The role of sink demand in carbon partitioning and photosynthetic reinvigoration following shoot decapitation
The role of sink demand in carbon partitioning and photosynthetic reinvigoration following shoot decapitation
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库需求在枝条断头后碳分配和光合作用恢复中的作用
DOI：
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发表时间：
1989
期刊：
影响因子：
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通讯作者：
T. Blake
中科院分区：
文献类型：
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作者：
T. Tschaplinski;T. Blake
为了确定碳分配与光合作用的关系，比较了生长旺盛的林地上部和生长较慢的黑杨完整地上部的光合作用、生长和碳分配。丛枝的相对高度增长速率是完整枝的2.2倍，净光合作用速率是完整枝的1.9倍。追逐4h后，铜绿叶输出新固定同化物的比例较大(11%比6%)。从灌木树叶输出的更多，与[14C]标记的光合作用产物以淀粉形式沉积在标记施放点下方4厘米的茎中的比例更大相关。铜绿叶的同化物水平下降到完整植株叶片的15%，但铜绿叶的蔗糖浓度是标记蔗糖的两倍。在幼嫩枝条中，碳水化合物占可溶性[14C]标记的光合作用产物的55%，而完整枝条中这一比例为40%。研究结果表明，云杉地上部的碳分配和分配向新同化物的生产和输出转变，并支持光合作用速率对同化物的库需求作出响应的假说。
Photosynthesis, growth, and carbon partitioning of vigorous coppice shoots were compared with the slower growing intact shoots of Populus maximowiczii×nigra L. MN9 to determine the relationship between carbon partitioning and photosynthetic rate. Relative height growth rate of coppice shoots was 2.2 times that of intact shoots with net photosynthetic rate 1.9 times that of intact shoots. Coppice leaves exported a larger proportion of newly-fixed assimilate (11% compared with 6%) after a 4-h chase. The greater export from coppice leaves was correlated with a greater proportion of [14C]-labelled photosynthate deposited as starch in stems 4 cm below the point of label application. Coppice leaf assimilate levels were reduced to 15% that of leaves on intact plants, but coppice leaves had twice the concentration of labelled sucrose. Carbohydrates constituted 55% of the water-soluble [14C]-labelled photosynthate in leaves of coppice shoots compared with 40% in intact shoots. The results suggest that carbon allocation and partitioning in coppice shoots were altered towards production and export of new assimilate, and support the hypothesis that photosynthetic rate is responsive to sink demand for assimilates.