Growth in elevated CO2 protects photosynthesis against high-temperature damage
Growth in elevated CO2 protects photosynthesis against high-temperature damage
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DOI：
10.1046/j.1365-3040.2000.00574.x
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发表时间：
2000-06
影响因子：
7.3
通讯作者：
D. Taub;J. Seemann;J. Coleman
中科院分区：
文献类型：
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作者：
D. Taub;J. Seemann;J. Coleman
我们提出的证据表明，在温室和大田条件下，在大气CO2浓度升高的情况下，植物生长提高了各种植物对光合作用的高温耐受性。我们在包括内华达沙漠自由空气二氧化碳浓缩(FACE)设施在内的三个不同的生长设施中，在环境二氧化碳(-360pmolmol-1)和高二氧化碳浓度(550-1000pmolmol-1)下种植植物。来自环境和高二氧化碳处理的切叶暴露在28到48°C的温度范围内。在所研究的超过一半的物种中(7种植物中的4种、5种植物中的3种和5种植物中的3种)，来自高CO2种植植物的叶片的PSII效率(Fv/Fm)显著高于常温种植植物的叶片。这种增强的PSII耐热性在木本植物和草本植物以及单子叶和双子叶植物中都被发现。对黄瓜进行的详细实验表明，热胁迫后升高的叶片与环境中CO2生长的叶片相比，Fv/Fm较大是由于较高的Fm和较低的Fo所致，并且在热激后，升高的叶片与环境中CO2生长的叶片之间的Fv/Fm差异持续了至少20h。高CO2植株的黄瓜叶片具有Fo迅速升高的临界温度，比环境CO2植株的叶片平均高2.9℃，并在热激后保持较高的最大净CO2同化速率。鉴于光合作用被认为是对高温伤害最敏感的生理过程，而大气中CO2含量的增加将导致许多已经受到胁迫的环境中的温度上升，这种CO2诱导的植物高温耐受性的增加可能会对21世纪许多植物的生产力和分布产生重大影响。
We present evidence that plant growth at elevated atmospheric CO 2 increases the high-temperature tolerance of photosynthesis in a wide variety of plant species under both greenhouse and field conditions. We grew plants at ambient CO 2 (- 360 pmol mol -1 ) and elevated CO 2 (550-1000 μmol mol -1 ) in three separate growth facilities, including the Nevada Desert Free-Air Carbon Dioxide Enrichment (FACE) facility. Excised leaves from both the ambient and elevated CO 2 treatments were exposed to temperatures ranging from 28 to 48 °C. In more than half the species examined (4 of 7, 3 of 5, and 3 of 5 species in the three facilities), leaves from elevated CO 2 -grown plants maintained PSII efficiency (F v /F m ) to significantly higher temperatures than ambient-grown leaves. This enhanced PSII thermotolerance was found in both woody and herbaceous species and in both monocots and dicots. Detailed experiments conducted with Cucumis sativus showed that the greater F v /F m in elevated versus ambient CO 2 -grown leaves following heat stress was due to both a higher F m and a lower F o , and that F v /F m differences between elevated and ambient CO 2 -grown leaves persisted for at least 20 h following heat shock. Cucumis sativus leaves from elevated CO 2 -grown plants had a critical temperature for the rapid rise in F o that averaged 2.9 °C higher than leaves from ambient CO 2 -grown plants, and maintained a higher maximal rate of net CO 2 assimilation following heat shock. Given that photosynthesis is considered to be the physiological process most sensitive to high-temperature damage and that rising atmospheric CO 2 content will drive temperature increases in many already stressful environments, this CO 2 -induced increase in plant high-temperature tolerance may have a substantial impact on both the productivity and distribution of many plant species in the 21st century.