高、低糖甘蔗品种叶片转化酶活性与蔗糖代谢关系研究

甘蔗是一种重要的经济作物，在全球蔗糖生产中占主导地位。当前研究者们正致力于通过揭示蔗糖代谢的复杂性而提高蔗茎蔗糖分。为研究探讨甘蔗工艺成熟期不同阶段早熟（高糖）品种和晚熟（低糖）品种的叶片转化酶活性，测定了早熟和晚熟甘蔗品种光合作用很强的第3叶的可溶性酸性转化酶、中性转化酶活性以及叶片酸性转化酶与中性转化酶活性。结果表明，低糖甘蔗品种叶片的酸性转化酶活性较高，而中性转化酶活性较低。相关分析结果表明，叶片酸性转化酶活性与蔗糖分呈负相关，而与己糖含量呈正相关；相反，叶片中性转化酶与蔗糖分呈正相关，与己糖含量呈负相关。研究结果说明，不管甘蔗品种的熟性表现如何，其叶片转化酶在甘蔗糖分调节中均起主导作用。

Relationship between invertase (s) activity and sucrose metabolism in the leaves of high and low sugar cultivars of sugarcane (Saccharum officinarum L.)

Sugarcane (Saccharum spp. hybrids) is an important commercial crop and accounts for major global sucrose production. Nowadays consistent efforts are being made to increase sucrose content in cane through unravelling its metabolic complexities. This study was aimed at investigating the activity of foliar invertase (s) in the early maturing (high sugar) and late maturing (low sugar) sugarcane cultivars at various stages of cane maturation. In the present investigation, soluble acid invertase (SAI) and neutral invertase (NI) activities were determined in the photosynthetically active third leaf of early and late maturing sugarcane cultivars. The results showed a higher foliar SAI activity and lower NI activity in low sugar accumulating cultivars. The nature of association was also determined between specific activities of SAI/NI and sugar content. A negative correlation between SAI activity and sucrose concentration was noticed whereas there was a positive correlation between hexose content and SAI activity in the leaf. In contrast, a positive correlation between NI and sucrose level and negative correlation between NI and hexose was observed. Our results indicated that the foliar invertases, also play an essential role in regulation of sugar content in sugarcane, irrespective of their maturity behavior.