Entries by Jesus Leon

Development and cell cycle dynamics of the root apical meristem in the fern Ceratopteris richardii (bioRxiv)

Roots are essential organs for nutrient and water uptake and have been extensively investigated in angiosperms. Many studies suggest that roots originated through convergent evolution in vascular plants, a clade that includes seed plants and ferns. Besides Arabidopsis and crops, little is known about root development in extant early-divergent tracheophytes such as ferns, which represent […]

Review. Roles of plant retinoblastoma protein: cell cycle and beyond (EMBO J.)

The cell cycle is at the heart of processes such as cell division, fate acquisition and cell cycle exit towards differentiation. Decades of cell cycle research in animals and yeast have outlined the main components that control the cycle’s transitions, such as cyclins, cyclin-dependent kinases, E2F transcription factors and the Retinoblastoma (RB1) tumor suppressor. Mostly […]

DNA damage triggers reprogramming of differentiated cells into stem cells in Physcomitrella (Nature Plants) ($)

Wounding and other types of cellular damage, such as DNA damage-induced stem cell death, trigger cellular reprogramming to confer stem cell identity to damage-adjacent cells, thus establishing a new stem cell niche capable of repairing the injury. Studies in angiosperm models have identified the phytohormone auxin and the AP2/ERF transcription factor ERF115 as key players […]

Rocks in the auxin stream: Wound-induced auxin accumulation and ERF115 expression synergistically drive stem cell regeneration (PNAS)

Plants have evolved exquisite regenerative capacities to repair wounds or even reform complete organs thanks to the proliferative activity of stem cell niches residing in meristems. Different types of injuries elicit different developmental and regenerative responses. However, a key player seems to be the phytohormone auxin, which plays multiple roles in wound recovery or regeneration […]

Fluctuating auxin response gradients determine pavement cell-shape acquisition (PNAS)

The leaf epidermis is composed primarily of undulated pavement cells arranged in a jigsaw puzzle-like architecture, with neighboring cells flawlessly interlacing with one another thanks to synchronized growth, thus making it an ideal model to study morphogenesis regulation. Seeking to better understand cell-shape acquisition, a recent study by Grones et al. used a subpopulation of […]

Multiple metabolic innovations and losses are associated with major transitions in land plant evolution (Curr. Biol.)

The colonization of land by a single streptophyte algae lineage around 450 million years ago culminated in the evolution and radiation of all terrestrial flora, the embryophytes. Adapting and thriving in the land environment required many morphological and physiological innovations, as well as the acquisition of novel metabolic pathways. However, metabolic pathway knowledge is biased […]

Design principles of a minimal auxin response system (Nature Plants)

Auxin controls virtually all facets of growth and development. This plant hormone is sensed by TIR1/AFB F-box receptors which promote ubiquitin-mediated degradation of AUX/IAA transcriptional repressors, releasing ARF transcription factors from inhibition. Phylogenetic analyses divide the ARF family into three conserved classes: A/B/C, where A-ARFs act as activators, with some B and C-ARFs acting as […]

Review: Evo-physio: on stress responses and the earliest land plants (J. Exp. Bot.)

Streptophytes are a grade of mostly freshwater algae that transitioned into land, a singularity that in turn gave rise to all present terrestrial flora. This passage along the hydrological gradient that culminated in land habitation required key adaptations to overcome previously unencountered terrestrial stressors such as UV radiation, and hydric and temperature stress. In this […]

Phylogenomic evidence for reductive evolution of stomata (Curr. Biol.)

Colonization of the terrestrial environment by land plants (embryophytes), a monophyletic clade that evolved from freshwater streptophyte algae, forever changed Earth by transforming biogeochemical cycles. The evolution of stomata was a key adaptation that allowed the colonization of terra firma. Present in most land plants, stomata control the passage of carbon dioxide and water vapor, […]