CORRELATION BETWEEN THE CARBON ISOTOPE DISCRIMINATION IN LEAF STARCH AND SUGARS OF C-3 PLANTS AND THE RATIO OF INTERCELLULAR AND ATMOSPHERIC PARTIAL PRESSURES OF CARBON-DIOXIDE
CORRELATION BETWEEN THE CARBON ISOTOPE DISCRIMINATION IN LEAF STARCH AND SUGARS OF C-3 PLANTS AND THE RATIO OF INTERCELLULAR AND ATMOSPHERIC PARTIAL PRESSURES OF CARBON-DIOXIDE
复制标题
DOI：
10.1104/pp.88.4.1418
复制
发表时间：
1988-12-01
期刊：
影响因子：
7.4
通讯作者：
FARQUHAR, GD
中科院分区：
文献类型：
--
作者：
BRUGNOLI, E;HUBICK, KT;FARQUHAR, GD
对叶淀粉和可溶性糖中的碳同位素判别（Δ）进行了分析，它们代表了近期固定的大部分碳。将三种C3植物（黑杨×美洲黑杨、陆地棉和菜豆）置于黑暗中24小时以降低叶片中淀粉和糖的含量。然后在恒定条件下进行8小时的气体交换测量，随后提取淀粉和可溶性糖以分析碳同位素组成。根据气体交换测量结果计算细胞间二氧化碳分压（pi）与大气二氧化碳分压（pa）的比值，对时间进行积分并根据同化速率加权，以便与可溶性糖和淀粉中的碳同位素比值进行比较。在所有物种中，可溶性糖中的碳同位素判别与pi/pa密切相关（r = 0.93），叶淀粉中的Δ也是如此（r = 0.84）。发现淀粉比可溶性糖含有显著更多的13C，并对可能的解释进行了讨论。Δ与pi/pa之间的强相关性表明，叶淀粉和可溶性糖中的碳同位素分析可用于间接监测一天内按二氧化碳同化速率加权的pi/pa平均值。由于pi/pa与离体植物的蒸腾效率（摩尔CO2/摩尔H2O）呈负相关，淀粉和糖中的Δ可用于预测这种效率的差异。这种新方法可能在生态生理学研究以及C3植物育种计划中提高蒸腾效率的选择方面有用。
Carbon isotope discrimination (.DELTA.) was analyzed in leaf starch and soluble sugars, which represent most of the recently fixed carbon. Plants of three C3 species (Populus nigra L. .times. P. deltoides Marsh., Gossypium hirsutum L. and Phaseolus vulgaris L.) were kept in the dark for 24 hours to decrease contents of starch and sugar in leaves. Then gas exchange measurements were made with constant conditions for 8 hours, and subsequently starch and soluble sugars were extracted for analysis of carbon isotope composition. The ratio of intercellular, pi and atmospheric, pa, partial pressures of CO2, was calculated from gas exchange measurements, integrated over time and weighted by assimilation rate, for comparison with the carbon isotope ratios in soluble sugars and starch. Carbon isotope discrimination in soluble sugars correlated strongly (r = 0.93) with pi/pa in all species, as did .DELTA. in leaf starch (r = 0.84). Starch was found to contain significantly more 13C than soluble sugar, and possible explanations are discussed. The strong correlation found between .DELTA. and pi/pa suggests that carbon isotope analysis in leaf starch and soluble sugars may be used for monitoring, indirectly, the average of pi/pa weighted by CO2 assimilation rate, over a day. Because pi/pa has a negative correlation with transpiration efficiency (mol CO2/mol H2O) of isolated plants, .DELTA. in starch and sugars may be used to predict differences in this efficiency. This new method may be useful in ecophysiological studies and in selection for improved transpiration efficiency in breeding programs for C3 species.