贮藏温度对哈密瓜蔗糖代谢途径中14种酶活性的影响

为了系统研究哈密瓜在不同贮藏温度条件下的蔗糖积累和呼吸代谢情况，在不同贮藏温度（0、5、10、 15、20、25、30、35、40、45 ℃）测定哈密瓜外果皮、内果皮、外果肉、中果肉、内果肉5 个部位蔗糖、乳酸、呼 吸代谢途径中14 种酶的基因表达活性及其变化情况。结果表明：哈密瓜果实5 个部位中蔗糖转化酶和乳酸脱氢酶活 性最高，其活性大小依次为：内果皮＞外果肉＞外果皮＞中果肉＞内果肉；哈密瓜在5 ℃贮藏时，包括蔗糖转化酶 和乳酸脱氢酶的14 种酶的活性均处于最低水平，可见5 ℃可有效地控制蔗糖代谢，是哈密瓜的最适贮藏温度。

Effects of Different Storage Temperatures on the Activities of Fourteen Enzymes Involved in Sucrose Metabolism in Hami Melon

This study aimed to shed light on the respiratory metabolism and sucrose accumulation in Hami melon under
different storage conditions. The activities (gene expression levels) of fourteen enzymes involved in sucrose metabolism
were measured at different storage temperatures (0, 5, 10, 15, 20, 25, 30, 35, 40 and 45 ℃). These enzymes in the epicarp,
endocarp, outer pulp, middle pulp, inner pulp were investigated as well. The results showed that among these enzymes
examined, the activities of invertase and lactate dehydrogenase were the highest. The decreasing order of the two enzyme
activities in five tissues was as follows: endocarp ＞ outer pulp ＞ epicarp ＞ middle pulp ＞ inner pulp. When Hami melon
was stored at 5 ℃, the activities of all 14 enzymes were at a low level. Thus, 5 ℃ is the optimal storage temperature and
sugar metabolism can be controlled effectively at this temperature.