RNA-seq analysis of leaf transcriptome of two hazelnut genotypes (wild and TGL) inoculated and not inoculated with and ectomycorrhizal fungus (Tuber melanosporum)

Roots of the European hazelnut (Corylus avellana), i.e., one of the most economically important nut species, form symbiosis with ectomycorrhizal (ECM) fungi, including truffles. Although physical interactions only occur in roots, the presence of mycorrhizal fungi can lead to metabolic changes at systemic level, i.e., in leaves. However, how root colonization by ECM fungi modifies these processes in the host plant is so far not widely studied. This work was aimed to investigate the response in two hazelnut genotypes of C. avellana leaves from plants inoculated with the black truffle Tuber melanosporum. Transcriptomic profiles of leaves of colonized plants were compared to that of non-colonized plants, as well as sugar and polyphenolic content. Results showed that T. melanosporum might be considered a priming agent, leading to the systemic regulation of several genes involved in signaling and defense responses.