Effect of growth stage on the response of phenolics to climate change: An example with rice exposed to elevated CO2 from sowing till maturity

Elevated [CO2] reduced phenolic contents during the seedling, tillering, elongation and flowering stages. At maturity, however, a significant or trend of increase was observed (Fig.1). Leaf gas exchange parameters showed that acclimation of photosynthesis to CO2 could have led to that change in response. Indeed, plants grown at elevated [CO2] exhibited higher net photosynthetic rate (A) values from the seedling to the tillering stage, but a slight decrease during the flowering stage. That was accompanied with increased A/gs, and with reduced gs, Ci/Ca, E (Fig.2), chlorophylls and carotenoids (Fig.3).