The role of RNA interference in plant response to hypoxia

The response of plants to stress includes a genome-transcription reprogramming that consist in the activation of genes involved in direct stress protection and genes that encode regulatory proteins, whereas genes involved in growth are generally repressed (Mittler et al., 2012). Interestingly, miRNAs have been shown to play a role in the responses to hypoxia in animals (Crosby et al., 2009), and evidences are also available suggesting that hypoxia modulates the expression of various miRNAs in Arabidopsis roots (Moldovan et al., 2009; Licausi et al., 2011) and in corn roots (Zhai et al. 2013). We investigated the contribution of RNA-silencing, a complex of regulatory process that negatively affect gene expression, to plants tolerance to submergence. We first analysed how miRNAs abundance changed upon plant submergence, using Arabidopsis thaliana as model system. Moreover, we investigated if the expression level of the identified hypoxia-responsive miRNAs was directly regulated by the ERFVII transcription factors. Finally, we performed transcriptomic analysis to study the hypoxic response of mutants affected in post-transcriptional gene silencing (PTGS) and RNA-directed DNA methylation (RdDM).