Water relations after Ca, B and Si application determine fruit physical quality in relation to aquaporins in Prunus

Abstract As climacteric fruits, fleshy Prunus has a short ripening period and short shelf-life after harvest. Therefore, the main problem with these fruits is its physiological parameters related to the maintenance of firmness. In this work, the effects of combined foliar sprays (Ca+B and Ca+Si) on the physical and physiological parameters of prunus fruits were studied. Also, the involvements of aquaporin expression in relation to the maintenance of water and nutrients in the fruits were determined. Foliar treatments were applied to cherry (Prunus avium L.), apricot (Prunus armeniaca), doughtnut peach (Prunus persica L. var platycarpa), and nectarine (Prunus persica L.) trees grown under commercial conditions. The effects of treatments on fresh weight seemed to be dependent on the different species, with increases in apricot by Ca+Si and in nectarines by Ca+B. The firmness in cherries and apricots was enhanced by all the treatments. Also, apricot, doughnut peach and nectarine fruits did not show changes in osmotic potential, although increases in water potential and turgor potential were observed. Increases in some aquaporins only appeared in cherry and nectarine but not in apricot and doughnut peach which is in agreement with the results obtained in the activity of aquaporins in association with the retaining of electrolytes. Therefore, the results of this work indicate that the study of water relations involving aquaporins in mature prunus fleshy fruits could be a key aspect for the maintenance of turgor.