Elevated atmospheric CO 2 and the future of crop plants

Atmospheric CO 2 levels on Earth have risen steeply over the last 60 years and will continue to do so in future. CO 2 traps heat from earth's surface, which causes an increase in temperature and leads to other climatic changes. Crop plants are currently challenged by climate change. In general, elevated CO 2 increases photosynthetic rates, plant growth and the ability of plants to counteract stress. However, the effect of eCO 2 on respiration is not apparent. Plants growing at eCO 2 probably do not have sufficient respiratory ATP to drive cellular processes like nutrient uptake and transport, which impairs their nutritional quality. Here, we review how eCO 2 modulates growth and nutritional value of crop plants, emphasizing the contribution of photosynthesis and respiration. We highlight the mechanisms that modulate acclimation and adaptive responses of plants to eCO 2 and also discuss the ecological consequences. Finally, we project sorghum as a model for an eCO 2 ready crop.