Photorespiration Is Crucial for Dynamic Response of Photosynthetic Metabolism and Stomatal Movement to Altered CO2 Availability
Photorespiration Is Crucial for Dynamic Response of Photosynthetic Metabolism and Stomatal Movement to Altered CO2 Availability
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DOI：
10.1016/j.molp.2016.09.011
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发表时间：
2017-01-09
期刊：
影响因子：
27.5
通讯作者：
Weber, Andreas P. M.
中科院分区：
文献类型：
--
作者：
Eisenhut, Marion;Braeutigam, Andrea;Weber, Andreas P. M.
光呼吸是光合生物的一个重要过程，它会降低光合碳同化的效率，因此经常被认为是一个浪费的过程。通过比较光呼吸受损的野生型植物和突变体的响应，在环境中的CO2浓度的变化，我们表明，光呼吸也发挥了有益的作用，在短期驯化减少CO2的可用性。野生型植物响应与几个差异表达的基因，主要涉及干旱胁迫，这可能是一个结果，增强开放气孔和随之而来的水分流失后，转向低CO2。与此相反，光呼吸酶活性受损的突变体高度强调，不能调整气孔导度，以减少外部CO2的可用性。突变体植物的转录反应是一致的，表明一般的重编程，以处理减少CO2的可用性的后果，核酮糖-1，5-二磷酸的加氧增强和放大的人工受损的光呼吸代谢的信号。这种重新编程的核心是将资源从生长过程重新分配到压力反应。两者合计，我们的研究结果表明，不受限制的光呼吸代谢是一个先决条件，快速的生理适应减少二氧化碳的可用性。
The photorespiratory pathway or photorespiration is an essential process in oxygenic photosynthetic organisms, which can reduce the efficiency of photosynthetic carbon assimilation and is hence frequently considered as a wasteful process. By comparing the response of the wild-type plants and mutants impaired in photorespiration to a shift in ambient CO2 concentrations, we demonstrate that photorespiration also plays a beneficial role during short-term acclimation to reduced CO2 availability. The wild-type plants responded with few differentially expressed genes, mostly involved in drought stress, which is likely a consequence of enhanced opening of stomata and concomitant water loss upon a shift toward low CO2. In contrast, mutants with impaired activity of photorespiratory enzymes were highly stressed and not able to adjust stomatal conductance to reduced external CO2 availability. The transcriptional response of mutant plants was congruent, indicating a general reprogramming to deal with the consequences of reduced CO2 availability, signaled by enhanced oxygenation of ribulose-1,5-bisphosphate and amplified by the artificially impaired photorespiratory metabolism. Central in this reprogramming was the pronounced reallocation of resources from growth processes to stress responses. Taken together, our results indicate that unrestricted photorespiratory metabolism is a prerequisite for rapid physiological acclimation to a reduction in CO2 availability.