Regulation of Diurnal Carbohydrate Reserves and Translocation

昼夜碳水化合物储备为叶子提供碳供出口 在夜间和光合作用低的时候， 保持不间断的碳供应， 光合作用植物结构，用于生长、储存和 新陈代谢. 在一些植物中，如甜菜和大豆， 昼夜储备以淀粉的形式存在，而在其他植物中， 像蚕豆和菠菜一样，蔗糖积累。 的目标 我们的计划是系统地确定（1）碳如何 蔗糖和淀粉的分配和出口一起是 以一种方式调节，使昼夜碳水化合物储备增加， 离开并调节全天的当前出口率- 光合作用如何同化碳， 当出口受到限制或 光合作用增加，无论是在植物中积累蔗糖， 和那些没有的人 我们将衡量出口率的变化， 两种类型叶片的酶活性和代谢产物水平 当碳分配通过延长一天而改变时， 缩短了前一天晚上。 限制的方式 在接受国， 器官或增加光合作用通过提高二氧化碳的影响 光合作用和碳水化合物的积累将在 贮藏蔗糖和淀粉的植物。

Diurnal carbohydrate reserves provide leaves with carbon for export at night and during times of low photosynthesis, thereby maintaining an uninterrupted supply of carbon to non- photosynthesizing plant structures for growth, storage and metabolism. In some plants, like sugar beet and soybean, the diurnal reserve takes the form of starch, while in other plants, like fava bean and spinach, sucrose accumulates. The objectives of our program are to identify systematically (1) how carbon apportionment to sucrose and starch and of export together are regulated in a way that furnishes a diurnal carbohydrate reserve to leaves and regulates the current rate of export throughout the day- night cycle and (2) how photosynthetic carbon assimilation, carbon allocation and export interact when export is restricted or photosynthesis is increased, both in plants that accumulate sucrose and those that do not. We will measure changes in export rates, enzyme activities and metabolite levels in leaves of the two types of plants when carbon allocation is changed by extending the day or shortening the previous night. The ways in which restricting export by chilling-induced slowing of metabolism in the receiving organs or of increasing photosynthesis by raising CO2 affects photosynthesis and carbohydrate accumulation will be compared in sucrose-storing and starch storing plants.