Changes of Respiration, and the Contents of Ethylene, IAA and Peroxidase and Their Interrelationships During Senescence of Four Leafy Vegetables
Changes of Respiration, and the Contents of Ethylene, IAA and Peroxidase and Their Interrelationships During Senescence of Four Leafy Vegetables
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发表时间：
1988
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通讯作者：
Zhang Li
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作者：
Zhang Li
以大白菜（Brassica pekinensis）、结球甘蓝（Brassica oleracea L var capitata）、莴苣（Lactuca sativa L var capitata）和菠菜（Spinacia oleracea L var capitata）4种叶菜为试材，研究了不同叶位叶片呼吸强度、乙烯释放量、吲哚乙酸（IAA）水平和过氧化物酶活性与叶绿素（Chl）和可溶性蛋白质损失的关系。在光照条件下，用外源乙烯（4ppm）处理，观察了乙烯对叶片呼吸的影响，结果表明：叶片衰老过程中呼吸变化有两种模式：在叶绿素和可溶性蛋白质迅速损失的过程中，呼吸速率先上升，然后下降，如白菜、甘蓝和菠菜;在另一种情况下，呼吸速率保持不变，直到后期出现下降，就像在莴苣中观察到的那样。这两种类型的叶片对乙烯处理表现出不同的呼吸响应。在前者中，治疗导致更年期样上升提前发生，而不改变模式，而在后者中，治疗将下降模式改变为更年期样模式。这些反应分别与跃变型果实和非跃变型果实相似。在叶片衰老过程中，易衰老的大白菜和结球甘蓝，以及不易衰老的结球莴苣和菠菜乙烯产生量均呈现出类似跃变的模式，表明乙烯产生量的增加是叶片衰老的一般特征，而不限于衰老过程。在发育和衰老过程中，过氧化物酶活性升高，IAA含量下降。过氧化物酶活性与IAA含量呈显著负相关。IAA含量与乙烯产生量呈显著正相关，但在成熟和衰老叶片中，乙烯产生量增加，内源IAA含量下降。
Changes of respiration, ethylene production,indole-acetic acid (IAA) level, and peroxidaseactivity were followed in relation to the lossesof Chl and soluble proteins in leaves of differentpositions and during senescence of detachedmature leaves in darkness from four leafy ve-getables, Chinese cabbage (Brassica pekinensis),cabbage (Brassica oleracea L var capitata), headlettuce (Lactuca sativa L var capitata), and spinach(Spinacia oleracea). Treatment with exogenousethylene (4 ppm) in light was also conductedto observe the effect of ethylene on respiration.The results are summarized as follows: Two patterns of respiratory changes duringsenescence of the leaves were found.The respiration rate rose during rapid loss ofChl and soluble proteins, then declined, as wasobserved in Chinese cabbage, cabbage, andspinach. In the other, the respiration ratewas kept constant until at a later stagewhen a decline occurred, as was observed in headlettuce. These two types of leaves showed dif-ferent responses in respiration to the treatmentwith ethylene. In the former, the treatmentcaused the climacteric-like rise to occur earlierwithout changing the pattern, while in the lat-ter, the treatment changed the decline patterninto a climacteric-like one. These responseswere similar to those in climacteric and non-climacteric fruits respectively. Climacteric-like patterns in ethylene production were seenboth in Chinese cabbage and cabbage whichreadily abscise, and in head lettuce and spinachwhich hardly abscise during leaf senescence, in-dicating that the rise of ethylene production ischaracteristic of leaves senescence in general andis not restricted to abscission process. An in-crease in peroxidase activity and a decrease inIAA content were observed during developmentand senescence. A significant negative cor-relation was found to exist between the changesin peroxidase activity and in IAA content. Apositive correlation between IAA content andethylene production was observed in expandingleaves, but not in mature and senescing leaveswhere ethylene production increased but en-dogenous IAA level decreased.