Maize Transcription Factors ZmYY1,ZmYY2 Interact With RNA-binding Protein ZmRBM25 To Regulate ZmABR1 Expression

C₂H₂ zinc finger protein transcription factors in plants play an important roles in growth and development,response to stress,and regulation of plant hormone signal.The Arabidopsis C₂H₂ transcription factor AtYY1 is involved in plant stress response and ABA signaling.RNA binding proteins,as an important post-transcriptional regulators of eukaryotic cells,also play an important roles in RNA metabolism,plant growth and development,stress response,plant hormone signaling,and alternative splicing.Recent study shows that Arabidopsis RNA-binding protein RBM25 plays a key role in ABA-mediated alternative splicing and stress response.Mammalian human cells YY1 interacts with RBM25 to regulate gene expression has been reported recently.In this study,the important crop,maize was used as the experimental material.Using bioinformatics,biochemistry and molecular biology technology,we investigated the interaction between YY1 with RBM25 in maize and its possible biological function.The main results were as follows:1.Using bioinformatics technology,the maize homologous genes ZmYY1 and ZmYY2,which are highly conserved with Arabidopsis YY1,and the maize homologous gene ZmRBM25 were identified.Amino acid sequence analysis revealed that ZmYY1 and ZmYY2each contained five repeat tandem zinc finger protein domains.ZmRBM25 contained an RRM domain that recognizing single-stranded RNA at the N-terminal and a PWI domain that binding RNA at the C-terminal.2.Using DNA recombination technology,yeast expression vectors containing ZmYY1,ZmYY2 and ZmRBM25 were constructed respectively.The results of yeast two-hybrid experiments showed that the transcription factors ZmYY1 and ZmYY2 could interact with the C-terminal domain of the RNA-binding protein ZmRBM25,not the N-terminal domain,respectively.3.The results from Co-IP,LCI and Pull down experiments in vitro further proved that ZmYY1 and ZmYY2 could interact with the RNA-binding protein ZmRBM25,respectively.4.Expression pattern analysis showed that ZmYY1 was expressed in the root,stem and leaf of maize seedlings.It also could be strongly induced by ABA treatment.Subcellular localization results showed that both ZmYY1 and ZmYY2 are localized in the nucleus,respectively.5.Biological function analysis showed that ZmYY1 and ZmYY2 could improve the tolerance of yeast to salt stress and drought stress.Transcription activation experiments showed that ZmYY1 and ZmYY2 can positively regulate the transcriptional expression of ZmABR1 gene.ZmRBM25 could enhance the transcriptional regulation of ZmABR1.All together,this study demonstrated that maize transcription factors,ZmYY1 and ZmYY2,could interact with RNA-binding protein ZmRBM25 to regulate the expression of ZmABR1,and then participate in the ABA signaling pathway and response to abiotic stress.Our results provide a valuable data for maize genetic improvement in future.