Changes In The Expression Of Three Cold-Regulated Genes In ‘Elsanta’ And ‘Selvik’ Strawberry (Fragaria × Ananassa) Plants Exposed To Freezing

Cold temperatures in midwinter and late-spring frosts cause severe damages to strawberry plants cultivated in temperate climate regions. Despite the seriousness of the problem, the plant mechanism of defense against cold stress has not been fully elucidated yet, especially in its molecular aspect. The presented investigations were conducted on the cold-susceptible cultivar ‘Elsanta’ and the cold-tolerant cultivar ‘Selvik’. Expression profiles of three genes (CBF4, COR47 and F3H) were determined at three time-points: 0, 6 and 12 weeks after sub-zero treatment at -12 °C. The CBF4 gene was very strongly up-regulated in ‘Selvik’ plants and the highest value of the transcript level was detected just after the treatment (time - point 0). The F3H transcript in the treated ‘Selvik’ plants reached the level 4 times higher than in control plants in the 12^th week after treatment (time-point 3). In ‘Elsanta’ plants, the CBF4 and COR47 genes were slightly up-regulated (time-point 2), while the F3H gene showed stability of expression. High positive correlation between the transcript level of COR47 and transcript level of CBF4 genes was observed for both cultivars.