Accelerated senescence under elevated CO2 (eCO2) has not received sufficient attention, and its impact on the effect of CO2‐fertilization is unclear. To investigate the relationship between plant senescence and CO2 concentration, a pot experiment was conducted in four potato genotypes under low CO2 (LC), medium CO2 (MC) and high CO2 (HC) conditions. Nitrogen (N) uptake and cumulative transpiration were analysed to clarify whether eCO2‐induced senescence could be explained by low N uptake due to reduced transpiration. Compared to LC, the lifespan of potato plants under MC and HC was reduced by 3%–6% and 12%–32%, respectively, depending on the genotype. Biomass accumulation at full senescence was reduced when lifespan was shortened by approximately 5% and 10% under MC and HC, respectively. Cumulative transpiration was less affected by eCO2 during early developmental stages but decreased under eCO2 as plants aged. Plant water use decreased with a shortened lifespan under eCO2, but there was no reduction in N uptake, which was attributed to the high N uptake per unit of water used. The results of this study indicate that senescence in potato genotypes is non‐linearly related to CO2 concentration and cannot be explained by reduced N acquisition via reduced transpiration. The positive effect of CO2 fertilization can be reversed by accelerated senescence under eCO2.

中文翻译：

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马铃薯 CO2 升高时加速衰老逆转 CO2 受精效应：与氮获取的弱关系


高二氧化碳（eCO2）下的加速衰老尚未受到足够的重视，其对二氧化碳受精效果的影响尚不清楚。为了研究植物衰老与CO2浓度之间的关系，在低CO2（LC）、中CO2（MC）和高CO2（HC）条件下对四种马铃薯基因型进行了盆栽试验。对氮 (N) 吸收和累积蒸腾进行了分析，以阐明 eCO2 诱导的衰老是否可以通过蒸腾减少导致的低氮吸收来解释。与 LC 相比，MC 和 HC 处理下的马铃薯植株寿命分别缩短了 3%–6% 和 12%–32%，具体取决于基因型。当MC和HC下寿命分别缩短约5%和10%时，完全衰老时的生物量积累减少。在早期发育阶段，累积蒸腾量受 eCO2 的影响较小，但随着植物衰老，累积蒸腾量在 eCO2 的影响下有所下降。在eCO2下，植物用水量随着寿命的缩短而减少，但氮吸收量没有减少，这归因于每单位用水的高氮吸收量。这项研究的结果表明，马铃薯基因型的衰老与二氧化碳浓度呈非线性相关，并且不能用蒸腾作用减少导致的氮获取减少来解释。 CO2 施肥的积极作用可以通过 eCO2 下的加速衰老来逆转。