Expression of betaine aldehyde dehydrogenase gene in transgenic tomato hairy roots leads to the accumulation of glycine betaine and contributes to the maintenance of the osmotic potential under salt stress

Genetically engineered tomato hairy root lines with the ability to synthesi ze glycine betaine were established by introducing the betaine aldehyde deh ydrogenase gene (BADH-1) from sorghum plants. The lines showed a mikimopine activity, confirming the transformation with pRi plasmid. The stable integ ration of the BADH gene into the tomato genome was confirmed by Southern bl otting analysis. The expression of BADH mRNA could be detected in the tomat o hairy roots by Northern analysis, The osmotic potential(Psi (S)) of the t ransgenic hairy roots was sufficient to allow water uptake. The accumulatio n of betaine was detected by H-1-NMR analysis. The accumulation of betaine in the transgenic hairy roots contributed to the maintenance of the osmotic potential of the cells.