EFFECTS OF WATER-STRESS ON THE GAS-EXCHANGE, THE ACTIVITIES OF SOME ENZYMES OF CARBON AND NITROGEN-METABOLISM, AND ON THE POOL SIZES OF SOME ORGANIC-ACIDS IN MAIZE LEAVES
EFFECTS OF WATER-STRESS ON THE GAS-EXCHANGE, THE ACTIVITIES OF SOME ENZYMES OF CARBON AND NITROGEN-METABOLISM, AND ON THE POOL SIZES OF SOME ORGANIC-ACIDS IN MAIZE LEAVES
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DOI：
10.1007/bf00035247
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发表时间：
1986-01-01
影响因子：
3.7
通讯作者：
FOCK, HP
中科院分区：
文献类型：
--
作者：
BECKER, TW;FOCK, HP
水分胁迫的玉米 (Zea mays L.) 叶片在光合作用过程中叶片电导率大幅下降。 CO2 净吸收和蒸发在轻度应激（.psi. = -0.6 至 -1.0 MPa）下快速下降，而在更严重的应激（.psi. = -1.0 至 -1.2 MPa）下下降较慢，而细胞间隙 (Ci) 中的 CO2 浓度并未下降至 CO2 补偿点。本研究中测试的光合碳代谢酶的活性下降了约。 .psi 时为 30%。 = -1.2 兆帕。谷氨酰胺合成酶活性不受水分胁迫影响，而硝酸还原酶活性几乎完全受到抑制。与 .psi 相关的酶活性下降。与受胁迫叶片的总可溶性蛋白含量的同时减少相关。苹果酸、丙酮酸和草酰乙酸的总叶池与.psi.几乎呈线性下降，因此明显与几乎恒定的Ci相矛盾。与对照（.psi. = 0.6 MPa）相比，柠檬酸盐和异柠檬酸盐的含量在.psi 下显着增加。 = -0.9 MPa，并在 .psi 下再次下降。 = -1.2 兆帕。
Water-stressed maize (Zea mays L.) leaves showed a large decrease in leaf conductance during photosynthesis. Net CO2 uptake and evaporation declined fast at mild stress (.psi. = -0.6 to -1.0 MPa) and slower at more severe stress (.psi. = -1.0 to -1.2 MPa), whereas the CO2 concentration in the intercellular spaces (Ci) did not drop to the CO2 compensation point. The activities of the enzymes of photosynthetic carbon metabolism tested in this study dropped by approx. 30% at .psi. = -1.2 MPa. Glutamine synthetase activity was unaffected by water stress, whereas the activity of nitrate reductase was almost completely inhibited. The decline of enzyme activities in relation to .psi. was correlated with a concomitant decrease in the content of total soluble protein of the stressed leaves. The total leaf pools of malate, pyruvate and oxaloacetate decreased almost linearly in relation to .psi., thus obviously contradicting the almost constant Ci. In comparison to the controls (.psi. = 0.6 MPa) the content of citrate and isocitrate increased markedly at .psi. = -0.9 MPa and decreased again at .psi. = -1.2 MPa.