Growing plants on oily, nutrient-poor soil using a native symbiotic fungus

Area of Science:

• Environmental microbiology
• Plant pathology
• Bioremediation

Background:

• Oil-sand mining creates contaminated coarse tailings (CT) hostile to plant and microbial life.
• Fungal endophytes can enhance plant abiotic stress tolerance and aid in soil remediation.

Purpose of the Study:

• To isolate and characterize a fungal endophyte from plants growing on CT.
• To evaluate the potential of this endophyte for revegetating and remediating CT.

Main Methods:

• Isolation of Trichoderma harzianum (TSTh) from a dandelion on CT.
• Assessing TSTh's effect on seed germination, seedling growth, and plant physiology in CT.
• Measuring plant-secreted peroxidase and petrochemical mobilization.
• Evaluating TSTh's growth on petrochemicals and its metabolic activity under micro-aerobic conditions.

Main Results:

• TSTh colonization enabled germination and flourishing of various plants on CT without fertilizer.
• TSTh significantly increased germination speed, percent germination, biomass, water use efficiency, and drought recovery.
• TSTh-colonized plants doubled peroxidase secretion and petrochemical mobilization from CT.
• TSTh demonstrated growth on petrochemicals and metabolized 13C-phenanthrene under low oxygen.

Conclusions:

• Trichoderma harzianum strain TSTh effectively promotes plant growth and survival on oil-sand tailings.
• TSTh contributes to the bioremediation of petrochemical contaminants through enhanced peroxidase activity and direct metabolism.
• TSTh shows significant potential for revegetation and remediation of contaminated industrial sites.