Table 2.

Comparing the effect of CO₂ to the effect of adding ‘a spoonful of sugars.’

DOI: http://dx.doi.org/10.7554/eLife.02245.013

Plant quality indicator	Effect of adding 5g of TNC (%)	Effect of elevated CO2 (%)
Grains and tubers:
TNC	2.6	1 to 15
TNC:protein	7	6 to 47
TNC:minerals	7	6 to 28
protein	−4.8	−14 to −9
minerals	−4.8	−10 to −5
Foliar tissues:
TNC	27	15 to 75
TNC:protein	33	26 to 125
TNC:minerals	33	24 to 98
protein	−4.8	−19 to −14
minerals	−4.8	−12 to −5

Changes (%) in various plant quality indicators caused by: (1) Adding a teaspoon of TNC (∼5g of starch-and-sugars mixture) per 100g of dry mass (DM) of plant tissue, an:d (2) growing plants in twice-ambient CO₂ atmosphere. Changes due to the addition of TNC are calculated assuming:the baseline TNC content of 65% for grains and tubers, and 15% for foliar tissues. The C content is assumed to be ∼42% for plant tissues and TNC.