A group from Department for Sustainable Food Process, CRAST Research Centre, Università Cattolica del Sacro Cuore, Piacenza, Italy, etc. has reported about investigation of Trichoderma-mediated impact of heat, drought, and their combined stress on Arabidopsis thaliana, considering physiological responses, molecular implications at metabolome level, as well as the root and rhizosphere bacterial microbiota.
Plants treated with Trichodelma spp. were characterized by an increment of the fresh biomass even during drought and heat stress, suggesting that the increase in fresh weight observed was mainly due to an accumulation of water inside plant tissues.
The inoculation with Trichoderma spp. leaded to increased production of N-containing metabolites (including alkaloids and polyamines), phenylpropanoids, phytoalexins, tarpens, glucosinolates. It was also found that phytoholmons such as auxin-related substances (i.e., indole-3-acetaldehyde, indole-3-carboxaldehyde, and indole-3-ethanol), small peptides, and volatile organic compounds are upregulated by the inoculation with Trichoderma. And also, the soil microbiomes shifted in abundance and composition in response to environmental factors and Trichoderma treatments. Proteobacteria were the most predominant in roots and soil, on average, 89.6% of roots and 59.4 % of soil. Besides Proteobacteria in soil samples, one of the most abundant phyla were Bacteroides and Actinobacteroides.
They concluded that a holobiont approach, in other words, an multi-omics approach, is needed to understand the coordinated and complex dynamic interactions between the plant and its rhizosphere bacteria.