The effect of endophytic Peyronellaea from heavy metal-contaminated and uncontaminated sites on maize growth,heavy metal absorption and accumulation

Heavy metal (HM) tolerance, effects on maize growth, heavy metal absorption and accumulation by endophytic Peyronellaea from HM-contaminated and uncontaminated sites were studied to evaluate the hypothesis that endophytes from HM-contaminated sites would enhance HM-tolerance in hosts. Although we found that certain endophytes improved tolerance of plants to heavy metals, isolates from the HM-contaminated site were not more tolerant to heavy metals than those from the uncontaminated site. Pot experiments indicated that growth and heavy metal absorption and accumulation by host plants in HM-polluted environments could be affected by inoculation with HM-tolerant endophytic fungi, and isolates showed a high intraspecific variability. However, there was no significant difference in growth between the maize inoculated with the endophytes from the HM-contaminated site and uncontaminated site under lead stress. Similarly, the HM content in the shoots and roots of maize inoculated with the isolates from the HM-contaminated site was not always higher than that in maize inoculated with endophytes from the uncontaminated site. Therefore, based on our experiments it is suggested that HM-tolerance due to endophytes and their effects on host plant growth and heavy metal absorption and accumulation were not correlated with origin of the endophytes.