Cyclic electron flow around photosystem 1 is required for adaptation to salt stress in wild soybean species Glycine cyrtoloba ACC547

Abstract

A wild soybean species Glycine cyrtoloba ACC547 was found to possess a high salinity resistance trait. It maintained higher net photosynthetic rate (PN) and maximal photochemical efficiency (Fv/Fm) than the soybean Glycine max cultivar Melrose under salt stress. Saline treatment enlarged the post-illumination transient increase in chlorophyll fluorescence in ACC547 much more than that in Melrose, indicating that its cyclic electron flow around photosystem 1 (CEF1) was accelerated more by salt stress. Additionally, ACC547 maintained higher nonphotochemical dissipation of excitation energy than Melrose under salt stress. It is suggested that the salinity resistance of ACC547 might be due to the CEF1-coupled dissipation of excess excitation energy.