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Sorin, C.

Publications and source records attributed to Sorin, C..

3 recordsLinked to original sources

The transcription factor NF-YA10 determines the area explored by Arabidopsis thaliana roots through direct regulation of LAZY and TAC genes

Root developmental plasticity relies on transcriptional reprogramming, which largely depends on the activity of transcription factors (TFs). NF-YA2 and NF-YA10 (Nuclear Factor A2 and A10) are down-regulated by the specific miRNA isoform miR169defg, in contrast to miR169a. Here, we analyzed the role of the Arabidopsis thaliana TF NF-YA10 in the regulation of lateral root development. Plants expressing a version of NF-YA10 resistant to miR169 cleavage showed a perturbation in the lateral root gravitropic response. By extracting novel features of root architecture using the ChronoRoot deep-learning-based phenotyping system, we uncovered a differential emergence angle of lateral roots over time when compared to Col-0. Detailed phenotyping of root growth dynamics revealed that NF-YA10 activity modulates the area explored by Arabidopsis roots. Furthermore, we found that NF-YA10 directly regulates TAC1 and LAZY genes by targeting their promoter regions, genes previously linked to gravitropism. Hence, the TF NF-YA10 is a new element in the control of LR gravitropism and root system architecture.

plant biology↗

A conserved HSF:miR169:NF-YA loop involved in tomato and Arabidopsis heat stress tolerance

Regulatory feedbacks are at the basis of different stress and developmental networks in plants. Here, we report that tomato and Arabidopsis plants improve their heat stress tolerance through Heat stress transcription factor (HSF)-mediated transcriptional regulation of MIR169 and post-transcriptional regulation of NF-YA transcription factors. We show that HSFs recognize tomato and Arabidopsis MIR169 promoters using yeast-one-hybrid/ChIP-qPCR. Silencing tomato HSFs using virus-induced-gene-silencing (VIGS) reduce Sly-MIR169 levels and enhance Sly-NF-YA9/A10 target expression. Further, tomato transgenic plants overexpressing Sly-MIR169 and Sly-NF-YA9/A10-VIGS knock-down tomato plants as well as Arabidopsis plants overexpressing At-MIR169d and At-nf-ya2 mutants showed a link with increased heat tolerance. In contrast, Arabidopsis plants overexpressing At-NF-YA2, or those expressing a non-cleavable At-NF-YA2 form (miR169-resistant At-NF-YA2) as well as plants inhibited for At-miRNA169d regulation (miR169d mimic plants) were more sensitive to heat stress, highlighting NF-YA as negative regulator of heat tolerance. Furthermore, post-transcriptional cleavage of NF-YA by elevated miR169 levels result in alleviating the repression of heat stress effectors HSFA7a/b in tomato and Arabidopsis revealing a retroactive control of HSFs by the miR169:NF-YA node. Hence, a regulatory feedback loop involving HSFs, miR169s and NF-YAs plays a critical role in the regulation of heat stress response in tomato and Arabidopsis plants.

genomics↗

Two ecotype-related long non-coding RNAs in the environmental control of root growth

BackgroundRoot architecture varies widely between species and even between ecotypes of the same species despite the strong conservation of the protein-coding portion of their genomes. In contrast, non-coding RNAs evolved rapidly between ecotypes and may control their differential responses to the environment as several long non-coding RNAs (lncRNAs) can quantitatively regulate gene expression.\n\nResultsRoots from Columbia (Col) and Landsberg erecta (Ler) ecotypes respond differently to phosphate starvation. We compared complete transcriptomes (mRNAs, lncRNAs and small RNAs) of root tips from these two ecotypes during early phosphate starvation. We identified thousands of new lncRNAs categorized as intergenic or antisense RNAs that were largely conserved at DNA level in these ecotypes. In contrast to coding genes, many lncRNAs were specifically transcribed in one ecotype and/or differentially expressed between ecotypes independently of the phosphate condition. These ecotype-related lncRNAs were characterized by analyzing their sequence variability among plants and their link with siRNAs. Our analysis identified 675 lncRNAs differentially expressed between the two ecotypes including specific antisense RNAs targeting key regulators of root growth responses. Mis-regulation of several intergenic lncRNAs showed that at least two ecotype-related lncRNAs regulate primary root growth in Col.\n\nConclusionsThe in depth exploration of the non-coding transcriptome of two ecotypes identified thousands of new lncRNAs showing specific expression in root apexes. De-regulation of two ecotype-related lncRNAs revealed a new pathway involved in the regulation of primary root growth. The non-coding genome may reveal novel mechanisms involved in ecotype adaptation of roots to different soil environments.

plant biology↗