GENOME-WIDE IDENTIFICATION AND EXPRESSION ANALYSIS OF AAO GENE FAMILY IN MAIZE

Ascorbic acid oxidase (AAO) is a member of the multi-copper oxidase family and plays an important role in plant growth and development. The functional characteristics and expression patterns of the AAO gene family were analyzed using the maize (Zea mays L.) B73 genomic mRNA and amino acid database. Bioinformatics analysis of the whole genome AAO gene of maize had identified 36 AAO gene members, and predictive analysis was performed on the chromosomal location, the mode and time of gene differentiation, protein physicochemical properties and secondary structure, gene structure, conserved elements, phylogenetic tree and expression patterns of these genes. The results showed that 36 ZmAAO were unevenly distributed on 10 chromosomes. The genes differentiation was dominated by fragment replication, and the differentiation time was about 3.325.75 million years. ZmAAO proteins were mostly basic proteins. The protein secondary structure is mainly composed of irregular curls. The analysis of gene structure and conserved motifs showed that there was no significant difference in the number of introns in ZmAAO genes, and the amino acid sequence was highly conserved. The phylogenetic trees can be divided into 4 subfamilies, in which maize, rice and sorghum has a large number of orthologous genes and close genetic relationships. The expression pattern analysis found that the expression level of ZmAAO was different in different tissues, which indicates that it functions differently. After high temperature stress, the expression level of ZmAAO gene was significantly different in different tissues, indicating that some ZmAAO genes respond to high temperature stress. These results provide a theoretical basis for studying the biological function of this gene family and breeding high temperature resistant varieties in the future.