The Physiological Effects Of Ca～(2+)-ATPase Inhibitors On Ripening And Senescence Of Peach Fruit

The experiment was performed using'Okubao'peach fruit, which were infiltrated with solutions of Ca²⁺-ATPase inhibitors, i.e. 0.5mmol/L, 1.0mmol/L sodium orthonadate (SO)and 0.05mmol/L, 0.1mmol/L erythrosine B(EB) for four hours, while water infiltration as control. The fruits were then dried and stored at the room temperature (25℃). The physiology-biochemistry characteristics were studied, such as: respiratory rate, fruit firmness, soluble protein content, and the pectin content. The activity of hydrolytic enzymes related with degradation of cellular wall, i.e. Polygalacturonase (PG), Pectinmethylesterase(PME),β-D-Galactosidase(β-Gal), were also studied. The purpose was to discover the controlling mechanism of Ca²⁺-ATPase to the fruit softening and senescence.The results as the follows:1. The fruit firmness descended rapidly at third d after harvest. The soluble protein content increased. The peak of respiration rate appeared at day 6 of storage. the proto pectin content declined, and soluble pectin content raised during the storage.2.The activity of PME, PG andβ-Gal increased along with the extension of the storing time. The activity of PME changed gentle; The activities of PG and PME appeared the peak in the later storage period. The activity of PG showed a similar change to the activity ofβ-Gal.3. The inhibitors of Ca²⁺-ATPase,i.e. Na₃VO₄ and EB, not only promoted significantly the respiration rate, but also enhanced its peak value, except for not altering its peak time. The inhibitors reduced the firmness compared with that of control, and increased soluble pectin content, decreased proto pectin content, thus stimulated fruits softening and senescence.4. Na₃VO₄ and EB enhanced the activity of cell wall hydrolase during storage. The activity of PG was increased and the time of peak was also advanced compared with that of control. However, which only enhanced the peak value of PME andβ-Gal , didn't alter the appearing time of peak value. In brief, the effects of Na₃VO₄ and EB on fruits suggested that Ca²⁺-ATPase take part in the softening process of fruits, and accelerate fruits senescence...