The linear electron transport to assimilation ratio (ETR/A) has been used to evaluate the stress status of plants and the ETR measurement accuracy.However,how ETR/A responds to short- and long-term CO_(2) variations r...The linear electron transport to assimilation ratio (ETR/A) has been used to evaluate the stress status of plants and the ETR measurement accuracy.However,how ETR/A responds to short- and long-term CO_(2) variations remains uncertain.Here,we assessed the short-term,instantaneous CO_(2) response (seconds to minutes) of ETR/A in sunflower (Helianthus annuus) and cowpea (Vigna unguiculata) in a controlled experiment.Additionally,we compiled published data to investigate the effect of elevated growth CO_(2) (long-term) on ETR/A across plant functional groups.Our results showed that ETR,photosystem II photochemical efficiency,and photochemical quenching increase while ETR/A decreases with increasing CO_(2) for both sunflower and cowpea.The CO_(2) sensitivity of ETR and ETR/A is greater at low [CO_(2)] (Rubisco-limiting condition) than at moderate to high [CO_(2)] (electron transport-limiting stage).The meta-analysis showed that plant functional groups and long-term CO_(2) significantly affect ETR/A,which challenges the universal applicability of current empirical ETR/A thresholds across species and environments.Long-term CO_(2) elevation increased A without altering ETR,resulting in a 21% reduction in ETR/A compared to ambient CO_(2).Our results demonstrate an imbalance between electron transport and carboxylation under elevated CO_(2),potentially constraining photosynthetic performance under future climate scenarios.展开更多
基金supported by the National Natural Science Foundation of China (NSFC 32120103005 and 32201277)the Natural Science Foundation of Fujian Province,China (2023J01289)。
文摘The linear electron transport to assimilation ratio (ETR/A) has been used to evaluate the stress status of plants and the ETR measurement accuracy.However,how ETR/A responds to short- and long-term CO_(2) variations remains uncertain.Here,we assessed the short-term,instantaneous CO_(2) response (seconds to minutes) of ETR/A in sunflower (Helianthus annuus) and cowpea (Vigna unguiculata) in a controlled experiment.Additionally,we compiled published data to investigate the effect of elevated growth CO_(2) (long-term) on ETR/A across plant functional groups.Our results showed that ETR,photosystem II photochemical efficiency,and photochemical quenching increase while ETR/A decreases with increasing CO_(2) for both sunflower and cowpea.The CO_(2) sensitivity of ETR and ETR/A is greater at low [CO_(2)] (Rubisco-limiting condition) than at moderate to high [CO_(2)] (electron transport-limiting stage).The meta-analysis showed that plant functional groups and long-term CO_(2) significantly affect ETR/A,which challenges the universal applicability of current empirical ETR/A thresholds across species and environments.Long-term CO_(2) elevation increased A without altering ETR,resulting in a 21% reduction in ETR/A compared to ambient CO_(2).Our results demonstrate an imbalance between electron transport and carboxylation under elevated CO_(2),potentially constraining photosynthetic performance under future climate scenarios.
