不同成熟度烟叶采后抗氧化能力和能量代谢研究

Study on Antioxidant Capacity and Energy Metabolism of Postharvest Tobacco Leaves with Different Maturity

为探究抗氧化能力和能量代谢在采后烟叶颜色变化中的作用,准确把握和理解采收成熟度,在自然条件下采用暗箱试验测定了不同成熟度采后烟叶的变黄程度、变褐程度、变黄指数、变褐指数、丙二醛(MDA)含量、浸出液电导率、抗氧化酶(SOD、POD、CAT)活性、能量相关物质(ATP、ADP和AMP)含量、能荷和呼吸代谢酶(CCO和SDH)活性。结果表明,随着采收成熟度的提高,采后烟叶变黄变褐发展更快,在试验期间的抗氧化酶(SOD、POD、CAT)和能量代谢酶(SDH、CCO)高活性时间持续更短。同时,高成熟度采后烟叶在试验中MDA含量和浸出液电导率更较高,且ATP含量高峰出现较早,ATP含量和能荷在试验期间保持高水平的持续时间更短。低成熟度采后烟叶变黄变褐发展更缓慢可能与其较高抗氧化能力和能量代谢有关。

for accurately grasping and understanding harvest maturity and explore the role of antioxidant capacity and energy metabolism in postharvest tobacco leaf discoloration,the harvested tobacco leaves were placed in a dark environment.The changes of yellowing,browning,MDA content,conductivity of leaching solution,adenosine triphosphate(ATP)content,adenosine diphosphate(ADP)content,adenosine triphosphate(AMP)content,energy charge(EG)and activities of superoxide dismutase(SOD),peroxidase(POD),catalase(CAT),succinate dehydrogenase(SDH)and cytochrome oxidase(CCO)of samples were determined during the experiment.With the increase of harvest maturity,the yellowing and browning of postharvest tobacco leaves started earlier and developed faster.During the test,the antioxidant enzymes(SOD,POD,CAT)and energy metabolism enzymes(SDH,CCO)were highly active.At the same time,the high-maturity postharvest tobacco leaves had higher MDA content and leachate conductivity in the experiment,and the ATP content peak appeared earlier,and the ATP content and energy charge remained high during the experiment for a shorter period of time.These results indicated that the slower development of yellowing and browning of tobacco leaves after harvest at low maturity may be related to higher antioxidant capacity and energy metabolism.