Transcriptome Comparison of Defense Responses in the Rice Variety ‘Jao Hom Nin’ Regarding Two Blast Resistant Genes, <i>Pish</i> and <i>Pik</i>

Jao Hom Nin (JHN) is a Thai rice variety with broad-spectrum resistant against rice blast fungus. JHN contains two rice blast resistant genes, <i>Pish</i> and <i>Pik</i>, located on chromosome 1 and on chromosome 11, respectively. To understand the blast resistance in JHN, the study of the defense mechanism related to the <i>Pish</i> and <i>Pik</i> genes is crucial. This study aimed to dissect defense response genes between the <i>Pish</i> and <i>Pik</i> genes using the RNA-seq technique. Differentially expressed genes (DEGs) of <i>Pish</i> and <i>Pik</i> backcross inbred lines were identified between 0 and 24 h after inoculation with rice blast spore suspension. The results showed that 1248 and 858 DEGs were unique to the <i>Pish</i> and <i>Pik</i> lines, respectively. The wall-associated kinase gene was unique to the <i>Pish</i> line and the zinc-finger-containing protein gene was unique to the <i>Pik</i> line. Pathogenicity-related proteins PR-4 and PR-10 were commonly found in both <i>Pish</i> and <i>Pik</i> lines. Moreover, DEGs functionally categorized in brassinosteriod, jasmonic acid, and salicylic acid pathways were detected in both <i>Pish</i> and <i>Pik</i> lines. These unique and shared genes in the <i>Pish</i> and <i>Pik</i> rice blast defense responses will help to dissect the mechanisms of plant defense and facilitate rice blast breeding programs.