Bioremediation is an ecologically-friendly approach for the restoration of heavy metal-contaminated sites and can exploit environmental microorganisms such as bacteria and fungi. These microorganisms are capable of removing and/or deactivating pollutants from contaminated substrates through biological and chemical reactions. Moreover, they interact with the natural flora, protecting and stimulating plant growth in these harsh conditions. In this study, we isolated a group of endophytic fungi from Agrostis stolonifera grasses growing on toxic waste from an abandoned lead mine (up to 47,990 Pb mg/kg) and identified them using DNA sequencing (nrITS barcoding). The endophytes were then tested as a consortium of eight strains in a growth chamber experiment in association with the grass Festuca arundinacea at increasing concentrations of lead in the soil to investigate how they influenced several growth parameters. As a general trend, plants treated with endophytes performed better compared to the controls at each concentration of heavy metal, with significant improvements in growth recorded at the highest concentration of lead (800 galena mg/kg). Indeed, this set of plants germinated and tillered significantly earlier compared to the control, with greater production of foliar fresh and dry biomass. Compared with the control, endophyte treated plants germinated more than 1-day earlier and produced 35.91% more plant tillers at 35 days-after-sowing. Our results demonstrate the potential of these fungal endophytes used in a consortium for establishing grassy plant species on lead contaminated soils, which may result in practical applications for heavy metal bioremediation.

Agricultural crops growing in saline soils produce sub-optimal yields due to the negative effects of excess salts on plant growth and development. Salinity stress for crops is likely to increase as a result of climate change and the consequent salinisation of soils, particularly in coastal areas. In this study, we recovered fungal endophytes from the seeds of the wild barley relative Hordeum secalinum and tested their effects on a barley cultivar grown in a controlled environment under four levels of continuously applied salt stress: 0, 75, 150 and 250 mM NaCl. For the unstressed plants and plants stressed with 75 mM NaCl we found an endophyte-associated increase in early growth, grain dry weight, shoot dry weight, root dry weight, number of tillers, number of heads and number of grains. However, this relationship was reversed for the plants grown with 150 and 250 mM NaCl, where the endophytes negatively affected these traits. Plants stressed with the highest concentration of NaCl (250 mM) produced no grain. These results suggest that the endophytes may have potential to benefit field grown barley crops growing on moderately salt-stressed sites.

The common ash (Fraxinus excelsior) is one of the most important native tree species in Ireland but is threatened by the spread of ash dieback (also known as Chalara disease). The disease is caused by the fungal pathogen Hymenoscyphus fraxineus, which is decimating ash in Europe. The first part of this review summarises the scientific discoveries on H. fraxineus, focusing on its origin and infection cycle as well as its impact on Irish forestry. In addition to directly damaging ash, the action of H. fraxineus makes ash trees more vulnerable to attack by other opportunistic secondary pathogens, which accelerate their death. Ireland, as an island, has a natural barrier which slows the spread of pathogens compared to many other countries in the European mainland, but the threat of further pathogen introduction remains real and likely. The second part of this review focuses on the spread of other pathogens of ash, and on their incidence and importance in Ireland.

This is the first report of the ash sawfly, Tomostethus nigritus, in the Republic of Ireland. We observed defoliated leaves of Fraxinus excelsior L. and T. nigritus larvae at a forestry plantation in Co. Kildare. Morphological observation of the larvae and DNA analysis using mitochondrial COI barcoding confirmed the identification of this pest of ash.