TY - JOUR
T1 - Evidence that the BONZAI1/COPINE1 protein is a calcium- and pathogen-responsive defense suppressor
AU - Lee, Tzuu Fen
AU - McNellis, Timothy W.
N1 - Funding Information:
Acknowledgements We thank Dr. Brian J. Staskawicz for the ndr1-1 seeds and Dr. Xin Li for the snc1 seeds. This work was supported in part by a United States Department of Agriculture Cooperative State Research, Education, and Extension Service grant program (USDA-CSREES grant no. 2002-35319-11561 to T. W. M.). This work was also supported by the Department of Plant Pathology at the Pennsylvania State University and by the Intercollege Graduate Program in Plant Biology at the Pennsylvania State University.
PY - 2009/1
Y1 - 2009/1
N2 - Copines are calcium-responsive, phospholipid-binding proteins involved in cellular signaling. The Arabidopsis BONZAI1/COPINE1 (BON1/CPN1) gene is a suppressor of defense responses controlled by the disease resistance (R) gene homolog SNC1. The BON1/CPN1 null mutant cpn1-1 has a recessive, temperature- and humidity-dependent, lesion mimic phenotype that includes activation of Pathogenesis-Related (PR) gene expression. Here, we demonstrated that the accumulation of BON1/CPN1 protein in wild-type plants was up-regulated by bacterial pathogen inoculation and by the activation of defense signaling responses controlled by two R genes, SNC1 and RPS2. Interestingly, however, over-accumulation of BON1/CPN1 in two BON1/CPN1 promoter T-DNA insertion mutants did not affect resistance to a bacterial pathogen. Promoter deletion analysis identified a 280 bp segment of the BON1/CPN1 promoter as being required for pathogen-induced gene expression; the same promoter region was also required for calcium ionophore-induced gene expression. Leaf infiltration with calcium ionophore triggered high-level PR gene expression specifically in cpn1-1 plants grown under permissive conditions, while co-infiltration of the calcium chelator EGTA attenuated this effect. These results explain the conditional nature of the cpn1-1 phenotype and are consistent with BON1/CPN1 being a calcium- and pathogen-responsive plant defense suppressor.
AB - Copines are calcium-responsive, phospholipid-binding proteins involved in cellular signaling. The Arabidopsis BONZAI1/COPINE1 (BON1/CPN1) gene is a suppressor of defense responses controlled by the disease resistance (R) gene homolog SNC1. The BON1/CPN1 null mutant cpn1-1 has a recessive, temperature- and humidity-dependent, lesion mimic phenotype that includes activation of Pathogenesis-Related (PR) gene expression. Here, we demonstrated that the accumulation of BON1/CPN1 protein in wild-type plants was up-regulated by bacterial pathogen inoculation and by the activation of defense signaling responses controlled by two R genes, SNC1 and RPS2. Interestingly, however, over-accumulation of BON1/CPN1 in two BON1/CPN1 promoter T-DNA insertion mutants did not affect resistance to a bacterial pathogen. Promoter deletion analysis identified a 280 bp segment of the BON1/CPN1 promoter as being required for pathogen-induced gene expression; the same promoter region was also required for calcium ionophore-induced gene expression. Leaf infiltration with calcium ionophore triggered high-level PR gene expression specifically in cpn1-1 plants grown under permissive conditions, while co-infiltration of the calcium chelator EGTA attenuated this effect. These results explain the conditional nature of the cpn1-1 phenotype and are consistent with BON1/CPN1 being a calcium- and pathogen-responsive plant defense suppressor.
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U2 - 10.1007/s11103-008-9413-6
DO - 10.1007/s11103-008-9413-6
M3 - Article
C2 - 18855102
AN - SCOPUS:56949084032
SN - 0167-4412
VL - 69
SP - 155
EP - 166
JO - Plant molecular biology
JF - Plant molecular biology
IS - 1-2
ER -