Brachypodium distachyon Transcriptome or Gene expression. Brachypodium distachyon

To explore the usefulness of Brachypodium distachyon for drought studies, a reproducible in soil drought assay was developed. Spontaneous soil drying led to a 45% reduction in leaf size, and this most mostly due to a decrease in cell expansion, whereas cell division remained largely unaffected by drought. To investigate the molecular basis of the observed leaf growth reduction, Brachypodium leaf 3 was dissected in three zones, namely the proliferation, expansion and mature zone, and subjected to transcriptome analysis using a Affymetrix whole-genome tiling array. This approach allowed us to highlight that transcriptome profiles of different developmental leaf zones respond differently to drought. Several genes and biological processes involved in drought tolerance were identified. Mainly, we observed an increased energy availability in the proliferation zone along with an upregulation of sterol synthesis that may influence membrane fluidity. Overall design: 24 samples of Brachypodium leaf 3 harvested about 24 hours after the emergence of leaf 3, mild drought stress was performed for 2 biological replicates, severe drought stress and control condition was performed for 3 biological replicates. 3 developmental zones, namely the proliferation, expansion and mature zone, are dissected from leaf 3.