Transcriptional effects of Trichoderma on Sinorhizobiuma meliloti

We selected 4 strains of the model rhizobium Sinorhizobium meliloti and 4 Trichoderma species. In an experimental scheme of 4 x 4 interactions, we investigated the fungal growth inhibition by dual cultures, the rhizobia growth inhibition and the transcriptomic response elicited by fungal spent media, as well as spent media effects on rhizobia and on rhizobia-host legume plant symbiosis. Fungal spent media had large and specific x strain specific effect on rhizobia, indicating a general rhizobia genotype x fungal genotype interaction. In particular, a high number of genes was shown to be differentially expressed in rhizobia strains, as well as changes in exopolysaccharide, auxin production and in plant symbiotic phenotypes were identified.