Ekspresi Gen PR1 dan PBZ1 yang terlibat dalam Sistem Toleransi Tanaman Padi terhadap Penyakit Blas (Isolat 173)

Abstract

Pathogenesis Related 1 (PR1) and Pathogenesis Related 10 (PBZ1) genes are involved in the rice defense system against pathogen attack. The aim of this research is to analyze the expression of both genes on rice infected by Pyricularia grisea (isolat 173). The first step of this research was the analysis of virulence of P. grisea isolat 173B and 173M. The highest virulent isolat was subsequently used to analyze the resistance of five rice varieties (Cisokan, IR64, Krueng Aceh, Kencana Bali and Cirata). The second step was the analysis expression of the PR1 and PBZ1 genes in rice infected by P. grisea. The gene expression analysis was based on PCR method by using cDNA as the template and spesific primer. Result of this research showed that isolat 173M has higher virulence than 173B, so the isolat 173M then was used as inoculum to infect the rice for resistance analysis of five rice varieties against P. grisea and the analysis of genes expression. The analysis of resistance varieties of rice showed that Kencana Bali and Cirata were susceptible, IR64 was resistant, while Krueng Aceh showed the moderate susceptibility and Cisokan was moderate resistant against isolat 173M. The analysis of expression of PR1 and PBZ1 genes was carried out in Cisokan as a moderate resistant and Kencana Bali as susceptible varieties. The expression of PR1 and PBZ1 genes were induced by pathogen attack. The induction of PR1 gene expression in Kencana Bali was detected on 7th day after infection, while in Cisokan on 3rd day after infection. On the other hand the induction of PBZ1 gene expression in Kencana Bali was detected on 3rd until 7th day after infection, while in Cisokan at 1st until 7th day after infection. In control plants, both PR1 and PBZ1 genes were not expressed. This result indicate, that the expression rate of PR1 and PBZ1 genes has an important role in the tolerance system of rice to P. grisea.