Some photosynthetic responses to salinity resistance are transferred into the somatic hybrid descendants from the wild soybean <i>Glycine cyrtoloba</i> ACC547

Abstract

The somatic hybrid descendants between a cultivated soybean Glycine max Melrose and a wild species Glycine cyrtoloba ACC547 were found to possess some salinity‐resistant traits of the wild soybean. Under salt stress, two of the descendants as well as their wild parent grew better than their cultivated parent. In addition, salinity‐induced decline in the net photosynthetic rate and the maximum photochemical efficiency was much less in the wild species and the descendants than in Melrose when stressed for more than 5 days. Analysis of the postillumination transient increase in chlorophyll fluorescence and the dark rereduction of the oxidized primary electron donor in photosystem I (PSI) (P700 + ) indicated that salinity induced a significant upregulation of the cyclic electron flow around PSI (CEF1) in the wild species and the hybrid descendants. Similar to their wild parent, the descendants maintained higher non‐photochemical dissipation of excess excitation energy than their cultivated parent under salt stress. As a consequence, there were lower levels of superoxide radical and membrane lipid peroxidation in the plants of the descendants and the wild species. Based on these results, we proposed that the high salinity resistance of the descendants might be because of, at least partially, the trait inherited from the wild species of the enhanced CEF1 which contributed to the sufficient dissipation of excess excitation energy to protect photosynthetic apparatus from the damage of reactive oxygen species.