The effect of nitrogen deficiency on leaf gas exchange and chlorophyll fluorescence parameters in sunflower
The effect of nitrogen deficiency on leaf gas exchange and chlorophyll fluorescence parameters in sunflower
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DOI：
10.1016/0168-9452(96)04442-1
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发表时间：
1996-08-16
期刊：
影响因子：
5.2
通讯作者：
Soldatini, GF
中科院分区：
文献类型：
--
作者：
Ciompi, S;Gentili, E;Soldatini, GF
向日葵（Helianthus annuus L.）在移植24天后，分析用完全或缺氮营养溶液生长的植株的气体交换和叶绿素荧光。在氮胁迫下，光合速率下降，气孔导度上升，胞间CO_2浓度增加（约+60%）。这表明A（max）（光饱和水平下的光合活性）的下降是由于与叶肉活性降低相关的限制，而不是气孔限制。在低光强下，PSII的光合效率不受影响。在氮胁迫植物叶片淀粉含量显着下降。蔗糖/淀粉比上升，在N-胁迫植物，表明碳分配的趋势已经转向蔗糖。这一结果与在氮胁迫植物中观察到的较低的茎/根比一致。
Fully expanded leaves of sunflower (Helianthus annuus L.) growing with either complete or nitrogen-deficient nutrition solution were analysed for gas exchange and chlorophyll fluorescence after 24 days from the transplanting. Under N-stress the decline in photosynthesis and the rise in stomatal conductance determined at light saturation level were accompanied by an increase of the intercellular CO2 concentration (about +60%). This indicates that the decline in A(max) (photosynthetic activity at light saturation level) was due to limitation related to a reduced mesophyllic activity, rather than to stomatal limitation. At low light intensity photosynthetic efficiency of PSII was not affected. In N-stressed plants starch content decreased significantly in leaves. The sucrose/starch ratio rose in N-stressed plants, indicating that the carbon partitioning trend had shifted towards sucrose. This result is in accordance with the lower shoot/root ratio observed in nitrogen-stressed plants.