CARBON-ISOTOPE COMPOSITION OF BIOCHEMICAL FRACTIONS AND THE REGULATION OF CARBON BALANCE IN LEAVES OF THE C-3-CRASSULACEAN ACID METABOLISM INTERMEDIATE CLUSIA-MINOR L GROWING IN TRINIDAD
CARBON-ISOTOPE COMPOSITION OF BIOCHEMICAL FRACTIONS AND THE REGULATION OF CARBON BALANCE IN LEAVES OF THE C-3-CRASSULACEAN ACID METABOLISM INTERMEDIATE CLUSIA-MINOR L GROWING IN TRINIDAD
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DOI：
10.1104/pp.106.2.493
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发表时间：
1994-10-01
期刊：
影响因子：
7.4
通讯作者：
MAXWELL, C
中科院分区：
文献类型：
--
作者：
BORLAND, AM;GRIFFITHS, H;MAXWELL, C
碳同位素比（δ（13）Cs）进行了测量，从自然暴露和阴影的C-3-景天科酸代谢（CAM）中间Clusia小，在黎明和黄昏采样天在特立尼达的雨季和旱季的叶子定量提取的各种生化组分。由于CAM的活性增加响应水的可用性降低和较高的光子通量密度，有机酸和可溶性糖富集在C-13约3.5至4千分之一的植物相比，在雨季采样。CAM的诱导伴随着储备碳水化合物库的大小加倍。此外，化学计量的测量表明，叶绿体储备和可溶性糖的降解是必要的，以提供磷酸烯醇式丙酮酸在夜间合成的有机酸。结果还表明，在叶片中存在两个可溶性糖库。一个是富含C-13的液泡池，第二个是C-13耗尽的运输池。在CAM过程中表达的碳同位素歧视的估计，来自无机碳，有机酸和碳水化合物池之间的运输过夜，范围从0.9至3.1千分之一。结构物质的δ（13）C在雨季和旱季之间没有显著变化，表明用于生长的大部分碳来自C-3羧化。
Carbon-isotope ratios (delta(13)Cs) were measured for various biochemical fractions quantitatively extracted from naturally exposed and shaded leaves of the C-3-Crassulacean acid metabolism (CAM) intermediate Clusia minor, sampled at dawn and dusk on days during the wet and dry seasons in Trinidad. As the activity of CAM increased in response to decreased availability of water and higher photon flux density, organic acids and soluble sugars were enriched in C-13 by approximately 3.5 to 4 parts per thousand compared to plants sampled during the wet season. The induction of CAM was accompanied by a doubling in size of the reserve carbohydrate pools. Moreover, stoichiometric measurements indicated that degradation of both chloroplastic reserves and soluble sugars were necessary to supply phosphoenolpyruvate for the synthesis of organic acids at night. Results also suggest that two pools of soluble sugars exist in leaves of C. minor that perform CAM, one a vacuolar pool enriched in C-13 and the second a transport pool depleted in C-13. Estimates of carbon-isotope discrimination expressed during CAM, derived from the trafficking among inorganic carbon, organic acids, and carbohydrate pools overnight, ranged from 0.9 to 3.1 parts per thousand. The delta(13)C of structural material did not change significantly between wet and dry seasons, indicating that most of the carbon used in growth was derived from C-3 carboxylation.