Analysis Of DA1 Gene Family And Function Of TaDA1 And TaDAR1 In Wheat

Ubiquitin receptor DA1 negatively regulates seed and organ size.At present,the DA1 gene family members have been systematically identified in Arabidopsis,rice,rape,soybean and maize,but DA1 gene of wheat has not been analyzed in the whole genome.In this study,the DA1 gene family members of wheat(Triticum aestivum L.)were identified by bioinformatics,and q RT-PCR was used to analyze their expression profiles in various tissues and under different adversities in wheat Chinese Spring,and TaDA1-B and TaDAR1-5A genes were cloned for functional verification by overexpression in Arabidopsis mutant da1-1,and their protein interaction with TaGW2 were analyzed.The main results are as follows:1.A total of 12 DA1 homeologous genes were obtained by bioinformatics methods.These genes were mainly distributed on chromosome 2B,2D,4A,4B,4D,5A,5B,5D of wheat,and predicted their isoelectric point,molecular weight and subcellular location.According to phylogenetic tree analysis,TaDA1 s family members were clustered into three subgroups,including three TaDA1 members,six TaDAR1 members and three TaDAR2 members.Gene structure and motif analysis showed that TaDA1-D1 gene was small and contained only DA1-like domain,other genes were highly conserved in gene structure and function.The analysis of cis-acting elements showed that most of the cis-acting elements in TaDA1 s promoter region responded to hormone,growth and environment.2.The expression characteristics of TaDA1 s gene were analyzed by transcriptome and q RT-PCR experiments.TaDA1 s genes were expressed in various tissues of wheat.The hormone ABA inhibited TaDA1 s gene expression,while TaDA1-B/D,TaDAR1-5A/5B/5D had significant differences in gene expression under low temperature and salt stress conditions,indicating that TaDA1-B/D,TaDAR1-5A/5B/5D may play a major role in wheat DA1 gene family.3.The results of yeast two hybrid showed that full length of TaGW2 had clear transcriptional self activation,and TaDA1-A,TaDA1-B and TaDAR1-5A also had weak self activation.We did not detect obvious interaction between TaDA1 s and TaGW2 by yeast two hybrid system.While LCI experiments showed that TaDAR1-5A had a weak interaction with TaGW2.Furthermore,we searched the database and got seven potential genes interacting with TaDA1 s,without TaGW2.In addition,TaDA1-B and TaDAR1-5A were overexpressed in Arabidopsis mutant da1-1,the T1 generation transgenic results showed the increase of 100 grain weight of TaDA1-B and TaDAR1-5A transgenic lines compared with that of da1-1.The phenotypes needs to be further investigated.