Some biochemical features of Olea europaea L. frost resistance

A.E. Paliy, I.N. Paliy
The effect of freezing temperatures on the biochemical parameters of leaves in Olea europaea L. cultivars in the collection of Nikita Botanical Gardens was studied. The objects of the research were: frost-resistant cultivar ‘Nikitskaya’, slightly frost-resistant cultivars – ‘Askolyana’, ‘Razzo’, ‘Correggiolo’ and subspecies – O. europaea subsp. cuspidata. In the studies of biochemical parameters under controlled conditions, the method of cuttings cooling in a climate control chamber was used. In the olive leaves collected in field, peroxidase activity was 1.13-1.58 a.u. g-1 s‑1. The maximum activity of this enzyme was noted in the frost-resistant cultivar ‘Nikitskaya’. After the exposure of freezing temperatures, peroxidase activity increased in most the studied samples, except the cultivar ‘Nikitskaya’ (the activity was unchanged). The activity of polyphenol oxidase after freezing increased in all the studied cultivars. The greatest increase in enzyme activity was observed in O. europaea subsp. cuspidata and ‘Correggiolo’ cultivar. Catalase activity, in the experiment treatments, changed diversely. In the cultivars ‘Ascolana’ and 'Correggiolo', catalase activity decreased, in the cultivars ‘Nikitskaya’, ‘Razzo’ and subspecies O. europaea subsp. cuspidate it increased. The decrease in catalase activity in the cultivars ‘Ascolana’ and ‘Correggiolo’ was, probably, associated with a significant increase in peroxidase activity and was due to the competition of these enzymes over the substrate. In the olive cultivars leaves collected in field, the total content of phenolic compounds was 915-1,282 mg 100 g‑1, flavonoids 860-1,062 mg 100 g‑1, proline 15-24 μg g‑1. The effect of low-temperature stress did not cause significant changes in the content of phenolic compounds and flavonoids, but it resulted in a significant increase in proline concentration. Thus, a precise correlation between the frost resistance of the studied O. europaea cultivars with the changes in redox enzymes activity and proline content was revealed. The presented data suggested the participation of the above mentioned biochemical indicators in the process of European olive adaptation to the effect of freezing temperatures.
Paliy, A.E. and Paliy, I.N. (2021). Some biochemical features of Olea europaea L. frost resistance. Acta Hortic. 1324, 395-400
DOI: 10.17660/ActaHortic.2021.1324.61
Olea europaea, enzyme activity, phenolic compounds, flavonoids, proline, low temperature stress

Acta Horticulturae