Scion/Rootstock Interaction and Tolerance Expression of Tomato to FORL

It is well known that grafting could enhance the tolerance of vegetable crops to soil borne pathogens. The large availability of rootstocks for tomato has increased the plant host variability and thus the interaction with pathogens. Considering above, the aim of this research was to study whether scion-rootstock combination may affect the sensitivity to Fusarium oxysporum f. sp. radicis-lycopersici (FORL) in tomato plants and to assess if proteins are differently expressed in the rootstock in relation to its sensitivity to the pathogen. Plants of tomato hybrids with different vigour, 'Costoluto Genovese' (less vigorous) and 'Kadima' (more vigorous), were grafted onto 'Cuore di Bue' and 'Natalia', a sensitive and a tolerant hybrid to FORL, respectively. Disease symptoms, plant biomass, and protein pattern were evaluated 45 days after FORL inoculation. Non inoculated plants were used as control. Vascular browning of tomato stem of inoculated plants was significantly influenced by the rootstock, but FORL symptoms were also different according to the scion used. Plant growth was slightly influenced by fungal inoculation, regardless the grafting combination. For protein pattern, the 2-D electrophoresis and mass spectrometry results showed a qualitative and quantitative higher expression of proteins due to pathogen infection in the tolerant rootstock 'Natalia' compared to the sensitive one, suggesting an involvement in plant defence response.