Infection of post-harvest peaches by Monilinia fructicola accelerates sucrose decomposition and stimulates the Embden-Meyerhof-Parnas pathway.

To study the changes in sugar metabolism caused by fungal infection in post-harvest peaches, fruit from two cultivars ('Baifeng' and 'Yulu') was inoculated with Monilinia fructicola and stored at 10 °C. During disease development, soluble sugar content was monitored, as well as the activities and expression of selected enzymes. Disease progression was accompanied by a decrease in sucrose content and increases in reducing sugars and soluble solids, consistent with higher enzyme activities for acid invertase, neutral invertase and sucrose synthase-cleavage, and lower activities for sucrose synthase-synthesis and sucrose phosphate synthase. Activities of phosphofructokinase, hexokinase, and pyruvate kinase, which are related to hexose metabolism, also increased. These changes stimulate the Embden-Meyerhof-Parnas (EMP) pathway. We conclude that the fungal disease in peach fruit accelerates the decomposition of sucrose, thereby providing more glucose as a substrate to the EMP pathway.