ISSN:
1365-3040
Quelle:
Blackwell Publishing Journal Backfiles 1879-2005
Thema:
Biologie
Notizen:
The bacterial gene mtlD, which encodes mannitol 1-phosphate dehydrogenase (E. C. 1. 1. 1. 17), was transformed into Arabidopsis thaliana and expressed under control of the CaMV 35S promoter. MtlD-transformants accumulated mannitol, a sugar alcohol that is not normally found in Arabidopsis. Amounts of soluble carbohydrates, sucrose, glucose, fructose, myo-inositol and mannitol were determined in different tissues of wild-type and transgenic plants. We estimated that less than 1& of the carbon assimilated was converted into mannitol by the transgenic plants. The establishment of individual transformed lines (after self-crossing three times) resulted in high and low mannitol-producing lines which were stably maintained. The presence of mannitol did not alter plant appearance or growth habit. When MtlD-expressing seeds and control seeds (T3 generation) were imbibed with solutions containing NaCl (range 0 to 400 mol m−3), transgenic seeds containing mannitol germinated in medium supplemented with up to 400 mol m−3 NaCl, while control seeds ceased germination at 100 mol m−3 NaCl. It is doubtful whether the ability to germinate in high salt was a result of an osmotic effect exerted by elevated levels of mannitol, considering that mannitol concentrations were in the mol m−3 range in seeds. A specific effect of polyols, for example on the integrity of subcellular membranes or enzymes, cannot be excluded.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1111/j.1365-3040.1995.tb00584.x
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