# Signaling in the Tomato Immunity against _Fusarium oxysporum_
## 2 Results
### Movione Tomato Plants Activate an Early JA-and ABA-Mediated Defense Response after Fol Infection
The analysis supported that different metabolites seem to be involved in the compatible and incompatible interaction and depending on time of infection. Analyzing the PC1 of the loading plot, the specific VOCs that strongly contributed to the separation of samples according to the interaction type were identified. Figure 4: Score plot of the PCA based on the whole array of the mass spectra within an \(m/z\) range from 35 to 250. VOCs were analyzed from susceptible Momor (MOM; white) and resistant Movione (MOV; gray) tomato plants infected by _Fusarium oxysporum_ f. sp. _Iycpersici_ at 7 and 14 dpi. PC1 and PC2 explain the 19% and 12% of variance separating the samples according to the type of interaction and timing of the fungal infection, respectively. Statistically differential metabolites according to _t_-test for both incompatible (MOV/MOM ratio \(\geq\) 1.7) and compatible (MOV/MOM ratio \(\leq\) 0.8) interactions are shown in boxes. The statistical volatiles differentially released during ETI establishment in resistant MOV tomato plants infected by _Fol_ were extracted from the positive part of PC1 and are listed in Table S2 (MOV/MOM ratio > 1). Among them, some terpenids were significantly emitted by resistant plants after 7 days of fungal inoculation: the monoterpene 3-carene, along with two aldehyde monoterpenoids and (\(Z\))-linalo oxide, two nor-isoprenoids (dihydroactinidiolide and \(\beta\)-ionone), and four sesquiterpenes (\(\alpha\)-caryophyllene and three isoforms of elemene). In addition, 2-ethylhexanoic acid, 2,2-dimethyldecane, and three unknown compounds (unk 1-3) were the volatiles significantly over-emitted by the resistant tomato plants at the beginning of the infection. Interestingly, the volatile profile at 14 dpi was characterized by the emission of benzenoids and C5-fatty acid derivatives such as isobutylbenzene, benzeneacetaldehyde, methylbenzene, 5-ethyl-2-furanone, and (\(E\))-2-pentenal. Only the sesquiterpenes \(\alpha\)- and \(\beta\)-caryophyllene were also significantly induced in the incompatible interaction together with the apocarotenoid geranylacetone, an unknown nitrogen compound (unk 2), the hydrocarbon 2,2-dimethyldecane, and the sulfur compound 2-ethylthiophene (Figure 4). Particularly, \(\alpha\)-caryophyllene, 2,2-dimethyldecane, and unk 2 were significantly over-emitted by MOV plants during all of the experiment. Similarly, the analysis of the negative side of the PC1 loading plot allowed for identifying the VOCs emitted by the susceptible MOM tomato plants upon _Fol_ infection, showing the metabolites detailed in Table S3 (MOV/MOM ratio < 1) and summarized in Figure 4. Benzenoids and fatty acid derivatives were differentially over-emitted by the vulnerable plants. In the first group, methyl salicate (MeSA) and ethyl salicate (EtSA) were over-emitted at 7 and 14 dpi, respectively. On the other hand, the production of some aldehydes and ketones derived from the fatty acid degradation as 2-nonenal, 2-hexanone, 2-heptanone, and 3-heptanone was induced during all of the infection process. However, 3-buten-2-one, butanal, and 2-butanone were emitted exclusively at the beginning of the infection process, and 2-pentanone at the end. The statistically significant and most over-emitted discriminant VOCs from the resistant MOV (MOV/MOM ratio \(\geq\) 1.7) and the susceptible MOM (MOV/MOM ratio \(\leq\) 0.8) tomato plants are summarized in Figure 4.