Effects of simultaneous expression of heterologous genes involved in phytochelatin biosynthesis on thiol content and cadmium accumulation in tobacco plants.
Transgenic tobacco (Nicotiana tabacum cv. LA Burley 21) lines expressing three genes encoding enzymes thought to be critical for the efficient production of phytochelatins, (i) serine acetyltransferase (EC 2.3.1.30) involved in the production of O-acetylserine, the cysteine precursor, (ii) gamma-glutamylcysteine synthetase (EC 6.3.2.2) involved in the production of gamma-glutamylcysteine, the precursor of glutathione, and (iii) phytochelatin synthase (EC 2.3.2.15), were obtained and analysed for non-protein thiol content and cadmium accumulation. After a 3 week exposure to 15 microM CdCl2, plants expressing transgenes (either separately or in combination) had increased cadmium concentration in roots but not in shoots compared with the wild type. Nearly all transgenic lines analysed had more non-protein thiols than the wild type. The greatest effects (about 8-fold elevation of thiols) were found in one of the lines simultaneously expressing the three transgenes. Despite the fact that a multi-transgene strategy described in this work resulted in a strong increase in the levels of several classes of non-protein thiols in transgenic plants, other factors appeared to restrict cadmium accumulation in shoots.
Wawrzynski
Adam
A
Institute of Biochemistry and Biophysics, Polish Academy of Sciences, ul. Pawińskiego 5A, 02-106 Warsaw, Poland.
Kopera
Edyta
E
Wawrzynska
Anna
A
Kaminska
Jolanta
J
Bal
Wojciech
W
Sirko
Agnieszka
A
D019881:Aminoacyltransferases / Q000235:genetics / Q000378:metabolism; D002104:Cadmium / Q000378:metabolism*; D015870:Gene Expression; D017343:Genes, Plant; D005721:Glutamate-Cysteine Ligase / Q000235:genetics / Q000378:metabolism; D005978:Glutathione / Q000096:biosynthesis*; D054811:Phytochelatins; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000378:metabolism; D051050:Serine O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D013438:Sulfhydryl Compounds / Q000378:metabolism*; D014026:Nicotiana / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*
D013438:Sulfhydryl Compounds; D002104:Cadmium; D054811:Phytochelatins; D051050:Serine O-Acetyltransferase; D019881:Aminoacyltransferases; C093784:glutathione gamma-glutamylcysteinyltransferase; D005721:Glutamate-Cysteine Ligase; D005978:Glutathione