Tomato-Aphid Interactions in Plants Grown on Soil with Biochar

Abstract

Plants are affected by various types of stress. The resistance or the susceptibility of plants to stress depends on the mutual characteristics of the plant and the stress. The plant can counteract the stress through the expression of specific genes, through changes in metabolism or through quantitative and qualitative variations of gene expression. Biotic stress is due to the action of viruses, bacteria and small insects and it is the cause of most of the reduction in crop yield. Biochar is a fine-grained vegetable carbon that is obtained from the pyrolysis of different types of plant biomass, and, if added to the soil, it can improve soil characteristics and at the same time it can reduce carbon emissions. Biochar also appears to have an unclear role in the activation of systemic resistance responses to pathogens. Biochar has a carbon content of about 90%; its high porosity increases the retention of water and nutrients by reducing the need for water and fertilizers and increasing agricultural yield. Aphids are one of the major sources of biotic stress for the tomato ( <i> Solanum lycopersicum </i> ), a crop of significant agro-food and socio-economic importance, especially in the Mediterranean area and in southern Italy. In this study, we first evaluated, through a proteomic analysis, the differential protein expression of tomato leaves infected by aphid and grown on control soils and on biochar-modified soil. The results of the proteomic analysis showed a differential expression mainly in the proteins involved in stress and defense, so we decided to deepen this aspect through a molecular analysis. A Real-time PCR of some fundamental genes involved in the Jasmonic acid pathway was made because, although it is clear that aphid infection activates the salicylic acid pathway, we have less data in literature about the resulting tissue damage involves Jasmonic Acid (JA). The regulation of jasmonic acid after phytophagous insects attack is particularly important for the plant’s ability to initiate promptly to the defense responses.