Lead tolerant endophyte Trametes hirsuta improved the growth and lead accumulation in the vegetative parts of Triticum aestivum L.

Abstract

Rapid industrialization and increasing population are continuously adding contaminants to our environment. Among those, heavy metals are considered to be one of the serious threats to the ecosystem due to their persistent nature. Microbe assisted phytoremediation is an effective tool for metal remediation as microbes enhance the metal availability and uptake to the host plants or reduce it by binding them intracellularly or extracellularly. An endophytic fungus, Trametes hirsuta , was isolated from Chenopodium album L. plant growing in the lead (Pb) contaminated soil of an industrial area. This is the first study citing Trametes hirsuta , as a root endophyte of Chenopodium album L. This endophytic fungus was found to be tolerant to high concentration of Pb i.e., 1500 mg L −1 , when tested in-vitro . Wheat ( Triticum aestivum L.) seedlings were infected by Trametes hirsuta and Pb tolerance was observed. With the fungal inoculation plants cumulative growth and total chlorophyll content increased by 24% and 18%, respectively as compared to their respective non-inoculated controls at 1000 mg kg −1 Pb. Similary, 50% more Pb accumulation was measured in the shoots of fungal inoculated plants at 1500 mg kg −1 Pb as compared to control. Thus, the results of the present study suggest that mutualism with endophytic fungi can improve the survival of host plants in metal contaminated soils, additionally it can also assist the phytoextraction of heavy metals from polluted sites by increasing their uptake by the host plants.

Endophytic Fungi: Biological Control and Induced Resistance to Phytopathogens and Abiotic Stresses

“…Endophytes have stood out for their ability to synthesize and accumulate secondary metabolites in the tissues of their hosts which can influence the functioning of antioxidant enzymes, in turn activating the cascade of defense signals and promoting the positive regulation of gene expression of important enzymes during the production of secondary metabolites [ 221 ]. In this sense, several studies have shown that the association of endophytes increases tolerance to abiotic stresses [ 221 , 222 , 223 , 224 , 225 , 226 ].…”

“…The role of endophytes in providing tolerance to heavy metal stresses has been observed in plant cultures such as Triticum aestivum [ 224 , 240 ], Lycopersicon esculentum [ 241 ], and Glycine max [ 242 ], among others. For example, the endophytic P. roqueforti fungus induced resistance in T. aestivum plants grown in soil contaminated with heavy metals, restricting heavy metal transfer from the soil to the plants, and secreting indole acetic acid.…”

“…In contrast, wheat plants not inoculated under heavy metal stress showed stunted growth with chlorosis symptoms. The inoculation of P. roqueforti can establish a symbiotic relationship with host plants, which is useful for stabilizing heavy metals, meaning that it helps host plants to flourish in soil that is highly contaminated with heavy metals [ 224 ]. Thus, the endophytic fungi increase the host plant’s capacity to accumulate heavy metals by direct or indirect mechanisms in addition to cell detoxification by enzymatic activity.…”

Endophytic Fungi-Mediated Biocatalysis and Biotransformations Paving the Way Toward Green Chemistry

“…In another study, in vitro bioremediation potential of endophytic fungal consortium isolated from Agrostis stolonifera in lead-contaminated soil has been reported to stimulate the growth of test plant Festuca arundinacea Schreb under heavy metal toxicity ( Soldi et al, 2020 ). Similarly, endophytic fungus, Trametes hirsuta , isolated from lead-stressed Chenopodium album L. plant has been documented to provide lead tolerance to Triticum aestivum L. seedlings and thus resulted in endophyte-assisted phytoremediation ( Malik et al, 2020 ). The recent functional role of mercury-resistant endophytic fungal strains ( Aspergillus sp.…”

Fungi Inhabiting the Wheat Endosphere

“…tritici , and F. culmorum . Meanwhile, Malik et al [ 163 ] showed that inoculation with endophytic fungus Trametes hirsuta , isolated from the Chenopodium album L. plant, may improve the survival of wheat plants in metal-contaminated soils and may additionally assist in the phytoextraction of heavy metals (Pb). Similar properties in relation to wheat plant were revealed for P. ruqueforti isolated from the endosphere of Solanum surattense [ 164 ].…”