The Arabidopsis DREB1A gene driven by the stress-inducible rd29A promoter increases salt-stress tolerance in proportion to its copy number in tetrasomic tetraploid potato (Solanum tuberosum)
Transgenic potato lines of cv. Desiree containing the <i>DREB1A</i> gene driven by the <i>rd29A</i> promoter were generated using <i>Agrobacterium</i>-mediated transformation. The morphological appearance of the 120 transgenic lines was classified into three categories as determined by <i>in vitro</i> test-tube evaluation. Southern blot analyses of genomic DNA were conducted using the restriction enzymes <i>Hin</i>dIII and <i>Dra</i>I. There were significant differences between the transgenic lines and DSC in the quantitative salinity-tolerance evaluations at 1 M NaCl. Two transgenic lines were recognized as highly tolerant to salinity based on Duncan multiple range testing. Furthermore, there was a significant correlation between the mean tolerance level of the transgenic lines and the <i>DREB1A</i> copy number estimated from the Southern hybridization experiments. Northern hybridization experiments were subsequently done using a <i>DREB1A</i> cDNA probe and transgenic lines with different levels of salinity tolerance. Salt-tolerant transgenic lines expressed substantially more of the transgene at 2 to 5 h of salt treatment, after which the expression returned to basal levels. These observations suggest that the gene transfer of <i>rd29A::DREB1A</i> can be used to increase the salt tolerance of important agricultural crops, such as tetrasomic polyploid potatoes, as occurs in diploid model species, such as <i>Arabidopsis</i>.
- Plant biotechnology
Plant biotechnology 23(2), 169-177, 2006-03-01
Japanese Society for Plant Cell and Molecular Biology