Biology subjects

de Zeeuw, T.

Publications and source records attributed to de Zeeuw, T..

3 recordsLinked to original sources

bioRxiv2026

The SAUERKRAUT transposable element acceleratesArabidopsis floral transition

Salt stress alters plant development, including the floral transition, but regulation of timing of flowering by salt is poorly understood at the molecular level. To identify genetic loci regulating the floral transition under high soil salinity, we performed a genome-wide association study (GWAS) in Arabidopsis thaliana and identified natural variation at the UGT74E1-UGT74E2-BT3 (UUB) locus that correlates with bolting time specifically in response to salt stress. Genetic analysis revealed BT3 as a novel repressor of the floral transition in control conditions. Similarly, the putative IBA glycosylases UGT74E1 & UGT74E2 delay the floral transition in control conditions. Furthermore, we identified that IBA homeostasis regulators TOB1 and ECH2/IBR10 play a key role in the floral transition, and that ECH2/IBR10 are required for the early flowering phenotype of the ugt74e1/ugt74e2 double mutant, indicating that UGT74E1 & UGT74E2 delay flowering by altering IBA homeostasis. A pangenome analysis of the UUB locus revealed variation in the occurrence of the DNA transposon SAUERKRAUT (SKRT). CRISPR-mediated SKRT deletion in Col-0 affected gene expression both within and outside the UUB locus and caused a salt-dependent delayed floral transition. The delayed bolting phenotype of the skrt-2 mutant also depends on ECH2/IBR10 function, indicating that SKRT accelerates the floral transition by altering IBA homeostasis. Finally, targeted demethylation of SKRT resulted in delayed floral transition under salt stress. Taken together, our data show a role for SKRT and its DNA methylation levels in the salt-dependent bolting time response in Arabidopsis, revealing a novel molecular mechanism to control flowering in adverse conditions.

plant biology↗

bioRxiv2023

Warm temperature and mild water stress cooperatively promote root elongation

Warm temperatures have a dramatic effect on plant development. In shoots, stems elongate, and leaves are raised in a developmental programme called thermomorphogenesis. This results in enhanced leaf cooling capacity1. Thermomorphogenesis is tightly intertwined with light signalling pathways. The level of integration is so high that it has been proposed that shoot temperature sensing may have evolved from the co-option of an existing light signalling pathway during the colonisation of land by plants2. Roots also undergo thermomorphogenesis, but the mechanism by which this occurs is less well understood. Main root elongation is enhanced at warm temperatures, and this response is independent of many of the light and temperature signalling components of the shoot3. Roots develop in darkness and so it is a reasonable assumption that root temperature signalling is not through modulation of light signalling. It was recently speculated that due to the close correlation between warm temperature and soil moisture content, root temperature signalling could feasibly be related to water availability signals2. In this study we tested the interaction between temperature and water availability signalling in plant roots. We found that these environmental factors co-operatively enhance main root elongation. This interaction effect was dependent on SUCROSE NON-FERMENTING RELATED KINASE 2.2 (SnRK2.2) and SnRK2.3 and the E3 ubiquitin ligase CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1). We found that SnRK2.2 / 2.3 and COP1 have opposite effects on the stability of the transcription factor ELONGATED HYPOCOTYL 5 (HY5) in elongation zone hair cells. The stability of HY5 in these cell types generally corresponded to the degree of root elongation seen in each mutant background. Our study reveals several molecular components of root thermomorphogenesis and highlights the importance of an integrative approach to plant environmental signalling. Our results may have direct implications for agricultural land management, especially as global climates become more unpredictable.

plant biology↗

bioRxiv2021

A molecular framework for control of oriented cell division in the Arabidopsis embryo

Premitotic control of cell division orientation is critical for plant development, as cell walls prevent extensive cell remodelling or migration. Whilst many divisions are proliferative and add cells to existing tissues, some divisions are formative, and generate new tissue layers or growth axes. Such formative divisions are often asymmetric in nature, producing daughters with different fates. We have previously shown that in the Arabidopsis thaliana embryo, developmental asymmetry is correlated with geometric asymmetry, creating daughter cells of unequal volume. Such divisions are generated by division planes that deviate from a default "minimal surface area" rule. Inhibition of auxin response leads to reversal to this default, yet the mechanisms underlying division plane choice in the embryo have been unclear. Here we show that auxin-dependent division plane control involves alterations in cell geometry, but not in cell polarity or nuclear position. Through transcriptome profiling, we find that auxin regulates genes controlling cell wall and cytoskeleton properties. We confirm the involvement of microtubule (MT)-binding proteins in embryo division control. Topology of both MT and Actin cytoskeleton depend on auxin response, and genetically controlled MT or Actin depolymerization in embryos leads to disruption of asymmetric divisions, including reversion to the default. Our work shows how auxin-dependent control of MT- and Actin cytoskeleton properties interacts with cell geometry to generate asymmetric divisions during the earliest steps in plant development.

plant biology↗