Drought-tolerance phenotypes (right side) of transgenic cotton correlated with increased root biomass (lower right) for a "stacked" line over-expressing Arabidopsis AtRAV2 and AtABI5 transcription factor genes.  Left side images show severe wilting and relatively smaller root biomass of deficit-irrigated control Coker312 genotype. Upper images were taken in the evening after withholding water for 10 days (34 days after sowing).  Comparison of leaf turgidity and root mass in control Coker312 (left side) versus stacked RAV2^4-8-1 x ABI5^13-4-1 transgenic progeny line (right side) after 90 days growth under repeated deficit irrigation treatments shows drought adaptation by the stacked transgenic line.