丛枝菌根真菌对镉胁迫小麦幼苗解毒效应的研究

Study on mitigation of cadmium stress in wheat seedlings by inoculation with arbuscular mycorrhizal fungi

以小麦(Triticum aestivum L.)为材料,采用土培试验,研究了接种丛枝菌根真菌对镉(Cd)胁迫小麦幼苗超氧阴离子产生速率、球囊霉素相关土壤蛋白(GRSP)、根内Cd含量、植物螯合肽(PC)含量及植物螯合肽合成酶(PCS)活性的影响。结果表明,Cd胁迫未接种丛枝菌根真菌造成小麦叶片超氧阴离子产生速率、PC含量、PCS活性及根内Cd含量显著增加,且随着胁迫质量分数的增加而极显著上升;胁迫质量分数下接种丛枝菌根真菌较未接种相比,小麦叶片内超氧阴离子产生速率、PC含量和PCS活性降低,根际土壤GRSP及根内Cd含量则极显著升高。本研究表明,接种丛枝菌根真菌可通过土壤GRSP鳌合作用将部分Cd固定在土壤中,同时增加根系中Cd的含量,缓解Cd胁迫对叶片造成的氧化伤害,解除Cd的部分毒性。

The pot experiments were carried out with wheat(Triticum aestivum L.)as materials to study the detoxification effects of arbuscular mycorrhizal fungi(AMF)on wheat seadlings under cadmium stress.The production rate of superoxide anion,the glomalin-related soil protein(GRSP)in soil,the contents of Cd in root contents of phytochelatins(PC),and the activity of phytochelatin synthetase(PCS)in leaves were studied.The results showed that without inoculation of AMF under Cd stress,the production rate of superoxide anion,contents of PC,activity of PCS in leaves and the contents of Cd in root increased significantly compared with the control,and all increased significantly with the rise of Cd stress mass concentrations.While the production rate of superoxide anion,content of PC and the activity of PCS in leaves decreased significantly,and the contents of GRSP in rhizosphere soil,the contents of Cd in roots of wheat were significantly increased in inoculated AMF than in non-inoculated AMF under the same mass concentrations of Cd stress.This study revealed that the AMF could alleviate Cd stress for GRSP chelated part of Cd in rhizosphere soil,and the contents of Cd in roots increased,therefore,the oxidative damage was mitigated in leaves caused by Cd stress.