Disease relevance of PR1

• The Arabidopsis PAD4 gene previously was found to be required for expression of multiple defense responses including camalexin synthesis and PR-1 gene expression in response to infection by the bacterial pathogen Pseudomonas syringae pv. maculicola [1].

High impact information on PR1

• In the npr1-1 background, the sni1 (suppressor of npr1-1, inducible 1) mutant shows near wild-type levels of PR1 expression and resistance to pathogens after induction [2].
• The expression of systemic acquired resistance (SAR) in plants involves the upregulation of many Pathogenesis-Related (PR) genes, which work in concert to confer resistance to a broad spectrum of pathogens [3].
• We show that TGA2 and NPR1 are recruited to PR-1 independently of each other and of SA treatment [4].
• Although ssi2 fad6 plants are rescued in their morphological phenotypes, including larger size, absence of visible lesions, and straight leaves, these plants continue to exhibit microscopic cell death and express the PR-1 gene constitutively [5].
• Intact LOS and the lipid A and core oligosaccharides derived from it were all able to induce the defense-related genes PR1 and PR2 in Arabidopsis and to prevent the hypersensitive response caused by avirulent bacteria [6].

Biological context of PR1

• Analysis of marker gene expression using these HIFs indicated a negative correlation between the induced amount of transcripts of SA-dependent genes PR1, ICS and PR5, and the in planta bacterial growth in the HIF segregating at PRP-Ps2 locus, suggesting an implication of PRP-Ps2 in the activation of SA dependent responses [7].
• Two additional PR-1-like genes were identified through in-silico analysis of apple ESTs deposited in GenBank [8].
• The thaxtomin A-induced form of programmed cell death (PCD) was not a typical HR, since defence responses generally preceding or associated with the HR, such as rapid medium alkalization, oxidative burst and expression of defence-related genes PR1 and PDF1.2, were not observed in plant cells following addition of thaxtomin A [9].
• We have characterized cis-acting regulatory elements in the PR-1 promoter involved in INA induction using deletion analysis, linker-scanning mutagenesis, and in vivo footprinting [10].
• High signal ratios of the ChIP sample versus raw chromatin for clusters of neighboring probes provided evidence for 51 putative binding sites for TGA2, including the only previously confirmed site in the promoter of PR-1 (At2g14610) [11].

Associations of PR1 with chemical compounds

• These WRKY25-overexpressing plants also displayed reduced expression of the SA-regulated PR1 gene after the pathogen infection, despite normal levels of free SA [12].
• In addition, the pathogenesis-related (PR) genes encoding beta-1,3-glucanase, osmotin, and PR1 were constitutively expressed in 35S::VR-EIL lines without added ethylene, and were hyperinduced in response to ethylene treatment [13].
• Treatment of Arabidopsis ecotype Columbia-0 plants with thiamine resulted in the activation of PR-1 but not PDF1 [14].
• Furthermore, benzothiadiazole, a functional analog of salicylic acid, induced PR1 expression faster and to a higher level in the AtNPR1-expressing wheat than in the nontransgenic plants [15].

Regulatory relationships of PR1

• The susceptibility of WRKY33-over-expressing plants to P. syringae is associated with reduced expression of the salicylate-regulated PR-1 gene [16].
• PR1 expression is induced rapidly to a high level in the fungus-challenged spikes of the AtNPR1-expressing wheat [15].

Other interactions of PR1

• Ectopic CAPIP2 expression in Arabidopsis was accompanied by the expression of Arabidopsis PR-1 and PDF1.2 genes [17].

References