State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
Sci Total Environ. 2023 Nov 10;898:165585. doi: 10.1016/j.scitotenv.2023.165585. Epub 2023 Jul 17.
Much attention has been paid to the environmental toxicity and ecological risk caused by cyclic tetramethylene tetranitramine (HMX) pollution in military activity sites. In this study, the response mechanism of alfalfa plants to HMX was analyzed from the aspects of the photosynthetic system, micromorphology, antioxidant enzyme system, mineral metabolism, and secondary metabolism, in order to improve the efficiency of plant restoration. Exposure to 5 mg·L HMX resulted in a significant increase in leaf N content and a significant increase and drift of the Fourier transform infrared protein peak area. Transmission electron microscopy images revealed damage to the root system subcellular morphology, but the plant leaves effectively resisted HMX pressure, and the photosynthetic parameters essentially maintained steady-state levels. The root proline content decreased significantly by 23.1-47.2 %, and the root reactive oxygen species content increased significantly by 1.66-1.80 fold. The roots regulate the transport/absorption of many elements that impart stress resistance, and Cu, Mn, and Na uptake is significantly associated with secondary metabolism. The metabolism of roots was upregulated in general by HMX exposure, with the main differences appearing in the content of lipids and lipid-like molecules, further confirming damage to the root biofilm structure. HMX causes an imbalance in the energy supply from oxidative phosphorylation in roots and generates important biomarkers in the form of pyrophosphate and dihydrogen phosphate. Interestingly, HMX had no significant effect on basic metabolic networks (i.e., glycolysis/gluconeogenesis and the tricarboxylic acid cycle), confirming that alfalfa has good stress resistance. Alfalfa plants apparently regulate multiple network systems to resist/overcome HMX toxicity. These findings provide a scientific basis for improving plant stress tolerance and understanding the HMX toxicity mechanism.
人们高度关注军事活动场所中环四亚甲基四硝胺（HMX）污染造成的环境毒性和生态风险。本研究从光合作用系统、微观形态学、抗氧化酶系统、矿物质代谢和次生代谢等方面分析了紫花苜蓿植物对 HMX 的响应机制，以期提高植物修复效率。暴露于 5mg·L HMX 导致叶片氮含量显著增加，傅里叶变换红外蛋白质峰面积显著增加和漂移。透射电子显微镜图像显示根系亚细胞形态受到损害，但植物叶片有效地抵抗 HMX 压力，光合作用参数基本保持稳定水平。根脯氨酸含量显著下降 23.1-47.2%，根活性氧含量显著增加 1.66-1.80 倍。根调节许多赋予抗逆性的元素的运输/吸收，Cu、Mn 和 Na 的吸收与次生代谢显著相关。HMX 暴露总体上上调了根系的代谢，主要差异出现在脂质和类脂分子的含量上，进一步证实了根生物膜结构的损伤。HMX 导致根部氧化磷酸化的能量供应失衡，并以焦磷酸和二磷酸的形式产生重要的生物标志物。有趣的是，HMX 对基本代谢网络（即糖酵解/糖异生和三羧酸循环）没有显著影响，这证实了紫花苜蓿具有良好的抗应激能力。紫花苜蓿植物显然调节多个网络系统来抵抗/克服 HMX 毒性。这些发现为提高植物的应激耐受性和理解 HMX 毒性机制提供了科学依据。
