MicroRNA control of stem cell reconstitution and growth in root regeneration.

Plants display a remarkable regeneration capacity, which allows them to replace damaged or lost cells, tissues and organs, and thus recover from a broad spectrum of injuries. Even lost stem cells can be regenerated from non-stem cells after competence acquisition, highlighting the enormous plasticity of plant cells. However, the molecular mechanisms underlying this process are still poorly understood.

Principles of miRNA/miRNA* function in plant MIRNA processing.

MicroRNAs (miRNAs) are essential regulators of gene expression, defined by their unique biogenesis, which requires the precise excision of the small RNA from an imperfect fold-back precursor. Unlike their animal counterparts, plant miRNA precursors exhibit variations in sizes and shapes. Plant MIRNAs can undergo processing in a base-to-loop or loop-to-base direction, with DICER-LIKE1 (DCL1) releasing the miRNA after two cuts (two-step MIRNAs) or more (sequential MIRNAs).

Molecular mechanisms regulating GROWTH-REGULATING FACTORS activity in plant growth, development, and environmental responses.

Plants rely on complex regulatory mechanisms to ensure proper growth and development. As plants are sessile organisms, these mechanisms must be flexible enough to adapt to changes in the environment. GROWTH-REGULATING FACTORS (GRFs) are plant-specific transcription factors that act as a central hub controlling plant growth and development, which offer promising biotechnological applications to enhance plant performance.

Interplay among ZF-HD and GRF transcription factors during Arabidopsis leaf development.

The growth-regulating factor (GRF) family of transcriptional factors are involved in the control of leaf size and senescence, inflorescence and root growth, grain size, and plant regeneration. However, there is limited information about the genes regulated by these transcriptional factors, which are in turn responsible for their functions. Using a meta-analysis approach, we identified genes encoding Arabidopsis (Arabidopsis thaliana) zinc-finger homeodomain (ZF-HD) transcriptional factors, as potential targets of the GRFs.

Potent inhibition of TCP transcription factors by miR319 ensures proper root growth in Arabidopsis.

Proper root growth depends on the clearance of TCP transcripts from the root apical meristem by microRNA miR319. The evolutionarily conserved microRNA miR319 regulates genes encoding TCP transcription factors in angiosperms. The miR319-TCP module controls cell proliferation and differentiation in leaves and other aerial organs.