Disease relevance of CPR5

• The cpr5 plants were found to be constitutively resistant to two virulent pathogens, Pseudomonas syringae pv maculicola ES4326 and Peronospora parasitica Noco2; to have endogenous expression of the pathogenesis-related gene 1 (PR-1); and to have an elevated level of salicylic acid (SA) [1].

High impact information on CPR5

• These latter results indicate that cpr5 and cpr6 regulate resistance through distinct pathways and that SA-mediated, NPR1-independent resistance works in combination with components of the JA/ET-mediated response pathways [2].
• However, the cpr5 npr1 plants retained heightened resistance to P. parasitica Noco2 and elevated expression of the defensin gene PDF1.2, implying that NPR1-independent resistance signaling also occurs [1].
• Therefore, we conclude that cpr5 acts upstream of SA in inducing SAR [1].
• CPR5 is involved in cell proliferation and cell death control and encodes a novel transmembrane protein [3].
• The dual role of CPR5 in cell proliferation and cell death control suggests a regulatory link between these two processes [3].

Biological context of CPR5

• Identification of a novel gene HYS1/CPR5 that has a repressive role in the induction of leaf senescence and pathogen-defence responses in Arabidopsis thaliana [4].
• The analysis of the cellular phenotypes of two T-DNA-tagged cpr5 alleles revealed an additional role for CPR5 in the regulation of endoreduplication and cell division [3].
• This type of programmed cell death is mimicked by the constitutive pathogene response5 (cpr5) mutant in Arabidopsis in the absence of pathogens, suggesting a role for CPR5 in programmed cell death control [3].
• First, the constitutive disease resistance exhibited by cpr1, cpr5, and cpr6 is completely suppressed by the SA-deficient eds5 mutant but is only partially affected by the SA-insensitive npr1 mutant [2].
• Furthermore, we found that the constitutive expressor of pathogenesis-related genes 5 (cpr5) mutant, which shows spontaneous pathogen-defence responses and abnormal trichomes, has a point mutation in the HYS1 gene, suggesting that these independently isolated mutants are allelic to each other [4].

Associations of CPR5 with chemical compounds

• In addition, cpr5 and cpr6 induce expression of PDF1.2, a defense-related gene associated with activation of the jasmonate/ethylene-mediated resistance pathways. cpr5 also forms spontaneous lesions [5].

Regulatory relationships of CPR5

• The cpr5 mutant of Arabidopsis expresses both NPR1-dependent and NPR1-independent resistance [1].

References