Plant’s stomatal physiology and anatomical features are highly plastic and are influenced by diverse environmental signals including the concentration of atmospheric CO₂ and nutrient availability. Recent reports suggest that the form of nitrogen (N) is a determinant of plant growth and nutrient nitrogen use efficiency (NUE) under elevated CO₂ (EC). Previously, we found that high nitrate availability resulted in early senescence, enhanced reactive oxygen species (ROS), and reactive nitrogen species (RNS) production and also that mixed nutrition of nitrate and ammonium ions were beneficial than sole nitrate nutrition in wheat. In this study, the interactive effects of different N forms (nitrate, ammonium, mixed nutrition of nitrate, and ammonium) and EC on epidermal and stomatal morphology were analyzed. Wheat seedlings were grown at two different CO₂ levels and supplied with media devoid of N (N₀) or with nitrate–N (NN), mixed nutrition of ammonium and nitrate (MN), or only ammonium-N (AN). The stoma length increased significantly in nitrate nutrition with a consistent reduction in stoma width. Guard cell length was higher in EC treatment as compared to AC. The guard cell width was maximum in AN-grown plants at EC. Epidermal cell density and stomatal density were lower at EC. Nitrate nutrition increased the stomatal area at EC while the reverse was true for MN and AN. Wheat plants fertilized with AN showed a higher accumulation of superoxide radical (SOR) at EC, while in NN treatment, the accumulation of hydrogen peroxide (H₂O₂) was higher at EC. Reactive oxygen species, particularly H₂O₂, can trigger mitogen-activated protein kinase (MAPK) mediated signaling and its crosstalk with abscisic acid (ABA) signaling to regulate stomatal anatomy in nitrate-fed plants. The SOR accumulation in ammonium- and ammonium nitrate–fed plants and H₂O₂ in NN-fed plants might finely regulate the sensitivity of stomata to alter water/nutrient use efficiency and productivity under EC. The data reveals that the variation in anatomical attributes viz. cell length, number of cells, etc. affected the leaf growth responses to EC and forms of N nutrition. These attributes are fine targets for effective manipulation of growth responses to EC.

植物的气孔生理和解剖特征具有高度的可塑性，并受到各种环境信号的影响，包括大气 CO ₂浓度和养分有效性。最近的报告表明，在 CO _{2升高的情况下，氮 (N) 的形式是植物生长和养分氮利用效率 (NUE) 的决定因素。}（欧共体）。此前，我们发现高硝酸盐利用率导致小麦提前衰老，增强活性氧 (ROS) 和活性氮 (RNS) 的产生，并且硝酸盐和铵离子的混合营养比单独的硝酸盐营养更有益于小麦。本研究分析了不同氮形式（硝酸盐、铵、硝酸盐和铵的混合营养）和EC对表皮和气孔形态的交互作用。小麦幼苗在两种不同的 CO ₂水平下生长，并提供不含 N (N ₀) 或硝酸盐-N (NN)，铵和硝酸盐 (MN) 的混合营养物，或仅铵-N (AN)。硝酸盐营养的气孔长度显着增加，气孔宽度持续减小。与 AC 相比，EC 处理中的保卫细胞长度更高。在 EC 的 AN 生长的植物中，保卫细胞宽度最大。EC的表皮细胞密度和气孔密度较低。硝酸盐营养增加了 EC 的气孔面积，而 MN 和 AN 则相反。AN 施肥的小麦植株在 EC 处显示出更高的超氧自由基 (SOR) 积累，而在 NN 处理中，过氧化氢 (H ₂ O ₂ ) 在 EC 处的积累更高。活性氧，特别是 H ₂ O ₂, 可以触发丝裂原活化蛋白激酶 (MAPK) 介导的信号及其与脱落酸 (ABA) 信号的串扰以调节硝酸盐喂养植物的气孔解剖结构。硝酸铵和硝酸铵喂养植物中的 SOR 积累以及 NN 喂养植物中的 H ₂ O ₂可能会精细调节气孔对改变 EC 下水/养分利用效率和生产力的敏感性。数据显示解剖属性的变化，即。细胞长度、细胞数量等影响叶片生长对 EC 和 N 营养形式的反应。这些属性是有效控制对 EC 的生长反应的良好目标。