Growth characteristics and absorption kinetics of five endophytic fungal strains under aluminum stress
The growth and absorption kinetics of different endophytic fungi in the presence Al3+were analyzed to identify strains with strong aluminum resistance.Five strains of endophytic fungi isolated from aluminum-resistant trees in southern acidic red soils were selected for the experiment,including Pestalotiopsis,Alternaria,Coniothyrium,Penicillium,and Thermomyces spp.These strains were subjected to five different Al3+concentration gradients(0,0.555,0.746,1.111,and 1.852 mmol·L-1).The growth characteristics of these fungi strains and their absorption and adsorption of Al3+,cation exchange capacity,and absorption kinetics were studied.The results showed that the overall biomass of the five endophytic fungal strains increased,but decreased at higher Al3+concentrations.All five strains had strong aluminum tolerance when the Al3+concentration was below 1.111 mmol·L-1.However,their tolerance significantly decreased as the concentration reached 1.852 mmol·L-1.The absorption and adsorption of Al3+by the various strains increased with increasing aluminum concentration.Compared with the other fungal species tested,Penicillium spp.had the greatest biomass(158 mg),a higher tolerance index,more favorable absorption kinetics indicators,and higher adsorptive Al3+and lower absorbent Al3+contents.Based on the above indicators,the cell walls of Penicillium spp.have greater adsorption of Al3+compared to the cell walls of the other four strains,which may help prevent Al3+entering the cell.
endophytic fungialuminum stressabsorption kineticscation exchange capacityabsorption and adsorption
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维普
