Effect of endophytic fungi on the phytoextraction potential of the hyperaccumulator Noccaea caerulescens

International audienceNoccaea caerulescens, a Cd, Ni and Zn hyperaccumulator, appears to be one of the best candidates for the phytoremediation of soils contaminated by metallic trace elements. However, its use is limited by its slow growth rate and limited biomass production. Inoculation of plants with endophytic fungi could lead to a better development under both biotic and abiotic stresses, either by direct effects (secretion of phytohormones, siderophores or enzymes) or by indirect effects (resistance to pathogens), improving thus the phytoextraction potential. However, very few tests have been conducted to date with hyperaccumulating plants. In this work, five endophytic growth-promoting DSE-like fungi strains were evaluated for their potential in improving the Cd and Zn phytoextraction when grown on contaminated soils (PC18and PR). Both soils were sampled from agricultural sites contaminated by anthropogenic activities. They differed by their trace element content with respectively high and low total and available Cd and Zn concentrations in PR and PC18. DSE strains came from a collection obtained from roots of poplar grown on a metal contaminated site. After inoculation, N. caerulescenswas cultivated for three months in controlled conditions. The results highlight a significant interaction between soil and strains. Only one strain had a significant effect on the production of shoot dry biomass. We also observed variations in the effects of strains on both concentrations in major nutrients and trace elements in plant parts. Thus, the phytoextraction potential of metals could be improved following inoculation with DSE strains with, however, a strain and soil-dependent respons