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

Abstract

Genetically engineered tomato hairy root lines with the ability to synthesize glycine betaine were established by introducing the betaine aldehyde dehydrogenase gene (BADH-1) from sorghum plants. The lines showed a mikimopine activity, confirming the transformation with pRi plasmid. The stable integration of the BADH gene into the tomato genome was confirmed by Southern blotting analysis. The expression of BADH mRNA could be detected in the tomato hairy roots by Northern analysis. The osmotic potential (Ψ _s) of the transgenic hairy roots was sufficient to allow water uptake. The accumulation of betaine was detected by ¹H-NMR analysis. The accumulation of betaine in the transgenic hairy roots contributed to the maintenance of the osmotic potential of the cells.

Key Words:

• glycine betaine
• hairy root
• salt tolerance
• tomato
• transformation