Studies of the relationship between isoprene emission rate and CO2 or photon‐flux density using a real‐time isoprene analyser
Studies of the relationship between isoprene emission rate and CO2 or photon‐flux density using a real‐time isoprene analyser
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使用实时异戊二烯分析仪研究异戊二烯排放速率与 CO2 或光子通量密度之间的关系
DOI：
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发表时间：
1991
期刊：
影响因子：
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通讯作者：
R. Fall
中科院分区：
文献类型：
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作者：
R. Monson;A. Hills;P. Zimmerman;R. Fall
抽象的。使用最近开发的在线异戊二烯分析仪与气体交换系统和叶绿素荧光计相结合，研究了异戊二烯发射率随光子通量密度和二氧化碳分压变化的变化。变暗后，白杨（Populus tremuloides Michaux.）叶子的异戊二烯排放速率立即开始下降，这表明异戊二烯或其前体的内部库很小，并且瞬时排放速率与合成速率紧密耦合。在变暗后 5 分钟内观察到异戊二烯的照明后爆发，并在所检查的四种异戊二烯发射物种中持续 15-20 分钟。在桉树（Eucalyptus globulus Labill.）的叶子中，光照后爆发的强度取决于变暗之前存在的光子通量密度，而不是环境二氧化碳分压。照明后爆发对光子通量密度的依赖性与异戊二烯发射的稳态速率的依赖性相似。细胞间CO2分压从24.5Pa逐步增加至60Pa，导致异戊二烯发射速率和非光化学荧光猝灭立即降低，但CO2同化速率增加。鉴于最近的几项研究将异戊二烯排放与叶绿体过程联系起来，本研究的结果表明，这种联系并不依赖于通过还原性戊糖磷酸途径的二氧化碳通量速率，而是依赖于涉及不受二氧化碳分压明显影响的代谢物的更复杂的关系。
Abstract. Studies of the isoprene emission rate in response to changes in photon-flux density and CO2 partial pressure were conducted using a recently developed on-line isoprene analyser combined with a gas exchange system and chlorophyll fluorometer. Upon darkening, the isoprene emission rate from leaves of aspen (Populus tremuloides Michaux.) began to decline immediately, demonstrating that the internal pool of isoprene, or its precursors, is small and that the instantaneous emission rate is tightly coupled to the rate of synthesis. A post-illumination burst of isoprene was observed within 5 min after darkening and lasted for 15–20 min in four isoprene-emitting species that were examined. In leaves of eucalyptus (Eucalyptus globulus Labill.), the magnitude of the post-illumination burst was dependent on the photon-flux density that existed before darkening, but not on ambient CO2 partial pressure. The dependence of the post-illumination burst on photon-flux density paralleled that for the steady-state rate of isoprene emission. A step-wise increase in intercellular CO2 partial pressure from 24.5 to 60 Pa resulted in an immediate decrease in isoprene emission rate and non-photochemical fluorescence quenching, but an increase in CO2 assimilation rate. Given the several recent studies that link isoprene emission to chloroplastic processes, the results of this study indicate that the linkage is not dependent on the rate of CO2 flux through the reductive pentose phosphate pathway, but rather on more complex relationships involving metabolites not appreciably influenced by CO2 partial pressure.