Effect of methyl jasmonate (JA-Me) on the content of flavonols in the leaf blade and petiole of G. biloba. Mean results ± SD followed by the same letter calculated for the natural senescence process and JA-Me treatment separately were not significantly different (p < 0.05) according to Tukey’s test. Description of samples: 1, initial time (9 September); 2, naturally senesced yellow leaves (20 October); C, control (lanolin); Ad, JA-Me applied to the adaxial side of the leaf blade; Ab, JA-Me applied to the abaxial side of the leaf blade. C, Ad, and Ab samples were collected for analysis on 30 September.