Cytosolic/Plastid Glyceraldehyde-3-Phosphate Dehydrogenase Is a Negative Regulator of Strawberry Fruit Ripening

Cytosolic glyceraldehyde-3-phosphate dehydrogenase (GAPC) and plastid glyceraldehyde-3-phosphate dehydrogenase (GAPCp) are key enzymes in glycolysis. Besides their catalytic function, GAPC/GAPCp participates in the regulation of plant stress response and growth and development. However, the involvement of GAPC/GAPCp in the regulation of fruit ripening is unclear. In this study,FaGAPC2andFaGAPCp1in strawberries were isolated and analyzed.FaGAPC2andFaGAPCp1transcripts showed high transcript levels in the fruit. Transient overexpression ofFaGAPC2andFaGAPCp1delayed fruit ripening, whereas RNA interference promoted fruit ripening and affected fruit anthocyanins and sucrose levels. Change in the expression patterns ofFaGAPC2andFaGAPCp1also influenced the expression of several glycolysis-related and ripening-related genes such asCEL1,CEL2,SS,ANS,MYB5,NCED1,ABI1,ALDO,PK, andG6PDH, and H(2)O(2)level and reduced glutathione (GSH)/glutathione disulfide (GSSG) redox potential. Meanwhile, metabolomics experiments showed that transient overexpression ofFaGAPCp1resulted in a decrease in anthocyanins, flavonoids, organic acid, amino acids, and their derivatives. In addition, abscisic acid (ABA) and sucrose treatment induced the production of large amounts of H(2)O(2)and inhibited the expression ofFaGAPC2/FaGAPCp1in strawberry fruit. These results revealed thatFaGAPC2/FaGAPCp1is a negative regulator of ABA and sucrose mediated fruit ripening which can be regulated by oxidative stress.