Effects of water stress and high temperature on photosynthetic rates of two species of Prosopis
Effects of water stress and high temperature on photosynthetic rates of two species of Prosopis
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DOI：
10.1016/j.jphotobiol.2008.04.004
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发表时间：
2008-08-21
影响因子：
5.4
通讯作者：
Cardemil, Liliana
中科院分区：
文献类型：
--
作者：
Delatorre, Jose;Pinto, Manuel;Cardemil, Liliana
本研究的主要目的是比较辣椒和罗望鱼两种植物在高温和水分胁迫下的光合作用响应，以确定热休克或水分亏缺对这两种植物光合作用的影响。以光补偿点、光饱和点、最大光合作用速率、量子效率和暗呼吸速率为指标，测定了罗望子和海藻幼苗在-0.3和-2.5 Mpa水势和25℃、35℃和40℃三种温度下的光合作用速率与光量子流密度(PFD)的关系。还测定了热激、水分亏缺以及两者联合作用下的光化学效率，如F-v/F-m比值和Rubisco的含量。在相同的水势下，在25℃的温度下，当光强大于500亩摩尔光子m(-2)、S(-1)时，不同物种之间的光合速率没有显著差异(P>；0.05)。两种藻类的最大光合作用速率均随温度升高而降低，藻类的最大光合速率随水分亏缺而降低。在40℃、-2.5 Mpa条件下，藻罗巴的光合作用速率下降到罗望子的72%。赤潮藻的量子产率随着温度和水分的亏缺而降低，在40℃和-2.5 Mpa的条件下，量子产率下降了50%。在40摄氏度时，罗望子的暗呼吸比对照增加了62%，而藻罗巴的暗呼吸保持不变。光化学效率随温度升高和水分亏缺而降低，种间差异不明显。在35℃的温度下，海藻的Rubisco含量增加。水分亏缺降低了两种植物的Rubisco含量。这项工作的结果支持了这样的结论：在两个物种中，高温和水分亏缺之间的相互作用对光合作用响应的影响大于每个个体的胁迫，并且这种相互作用在藻类中比在罗望子中更明显。(C)2008爱思唯尔B.V.保留所有权利。
The main aim of this research was to compare the photosynthetic responses of two species of Prosopis, Prosopis chilensis (algarrobo) and Prosopis tamarugo (tamarugo) subjected to heat and water stress, to determine how heat shock or water deficit, either individually or combined, affect the photosynthesis of these two species. The photosynthetic rates expressed as a function of photon flow density (PFD) were determined by the O-2 liberated, in seedlings of tamarugo and algarrobo subjected to two water potentials: -0.3 MPa and -2.5 MPa and to three temperatures: 25 degrees C, 35 degrees C and 40 degrees C. Light response curves were constructed to obtain light Compensation and light saturation points, maximum photosynthetic rates, quantum yields and dark respiration rates. The photochemical efficiency as the F-v/F-m ratio and the amount of RUBISCO were also determined under heat shock, water deficit, and under the combined action of both stress. Photosynthetic rates at a light intensity higher than 500 mu mole photons m(-2) s(-1) were not significantly different (P > 0.05) between species when measured at 25 degrees C under the same water potential. The maximum photosynthetic rates decreased with temperature in both species and with water deficit in algarrobo. At 40 degrees C and -2.5 MPa, the photosynthetic rate of algarrobo fell to 72% of that of tamarugo. The quantum yield decreased in algarrobo with temperature and water deficit and it was reduced by 50% when the conditions were 40 degrees C and -2.5 MPa. Dark respiration increased by 62% respect to the control at 40 degrees C in tamarugo while remained unchanged in algarrobo. The photochemical efficiency decreased with both, high temperature and water deficit, without differences between species. RUBISCO content increased in algarrobo 35 degrees C. Water deficit reduced the amount of RUBISCO in both species. The results of this work support the conclusion that in both Prosopis species, the interaction between high temperature and water deficit affects photosynthesis responses greater than each individual stress, and that the interactive effect is more pronounce in algarrobo than in tamarugo. (c) 2008 Elsevier B.V. All rights reserved.