A single cis-element that controls cell-type specific expression in Arabidopsis

Knerova, J.; Dickinson, P. J.; Szecowka, M.; Burgess, S. J.; Mulvey, H.; Bagman, A.-M.; Gaudinier, A.; Brady, S. M.; Hibberd, J. M.

doi:10.1101/380188

bioRxiv · 10.1101/380188

A single cis-element that controls cell-type specific expression in Arabidopsis

Knerova, J.·Dickinson, P. J.·Szecowka, M.·Burgess, S. J.·Mulvey, H.·Bagman, A.-M.·Gaudinier, A.·Brady, S. M.·Hibberd, J. M.

View original source ↗Export metadata ↓

Abstract

C4 photosynthesis evolved repeatedly from the ancestral C3 state, improving photosynthetic efficiency by ∼50%. In most C4 lineages photosynthesis is compartmented between mesophyll and bundle sheath cells but how gene expression is restricted to these cell types is poorly understood. Using the C3 model Arabidopsis thaliana we identified cis-elements and transcription factors driving expression in bundle sheath strands. Upstream of the bundle sheath preferentially expressed MYB76 gene we identified a region necessary and sufficient for expression containing two cis-elements associated with the MYC and MYB families of transcription factors. MYB76 expression is reduced in mutant alleles for each. Moreover, down-regulated genes shared by both mutants are preferentially expressed in the bundle sheath. Our findings are broadly relevant for understanding the spatial patterning of gene expression, provide specific insights into mechanisms associated with evolution of C4 photosynthesis and identify a short tuneable sequence for manipulating gene expression in the bundle sheath.Competing Interest StatementThe authors have declared no competing interest.View Full Text

Source connections

Published article ↗

Explore related subjects

plant biology Preprint

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Knerova, J., Dickinson, P. J., Szecowka, M., Burgess, S. J., Mulvey, H., Bagman, A.-M., Gaudinier, A., Brady, S. M., Hibberd, J. M.. 2018-07-30. A single cis-element that controls cell-type specific expression in Arabidopsis. https://doi.org/10.1101/380188

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Photosynthesis-derived carbohydrate supply sustains CuCl2-induced phytoalexin production in rice leaves

Phytoalexins are antimicrobial metabolites whose biosynthesis is triggered by signaling activated by both biotic and abiotic elicitors, but the physiological conditions that sustain their production remain poorly understood. Here, we examined how light and carbohydrate availability affect CuCl2-induced production of diterpenoid (phytocassanes and momilactones) and flavonoid (sakuranetin) phytoalexins in rice (Oryza sativa L.) leaf disks. Darkness strongly suppressed both the accumulation of all three phytoalexin groups and the induction of their biosynthetic genes. In darkness, endogenous sucrose, glucose, and fructose declined to 3%-8% of the levels in the light, whereas early accumulation of jasmonic acid and jasmonoyl-L-isoleucine (JA-Ile) was not detectably reduced. Exogenous sucrose restored phytoalexin accumulation in darkness in a dose-dependent manner, together with the expression of the suppressed biosynthetic genes, whereas equimolar mannitol had no effect. Glucose also restored sakuranetin accumulation in darkness but only partially restored diterpenoid accumulation, whereas the glucose analog 2-deoxy-D-glucose did not, and it suppressed CuCl2-induced accumulation in the light in a dose-dependent manner. In the light, 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), an inhibitor of photosynthetic electron transport, depleted soluble sugars and suppressed phytoalexin accumulation, and sucrose reversed this suppression. Sugars alone induced little phytoalexin accumulation, indicating that carbohydrates act permissively rather than as elicitors. Diterpenoid phytoalexins depended more strongly on light than sakuranetin, yet both classes depended on carbohydrate availability. These results indicate that photosynthesis-derived carbohydrate supply sustains elicitor-induced phytoalexin production in rice leaves and largely accounts for its light dependence.

plant biology↗

bioRxiv2026

Transcriptome analysis provides insights into candidate genetic regulators of birch response to salt stress

Abstract Background: Soil salinization is a worldwide matter of concern and can result in a series of agricultural and ecological problems. Previous transcriptome data have shown genetic regulatory mechanisms of salt stress response in a salt-tolerant species of Betula halophila and a salt-sensitive species of B. platyphylla, but comparative analysis of transcriptional changes in the the two species remains limited. Aims: We compared gene expression in leaves of B. halophila and leaves and roots of B. platyphylla. Methods: Differentially expressed genes (DEGs) were identified after 24 h of salt stress, followed by Gene Ontology enrichment and gene regulatory network (GRN) construction. Selected DEGs were examined by quantitative real-time PCR (RT-qPCR). Results: Compared with 0 h, 956 DEGs were found in B. halophila leaves (BHLeaf), 2,955 in B. platyphylla leaves (BPLeaf), and 3,827 in B. platyphylla roots (BPRoot). BHLeaf DEG expression patterns were similar to those of BPRoot. DEGs from BHLeaf and BPRoot were enriched in cell wall organization or biogenesis, whereas hormone biosynthesis and signaling genes were altered mainly in B. platyphylla. RT-qPCR showed that selected DEGs were induced by 200 mM NaCl for 24 h in B. platyphylla. Conclusions: Our work uncovered genetic mechanisms of salt stress response commonly and uniquely occurring in two birch species and provides resources for breeding salt-tolerant birch.

plant biology↗

bioRxiv2026

Minimal requirements and evolution of polar membrane targeting in the land plant SOSEKI protein family

Accurate spatial distribution of polar proteins is essential for cell function, but mechanisms underlying polar protein targeting in plants are poorly understood. Here, we dissect the molecular mechanisms underlying the polar targeting of the SOSEKI1 (SOK1) protein in Arabidopsis thaliana. Using extensive mutagenesis and truncation analyses of the polarity domain, we mapped the minimal polarity fragment necessary and sufficient for stable polar targeting to a 25-amino-acid region. This region likely forms an amphipathic helix, and mutations reveal that both its polar and apolar faces are essential for membrane association and polarity. Using phylogenetic analysis, we reconstruct the evolutionary history of the minimal polar targeting region across land plants. Using cross-species expression and protein localization, we infer the ancestral polar SOK localization pattern and show how it remained remarkably conserved, only to diversify upon gene duplication. This work identifies a polar targeting peptide in plants, reveals a mechanism for polar membrane targeting of a plant protein family, and demonstrates both conservation and diversification within this family.

plant biology↗