Project description:Shoot branching (SB) is an undesired trait in many crops, including tomato, as it may redirect assimilates away from developing flowers and fruits. Better understanding of the molecular mechanisms underlying bud arrest could help to generate plants with improved architecture and reduced lateral SB. We have previously shown that overexpression of the microRNA156 (miR156) in tomato increases the number of side branches; here, we have characterized in detail how the miR156/SQUAMOSA PROMOTER-BINDING PROTEIN-LIKE (SPL/SBP) hub modulates axillary bud (AB) development by connecting multiple phytohormones with known SB-associated genes. We have demonstrated that miR156-targeted SlSBPs modulate SB by regulating the action of distinct hormones, such as gibberellin, auxin and abscisic acid (ABA). Our results showed that plants overexpressing a miR156-resistant version of SlSBP15 (rSBP15) displayed arrest ABs throughout development.
Project description:MicroRNAs (miRNAs) play diverse roles in plant development, but whether and how miRNAs participate in thermomorphogenesis remains ambiguous. Here we show that HYPONASTIC LEAVES1 (HYL1) – a key component of microRNA biogenesis – acts downstream of the thermal regulator PHYTOCHROME INTERACTING FACTOR 4 in temperature-dependent plasticity of hypocotyl growth in Arabidopsis. A hyl1-2 suppressor screen identified a dominant dicer-like1 (dcl1) allele, dcl1-24, which rescues hyl1-2’s defects in miRNA biosynthesis and warm temperature-induced hypocotyl elongation. Genome-wide miRNA and transcriptome analysis reveal microRNA156 (miR156) and its target SQUAMOSA PROMOTER-BINDING-LIKE 9 (SPL9) as critical regulators of thermomorphogenesis. Surprisingly, perturbation of the miR156/SPL9 module disengages seedling responsiveness to warm temperatures by impeding auxin sensitivity. Moreover, the miR156-dependent auxin sensitivity also operates in the shade avoidance response at lower temperatures. Thus, these results unveil the miRNA156/SPL9 module as a previously-uncharacterized genetic circuitry that enables plant growth plasticity in response to environmental temperature and light changes.
Project description:MicroRNAs (miRNAs) play diverse roles in plant development, but whether and how miRNAs participate in thermomorphogenesis remains ambiguous. Here we show that HYPONASTIC LEAVES1 (HYL1) – a key component of microRNA biogenesis – acts downstream of the thermal regulator PHYTOCHROME INTERACTING FACTOR 4 in temperature-dependent plasticity of hypocotyl growth in Arabidopsis. A hyl1-2 suppressor screen identified a dominant dicer-like1 (dcl1) allele, dcl1-24, that rescues hyl1-2’s defects in miRNA biosynthesis and warm temperature-induced hypocotyl elongation. Genome-wide miRNA and transcriptome analysis reveal microRNA156 (miR156) and its target SQUAMOSA PROMOTER-BINDING-LIKE 9 (SPL9) as critical regulators of thermomorphogenesis. Surprisingly, perturbation of the miR156/SPL9 module disengages seedling responsiveness to warm temperatures by impeding auxin sensitivity. Moreover, the miR156-dependent auxin sensitivity also operates in the shade avoidance response at lower temperatures. Thus, these results unveil the miRNA156/SPL9 module as a previously-uncharacterized genetic circuitry that enables plant growth plasticity in response to environmental temperature and light changes.
Project description:To identify genomic targets involved in the EML-dependent control of seed development, we performed ChIP-chip using whole genome Arabidopsis tiling arrays from p35S::EML1-GFP seedlings using GFP antibodies. The analysis showed that EML1 displayed preferential binding to transposable elements (TEs), while showing no preference for protein coding genes.
Project description:To investigate the function of RNA-binding protein HRLP in flowering time control, we created hrlp-2 mutant and collected 9-day-old seedlings to perform RNA-seq.
Project description:DELLA proteins act as hubs that relay environmental information to the multiple transcriptional circuits that control growth and development through physical interaction with transcription factors from different families. We have analyzed the presence of one DELLA protein at the Arabidopsis genome by chromatin immunoprecipitation coupled to large-scale sequencing and we find that it binds at the promoters of multiple genes. Enrichment analysis shows a strong preference for cis elements recognized by specific transcription factor families. In particular, we demonstrate that DELLA proteins are recruited by type-B ARABIDOPSIS RESPONSE REGULATORS (ARR) to the promoters of cytokinin-regulated genes, where they act as transcriptional co-activators. The biological relevance of this mechanism is underpinned by the necessity of simultaneous presence of DELLAs and ARRs to restrict root meristem growth and to promote photomorphogenesis. Provided are 3 biological replicates analysing RGA binding sites in Arabidopsis seedlings. ChIP-seq was performed on plants expressing RGA-GFP under the native RGA promoter and on non-transgenic control plants as reference