Carbon storage in soils is one of the most promising strategies for mitigating greenhouse gas emissions and the associated climate change. In this context, how plant root systems respond to the elevation of the atmospheric CO2 concentration is of crucial importance because these organs are the main source of C input into the soils. It is expected that root growth will be stimulated by elevated CO2 as a consequence of enhanced photosynthesis, and that this will favour belowground C sequestration. In addition, larger root systems with optimized architecture are also expected to improve water and nutrient acquisition by plants, and to indirectly stimulate photosynthetic CO2 capture. This review critically examines the evidence supporting these expectations from a molecular physiology perspective. We illustrate the strong but highly variable effects of elevated CO2 on root system size and architecture, and provide an update on the signalling mechanisms that may trigger these effects. This highlights the lack of knowledge on the physiological and genetic bases of the root growth and development response to elevated CO2, but shows that candidate genes and genetic resources are largely available to fill this gap.

中文翻译：

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根系生长和发育对二氧化碳升高的反应：潜在的信号机制以及在改善植物二氧化碳捕获和土壤碳储存方面的作用

土壤碳储存是减少温室气体排放和相关气候变化最有前途的策略之一。在这种情况下，植物根系如何响应大气二氧化碳浓度的升高至关重要，因为这些器官是输入土壤的碳的主要来源。预计由于光合作用增强，二氧化碳浓度升高将刺激根部生长，这将有利于地下碳封存。此外，具有优化结构的较大根系也有望改善植物对水和养分的获取，并间接刺激光合作用捕获二氧化碳。这篇综述从分子生理学的角度批判性地检验了支持这些期望的证据。我们说明了二氧化碳浓度升高对根系大小和结构的强烈但高度可变的影响，并提供了可能触发这些影响的信号机制的最新信息。这凸显了对根部生长和发育对二氧化碳升高的反应的生理和遗传基础的了解的缺乏，但表明候选基因和遗传资源在很大程度上可以填补这一空白。