COMPARATIVE STUDIES ON GENE EXPRESSION OF RICE AND WHEAT IN RESPONSE TO FUNGAL INFECTION

Abstract

Comparative sequence analysis is a powerful tool to study homologous gene families, define conserved gene functions between orthologs, and identify lineage- and species-specific genes. Most annotations of newly sequenced genomes are based on sequence similarities for which functional information is available. Apart from conserved sequences, inter-species differences provide important clues about evolutionary history and species-specific adaptations. In our study, we compared between two RNA-sequencing data sets of resistant variety of wheat (Triticum aestivum L.,) after infection with leaf rust fungus, Puccinia triticina and resistant variety of rice (Oryza sativa L.,) after infection with blast fungus, Magnaporthe oryzae. 31768 up-regulated genes in wheat and 3902 up-regulated genes in rice were filtered according to fold change more than 3 and excluding variants, 250 upregulated genes of wheat and rice were aligned and phylogenetic tree were generated. The result of phylogenetic tree showed close relationship between 55 aligned gene pairs of wheat and rice. Ten pairs of aligned gene pairs were selected, super family of these pairs were obtained, the result showed that each aligned pair of genes shared the same protein family and the same annotation and all pairs participate in plant defense pathways. Then, the gene expression of the ten pairs were validated by Real-time PCR after infecting wheat with Puccinia triticina and rice with Magnaporthe oryzae. Each aligned pair of the ten pairs shared the same manner of expression with few exceptions in rice.