Kar R K, Choudhuri M A
Plant Physiology and Biochemistry Laboratory, Department of Botany, Burdwan University, Burdwan 713104, India.
Plant Physiol. 1986 Apr;80(4):1030-3. doi: 10.1104/pp.80.4.1030.
Light treatment markedly accelerated chlorophyll loss in Hydrilla (Hydrilla verticillata [L.f.] Royle) over dark treatment whereas such acceleration could not be observed in spinach (Spinacia oleracea L.) leaf segments. Spermine, a polyamine, retarded the loss of chlorophyll in the dark but markedly accelerated this loss in the light during senescence of Hydrilla leaves. However, such effect of spermine in the dark was not so pronounced in spinach. The loss of protein was slower in the light than in the dark in both the species. Spermine arrested the loss of protein (as in spinach) or even raised the protein level over initial (as in Hydrilla). Loss of both soluble and insoluble protein was slower in light than in darkness. Spermine treatment, either in light or darkness, markedly accelerated the loss of soluble protein but raised the level of insoluble protein over initial in both the species. The pattern of change in alpha-amino nitrogen in either species could be correlated well with that of protein level. In Hydrilla, light increased the soluble protein fraction over initial and this rise was prevented by cycloheximide and not by chloramphenicol. Also, spermine augmented the protease activity (both acid and neutral) while light retarded the rise in protease activity during senescence of either species. Although spermine treatment reduced the leaching of alpha-amino nitrogen and electrolytes in Hydrilla, it augmented the same in spinach.
与黑暗处理相比，光照处理显著加速了黑藻（Hydrilla verticillata [L.f.] Royle）中叶绿素的损失，而在菠菜（Spinacia oleracea L.）叶片切段中未观察到这种加速现象。精胺作为一种多胺，在黑暗中延缓了黑藻叶片衰老过程中叶绿素的损失，但在光照下却显著加速了这种损失。然而，精胺在黑暗中的这种作用在菠菜中并不那么明显。在这两个物种中，光照下蛋白质的损失都比黑暗中慢。精胺阻止了蛋白质的损失（如在菠菜中），甚至使蛋白质水平高于初始水平（如在黑藻中）。可溶性和不溶性蛋白质的损失在光照下都比黑暗中慢。精胺处理，无论在光照还是黑暗条件下，都显著加速了可溶性蛋白质的损失，但使两个物种中不溶性蛋白质的水平高于初始水平。两个物种中α-氨基氮的变化模式与蛋白质水平的变化模式密切相关。在黑藻中，光照使可溶性蛋白质部分高于初始水平，这种升高被环己酰亚胺阻止，而不是被氯霉素阻止。此外，精胺增强了蛋白酶活性（酸性和中性），而光照在两个物种叶片衰老过程中延缓了蛋白酶活性的升高。虽然精胺处理减少了黑藻中α-氨基氮和电解质的渗漏，但它在菠菜中却增加了这种渗漏。
