Temporal and Spatial Variations of Carbohydrate Content in Rice Leaf Sheath and Their Varietal Differences
Temporal and Spatial Variations of Carbohydrate Content in Rice Leaf Sheath and Their Varietal Differences
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DOI：
10.1626/pps.8.546
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发表时间：
2005-01
影响因子：
2.5
通讯作者：
Hai He;M. Koike;T. Ishimaru;R. Ohsugi;T. Yamagishi
中科院分区：
文献类型：
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作者：
Hai He;M. Koike;T. Ishimaru;R. Ohsugi;T. Yamagishi
摘要水稻抽穗前叶鞘中积累的碳水化合物向籽粒转运，对产量形成有重要影响。为阐明水稻叶鞘碳水化合物代谢的内在机制，研究了水稻叶鞘碳水化合物代谢的时空变化及其品种间差异。结果表明，不同品种和不同发育阶段的甘薯叶片中碳水化合物的含量从叶鞘基部到顶端呈递减趋势。但叶鞘基部1/5处的淀粉含量占整个叶鞘淀粉含量的比例因品种而异，在35%~ 60%之间。比较IR 65598 -112-2（新株型）和日本晴叶鞘基部、中部和顶端淀粉代谢相关酶活性，发现ADP-葡萄糖焦磷酸化酶、分支酶和颗粒结合淀粉合成酶（GBSS）活性存在品种间差异。特别是GBSS活性可能在叶鞘淀粉含量空间变异的品种间差异中起重要作用。在IR 65598 -112-2中，叶鞘中的蔗糖含量极高，表明蔗糖可能是该品系碳水化合物储备之一。
Abstract In rice plant, carbohydrates accumulated in leaf sheaths before heading are translocated to grain and affect yield formation greatly. To clarify the intrinsic mechanism of carbohydrate metabolism in the leaf sheath, we investigated the temporal and spatial variations of carbohydrate metabolism in the third leaf sheath counted from the top and their varietal differences. The results revealed that the amount of carbohydrate decreased from the base to the tip of the leaf sheath, irrespective of variety and developmental stage. However, the proportion of starch content in the basal one-fifth of the leaf sheath to that in the whole sheath varied from 35% to 60% with the variety. Comparing the activities of enzymes related to starch metabolism at the base, middle and tip of the leaf sheath in IR65598-112-2 (New plant type) with those in Nipponbare, the activities of ADP-glucose pyrophosphorylase, branching enzyme and granule-bound starch synthase (GBSS) showed varietal differences. Particularly, the activity of GBSS may play an important role in the varietal difference in spatial variation of starch content in the leaf sheath. In IR65598-112-2, the sucrose content in the leaf sheath was extremely high, suggesting that sucrose may be one of the carbohydrate reserves in this line.