Biology subjects

Raissig, M.

Publications and source records attributed to Raissig, M..

3 recordsLinked to original sources

bioRxiv2026

A single-cell transcriptome atlas of the barley root apical meristem uncovers conserved and divergent roles of HvWOX5

Single-cell approaches have transformed plant developmental biology; however, cell-type-resolved resources for cereals remain limited. Here, we present a single-cell transcriptome atlas of the barley root apical meristem (RAM), which resolves 24 transcriptionally distinct cell populations. We assigned major root cell identities by integrating marker gene validation using Hybridization Chain Reaction (HCR) RNA fluorescence in situ hybridization and spatial transcriptomics with cross-species comparisons of published root atlases. Pseudotime analysis reconstructed developmental trajectories from the quiescent center to differentiating tissues, supporting the spatial and developmental organization of the atlas. We further demonstrated the utility of this resource by identifying HvWOX5 expression in the quiescent center and metaxylem and showing that HvWOX5 loss-of-function mutants displayed reduced root and meristem lengths, altered stem cell niche homeostasis, and disrupted metaxylem organization. Taken together, this atlas provides a framework for dissecting barley root development and identifies HvWOX5 as a key regulator of RAM organization and metaxylem patterning.

Plant Biology↗

bioRxiv2026

REVOLUTA regulates cell fate and wall patterning in the fruit endocarp

Explosive seed dispersal distinguishes Cardamine species from Arabidopsis and depends on polarized secondary cell wall (SCW) deposition in fruit endocarp b (endb) cells. How this SCW pattern is specified and environmentally modulated remains unclear. The polyploid Cardamine chenopodiifolia produces explosive aerial fruit and non-explosive subterranean fruit, creating a tractable system to address this problem. We show light triggers underground fruit to explode by reprogramming endb SCW patterning from uniform to polar. We identify the HD-ZIPIII transcription factor REVOLUTA as a central regulator of endb cell fate, SCW formation, and organ polarity in Arabidopsis and Cardamine hirsuta. In C. hirsuta, duplicated REVOLUTA paralogs are required for endb SCW deposition, while other HD-ZIPIII genes contribute redundantly to cell fate and organ polarity. REVOLUTA over-expression converts polar endb SCWs to uniform, producing non-explosive fruit. Together, these findings reveal a tunable developmental module underlying evolutionary transitions between explosive and non-explosive seed dispersal strategies.

plant biology↗

bioRxiv2025

Volatile-suppressed peptide signaling enhances volatile responses in plant-plant interactions

Plant volatiles shape plant-plant interactions by acting as defense regulators and response factors. While plant volatile biosynthesis is well understood, how their emission is regulated remains largely elusive. Here, we show that small peptide signaling regulates induced volatile release in maize. Following herbivore attack, green leaf volatiles such as (Z)-3-hexenyl acetate (HAC) are released and induce terpene and indole emissions from neighboring plants. This process is accompanied by reduced expression of the ZmCLE1E9 gene and the ZmBAM1A, ZmBAM1B and ZmBAM3C receptor genes in HAC-exposed plants. Exogenous ZmCLE1E9 peptide inhibits HAC-triggered volatile release by limiting stomatal aperture. This inhibition disappears in the Zmbam1a/Zmbam1b/Zmbam3c triple mutant. Molecular docking supports ZmCLE1E9 and ZmBAMs as ligand-receptor pairs. Furthermore, Zmcle1e9 and Zmbams triple mutants show increased volatile emissions upon HAC exposure. In summary, we show that upon HAC perception, maize plants enhance their capacity to release terpenes and indole via the suppression of CLE1E9 signaling. This behavior allows maize plants to rapidly deploy volatile cues in response to stress volatiles and thus shape the infochemical dynamics of multitrophic environments.

plant biology↗