Reda Małgorzata, Kabała Katarzyna, Stanisławski Jan, Szczepski Kacper, Janicka Małgorzata
Department of Plant Molecular Physiology, Faculty of Biological Sciences, University of Wrocław, Kanonia 6/8, 50-328 Wrocław, Poland.
Int J Mol Sci. 2025 Feb 13;26(4):1599. doi: 10.3390/ijms26041599.
Nitric oxide (NO) functions as a signaling molecule in plant adaptation to changing environmental conditions. NO levels were found to increase in plants in response to low temperatures (LTs). However, knowledge of the pathways involved in enhanced NO production under cold stress is still limited. For this reason, we aimed to determine the role of different NO sources in NO generation in cucumber roots exposed to 10 °C for short (1 d) and long (6 d) periods. The short-term treatment of seedlings with LT markedly increased plasma membrane-bound nitrate reductase (PM-NR) activity and induced the expression of three genes encoding NR in cucumber (). On the other hand, long-term exposure was related to both increased cytoplasmic NR (cNR) activity and induced expression of the gene, encoding the amidoxime-reducing component (ARC) protein. The decrease in nitrite reductase (NiR) activity and the higher NO/NO ratio in the roots of plants exposed to LTs for 1 d suggest that tissue conditions may favor NR-dependent NO production. Regardless of NR stimulation, a significant increase in NOS-like activity was observed in the roots, especially during the long-term treatment of plants with LT. These results indicate that diverse NO-producing routes, both reductive and oxidative, are activated in cucumber tissues at different stages of cold stress.
一氧化氮（NO）在植物适应不断变化的环境条件中作为一种信号分子发挥作用。研究发现，植物中的NO水平会因低温（LT）而升高。然而，对于冷胁迫下NO产生增加所涉及的途径的了解仍然有限。因此，我们旨在确定不同NO来源在短期（1天）和长期（6天）暴露于10°C的黄瓜根中NO生成中的作用。用LT对幼苗进行短期处理显著提高了质膜结合硝酸还原酶（PM-NR）的活性，并诱导了黄瓜中三个编码NR的基因的表达（）。另一方面，长期暴露与细胞质NR（cNR）活性增加以及编码偕胺肟还原成分（ARC）蛋白的基因的表达诱导有关。暴露于LT 1天的植物根中亚硝酸还原酶（NiR）活性的降低和较高的NO/NO比率表明，组织条件可能有利于依赖NR的NO产生。无论NR是否受到刺激，在根中均观察到类似NOS的活性显著增加，尤其是在用LT对植物进行长期处理期间。这些结果表明，在冷胁迫的不同阶段，黄瓜组织中还原和氧化的多种NO产生途径均被激活。
