Insights into the suppressiveness of composts against Phytophthora nicotianae by omics

摘要

Phytophthora root rot caused by the soil-borne pathogen Phytophthora nicotianae is an economically important disease in pepper plants. Nowadays, there are no effective treatments for its control; the use of compost is a promising alternative. The useof composts in growing media to suppress several soil-borne pathogens has been widely studied. However, inconsistent results limit its practical use. We have investigated the suppressive capability of four compost-peat mixtures against P. nicotianae in pepper plants. Different parameters were measured to try to predict the suppressive effect of composts, including the enzymatic activity dehydrogenase, chemical features (pH, electrical conductivity, total carbon, total nitrogen) and organic fraction composition (by SP-MAS 13C-NMR spectroscopy). In addition, omic approaches such as metagenomics and metabolomics were performed. We observed that control of P. nicotianae seems to be related to the activity of a consortium of microorganisms, which is associated with the ability of materials to sustain sufficient microbial activity over time. We found that dehydrogenase activity was highly correlated with disease suppression. On the other hand, it seems that the study of the metabolome of composts may be a good tool to predict their suppressiveness against this oomycete. We conclude that the integration of different parameters may be a useful approach to improve disease suppression prediction of compost.