Transcriptional and Posttranscriptional Regulation of Drought Stress Treatments in Brachypodium Leaves

Plant sensing drought stress conditions activate complex molecular networks leading to a rapid reprogram- ming of plant physiology and metabolism, in order to survive in suboptimal conditions. Here, we describe a standardized in vivo soil drought assay to investigate the effects of drought stress on leaf growth. Since it is now clear that stress responses can be specific to developmental stages and cell types, we describe a procedure to dissect the leaf in three distinct areas in order to study transcriptional and posttranscriptional gene regulation on both organ and cellular levels. Noncoding RNAs, both small RNAs and long noncoding RNAs, are emerging to be deeply involved in abiotic stress responses, acting as molecular switches, interconnecting different response pathways. Here, we illustrate the methodology that has been used to identify miRNAs involved in drought response and to analyze the modulation of expression of their putative targets, in order to gain a complete picture of transcriptional and posttranscrip- tional regulation driven by noncoding RNAs.