Transcriptional repression of GTL1 by water-deficit stress promotes anthocyanin and polyamine biosynthesis to enhance drought tolerance

GT2-LIKE 1 (GTL1) is a negative regulator of stomatal development and its repressed expression under water deficit can result in enhanced drought tolerance. As a transcription factor, GTL1 has been implicated in diverse developmental roles. We hypothesized that GTL1 represses multiple drought tolerance pathways, leading to the drought tolerance phenotype of the gtl1-4 knockout mutant. RNA-Seq data indicates that GTL1 regulates genes involved in ribosome biogenesis in emerging leaves and secondary metabolite synthesis in expanding leaves. RNA was collected from emerging and expanding leaves of Col-0 wildtype Arabidopsis thaliana and the knockout mutant gtl1-4 that had been maintained under well-watered or a 30% media water content water-deficit stress. There were three biological replicates per genotype/treatment/leaf age combination, with 10 plants were pooled into a replicate. Emerging leaves were sampled one-day post-emergence and expanding leaves sampled at 14/15 days post-emergence.