Stomatal and non-stomatal limitations of photosynthesis under water stress in field-grown grapevines
Stomatal and non-stomatal limitations of photosynthesis under water stress in field-grown grapevines
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DOI：
10.1071/pp99019
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发表时间：
1999-01-01
期刊：
影响因子：
--
通讯作者：
Medrano, H
中科院分区：
文献类型：
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作者：
Escalona, JM;Flexas, J;Medrano, H
在田间种植的葡萄中，长期诱导的水分胁迫导致气孔导度逐渐下降，并伴随着CO2同化的减少（40%）。表观量子产率也降低（59%），这可能反映了电子消耗替代工艺的相对增加。从饱和CO2条件下与有限的二磷酸核酮糖（RuBP）再生相关的最大光合速率显著耗耗（37%）判断，也有向非气孔调节的转变，而对羧化效率的影响很小，不显著。所有实验数据均显示光合作用与气孔导度之间存在高度相关（87%），细胞间CO2浓度的下降与气孔导度的降低平行。结果表明，葡萄对土壤水分亏缺增加的田间响应涉及气孔和非气孔效应，但由于干旱的逐渐诱导，叶肉容量的调节机制能够调节平均CO2供给量。非气孔调节似乎主要在与RuBP再生相关的代谢途径中发挥作用。对两个品种进行了性状对比。丹魄成功地利用了无压力条件，而曼托内格罗则表现出更高的内在水利用效率，特别是在低水可用性条件下。这种优势似乎是由于较低的非气孔限制。
Long-term induced water stress in field-grown grapevine leads to a progressive decline of stomatal conductance, accompanied by a decrease in CO2 assimilation (40%). The apparent quantum yield also decreases (59%), which may reflect a relative increase in alternative processes for electron consumption. There is also a shift to non-stomatal regulation, as judged from significant depletions (37%) in maximum photosynthesis rate at saturating CO2 related to limited ribulose biphosphate (RuBP) regeneration, whereas small, non-significant effects are observed on carboxylation efficiency. A high correlation (87%) between photosynthesis and stomatal conductance is observed for all experimental data and declines in intercellular CO2 concentration parallel reductions in stomatal conductance. The data show that field response of grapevines to increasing soil water deficit involves stomatal and non-stomatal effects but, due to gradually induced drought, regulation mechanisms able to adjust mesophyll capacity to the average CO2 supply. The non-stomatal adjustment seems to be exerted mainly in metabolic pathways related with the RuBP regeneration. Contrasting characteristics were observed for both cultivars. Tempranillo exploited the non-stressful conditions successfully, whereas Manto Negro, responding to its reputation as more drought resistant, showed a higher intrinsic water use efficiency, particularly for low water availability. This advantage seems to be due to lower non-stomatal limitations.