Changes in the content of sugars and amino acid in the fruit of Lycopersicon esculentum after quercetin treatment

We studied the effect of low doses of quercetin, an exogenous flavonoid, on the content of various sugars in the fruit of Lycopersicon esculentum. The content of glucose in tomatoes calculated per dry weight increased 1.5- to 4.5-fold in the experiment compared with the control. Simultaneously, we observed a decrease in the content of total amino acids in the fruit of quercetin-treated plants (1.5 times compared to the control). The most significant changes were noted in the content of amino acids: glutamic (1.7-fold) and aspartic (1.6-fold). The treatment of plants with quercetin did not decrease their productivity. An increase in the level of glucose in tomatoes has been found in all 12 varieties studied. We discuss the mechanism of the possible effect of quercetin on tomato plants.