Photosynthetic and Molecular Markers of CO2-mediated Photosynthetic Downregulation in Nodu

Photosynthetic and Molecular Markers of CO2-mediated Photosynthetic Downregulation in

Nodulated Alfalfa

(A)lvaro Sanz-Sáez;Gorka Erice;Iker Aranjuelo;Ricardo Aroca;Juan Manuel Ruíz-Lozano;Jone Aguirreolea;Juan José Irigoyen

【期刊名称】《植物学报（英文版）》 【年(卷),期】2013(055)008

【摘要】Elevated CO2 leads to a decrease in potential net photosynthesis in long-term experiments and thus to a reduction in potential

growth.This

process

is

known

as

photosynthetic

downregulation.There is no agreement on the definition of which parameters are the most sensitive for detecting CO2 acclimation.In order to investigate the most sensitive photosynthetic and molecular markers of CO2 acclimation,the effects of elevated CO2,and associated elevated temperature were analyzed in alfalfa plants inoculated with different Sinorhizobium meliloti strains.Plants (Medicago sativa L.cv.Aragón) were grown in summer or autumn in temperature gradient greenhouses (TGG).At the end of the experiment,all plants showed acclimation in both seasons,especially under elevated summer temperatures.This was probably due to the lower nitrogen (N) availability

caused

by

decreased

N2-fixation

at

under growth

higher CO2

temperatures.Photosynthesis measured