Project description:Purpose: The goal of this study was to investigate the mechanisms involved in the initiation and development of crown-roots (CRs) in barley and to estimate the role of cytokinins (CKs) in this process. Method: stranded libraries were obtained from RNA extracted from the stem base of 1 day-after-germination (DAG) and 10DAG-seedlings of wild-type (WT) and AtCKX-overexpressing barley lines (OE-CKX). OE-CKX lines have a reduced content of endogenous CKs and are characterized by a higher number of CRs. Libraries were deep sequenced on Illumina HighSeq platform. Each sample was investigated in three independent biological replicates. Results: Using a data analysis workflow optimized for barley, we identified more than 4000 transcripts differentially expressed in the stem base of 1DAG and 10DAG-seedlings. Expression as determined by RNA-seq was validated by real-time PCR. Our data were compared to the transcriptomic profiling obtained from rice and we were able to identify genes potentially involved in the initiation/development of CRs in barley. Also the use of the transgenic line with altered endogenous CK content allowed us to conclude about the role of CKs in the process. Conclusions: Our study represents the first analysis aiming to understand the initiation and development of CRs in barley.
Project description:The molecular regulation of root initiation in monocots is still poorly understood. We report the development of the auxin-based crown-root inducible system (CRIS) in barley (Hordeum vulgare L.). Using this system coupled to RNAseq, we investigated the molecular events occurring during the early steps of crown-root (CR) initiation. The sequencing on the Illumina NovaSeq6000 platform yielded over 123 Gb data, representing more than 408 million reads. Using the last released barley annotation (Morex v2 Gene Models, 2019), we found that 427 genes were downregulated by auxin whereas 764 genes were upregulated. This study provides the first analysis of early event of crown-root initiation in cereals. It will serve as comparison with known genes in rice, maize and other cereals, and could be used in metagenomics studies.