印度梨形孢联合紫花苜蓿修复土壤镉污染研究

Study on the Remediation of Cadmium Pollution in Soil by Combination of Medicago sativa and Piriformospora indica

重金属污染土壤修复中,植物-微生物联合修复技术以其生态友好、成本低等优势越来越受到人们关注。印度梨形孢作为内生真菌,可与大多数植物形成互利共生的关系,增强植物局部和系统抗性,显示出独特的生物调控潜力。利用印度梨形孢定殖紫花苜蓿根部开展植物-微生物联合修复土壤重金属镉污染,设置印度梨形孢侵染与未侵染对照,分别实施不同浓度的(10、20、40、80 mg/kg)镉污染模拟,在不同浓度镉污染的土壤上种植紫花苜蓿,通过对植物生理、生化及分子水平的分析,确定印度梨形孢在重金属镉污染土壤植物修复中的强化机制。结果表明,印度梨形孢可在紫花苜蓿根部定殖,并可分泌生长素增加植物产量;其有效定殖能提高根际微生物活性;该真菌可以减轻宿主植物中的镉金属毒性,促进镉污染土壤的植物稳定过程;该真菌可诱导植物病程相关基因表达,提高植物在重金属环境中的抗逆能力。

As a kind of remediation method for heavy metal contaminated soil,plant-microorganism combined restoration technology has attracted much more attention due to its low cost and eco-friendly characteristics.Piriformospora indica,an endophytic fungus,can form a mutually beneficial symbiotic relationship with most plants,enhances biological and non-biological local and systemic resistance,and shows unique biological regulation potential.Based on the mutualistic symbiotic relationship between alfalfa and P.indica,different concentrations(10,20,40,80 mg/kg)of cadmium pollution simulation were performed between P.indica infection and non-infection control.The enhancement mechanism of P.indica in phytoremediation was determined by analyzing the growth parameters,rhizosphere colony activity and gene expression under heavy metal contamination.The results showed that P.indica colonizes the roots of alfalfa,improves rhizosphere colony activity,produces growth hormone,promotes plant growth,regulates disease-related gene expression,and increases the tolerance of plant in heavy metal environment.