Work

Elevated CO2 Modulates N Uptake and N Use Efficiency of Tobacco (Nicotiana tabacum L.) Response to Soil Progressive Drought at Topping Stage

Year: 2024

Type: article

Abstract: ABSTRACT Rising atmospheric CO2 concentration ([CO2]) is believed to mitigate the drought stress on plant, and is regulated by soil nitrogen availability. Nonetheless, effects of elevated [CO2] (e[CO2]) on plant response to drought and their interactive effects on plant N uptake and utilisation remain critical unknown. In this study, three‐month‐old potted tobacco plants (a C3 model and crop plant) cultivated at two CO2 concentrations (400 and 800 μmol mol −1) were exposed to progressive drought stress after budding‐topping. In this study, 15N isotopic technique used for analysing the fertiliser‐N transformation in soil and plant organs. Results shown drought generally decreased tobacco biomass, and soil nutrient supply significantly intensify this leaf biomass decreasing induced by drought, while e[CO2] could alleviate the soil drought and nutrient effects on biomass decreasing in upper‐leaf. During progressive drought, e[CO2]‐plants are able to maintain higher root hydraulic conductivity (Kr) than their a[CO2]‐counterparts, the higher Kr induced by e[CO2] were correlated with leaf stomatal conductance (gs) decrease and xylem sap ABA ([ABA]xylem) increase. In other words, soil nutrient supply enhanced the [ABA]xylem of drought‐stressed plants with 3–7 folds higher than none nutrient supply counterparts. Elevated [CO2] induced more fertiliser‐N accumulated in tobacco leaves, especially under well‐watered conditions, which in turn yielded higher photosynthetic nitrogen use efficiency in leaves but low in whole plant. These results suggested that e[CO2] could alleviate drought‐induced photosynthesis limitation by improving root biomass (mainly fine root) and Kr, but the alleviation varied with soil nutrient conditions, thereby mitigating the drought‐negative effects on upper‐leaf growth, finally improved tobacco water use efficiency and tobacco production.

Source: Journal of Agronomy and Crop Science

DOI: 10.1111/jac.70017

Authors: Lin Zhang, Fulai Liu, Guitong Li

Institutions: University of Copenhagen, Henan University, China Agricultural University

Language: English

Topic: Plant responses to elevated CO2

Subfield: Plant Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDGs: Climate action, Zero hunger

Open Access status: bronze

Funders: National Natural Science Foundation of China, China Postdoctoral Science Foundation