Poster: Oxidative stress

Abs # 90: Functional role of a one-Cys Prx in transgenic Tobacco

Presenter:	Jang, Ho Hee , archaea65@hotmail.com
Authors	Jang, Ho Hee  (A)   Jung, Bae Gyo  (A)   Jung, Ji Hyun  (A)   Jeon, Min Gyu  (A)   Kim, Sun Young  (A)   Lee, Young Mee  (A)   Cho, Moo Je  (A)   Lee, Sang Yeol  (A)
Affiliations:	(A): Environmental Biotechnology Research Center

We have identified a cDNA encoding plant 1Cys-peroxiredoxin using yeast two-hybrid screening technique. To investigate in vivo the real function of this protein, we generated transgenic tobacco plants constitutively expressing the R1C-Prx gene. The wild type and the transgenic R1C-Prx plants did not differ in their germination frequency, and both seeds exhibited more than 95% germination at 6days after imbibition. To measure the resistance of the transgenic R1C-Prx plants to radical stress, the whole wild type and transgenic R1C-Prx plants were infiltrated with 5mM H2 O2 solution and analyzed the oxidative damage of the plants. Then, the wild type tobacco plants showed serious lesions up to 12th or 13th leaf from the top, whereas the transgenic R1C-Prx plants showed similar damage only up to the 4th or 5th. The resistance against oxidative stress was confirmed again by employing an OxiBlot reagent kit, which immunologically detects the carbonyl group on oxidized proteins. The DNP-hydrazone generated from the reaction of protein carbonyl groups with 2,4-dinitrophenyldrazine, can be detected by an antibody specific to the DNP moiety on the proteins. In this experiment, the protein carbonyl contents present in the 10th leaf from the bottom of the transgenic R1C-Prx plants treated with 5mM H2 O2 were much less than those of wild type plants. From these results, it can be concluded that the in vivo function of 1Cys-Prx in plants may not be related to the maintenance of seed dormancy, but rather to protective activity against oxidative stress. [This work was supported by a grant from KoSEF to the EBRC (grant#:R15-2003-012-01001-0)]