Biology subjects

Budrys, A.

Publications and source records attributed to Budrys, A..

3 recordsLinked to original sources

bioRxiv2026

Genetic encoding of climate-responsive stomatal developmental plasticity in tomato

Flexible developmental programs enable plants to customize their organ size and cellular composition. In leaves of eudicots, the stomatal lineage produces two essential cell types, stomata and pavement cells, and plants can adjust the total numbers and ratios of these cell types in response to external cues. Central to this flexibility is the stomatal lineage-initiating transcription factor, SPEECHLESS (SPCH). Here we explore the mechanisms underlying SPCHs involvement in environmental response. Using multiplexed CRISPR/Cas9 editing of SlSPCH cis-regulatory sequences in tomato, we identified variants with altered stomatal development responses to drought, light and temperature cues. By creating and live-cell tracking translational reporters of SlSPCH and its paralogues SlMUTE and SlFAMA, we revealed the corresponding cellular events that lead to the environmental change-driven responses in stomatal production and leaf form. Plants bearing the novel reporters and SlSPCH variants are powerful resources for fundamental and applied studies of tomato resilience in response to climate change.

plant biology↗

bioRxiv2025

Transcriptional targets of SPEECHLESS and FAMA control guard cell division and expansion in the late stomatal lineage

Plant tissue development often relies on the specification of cell type initials with stem cell-like properties. These later undergo differentiation, losing division potential and acquiring specific identities and functions. In the stomatal lineage, protodermal cells develop into guard cells (GCs) through the action of bHLH transcription factors (TFs) SPEECHLESS (SPCH), MUTE and FAMA. Existing models support that these regulators act sequentially, but recent evidence indicates that SPCH expression and function are retained in late stomatal cells. Here, we combine transcriptomic and genetic approaches to define SPCHs function during the late stomatal lineage. We show that relative levels and activities of SPCH and FAMA control GC division and expansion. Through cell type-specific TF induction and mRNA sequencing, we identify late-lineage targets of both TFs, and through genetic perturbation of these targets, we demonstrate that their precise temporal regulation is required for proper GC morphology and function. Our findings reveal a previously unrecognized role for SPCH in late stomatal development and support a revised model in which the functions of stomatal bHLHs are not strictly separated in time.

plant biology↗

bioRxiv2023

Targeting editing of tomato SPEECHLESS cis-regulatory regions generates plants with altered stomatal density in response to changing climate conditions

Flexible developmental programs enable plants to customize their organ size and cellular composition. In leaves of eudicots, the stomatal lineage produces two essential cell types, stomata and pavement cells, but the total numbers and ratio of these cell types can vary. Central to this flexibility is the stomatal lineage initiating transcription factor, SPEECHLESS (SPCH). Here we show, by multiplex CRISPR/Cas9 editing of SlSPCH cis-regulatory sequences in tomato, that we can identify variants with altered stomatal development responses to light and temperature cues. Analysis of tomato leaf development across different conditions, aided by newly-created tools for live-cell imaging and translational reporters of SlSPCH and its paralogues SlMUTE and SlFAMA, revealed the series of cellular events that lead to the environmental change-driven responses in leaf form. Plants bearing the novel SlSPCH variants generated in this study are powerful resources for fundamental and applied studies of tomato resilience in response to climate change. Significance statementPlants can change their shape, size and cellular composition in response to environmental cues. Here, by precise gene editing of a core stomatal development regulator gene in tomato, we generate new alleles with enhanced or dampened responses to light and temperature cues. Combined with live imaging of development, we show the genetic and cellular pathways that contribute to customization of the leaf epidermis, and how this could lead to better climate-adapted varieties.

plant biology↗