Cooke R J, Oliver J, Davies D D
School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ England.
Plant Physiol. 1979 Dec;64(6):1109-13. doi: 10.1104/pp.64.6.1109.
Transfer of fronds of Lemna minor L. to adverse growth conditions or stress situations causes a lowering of the growth rate and a loss of soluble protein per frond, the extent of the loss being dependent on the nature of the stress. The loss or protein is due to two factors: (a) a decrease in the rate constant of protein synthesis (ks); (b) an increase in the rate constant of protein degradation (kd). In plants adapted to the stresses, protein synthesis increases and the initially rapid rate of proteolysis is reduced. Addition of abscisic acid both lowers ks and increases kd, whereas benzyladenine seems to alleviate the effects of stress on protein content by decreasing kd rather than by altering ks. Based on the measurement of enzyme activities, stress-induced protein degradation appears to be a general phenomenon, affecting many soluble proteins. The adaptive significance of stress-induced proteolysis is discussed.
将小浮萍的叶状体转移至不利的生长条件或胁迫环境中，会导致生长速率降低以及每片叶状体中可溶性蛋白质的损失，损失程度取决于胁迫的性质。蛋白质的损失归因于两个因素：(a) 蛋白质合成速率常数 (ks) 的降低；(b) 蛋白质降解速率常数 (kd) 的增加。在适应胁迫的植物中，蛋白质合成增加，最初快速的蛋白水解速率降低。脱落酸的添加既降低了ks 又增加了kd，而苄基腺嘌呤似乎是通过降低kd 而非改变ks 来减轻胁迫对蛋白质含量的影响。基于酶活性的测定，胁迫诱导的蛋白质降解似乎是一种普遍现象，会影响许多可溶性蛋白质。文中讨论了胁迫诱导蛋白水解的适应性意义。
