Increased thiol biosynthesis of transgenic poplar expressing a wheat O-acetylserine(thiol) lyase enhances resistance to hydrogen sulfide and sulfur dioxide toxicity.
O-acetylserine(thiol) lyase (OASTL), a key enzyme of the plant sulfur assimilatory pathway, catalyses the formation of cysteine from sulfide and O-acetylserine. Transgenic hybrid poplar (Populus sieboldi x P. grandidentata 'Y63') plants expressing cys1, encoding a wheat cytosolic OASTL, were developed in order to examine the role of this enzyme in thiol production following hydrogen sulfide or sulfur dioxide exposure and in the extent of damage induced in the plants by these pollutants. The transgenic cys1 plants accumulated up to several-fold higher cysteine and glutathione levels and were significantly more resistant in terms of foliar damage to the pollutants than WT plants. The transgenic poplar also showed higher tolerance to sulfite and hydrogen peroxide and, interestingly, accumulated several-fold higher sulfite reductase transcripts than WT plants in response to sulfur dioxide. These data clearly demonstrate the important role of OASTL and the sulfur reduction pathway in sulfur and oxidative stress amelioration, and support the notion that transgenic trees resistant to such pollutants can be generated for phytoremediation strategies.
Nakamura
Michimi
M
Department of Molecular Chemistry, Faculty of Science, Chiba University, Chiba, Japan.
Kuramata
Masato
M
Kasugai
Isao
I
Abe
Midori
M
Youssefian
Shohab
S
D015152:Blotting, Northern; D019757:Carbon-Oxygen Lyases / Q000235:genetics*; D006862:Hydrogen Sulfide / Q000633:toxicity*; D008957:Models, Genetic; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D032107:Populus / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D013438:Sulfhydryl Compounds / Q000378:metabolism* / Q000502:physiology; D013458:Sulfur Dioxide / Q000633:toxicity*; D014908:Triticum / Q000235:genetics*
D013438:Sulfhydryl Compounds; D013458:Sulfur Dioxide; C018725:O-acetylhomoserine (thiol)-lyase; D019757:Carbon-Oxygen Lyases; D006862:Hydrogen Sulfide