Relationship between the inhibition of leaf respiration by light and enhancement of leaf dark respiration following light treatment
Relationship between the inhibition of leaf respiration by light and enhancement of leaf dark respiration following light treatment
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DOI：
10.1071/pp97159
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发表时间：
1998-01-01
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影响因子：
--
通讯作者：
Siebke, K
中科院分区：
文献类型：
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作者：
Atkin, OK;Evans, JR;Siebke, K
叶片的呼吸作用(R，非光呼吸线粒体CO2释放)受到光的抑制。然而，在一段时间的光照后暴露在黑暗中也会导致R被暂时刺激(称为光增强暗呼吸，LEDR)。我们使用一种快速响应的二氧化碳交换系统来研究烟叶中的这些观察结果。关光后有两个CO_2释放高峰，第一个高峰出现在15-20岁的S(光呼吸后暴发)，第二个高峰在180-250岁的S(光呼吸后爆发)。LEDR存在于所有光照后实验中，与O-2或CQ(2)浓度无关。然而，在黑暗前期，LEDR随着光照度的增加而增加，这表明它对先前的光合作用有一定的依赖性。我们研究了在低CO2浓度下光对R的抑制作用(Gamma(*))：Gamma(*)是光中CO2净释放代表R的胞间CO2浓度。无论光质(红、蓝、白)如何，光对R的抑制作用约为50 S，甚至在3微克分子光子m(-2)、S(-1)时表现得尤为明显。光对R的抑制表现出与LEDR相似的光照依赖性，其抑制程度与LEDR水平呈正相关。在光照下，从350ppm切换到低二氧化碳浓度，导致胞间二氧化碳浓度为伽马(*)，导致R最初增加，然后稳定。因此，将叶片保持在伽马(*)并不会导致低估R。我们的数据表明，光和LEDR对R的抑制可能有一个共同的机制。
Respiration (R, non-photorespiratory mitochondrial CO2 release) in leaves is inhibited by light. However, exposure to darkness after a period of illumination can also result in R being temporarily stimulated (termed 'light enhanced dark respiration', LEDR). We used a fast-response CO2 exchange system to investigate these observations in tobacco leaves. After switching off the light, there were two peaks of CO2 release, the first at 15-20 s (the photorespiratory post-illumination burst) and the second at 180-250 s (LEDR). LEDR occurred in all post-illumination experiments, independent of O-2 or CQ(2) concentration. However, LEDR increased with increasing irradiance during the pre-dark period, suggesting some dependency on prior photosynthesis. We investigated the inhibition of R by light at low CO2 concentrations (Gamma(*)): Gamma(*) is the intercellular CO2 concentration at which net CO2 release represents R in the light. The inhibition of R in the light took about 50 s and was even evident at 3 mu mol photons m(-2) s(-1), regardless of the light quality (red, blue or white). The inhibition of R by light showed similar dependency on irradiance as LEDR, such that the degree of inhibition was positively correlated with the level of LEDR. In the light, switching from 350 ppm to a low CO2 concentration that resulted in the intercellular CO2 concentration being at Gamma(*), resulted in R initially increasing and then stabilising. Maintaining the leaf at Gamma(*) did not, therefore, lead to an underestimation of R. Our data suggest that a common mechanism may be responsible for both the inhibition of R by light and LEDR.