Molecular Biology and Genetic Engineering Division, Vasantdada Sugar Institute, Manjari (Bk), Pune, 412307, India.
Appl Biochem Biotechnol. 2014 Feb;172(4):1982-98. doi: 10.1007/s12010-013-0622-3. Epub 2013 Dec 7.
Sugarcane (Saccharum spp.) is a dynamic C4 polyploidy grass used as a major source of sucrose and an alternative for ethanol, food, and energy. Despite growing scientific interest, various sucrose metabolism regulatory aspects have been limited. Biochemical and gene expression studies were conducted on developmental stages, 240-420 days of planting (DAP) in mature leaves of three high and three low sucrose sugarcane cultivars. Sucrose synthase (SS) and sucrose phosphate synthase (SPS) activities were found to be remarkably higher at 240-360 DAP but decrease at 420 DAP. Twofold increases of SS activity was estimated at 240-360 DAP while SPS activity trend was found to be lower than the SS activity. In comparing SS and SPS activities with the brix of respective DAP, results show that these activities are significant and positively correlated with 'r' values of 0.69 and 0.68 for SS and SPS, respectively. However, the soluble acid invertase (SAI) and neutral invertase (NI) activities were found to decrease significantly with the maturity of cultivars, negatively correlating with brix at 'r' values 0.83 and 0.89 for SAI and NI, respectively. The antioxidant enzyme activity was modulated similar to the invertases activity. Of the six genes, ESAS 11 and 23 associated with sucrose accumulation and ESTS 34 and 41 associated with sugar transport in sugarcane were differentially expressed among the selected high and low sugarcane cultivars. Hence, these findings reinforce the selection of diverse sugarcane cultivars for gene expression studies targeting to quantitative traits and candidate marker determination.
甘蔗（Saccharum spp.）是一种动态的 C4 多倍体禾本科植物，被用作蔗糖的主要来源和乙醇、食品和能源的替代品。尽管人们对其越来越感兴趣，但各种蔗糖代谢调节方面的研究仍受到限制。对三个高糖和三个低糖甘蔗品种在成熟叶片中的发育阶段（种植后 240-420 天）进行了生化和基因表达研究。发现蔗糖合酶（SS）和蔗糖磷酸合酶（SPS）的活性在 240-360 DAP 时显著升高，但在 420 DAP 时降低。在 240-360 DAP 时，SS 活性估计增加了两倍，而 SPS 活性趋势低于 SS 活性。将 SS 和 SPS 活性与各自 DAP 的糖度进行比较，结果表明这些活性与“r”值呈显著正相关，分别为 0.69 和 0.68。然而，可溶性酸性转化酶（SAI）和中性转化酶（NI）的活性随着品种的成熟而显著下降，与糖度的相关性分别为“r”值为 0.83 和 0.89。抗氧化酶活性与转化酶活性相似。在这 6 个基因中，与蔗糖积累相关的 ESAS 11 和 23 以及与甘蔗中糖运输相关的 ESTS 34 和 41 在所选高糖和低糖甘蔗品种中表现出差异表达。因此，这些发现加强了对不同甘蔗品种的选择，以便针对数量性状和候选标记进行基因表达研究。
