School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin, 300130, China.
National-Local Joint Engineering Laboratory for Energy Conservation of Chemical Process Integration and Resources Utilization, Tianjin, China.
BMC Biotechnol. 2020 Apr 28;20(1):20. doi: 10.1186/s12896-020-00613-2.
The coexistence of polycyclic aromatic hydrocarbons (PAHs) and heavy metals has deleterious effects on environmental quality. Few reports have studied the mechanisms of plant inoculation with Piriformospora indica to remediate PAH-metal co-contaminated soil by analyzing the chemical speciation of the contaminants. This study investigated the influence of the inoculation of Medicago sativa with P. indica to remediate soil co-contaminated with phenanthrene (a kind of PAH) and cadmium (a heavy metal) by analyzing plant growth, physiological parameters and chemical speciation in rhizosphere and nonrhizosphere soils.
The presence of P. indica significantly increased plant tolerance, chlorophyll a, chlorophyll b, maximum quantum efficiency of PSII photochemistry and electron transport rate values in phenanthrene- and/or cadmium-contaminated soil. P. indica inoculation in M. sativa roots increased fluorescein diacetate activities in soils contaminated with phenanthrene, cadmium or both, especially in the nonrhizosphere. The presence of phenanthrene prevented the inoculated plant from accumulating cadmium to some extent, whereas the presence of cadmium did not prevent the degradation of phenanthrene in either the rhizosphere or the nonrhizosphere after P. indica colonization. Although the low bioavailability of cadmium in the rhizosphere restricted its transportation into the stem, P. indica colonization in plants effectively increased cadmium accumulation in roots in soil co-contaminated with cadmium and phenanthrene.
In conclusion, this work provides a theoretical basis for the use of P. indica combined with M. sativa for the remediation of PAH-metal co-contaminated soil.
多环芳烃（PAHs）和重金属共存对环境质量有有害影响。很少有报道研究过用内脐蠕孢菌接种植物来修复 PAH-金属复合污染土壤的机制，该方法通过分析污染物的化学形态来实现。本研究通过分析根际和非根际土壤中植物的生长、生理参数和化学形态，研究了接种苜蓿用内脐蠕孢菌修复受菲（一种 PAH）和镉（一种重金属）污染土壤的影响。
内脐蠕孢菌的存在显著提高了植物在受菲和/或镉污染土壤中的耐受性、叶绿素 a、叶绿素 b、PSII 光化学最大量子效率和电子传递速率值。内脐蠕孢菌在苜蓿根系中的接种增加了受菲污染土壤中的荧光素二乙酸酯活性，在受菲、镉或两者污染的土壤中，尤其是在非根际土壤中，这种作用更为明显。菲的存在在一定程度上阻止了接种植物对镉的积累，而在 P. indica 定殖后，镉的存在并没有阻止根际和非根际中菲的降解。虽然根际中镉的生物利用度较低限制了其向茎中的运输，但 P. indica 对植物的定殖有效地增加了根际和非根际中镉和菲复合污染土壤中根中镉的积累。
综上所述，本研究为利用内脐蠕孢菌结合紫花苜蓿修复 PAH-金属复合污染土壤提供了理论依据。
