Expression of the hypersensitive response-assisting protein in Arabidopsis results in harpin-dependent hypersensitive cell death in response to Erwinia carotovora.
Active defense mechanisms of plants against pathogens often include a rapid plant cell death known as the hypersensitive cell death (HCD). Hypersensitive response-assisting protein (HRAP) isolated from sweet pepper intensifies the harpin(Pss)-mediated HCD. Here we demonstrate that constitutive expression of the hrap gene in Arabidopsis results in an enhanced disease resistance towards soft rot pathogen, E. carotovora subsp. carotovora. This resistance was due to the induction of HCD since different HCD markers viz. Athsr3, Athsr4, ion leakage, H(2)O(2) and protein kinase were induced. One of the elicitor harpin proteins, HrpN, from Erwinia carotovora subsp. carotovora was able to induce a stronger HCD in hrap-Arabidopsis than non-transgenic controls. To elucidate the role of HrpN, we used E. carotovora subsp. carotovora defective in HrpN production. The hrpN(-) mutant did not induce disease resistance or HCD markers in hrap-Arabidopsis. These results imply that the disease resistance of hrap-Arabidopsis against a virulent pathogen is harpin dependent.
Pandey
Ajay-Kumar
AK
Institute of Plant and Microbial Biology, Academia Sinica 115, Taipei, Taiwan.
Ger
Mang-Jye
MJ
Huang
Hsiang-En
HE
Yip
Mei-Kuen
MK
Zeng
Jiqing
J
Feng
Teng-Yung
TY
D017360:Arabidopsis / Q000166:cytology* / Q000235:genetics / Q000378:metabolism / Q000382:microbiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism*; D016923:Cell Death; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D016973:Pectobacterium carotovorum / Q000502:physiology*; D010935:Plant Diseases / Q000382:microbiology*; D030821:Plants, Genetically Modified; D013997:Time Factors
D029681:Arabidopsis Proteins; D001425:Bacterial Outer Membrane Proteins; C075462:harpin protein, Erwinia amylovora; C506621:hypersensitive response-assisting protein, Arabidopsis; D019204:GTP-Binding Proteins