Strawberry PRPs fluctuate depending on genotype and seasonal conditions

The production and integration of small fruits are promoted in different agricultural and nutritional programmes. Strawberries are currently the most popular berries grown and consumed with an estimated amount of 3.8 million metric tons in 2007 worldwide. Despite of proven health benefits, strawberries contain allergenic Fra a 1, a PR-10 protein, which is constitutively expressed in the fruits and is responsive to stress or pathogen exposure. The current investigations showed that the content of total proteins of four strawberry cultivars and hybrids differed significantly in two consecutive years (2007-2008). All strawberry genotypes contained higher total protein amounts in 2007 compared to 2008, whereas the selection AN00.239.55 being the most responsive to climate difference (ten-fold lower protein content in 2007). The comparison of strawberries total protein values with temperature data indicated a correlation between temperature and protein content. Different strawberry genotypes expressed different amounts of Fra a 1 and three of them ('Adria', 'Sveva', and AN00.239.55) showed a decreased level by progressive ripening in the year 2007. However, the selections AN94.414.52 and AN00.239.55 showed an increased concentration of Fra a 1 in 2008. However, the cultivar 'Adria' was unaffected by climate alterations and showed the same progressive decrease of Fra a 1 in both years. The observed variations in Fra a 1 content of full ripe strawberries indicate a direct influence of environmental stresses on the expression of PR-10s