Abstract:

Previous omics analysis revealed that the ERF transcription factor OsDERF1 in rice responds to water stress.To explore the mechanism by which this transcription factor regulates the improvement of water use efficiency under water and nitrogen coupling in rice,this study further analyzed its expression pattern under partial root-zone drying(PRD)and coupling conditions of different nitrogen forms,aiming to provide a theoretical basis for understanding the mechanism of OsDERF1 regulating water use in rice under water and nitrogen coupling.The conventional rice variety Meixiangzhan 2 from Guangdong Province was used as the experimental material.Three water treatments(CK,PRD,PEG)and three ammonium/nitrate nitrogen ratios(A100/N0,A0/N100,A50/N50)were applied in a combined manner.The expression pattern of OsDERF1 in the root,stem,and leaf tissues of rice was analyzed.The structural characteristics and physicochemical properties of the OsDERF1 encoded protein were analyzed by bioinformatics methods.The results showed that the full length of the OsDERF1 coding region was 732 bp,encoding 243 amino acids.The molecular weight of the encoded protein was 25.97 ku,the theoretical isoelectric point was 4.77,the instability index was 54.36,and the average hydrophilicity coefficient was -0.475.Based on these characteristics,the protein was an unstable hydrophilic protein.Subcellular localization results showed that OsDERF1 was located in the nucleus,and the protein sequence contained an AP2 conserved domain,indicating that OsDERF1 was a nuclear transcription factor.qRT-PCR results showed that OsDERF1 was expressed in the root,stem,and leaf tissues of rice,but there were tissue expression differences:the relative expression level in the root was significantly higher than that in the leaf and stem.Further analysis of the effects of different treatments on the expression in each tissue revealed that the relative expression level in the root was the highest under PRD-L and A50/N50 coupling treatment.In summary,the relative expression level of the OsDERF1 transcription factor in the root tissue of rice was the highest under PRD and A50/N50 nitrogen form coupling treatment,and the expression level under stress conditions in the root was significantly higher than that in the non-stressed root.Based on this,it is speculated that OsDERF1 may respond to dual signals of water and nitrogen through the root tissue and participate in the molecular regulation mechanism of rice under drought stress.

Key words: Rice, Partial root-zone drying(PRD), Nitrogen form, Transcription factor OsDERF1

CLC Number: 

• S511稻