水稻中氮（N）缺乏的条件下，这种作用还未知。本研究的目的是确定单独或组合使用可溶性形式的Si和SA的叶面施用可以减轻水稻中的氮缺乏胁迫。处理包括仅施用3.45 g L ^-1 Si（喷洒在叶子上），仅施用4.5 mM SA，两者的组合以及不施用作为对照。净CO ₂评估了同化率，蒸腾作用，木质素和碳含量，C：N：P：Si化学计量比和谷物产量。叶面喷施Si与SA结合使用或单独施用SA并不能减轻水稻中的氮缺乏胁迫。然而，在缺氮条件下，施用硅可使水稻产量提高18.6％。我们的结果表明，Si在氮缺乏条件下的有益作用与C随Si的化学计量变化以及木质素合成的增加有关。