Gene expression in root growth processes
The EU-funded project TRANSPHO (Roles of non-coding RNAs in translational regulation during root developmental adaptation to phosphate starvation) was established to increase understanding of root growth processes, thereby improving crop plants through more environmentally friendly practices. One of the basic responses to abiotic stress is the alteration of gene expression, which can be regulated at multiple levels, including transcription, processing, translation and post-translational modifications. Translational control, regulation of the initiation and elongation or termination of ribosomes on a messenger RNA (mRNA), enables cells to rapidly control gene expression in response to environmental and developmental cues. Long non-coding RNAs (lncRNAs) are important regulators of gene expression in a variety of biological processes and in multiple species. They have been shown to regulate a wide range of biological processes, including stress responses. However, little is known about the impact of lncRNAs on translational regulation in plants. Researchers therefore adapted advanced technologies to plant biology in order to isolate ribosomes with a high purity from virtually any cell type and to sequence mRNA fragments. By employing this method TRANSPHO scientists were able to precisely map the position and number of ribosomes on RNAs at a genome-wide level. This new approach was used to monitor ribosome position and number across RNA transcripts in Arabidopsis roots undergoing phosphate deprivation. Researchers found that lncRNAs actually represent a reservoir of new small peptides, and identified potential translation of several hundred of them in the genome. Corresponding peptides were detected for 70 of them using mass spectrometry. TRANSPHO also revealed the association of hundreds of long non-coding antisense RNAs (NATs) with Arabidopsis ribosomes. NATs are RNA molecules complementary to endogenous mRNAs that act as regulators of the adaptation in plants to a wide range of environments. Project work is slated to lead to new tools for modulating gene expression in plants.
Keywords
Gene expression, root growth, TRANSPHO, translational regulation, ribosomes, lncRNA
