Farrar J F
School of Plant Biology, University College of North Wales, Bangor, Gwynedd, UK.
Symp Soc Exp Biol. 1988;42:203-35.
The partitioning of carbon within sources and sinks, and its transport between them, is considered in relation to temperature. The characteristic accumulation of non-structural carbohydrates in both sources and sinks at low temperature is due partly to growth being more sensitive than photosynthesis to reductions in temperature, and partly to the differential sensitivity that enzymes of carbohydrate metabolism show to temperature. Translocation in the phloem is reduced by low temperature, due partly to viscosity and partly, possibly, to displacement of the contents of sieve elements; cooling slowly has much less effect than cooling rapidly. Partitioning in the whole plant has two partial processes: acquisition, the rate of import into a sink region, and allocation, the proportional distribution of assimilate between two or more competing sinks. Each of these can be affected by temperature treatment of the sink, of the source, or of the transport path. Allocation between the two halves of a barley root system held at different temperatures could not be explained by effects of temperature on metabolism, sucrose uptake or viscosity of transport in phloem.
碳在源和库中的分配及其在它们之间的运输，是与温度相关联来考虑的。在低温下，源和库中均会积累非结构性碳水化合物，其特征性积累部分是由于生长比光合作用对温度降低更敏感，部分是由于碳水化合物代谢酶对温度表现出的差异敏感性。低温会降低韧皮部中的运输，部分原因是粘度，部分可能是由于筛管分子内容物的移位；缓慢冷却的影响远小于快速冷却。整株植物中的分配有两个部分过程：获取，即进入库区域的输入速率，以及分配，即同化物在两个或多个竞争库之间的比例分布。这些过程中的每一个都可能受到对库、源或运输路径进行温度处理的影响。处于不同温度下的大麦根系两半之间的分配，无法用温度对代谢、蔗糖吸收或韧皮部运输粘度的影响来解释。
