Heterotic growth of hybrids of Arabidopsis thaliana is enhanced by elevated atmospheric CO2

Abstract

Premise: With the global atmospheric CO₂ concentration on the rise, developing crops that can thrive in elevated CO₂ has become paramount. We investigated the potential of hybridization as a strategy for creating crops with improved growth in predicted elevated atmospheric CO₂.

Methods: We grew parent accessions and their F1 hybrids of Arabidopsis thaliana in ambient and elevated atmospheric CO₂ and analyzed numerous growth traits to assess their productivity and underlying mechanisms.

Results: The heterotic increase in total dry mass, relative growth rate and leaf net assimilation rate was significantly greater in elevated CO₂ than in ambient CO₂. The CO₂ response of net assimilation rate was positively correlated with the CO₂ response of leaf nitrogen productivity and with that of leaf traits such as leaf size and thickness, suggesting that hybridization-induced changes in leaf traits greatly affected the improved performance in elevated CO₂.

Conclusions: Vegetative growth of hybrids seems to be enhanced in elevated CO₂ due to improved photosynthetic nitrogen-use efficiency compared with parents. The results suggest that hybrid crops should be well-suited for future conditions, but hybrid weeds may also be more competitive.

Keywords: Arabidopsis thaliana; Brassicaceae; C24; elevated atmospheric CO2; heterosis; leaf mass per area; leaf nitrogen; leaf size; photosynthetic productivity; relative growth rate.