Estratégias químicas e moleculares para caracterização de produtos de origem vegetal

Abstract

Genetic characteristics and environmental conditions influence the chemical composition of fruits and vegetables so that it is possible to distinguish products from different cultivars produced under different environmental conditions. Plants are constantly exposed to biotic and abiotic stresses and, in order to adapt to these adverse conditions, molecular, biochemical and physiological changes occur. Among the mechanisms of abiotic stress responses, there is evidence that there is a signaling cascade involving calcium (Ca2+) and calcium-dependent protein kinases (CDPKs). Thus, this doctoral work covered two distinct approaches with two relevant fruit crops, the olive tree and the strawberry tree. For the cultivation of olive (Olea europaea L.) the effect of the genotype, that is, of different cultivars on the chemical composition of olive oil produced in Pinheiro Machado and processed under the same conditions and two subsequent crops, was evaluated. The composition of olive oils from the Arbequina, Arbosana, Coratina, Frantoio, Koroneike and Picual cultivars from the 2017 and 2018 crops was in accordance with the identity and quality parameters established for extra virgin olive oil (EVOO) and was influenced by the cultivar and by the harvest. EVOO produced in 2018 had higher levels of chlorophyll, caffeic acid, ligstroside aglycone, hydroxy oleuropein aglycone, syringic acid and hydroxytyrosol acetate compared to EVOOs from the 2017 harvest. Linoleic acid, ferulic acid, ligstroside aglycone and hydroxytyrosol acetate were the variables whose contents most contributed to the differentiation of oils depending on the cultivar in the two crops. The chemical characterization allowed to differentiate between monovarietal oils based on the crop and cultivar. The chemical characterization allowed differentiating between monovarietal oils based on the crop and cultivar. In the case of strawberry (Fragaria x ananassa) gene sequences encoding CDPKs were identified and the transitional profile of these genes was evaluated during the maturation process and under conditions of abiotic stresses. The identification of the FaCDPK family was performed from information from the GenomeDatabase for Rosaceae (GDR) and from an in housee RNA seq database, information on the gene structure, phylogeny, interatoma and expression profiles were generated. Nine new CDPK genes were identified and classified into four main groups, based on phylogenetic analysis and structural characteristics. FaCDPK genes were differentially expressed during fruit development and ripening, as well as in response to abiotic saline and water stress and treatment with abscisic acid hormone. Finally, the analysis of the interaction network revealed proteins involved in stress responses, especially RBOHs.