Title : Aluminum toxicity differentially affects carbohydrates concentration in Vaccinium corymbosum L. cultivars
Abstract:
S tarch is the main molecule of carbohydrate storage in plants, composed of glucose residues. It is commonly associated with storage organs such as roots, stems and leaves. Under stress, starch can be stored or degraded in plants, as well, remobilized to provide energy and carbon molecules when photosynthesis is limited or helping to generate organic acids and sugars. The aluminum (Al), at low pH, can be toxic (Al3+) to plants, altering the total carbohydrates, increasing organic acids and decreasing photosynthetic performance. Highbush blueberry is an important crop species cultivated in the south of Chile. The aim of this work was to determine the relation of starch with the concentration of soluble sugars, organic acids and photosynthesis, in highbush blueberry under 200 μM of AlCl3 at pH 4.5 in nutritive solution for 48h. The results showed significant differences (p0.05), but its tendency is to decrease in roots under Al. Photosynthesis showed a decrease (P<0.05) in Brigitta, Star and Duke cultivars under Al3+. Further, there is a positive correlation of starch with glucose (0.36) and fumarate (0.06), and negative correlation with fructose (-0.48), sucrose (-0.23) and photosynthesis (-0.12) (p<0.01). Finally, it is suggested that aluminum decreases photosynthesis, the concentration of carbohydrates and fumarate in highbush blueberry. On the other hand, starch is related to concentration of soluble sugars, and its increased could decrease photosynthesis. Acknowledgments: Fondecyt Iniciación N° 11160355 and FONDECYT Regular N° 1171286 projects.
