Exogenous GSNO and CPTIO treatment affected the ripening and glutathione metabolism of strawberry fruit

In order to investigate the effects of S-nitroso glutathione (GSNO) and nitric oxide synthase (NOS) inhibitors Carboxy-PTIO (CPTIO) on the ripening and antioxidant properties of isolated strawberry fruits, several parameters were measured including, strawberry fruit color, soluble sugar, firmness, ABA, GSH and ASA content, and enzymatic activity of GSNOR, GSR, APX, NADPH, NADP and G6PDH in strawberry fruit. The results showed that treatment with 500 μM GSNO and 500 μM CPTIO significantly delayed fruit coloring and inhibited the accumulation of anthocyanin, TSS, ABA and total phenol compared with the control. Meanwhile, the treated fruits maintained high firmness. The enzymatic activities of GSNOR, GR and G6PDH were enhanced, and the ratio of NADP⁺/NADPH was increased. These results suggest that GSNO and CPTIO can delay the ripening process and accelerate the glutathione metabolism of strawberry fruits.