Physiology and Ecology Laboratory, College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang, 524088, China.
Rice Physiology and Ecology Research Laboratory, College of Agriculture, Shenyang Agricultural University, Shenyang, 110000, China.
J Plant Physiol. 2023 Nov;290:154105. doi: 10.1016/j.jplph.2023.154105. Epub 2023 Oct 10.
Studying the effects of nitrogen limitation on carbon, nitrogen metabolism, and nutrient uptake of mung bean is a scientific issue. In this study, urea (CO(NH), 125 kg hm) was applied at the V2, V6, R1, R2, and R4 stages, respectively, to ensure sufficient N resources during the growth process of mung beans. This study found that nitrogen limitation inhibited mung bean photosynthesis and reduced photosynthetic efficiency, which was manifested by reducing Pn (net photosynthetic rate), Gs (stomatal conductance), Tr (transpiration rate), and Ci (intercellular carbon dioxide concentration). Second, nitrogen limitation reduced N metabolism-related enzyme activity, such as NR (nitrate reductase), GOGAT (glutamate synthase), and GDH (glutamate dehydrogenase), indicating that nitrogen limitation inhibited the process of nitrogen metabolism, reducing nitrogen assimilation. Meanwhile, topdressing N fertilizer can promote the P and K uptake, and improve the partial factor productivity of P and K, which suggests that nitrogen limitation reduced P and K use efficiency. In addition, this study found that Lvfeng5 responded more significantly to nitrogen fertilizers, and had higher nitrogen use efficiency or better adaptability compared with Lvfeng2. This study provided valuable insights into the physiological and metabolic responses of mung beans to nutrient deficiency.
研究氮素限制对绿豆的碳、氮代谢和养分吸收的影响是一个科学问题。本研究分别在 V2、V6、R1、R2 和 R4 期追施尿素（CO(NH)₂，125kg·hm⁻²），以保证绿豆生长过程中有充足的氮素资源。研究发现，氮素限制抑制绿豆光合作用，降低光合效率，表现为 Pn（净光合速率）、Gs（气孔导度）、Tr（蒸腾速率）和 Ci（胞间二氧化碳浓度）降低。其次，氮素限制降低了与氮代谢相关的酶活性，如 NR（硝酸还原酶）、GOGAT（谷氨酸合酶）和 GDH（谷氨酸脱氢酶），表明氮素限制抑制了氮代谢过程，降低了氮同化。同时，追施氮肥可以促进 P 和 K 的吸收，提高 P 和 K 的偏生产力，表明氮素限制降低了 P 和 K 的利用效率。此外，本研究发现，与 Lvfeng2 相比，Lvfeng5 对氮肥的响应更为显著，具有更高的氮素利用效率或更好的适应性。本研究为绿豆对养分缺乏的生理和代谢响应提供了有价值的见解。
