## 4 Conclusions  
Taken together, these results suggest that _E. sativa_ is a reliable source for the extraction of AGs for the development of bioproducts, with different organs carrying different AG profiles, and Na\({}_{2}\)SO\({}_{4}\) is a promising elicitor. Salt enrichment one week after seedling emergence seems to have an impact on GER accumulation in roots and of dimeric 4-MBGSL in apical leaves. These two metabolites exhibited a negative correlation with each other. Moreover, an increase in GER has been observed to be associated with an increase in the _BCAT4_ gene in roots, while the increase in dimeric 4-MBGSL in leaves does not seem to directly depend on any of the tested biosynthetic genes, which are interestingly all down-regulated. This elicitation strategy, even though it requires further optimization, seems promising especially in modulating GER content in roots, which are a byproduct of _E. sativa_ salad cultivation and, thus, interesting in a circular economy perspective. Further studies with different processing and sampling times, and a fine characterization of _E. sativa_ gene families through genome sequencing, RNA-seq and their integration with metabolomic data, would provide insights into their organ-specific roles in the synthesis, regulation, transport and accumulation of AGs. Ultimately, this could also help define the best rocket management practices for selective enhancement of AGs and develop strategies aimed at improving the yield in specific plant organs. Such controlled modulation would be useful for downstream industrial applications, both in the agronomic sector for the development of products that exploit the antimicrobial properties of GSL hydrolysis products, and in  
Figure 3: Correlation analysis among glucosinolate (glucoerucin (GER); glucoeraphanin (GRA); dimeric 4-mercaptoethanol GSL (dimeric 4-MBGSL)) content and gene expression (_BCAT4; MAMI; SüRI; CYP83A1; MYC3; MYC4; MYB28a, MYB28b_) performed with the R package ‘corrplot’. Red circles indicate a negative correlation, blue circles a positive one. ‘\(\arcsec\) indicates \(p\leq 0.05\), ‘\(\arcsec\)’\(p\leq 0.01\). the food sector for ingredients enriched in GSLs, which have been demonstrated to have health benefits. The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app15158757/s1](https://www.mdpi.com/article/10.3390/app15158757/s1)]([https://www.mdpi.com/article/10.3390/app15158757/s1](https://www.mdpi.com/article/10.3390/app15158757/s1)), Table S1: Primer sequences used for RT-qPCR; Figure S1: Representative HPLC-UV chromatogram of _Eruca sativa_ desulfated aliphatic glucosionolates partially purified from leaves; Table S2: Main aliphatic glucosionolates isolated by HPLC-UV preparative chromatography from _Eruca sativa_ leaves together with retention times and UV spectra; Figure S2: 1H NMR spectrum of dimeric 4-mercaptoethanolSULTed GSL in D\({}_{2}\)O; Figure S3: 1H NMR spectrum of 4-(-b-D-glucopyrananoyldisulfanyl)butyl desalted GSL in D\({}_{2}\)O; Table S3: Assignment of NMR data; Figure S4: Full MS scan and MS spectra of dimeric 4-mercaptoethanolbutyl and 4-(b-D-glucopyranosyldisulfanyl)butyl desalted-GSL; Figure S5: Aliphatic glucosionolates content in _Eruca sativa_ basal leaves after the elicitation with Na\({}_{2}\)SO\({}_{4}\). References [52; 53] are cited in the Supplementary Materials, while references [34; 37; 42] are cited in both the main text and the Supplementary Materials. Conceptualization, E.P., L.R. and L.B. ; methodology, E.P., G.M., L.U., R.C. and A.F. ; software, L.R. ; formal analysis, A.M., L.M., R.M., A.F. and F.N. ; investigation, E.P., L.R., C.B., L.U. and L.R. ; resources, A.F. and L.B. ; data curation, E.P. and L.R. ; writing--original draft preparation, E.P., L.R. and L.B. ; writing--review and editing, G.M., C.B. and L.U. ; supervision, L.R. and L.B. ; project administration, L.B. ; funding acquisition, L.B. All authors have read and agreed to the published version of the manuscript.