Mycorrhizal fungi enhance nutrient uptake but disarm defences in plant roots, promoting plant-parasitic nematode populations

Publication date: Available online 3 September 2018Source: Soil Biology and BiochemistryAuthor(s): Adam Frew, Jeff R. Powell, Gaétan Glauser, Alison E. Bennett, Scott N. JohnsonAbstractArbuscular mycorrhizal (AM) fungi are ubiquitous components of the soil biota which live symbiotically with terrestrial plants. Substantial research has examined how AM fungi alter interactions between plants and plant antagonists. Plant-parasitic nematodes are an important group of soil-dwelling invertebrates that inflict considerable damage to crops, representing a serious threat to food security. The effects of the AM symbiosis on plant-parasitic nematodes can be variable, and the mechanisms driving such variability remain ambiguous.We tested the impacts of inoculation with AM fungi on the root metabolic profile and nutritional chemistry of two varieties of wheat (Triticum aestivum), and how this affected populations of the plant-parasitic nematode Pratylenchus neglectus.AM fungi reduced plant biomass by almost 24%, yet increased root concentrations of phosphorus, potassium and zinc by 50%, 15% and 16%, respectively. Contrary to our predictions, nematode populations were 47–117% higher on AM inoculated plants, depending on variety. Untargeted metabolomic profiling revealed significant effects of mycorrhizal colonisation on certain markers of biological interest, these compounds were the benzoxazinoid glucoside defence compounds DIBOA-Glc, HMBOA-Glc and HDMBOA-Glc. Overall, mycorrhizae red...
Source: Soil Biology and Biochemistry - Category: Biology Source Type: research