Abstract
A glutathione transferase (GST) related to the theta (T) class of enzymes found in plants and animals has been cloned from the potato pathogen Phytophthora infestans. The cDNA encoded a 25 kDa polypeptide termed PiGSTT1 which was expressed in E. coli as the native protein. The purified recombinant enzyme behaved as a dimer (PiGSTT1-1) and while being unable to catalyse the glutathione conjugation of 1-chloro-2,4-dintrobenzene, was highly active as a glutathione peroxidase with organic hydroperoxide substrates. In addition to reducing the synthetic substrate cumene hydroperoxide, PiGSTT1-1 was shown to be highly active toward 9(S)-hydroperoxy-(10E,12Z,15Z)-octadecatrienoic acid = 9(S)-HPOT, which is formed in potato plants during infection by P. infestans as a precursor of the antifungal oxylipin colnelenic acid. An antiserum was raised to PiGSTT1-1 and used to demonstrate that the respective enzyme was abundantly expressed in P. infestans both cultured on pea agar and during the infection of potato plants.
Original language | English |
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Pages (from-to) | 1427-1434 |
Number of pages | 8 |
Journal | Phytochemistry |
Volume | 67 |
Issue number | 14 |
Early online date | 23 Jun 2006 |
DOIs | |
Publication status | Published - 01 Jul 2006 |
Keywords
- detoxification
- glutathione peroxidase
- oxylipin
- phytoalexin
- phytopathogenic fungi
- phytophthora infestans
- potato
- solanum tuberosum