Genome-Wide Analysis Of WRKY Genes And Evolution Pattens In Zea Mays And Medicago Truncatula

WRKY proteins are plant-specific transcription factor family, named by conservedstructural region of WRKY and Highly-conserved amino acid sequence of WRKY GQK.Expression of WRKY genes are rapidly induced after suffering hurt, pathogens or abioticstress in many plants. The results of some research showed that WRKY had important rolein conduction of innate immune signals. The study on WRKY gene from plants hasbecome a hot spot. In this paper, the WRKY gene from the whole genome of Zea maysand Medicago truncatula was analyzed to study the relationship between gene structureand evolution by bioinformatics. The main results were as below:1． In this paper, taking model plant Zea mays as the object of study, by HMM andBLAST,126WRKY genes were obtained in final. The latest whole genomedatabase(Mt2.0) from Medicago truncatula was studied, and28WRKY genes were found.2． The duplication of WRKY genes from Zea mays and Medicago truncatula wasstudied. The results showed that there were84duplicated WRKY domains in Zea mays,which was59.1％in the whole WRKY domains. There were19duplicated WRKY genesin Medicago truncatula, which was57.3％in the whole WRKY domains, lower than thatin Zea mays.3． By chromosomal localization of Zea mays, the most of WRKY genes distributionwas in chromosome2, which was19. The second was in chromosome3and7, whichrespectivly were16. There were8WRKY genes in chromosome5in Medicago truncatula,in which, there were6genes in chromosome8, while there was no WRKY gene inchromosome2and6.4． WRKY domain of Zea mays was analyzed by phylogenetics, the domain ofN-terminal and C-terminal of the first type was found in the same evolutionary branch,which illustrated that there were individual origin and evolutionary relationships amongthem. By the comparision of domain sequence, we could found that the typeⅠ and typeⅡ was conserved, which had high homology. The WRKY domain in Zea mays andSorghum bicolor was compared and analyzed, the results showed that N-terminal andC-terminal of the first type clustered togather, which illustrated the domain of WRKY geneof the first type was conserved, maybe they had common origin. We also found that thefirst type was the most conserved WRKY domain.5． There were28WRKY genes in the whole genome of Medicago truncatula,taking0.072%in all the genes, which was much less than that in Oryza sativa and Zea mays. thisillustrated that WRKY genes from Zea mays and Medicago truncatula had obvious difference in evolution, and maybe the difference had existed before the differentiationbetween monocot and dicot. N-WRKY of5genes from the first type were distributed inthe same branch, and the genes of C-WRKY were also distributed in the same branch.Theresults illustrated that the origin of N-WRKY and C-WRKY was different,which was thesame with that in Zea Mays L. Comserved motif sequences from the WRKY genes ofMedicago truncatula were also analyzed,5conserved motif of WRKY domain wasobtained.In a word, the structure, number, evolution of WRKY gene from Zea mays andMedicago truncatula were analyzed in this paper, which could play important theoreticaland practical significance for cloning and functional study of WRKY gene.