6-BA处理对采后西兰花呼吸途径及能量水平的影响

Effect of 6-Benzylaminopurine on the Respiratory Pathway and Energy Level in Postharvest Broccoli

摘要:

为了研究6-苄氨基嘌呤（6-BA）处理对采后西兰花呼吸途径及其能荷水平的影响，本试验以清水浸泡为对照，以30 mg/L 6-BA浸泡为处理，在（15±1） ℃，相对湿度90%~95%的条件下，研究了6-BA处理对采后西兰花外观品质，总呼吸强度，呼吸途径如三羧酸循环途径（TCA）、磷酸戊糖途径（PPP）、细胞色素（CP）途径和交替途径（AP）的改变，超氧阴离子（O2-?）的积累，一磷酸腺苷（AMP）、二磷酸腺苷（ADP）、三磷酸腺苷（ATP）含量及能荷的影响。结果表明，6-BA处理延缓了西兰花褪绿黄化，可显著降低采后西兰花的总呼吸强度、CP和PPP的活性，提高了AP的表达量。另外，在贮藏后期（6~10 d），6-BA处理降低了西兰花组织TCA运行比例，促进了采后西兰花组织内ATP含量的积累及延缓能荷值的下降，从而抑制了组织内O2-?的积累。因此，6-BA处理对采后西兰花衰老的抑制作用可能与其对组织呼吸途径的调控及能量平衡的维持有关。

Abstract:

To explore the effect of 6-benzylaminopurine (6-BA) treatment on the respiratory pathway and energy level in postharvest broccoli florets, samples were treated with water (as the control) and with 30 mg/L 6-BA, respectively, and then stored at (15±1) ℃ and 90%~95% relative humidity. The effect of 6-BA treatment on the exterior quality, total respiration intensity, the change of respiratory pathways, including Krebs cycle (TCA) pathway, pentose phosphate pathway (PPP), cytochrome pathway (CP), and alternate pathway (AP), the accumulation of superoxide anion, as well as the levels of adenosine monophosphate (AMP), adenosine diphosphate (ADP), and adenosine triphosphate (ATP), and the energy status in postharvest broccoli florets were investigated. The results showed that 6-BA treatment delayed the yellowing of broccoli, significantly decreased the total respiration intensity and the activities of CP and PPP, and increased the expression level of AP. In addition, in the late stage of storage (six to ten days), 6-BA treatment reduced the proportion of TCA activity, promoted the accumulation of ATP, and delayed the decrease in the level of energy charge in postharvest broccoli, inhibiting the accumulation of superoxide anion in postharvest broccoli florets. Thus, the inhibitory effect of 6-BA on the senescence of postharvest broccoli florets might be associated with the regulation of respiratory pathways and the maintenance of energy balance in the broccoli tissues.