Poster: Plant-pathogen interactions
Abs #
541: Hypersensitive response induced by Erwinia carotovora in HRAP Arabidopsis was harpin mediated.
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Presenter: |
Pandey, Ajay K, shimla_akp@yahoo.com | Authors | Pandey, Ajay K (A) Ger, Man-jey (A) Huang, Hsuang En (A) Feng, Teng-yung (A) | | Affiliations: |
(A): Institute of Botany, Academia Sinica, Taipei, Taiwan-115, ROC
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Hypersensitive response-assisting protein (HRAP) is plant protein isolated from sweet pepper which is highly developmental specific and the expression is associated with young leaves at the reproductive stages. Previous studies form our lab have shown that HRAP protein intensifies the harpinPss-mediated hypersensitive response (HR). Overexpresion of HRAP in transgenic tobacco showed host resistance to virulent bacterial pathogens (Pseudomonas syringae pv. tabaci and Erwinia carotovora subsp. carotovora) infection. We postulated that the disease resistance of transgenic plants may result from the induction of a HR by a virulent pathogen infection. The current study focuses on studying the different HR mechanisms shown by HRAP transgenic in Arabidopsis thaliana when infected with the bacteria Erwinia carotovora subsp carotovora (ECC). The HRAP Arabidopsis showed HR when infected with ECC. The hydrogen peroxide level was significantly increased in HRAP transgenic as compared to wild type when infected with ECC. A molecular HR marker which includes Athsr-3 and Athsr-4 were highly induced in HRAP transgenic than in wild type Arabidopsis. We detected induction of two protein kinases in Arabidopsis upon infection with ECC. They were hisghly induced in HRAP transgenic than in wild type Arabidopsis. We also used harpin defective mutant of ECC to further check the sensitivity of HRAP towards harpin. Interestingly, no HR was observed when HRAP transgenic were infected with harpin deficient ECC, resulting in the disease symptoms. H2O2 levels were significantly lower in Arabidopsis infected with harpin defective mutant of ECC. Thus, the above results suggested that disease resistance of hrap transgenic comes from the sensitivity towards bacterial harpin (elicitor protein).
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