Overexpression of TaFBA-A10 from Winter Wheat Enhances Freezing Tolerance in Arabidopsis thaliana

Freezing stress is the principal abiotic stress that is not conducive to plant growth and yield. Fructose-1, 6-bisphosphate aldolase (FBA; EC 4.1.2.13) is a key metabolic enzyme, which plays an important role in Calvin cycle and glycolysis. In this study, we found that the expression of TaFBA10 from A genome in tillering nodes of strong cold resistance winter wheat cultivar Dongnongdongmai1 (Dn1) was significantly altered subjected to severe winter. In order to study the role of FBA on carbohydrate metabolism and response to freezing stress in plants, we constructed a plant overexpression vector of TaFBA-A10 and transferred it into Arabidopsis thaliana to obtain stable inherited T-3 generation plants, which were treated with freezing temperatures (- 10 degrees C). We found that overexpressing TaFBA-A10 led to the increased activity of FBA, as well as, enhancing the expression of key enzymes in Calvin cycle and glycolysis including SBPase, FBPase, GADPH, HXK, PFK and PyK under freezing stress. Although the phenotype of TaFBA-A10 overexpressing lines was not prominent, the electrical conductivity and MDA content of TaFBA-A10 overexpressing lines were significantly lower than those of wild type (WT) and fba mutants under freezing stress. The reducing sugar content and ROS scavenging ability of TaFBA-A10 overexpressing lines were higher than those of WT and fba mutants under freezing stress. These results could be concluded that TaFBA-A10 could regulate Calvin cycle and glycolysis rate to enhance freezing tolerance of plants by increasing FBA activity.

Automated summary

Overexpression of TaFBA-A10 in plants under freezing stress enhances FBA activity, increases expression of key enzymes in Calvin cycle and glycolysis, and ultimately improves freezing tolerance. TaFBA-A10 overexpressing lines exhibit lower electrical conductivity and MDA content, as well as higher reducing sugar content and ROS scavenging ability under freezing stress compared to wild type and fba mutants.