The alleviation mechanisms of cadmium toxicity in Broussonetia papyrifera by arbuscular mycorrhizal symbiosis varied with different levels of cadmium stress
The alleviation mechanisms of cadmium toxicity in Broussonetia papyrifera by arbuscular mycorrhizal symbiosis varied with different levels of cadmium stress
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DOI：
10.1016/j.jhazmat.2023.132076
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发表时间：
2023-07-19
影响因子：
13.6
通讯作者：
Tang，Ming
中科院分区：
文献类型：
--
作者：
Liang，Jingwei;Wang，Zhihao;Tang，Ming
丛枝菌根（AM）真菌对镉（Cd）毒害的缓解作用尚未完全阐明。本研究探讨了Rhizophagus irregularity对B.不同Cd浓度（0、30、90和270 mg kg-1Cd）胁迫下，紫堇幼苗的生长受到不同程度的影响。结果表明：（1）AM真菌共生促进了低、中Cd胁迫下紫茎泽兰的生长和光合作用，提高了作为胁迫信号的活性氧水平，维持了活性氧的平衡。(2)AM真菌共生调节AsA-GSH循环，缓解高Cd胁迫下ROS的过度产生。(3)AM真菌在高浓度Cd胁迫下能螯合更多的Cd，提高土壤pH和GRSP含量。(4)高浓度Cd胁迫下，AM植物叶片中的P能固定或螯合更多的Cd，而茎中的P则能保留更多的P。(5)AM共生体在中等Cd胁迫下增加根净Cd 2+流入和吸收，在高Cd胁迫下抑制根净Cd 2+流入和吸收，在中等Cd胁迫下上调重金属（HMs）转运相关基因，在高Cd胁迫下抑制HMs转运相关基因的转录。因此，可以初步探讨B.纸莎草河不规则共生依赖于镉胁迫水平。
The alleviation of cadmium (Cd) toxicity inBroussonetia papyriferaby arbuscular mycorrhizal (AM) fungi are still not completely elucidated. This study investigated the effects ofRhizophagus irregularison physiological and biochemical characteristics, and molecular regulation inB. papyriferaunder different levels of Cd (0, 30, 90 and 270 mg kg-1Cd) stress. Results showed that (1) AM symbiosis improved the growth and photosynthesis, enhanced ROS levels as stress signaling and maintained ROS balance under low and medium Cd stress. (2) AM symbiosis regulated AsA-GSH cycle to mitigate ROS overproduction under high Cd stress. (3) AM fungus can chelate more Cd under high Cd stress, increasing soil pH and GRSP content. (4) AM plants can fix or chelate more Cd by P in leaves and reserve more P in stems under high Cd stress. (5) AM symbioses increased root net Cd2+influx and uptake under medium Cd stress but inhibited under high Cd stress, with upregulation of genes related heavy metals (HMs) transport under medium Cd stress and inhibited the transcription of genes related HMs transport under high Cd stress. Therefore, the alleviation mechanisms of Cd toxicity inB. papyriferabyR. irregularissymbiosis depends on the levels of Cd stress.