Kerr P S, Rufty T W, Huber S C
United States Department of Agriculture, Agricultural Research Service, North Carolina State University, Raleigh, North Carolina 27695-7631.
Plant Physiol. 1985 Jul;78(3):576-81. doi: 10.1104/pp.78.3.576.
Diurnal patterns of nonstructural carbohydrate (starch, sucrose, and hexose sugars) concentration were characterized in different parts (leaves, petioles, stems, and roots) of vegetative soybean (Glycine max [L.] Merr.) plants. Pronounced changes in all carbohydrate pools were observed in all plant parts during the normal photosynthetic period; however, starch accumulation within leaves accounted for more than 80% of the nonstructural carbohydrate accumulated by the plant during the light period. Efficiency of utilization of starch and sucrose during the normal dark period differed among organs, with leaves being most efficient in mobilizing starch reserves and roots being most efficient in utilizing sucrose reserves. The vast majority (about 85%) of the whole plant carbohydrate reserves present at the end of the photosynthetic period were utilized during the normal dark period. Sink leaf expansion ceased in plants transferred to extended darkness and the cessation in leaf expansion corresponded with carbohydrate depletion in the subtending source leaf and the remainder of the plant. Collectively, the results indicated that under the conditions employed, leaves are the whole plant's primary source of carbon at night as well as during the day.
对营养期大豆（Glycine max [L.] Merr.）植株不同部位（叶片、叶柄、茎和根）非结构性碳水化合物（淀粉、蔗糖和己糖）浓度的日变化模式进行了表征。在正常光合作用期间，所有植株部位的所有碳水化合物库均出现了显著变化；然而，叶片内淀粉积累量占植株在光照期积累的非结构性碳水化合物的80%以上。在正常黑暗期，淀粉和蔗糖在各器官中的利用效率有所不同，叶片在调动淀粉储备方面效率最高，而根在利用蔗糖储备方面效率最高。光合期结束时植株中存在的绝大多数（约85%）碳水化合物储备在正常黑暗期被利用。转移到延长黑暗条件下的植株中，库叶扩展停止，叶片扩展停止与下方源叶及植株其他部分的碳水化合物耗尽相对应。总体而言，结果表明，在所采用的条件下，叶片在白天和夜间都是植株的主要碳源。
