The Function Of TaRanBP1 In Wheat Under Low Temperature Stress And Identification Of Its Upstream Transcription Factors

Wheat often suffers from sudden low temperature stress during different growth periods,which seriously threatens wheat production.Breeding and rationally using low temperature stress resistant varieties is one of the most economical,safe and effective ways to prevent the harm of low temperature stress.Our previous studies have shown that the abundance of wheat Ran BP1 protein is significantly up-regulated in wheat plants subjected to low temperature stress,and it is speculated that it may be involved in this stress.Therefore,we further explored itsmechanism of action under low temperature stress.Fluorescence quantitative PCR technology was used to determine that Ta Ran BP1 was expressed in different tissues of wheat,and the expression level in wheat leaves and ears was higher than that in roots and stems.The expression of Ta Ran BP1 gene increased in different degrees under different stress treatments.Using the barley stripe mosaic virus induced gene silencing(BSMV-VIGS)method,the Ta Ran BP1 gene in the wheat genome was silenced instantaneously.The wheat seedlings that were momentarily silenced during the low temperature treatment showed higher sensitivity than the control.The free proline(PRO)content of the plant leaves was significantly reduced,and the malondialdehyde(MDA)content was significantly increased.Antioxidant enzyme activity was compared with the control.Compared with the control,the expression of the related stress resistance genes in the wheat plants also decreased to different degrees.The freeze death rate of the wheat plants that were transiently silenced after low temperature stress was higher than that of the control plants.The overexpression of Ta Ran BP1 gene significantly increased the Pro content of Arabidopsis plants during low temperature stress,and significantly decreased the MDA content.Compared with WT plants,the antioxidant enzyme activity was significantly increased.The relevant stress resistance genes were all in the process of low temperature stress.With varying degrees of increase,the freezing death rate of overexpressing Arabidopsis plants was significantly lower than that of WT plants.The yeast one-hybrid technique was used to screen out the transcription factor Ta NAC4 that binds to the Ta Ran BP1 gene promoter.The yeast one-hybrid system and dual luciferase were used to detect the interaction between Ta Ran BP1 gene promoter and Ta NAC4 transcription factor.After silencing the Ta NAC4 gene using BSMV-VIGS technology,it was found that the wheat seedlings that were transiently silenced during low temperature treatment showed higher sensitivity than the control,the PRO content of the plant was significantly reduced,and the MDA content was significantly increased.Compared with the comparison,the expression of the related stress resistance genes in the wheat plants also decreased to different degrees compared with the control.The freezing death rate of the wheat plants that were silenced instantly after low temperature stress was higher than that of the control plants.Studies have shown that Ta Ran BP1 gene may be involved in different adversity stresses;through forward genetics and reverse genetics,it is preliminarily proved that Ta Ran BP1 gene plays a positive regulatory role in the response of wheat to low temperature stress;transcription factors screened by yeast one-hybrid technology Ta NAC4 interacts with Ta Ran BP1 gene,which may perform related functions in low temperature stress by regulating the expression of Ta Ran BP1 gene.