The influence of two strains of Trichoderma (T. harzianum strain T22 and T. atroviride strain P1) on the
growth of lettuce plants (Lactuca sativa L.) irrigated with As-contaminated water, and their effect on the
uptake and accumulation of the contaminant in the plant roots and leaves, were studied. Accumulation of
this non-essential element occurred mainly into the root system and reduced both biomass development
and net photosynthesis rate (while altering the plant P status). Plant growth-promoting fungi (PGPF) of
both Trichoderma species alleviated, at least in part, the phytotoxicity of As, essentially by decreasing
its accumulation in the tissues and enhancing plant growth, P status and net photosynthesis rate. Our
results indicate that inoculation of lettuce with selected Trichoderma strains may be helpful, beside the
classical biocontrol application, in alleviating abiotic stresses such as that caused by irrigation with Ascontaminated
water, and in reducing the concentration of this metalloid in the edible part of the plant.