PHOTOSYNTHETIC ACCLIMATION IN RICE LEAVES TO FREE-AIR CO_2 ENRICHMENT (FACE) RELATED TO BOTH RuBP CARBOXYLATION LIMITATION AND RuBP REGENERATION LIMITATION

摘要

After long-term exposure to elevated CO_2 concentration ([CO_2]) Pn in CO_2-enriched leaves is significantly lower than that in ambient leaves when measured at a same [CO_2] (DeLucia et al 1985, Spencer et a! 1986, Xu et al 1994a,b). The phenomenon isgenerally termed as photosynthetic acclimation. On the acclimation many studies have been made and some explanations have been proposed, for example, feedback inhibition by carbohydrate accumulation (DeLucia et al 1985) and decrease in Rubisco (Stitt 1991, Roger et al 1996, Moore et al 1999). However, the precise mechanism of the acclimation has not been clarified yet.