RESUMO
Probenazole (PBZ) induces non-race specific resistance in rice plants against rice blast fungus and PBZ1 was identified as a PBZ-inducible gene from rice. The induction of PBZ1 expression in suspension-cultured rice cells was investigated. Northern blot analysis indicated that PBZ1 was induced by PBZ in a dose-dependent manner. Enzyme-linked immunosorbent assay (ELISA) showed a dose and time-dependent accumulation of PBZ1 protein. Both mRNA and protein analysis showed that PBZ1 was not induced by salicylic acid or an active metabolite, 1,2-benzisothiazole-1,1-dioxide.
Assuntos
Regulação da Expressão Gênica de Plantas , Oryza/genética , Proteínas de Plantas/biossíntese , Tiazóis/farmacologia , Linhagem Celular , Oryza/química , Oryza/efeitos dos fármacos , Proteínas de Plantas/genética , Ácido Salicílico/farmacologiaRESUMO
By using subtracted probes, two cDNA clones of rice, EL2 and EL3, were isolated as genes responsive within 6 min to N-acetylchitoheptaose, a potent biotic elicitor for phytoalexin biosynthesis. Analyses of the sequence of the cDNAs showed that both of EL2 and EL3 encoded basic proteins with no significant similarities to those of known genes.
Assuntos
Genes de Plantas , Oryza/genética , Extratos Vegetais/biossíntese , Sequência de Aminoácidos , DNA Complementar/genética , DNA de Plantas/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Dados de Sequência Molecular , Oligossacarídeos/farmacologia , Oryza/efeitos dos fármacos , Oryza/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Sesquiterpenos , Terpenos , FitoalexinasRESUMO
Probenazole (3-allyloxy-1,2-benzisothiazole-1,1-dioxide) induces disease resistance in rice against rice blast fungus. To investigate the molecular mechanism of probenazole-induced resistance, we isolated and characterized a cDNA clone of a probenazole-inducible gene in rice, which encoded a protein designated PBZ1. Sequence analysis revealed that significant homology at the amino acid level exists between the predicted PBZ1 protein and intracellular pathogenesis-related (IPR) proteins. Accumulation of PBZ1 mRNA was not induced by wounding, but markedly induced by inoculation with rice blast fungus. In addition, it was induced sooner by inoculation with an incompatible race than that with a compatible race. On the other hand, when the accumulation of the PBZ1 mRNA was examined after treatment with probenazole-related compounds, it was not fully correlated with anti-rice blast activity. However, it was induced after treatment with N-cyano-methyl-2-chloro-isonicotinamide (NCI), which belongs to another group of compounds known to induce disease resistance. Thus, although the accumulation of the PBZ1 mRNA was not fully correlated with anti-rice blast activity, our findings suggest that the PBZ1 gene has an important function during the disease resistance response in rice.