عنوان مجله
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ENVIRONMENTAL AND EXPERIMENTAL BOTANY
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چکیده
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Despite a drought- and erosion-tolerant root system, olive trees are vulnerable to abiotic stress due to limited
genetic variability. Though some olive cultivars are moderately tolerant to salinity stress, soil salinity is
increasing in the semi-arid and arid regions where olive cultivation is common, significantly reducing overall
production. In response, breeding programs may rely on proper selection markers for abiotic stresses, including
salinity, but these are generally lacking for olive. Here, physiological and biochemical parameters were measured
in four Olea europaea genotypes (Frantoio, Leccino, Lecciana, and Oliana) subjected to different intensities of
salinity stress (0 mM, 100 mM and 200 mM NaCl). At moderate and high salt concentrations, Na+ exclusion,
higher photosynthetic productivity and tissue water content in the tolerant cultivar Frantoio were linked with
increased production of polyphenols, with more favorable K+/Na+ values (quercetin and rutin), mitigation of
oxidative stress (oleuropein) and increased water absorption (luteolin). In Frantoio and Leccino, a significant
change of the proteome repertoire occurred, with overrepresentation of components regulating cellular metabolism, ion transport, redox insult and dissipation of excess photochemical energy. Conversely, Lecciana and
Oliana showed increased sensitivity to salinity stress in terms of photosynthetic parameters and elevated internal
Na+ concentrations, together with the lowest number of differentially represented proteins. These results
highlighted olive germplasm strategies to cope with osmotic stress, suggested a physiological and molecular basis
for the augmented responsiveness of tolerant cultivars and identified specific biomarkers as useful targets for
future breeding programs.
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