Salt Stress Differentially Affects the Primary and Secondary Metabolism of Peppers (Capsicum annuum L.) According to the Genotype, Fruit Part, and Salinity Level

A total of four Capsicum annuum L. genotypes ('Caro F1', 'Berenyi F1', 'Somborka' and 'Novosadka') were exposed to two intensities of salt stress. We observed a significant decrease in the sugar content in all salt stressed treatments, except for the sucrose content of the pericarp of the 'Caro F1' cultivar. Salt stress had a largely negative effect on the total and individual organic acid content, although the effect differed among cultivars. Using high performance liquid chromatography coupled with a mass spectrometer, most phenolics were identified in the pericarp (18), followed by the placenta (7) and seeds (8). Treatment with 40 mM NaCl caused the highest increase in individual phenols, followed by treatment with 20 mM NaCl. The cultivar 'Berenyi F1' was less affected by salt stress treatment than the other three cultivars in terms of content of individual and total phenols. Salt stress increased the content of capsaicinoids in all the cultivars. The pericarp of the cultivar 'Novosadka' showed 17.5 and 50 times higher total capsaicinoid content than the control in the 20 mM and 40 mM NaCl, respectively. With the results of several metabolite groups, we confirmed that the reaction and metabolic content to salt stress within the genus Capsicum is genotype-, fruit part-, and salinity level-dependent.

Automated summary

This study investigated the metabolic responses of different Capsicum annuum L. genotypes to salt stress. Salt stress led to a decrease in sugar and organic acid content, but an increase in phenolic compounds and capsaicinoids. The effect varied among genotypes and salt concentrations.