Department of Botany and Plant Pathology, Iowa State University, Ames, Iowa 50010.
Plant Physiol. 1972 Dec;50(6):655-9. doi: 10.1104/pp.50.6.655.
The possible role of pectin esterase in abscission of bean and coleus leaves was re-examined using improved methods for its extraction. Its possible role in abscission of flowers of tobacco and leaves of soybean. cotton, mulberry, magnolia, and euonymus was also examined. In seven of the eight species, no detectable changes in abscission zone pectin esterase activities immediately preceded abscission. Therefore, pectin esterase probably plays no causal role in abscission in these species.In coleus, activity in the abscission zone's distal portion decreased by one-half at most and remained unchanged in its proximal portion with abscission's onset. Also accompanying abscission in coleus was a decrease in the proportion of abscission zone pectin esterase extractable with 3 m sodium chloride at pH 7. These changes were not a general concomitant of senescence as they were not detected in the middle of abscising coleus petioles. Pectin esterase may play a role in coleus leaf abscission.
使用改进的提取方法，重新研究了果胶酯酶在豆科和长春花属叶片脱落中的可能作用。还研究了果胶酯酶在烟草花和大豆、棉花、桑树、玉兰和卫矛叶片脱落中的可能作用。在这 8 个物种中的 7 个中，在脱落前没有检测到可检测到的脱落区果胶酯酶活性的变化。因此，果胶酯酶在这些物种的脱落中可能不起因果作用。在长春花中，脱落区远侧部分的活性最多减少一半，而近侧部分的活性在脱落开始时保持不变。伴随长春花脱落的还有脱落区果胶酯酶可在 pH7 下用 3M 氯化钠提取的比例下降。这些变化不是衰老的一般伴随物，因为在脱落中的长春花叶柄中间没有检测到这些变化。果胶酯酶可能在长春花叶片脱落中起作用。
