Estudio de la expresión diferencial de genes implicados en la producción de glucosinolatos y cuantificación de otros compuestos de interés biomédico en Arabidopsis thaliana, Brassica oleracea y Eruca vesicaria

Glucosinolates (GSLs) are a group of secondary metabolites mainly produced by plants belonging to the botanical family Brassicaceae (Cruciferae). Crucifers are a large taxonomic group, which includes many food crops like mustard, turnip, cabbage, radish, kale (Brassica oleracea var. sabellica) or rocket (Eruca vesicaria subsp. sativa). The model species Arabidopsis thaliana is also a crucifer. GSLs hydrolysis products, isothiocyanates (ITCs), in combination with other metabolites like phenols or antioxidants, have shown great potential in the treatment of different types of cancer. The production of these compounds is affected by abiotic factors, like salt or salinity, and also by plant domestication. In this work, we used A. thaliana Col-0 plants to evaluate the effect of salinity and drought stress on the differential expression of genes involved in the synthesis of GSLs, and also on the content of phenols and antioxidant activity. We also investigated the effect of domestication on these three parameters, by the use of wild and cultivated B. oleracea and E. vesicaria subspecies. We used two accessions of kale (B. oleracea var. sabellica), cultivated, one accession of wild cabbage (B. oleracea var. oleracea), two accessions of cultivated rocket (E. vesicaria subsp. sativa) and one accession of wild rocket (E. vesicaria). Expression of MYB28, CYP79F1, UGT74B1 and FMOGS-OX5 GSLs synthesis genes was quantified by RT-qPCR, using the housekeeping gene TIPS41. To perform the gene expression assays, we designed and evaluated polyvalent primer pairs which could amplify in the three species of the study. Phenol content and antioxidant activity were measured by colorimetric assays. Our results show that, while salinity stress makes GSL gene expression, antioxidant activity and phenol content slightly decrease, drought stress makes all three parameters increase. In general, wild B. oleracea plants presented higher expression levels of the genes evaluated, and also higher phenol content and antioxidant activity than the cultivated ones. On the other hand, wild E. vesicaria plants showed lower values in the three parameters evaluated than their cultivated relatives, showing that plant domestication may have different effects depending on the species