Expression analysis of innate immunity related genes in the true/field blast resistance gene-mediated defence response.

Rice blast resistance () genes-mediated resistance response depends on various resistance-related genes involved in incompatible interactions. In this work, the expression profiles of innate rice immunity related genes were examined in the mediated resistance response of true/field resistance genes. Three sets of rice near-isogenic lines (NILs) were used: the resistant NILs carrying true resistance genes in the genetic background of the susceptible cultivar Nipponbare (NB), NB-Pib, NB-Pizt, NB-Pik and NB-Pita2; NILs bearing field resistance genes in the susceptible cultivar Aichiasahi (AA) AA-pi21, Kahei (KHR). The marker gene of salicylic acid (SA) signalling was upregulated in all tested cultivars. And, (marker gene of jasmonic acid signalling) showed higher upregulation in the resistance lines with nucleotide-binding sites and leucine-rich repeat (NBS-LRR) genes , , , and than in NB and KHS. of abscisic acid (ABA) signalling may be involved in the interaction, including , , and . However, was shown to negatively regulate interaction. and were differentially expressed and strongly activated at a later stage by 48 h post-inoculation. Interestingly, there was evidence that and played an important role in the mediated response. It was shown that could be upregulated in the true resistance line NB-Pita2 and the field resistance line KHR, while and could be upregulated in all tested lines. The involvement of these genes illustrated the complexity of the downstream signalling pathways in the mediated resistance response of true/field resistance genes.