Xiang Tong, Bao Guozhang, Pan Xinyu, Chen Weiwei, Hu Jinke, Li Guomei
Key Laboratory of Groundwater Resources and Environment of the Ministry of Education (Jilin University), Jilin Provincial Key Laboratory of Water Resources and Environment, College of New Energy and Environment, Jilin University, Changchun, Jilin Province, 130012, China.
Yushu Forestry and Grassland Comprehensive Service Center, Yushu, 815000, China.
BMC Plant Biol. 2025 Jul 24;25(1):956. doi: 10.1186/s12870-025-07001-y.
Affected by global warming, freeze-thaw occurs more frequently in Northeast China. Meanwhile, as a major grain-producing area, this region is influenced by the invasive plant Solanum rostratum Dunal. Moreover, due to the long-term application of chemical fertilizers, soil cadmium pollution has been aggravated. Therefore, crops in Northeast China may suffer from compound stress simultaneously. However, the impact of combined stress on plants has not been given enough attention, and the interrelationships between different stresses have not been thoroughly studied. This experiment adopted the indoor simulation method. By determining the changing trends and amplitudes of relative conductivity (RC), soluble protein (SP), chlorophyll (Chl), malondialdehyde (MDA) content, and the activities of superoxide dismutase (SOD) and peroxidase (POD), the influence effects of the combined stress of freeze-thaw, S. rostratum extract, and cadmium chloride on the growth and metabolism of seedlings could be judged.
Under the combined stress of freeze-thaw, cadmium chloride, and S. rostratum extract, the growth of rye seedlings was inhibited; The relative conductivity (RC) increased by 1.92-71.07%, and the content of malondialdehyde (MDA) increased by 17.34-28.11%; The soluble protein (SP) content decreased by 17.82-22.14%; The activities of superoxide dismutase (SOD) and peroxidase (POD) both increased, but POD activity was inhibited at the lowest point of freeze-thaw (-5℃); The chlorophyll (Chl) content decreased by 9.68-19.67%.
Stress affects osmotic pressure, and seedlings need to accumulate osmoregulatory substances to maintain cell osmotic balance. Compared to a single stress factor, the combined stress of freeze-thaw, cadmium chloride, and S. rostratum extract further enhanced the physiological damage to plants. This compound stress leads to electrolyte leakage, intensified membrane lipid peroxidation, inhibition of protein synthesis, increased osmotic pressure, and disruption of cell osmotic balance. Combined stress further promotes the accumulation of reactive oxygen species (ROS) in the seedlings, leading to oxidative damage and inhibiting photosynthesis.
受全球变暖影响，中国东北地区冻融现象愈发频繁。同时，作为主要粮食产区，该地区受到入侵植物刺萼龙葵的影响。此外，由于长期施用化肥，土壤镉污染加剧。因此，中国东北地区的作物可能同时遭受复合胁迫。然而，复合胁迫对植物的影响尚未得到足够重视，不同胁迫之间的相互关系也未得到深入研究。本实验采用室内模拟方法。通过测定相对电导率（RC）、可溶性蛋白（SP）、叶绿素（Chl）、丙二醛（MDA）含量以及超氧化物歧化酶（SOD）和过氧化物酶（POD）活性的变化趋势和幅度，判断冻融、刺萼龙葵提取物和氯化镉复合胁迫对幼苗生长和代谢的影响效应。
在冻融、氯化镉和刺萼龙葵提取物的复合胁迫下，黑麦幼苗生长受到抑制；相对电导率（RC）升高了1.92 - 71.07%，丙二醛（MDA）含量增加了17.34 - 28.11%；可溶性蛋白（SP）含量下降了17.82 - 22.14%；超氧化物歧化酶（SOD）和过氧化物酶（POD）活性均升高，但在冻融最低点（-5℃）时POD活性受到抑制；叶绿素（Chl）含量下降了9.68 - 19.67%。
胁迫影响渗透压，幼苗需要积累渗透调节物质以维持细胞渗透平衡。与单一胁迫因素相比，冻融、氯化镉和刺萼龙葵提取物的复合胁迫进一步增强了对植物的生理伤害。这种复合胁迫导致电解质渗漏、膜脂过氧化加剧、蛋白质合成受到抑制、渗透压升高以及细胞渗透平衡被破坏。复合胁迫进一步促进了幼苗中活性氧（ROS）的积累，导致氧化损伤并抑制光合作用。
