陈化马铃薯切片内源乙烯和抗氰呼吸途径发生、运行的关系

RELATIONSHIP BETWEEN ENDOGENOUS ETHYLENE AND THE DEVELOPMENT AND OPERATION OF THE ALTERNATIVE PATHWAY IN AGED POTATO TUBER SLICES

马铃薯(Solanum tuberosum L.)切片在24h陈化期间,总呼吸速率(V_t)明显升高,交替途径容量(V_(alt))增加更为显著。交替途径实际活性(ρV_(alt))及其对V_t的贡献(ρV_(alt)/V_t)在陈化初期上升,12h后基本保持稳定;相应交替途径运行系数ρ值随陈化进程不断下降。陈化切片内源乙烯产生的时间曲线与V_(alt)的变化趋势一致,而与ρV_(alt)的趋势不同。用乙烯相关效应剂进行实验,发现促进乙烯产生的ACC及Cu^(2+)可促进V_(alt)的发生,而抑制乙烯产生或其生理作用的Co^(2+)及Ag^+则可部分抑制V_(alt)的发生。所有上述效应剂虽然对ρV_(alt)及ρV_(alt)/V_t值在12h前有所影响,但都不能改变切片陈化期间交替途径ρ值不断下降的趋势。这些结果表明,内源乙烯对马铃薯切片陈化过程中交替途径的实际运行稍有影响,但对抗氰容量的诱导发生具有重要的调控作用。

The relationship between endogenous ethylene and the development and the operation of the alternative respiration pathway in aged potato ( Solatium tuberosum L.) tuber slices were investigated . During the 24 h aging period under 30℃, along with the great increase of the total respiratory rate (Vt) of the slices, the alternative pathway capacity (Valt) developed continuously, and the Valt/Vt values kept increasing as well. Both the alternative pathway activity (pValt) and its contribution to Vt(pValt/Vt) also increased gradually before 12 h of aging, but kept constant from 12 h to 24 h. The time course of the endogenous ethylene production of the aged slices was similar to the changing trends of Valt and Valt/Vt, but different from those of pValt and pValt/Vt values. ACC and Cu2+ treatment which stimulated ethylene production of the aged slices enhanced their Valt and Valt/ Vt values, Co2+ and Ag+ treatment resulted in a decreased effect. However, all the above treatments of ethylene-related agents could not alter the continuously decreasing trend of the p value of the alternative pathway of the aged slices. And their effects on pValt, and pValt/V1 values were only observed before 12 h of aging. These results suggested that the endogenous ethylene was essential to the development of the capacity of alternative pathway, but could only slightly influence the operation of the activity of the alternative pathway in aged potato tuber slices.