Biology subjects

Wendrich, J. R.

Publications and source records attributed to Wendrich, J. R..

3 recordsLinked to original sources

bioRxiv2022

Cell type-specific attenuation of brassinosteroid signalling drives stomatal asymmetric cell division

In Arabidopsis thaliana, the negative brassinosteroid (BR) signalling regulator, BR INSENSITIVE2 (BIN2) promotes and restricts stomatal asymmetric cell division (ACD) depending on its subcellular localization, which is regulated by the stomatal lineage-specific scaffolding protein POLAR. BRs inactivate BIN2, but how they govern stomatal development remains unclear. Mapping the single-cell transcriptome of stomatal lineages with either exogenous BRs or the specific BIN2 inhibitor revealed that the two modes of BR activation triggered spatiotemporally distinct transcriptional responses. We established that when in a complex with POLAR and its closest homolog POLAR-LIKE1, BIN2 is insulated from BR-mediated inactivation, nevertheless, it remains sensitive to the inhibitor. Subsequently, BR signalling is attenuated in ACD precursors, whereas it remains active in epidermal cells that would undergo differentiation. Our study demonstrates how scaffold proteins contribute to cellular signal specificity of hormonal responses in plants.

plant biology↗

bioRxiv2021

A morpho-transcriptomic map of brassinosteroid action in the Arabidopsis root

The effects of brassinosteroid signaling on shoot and root development have been characterized in great detail but did not identify a simple consistent positive or negative impact on a basic cellular parameter that would comprehensively explain the phenotype of brassinosteroid-related mutants. Here we combined digital 3D single-cell shape analysis and single-cell mRNA sequencing to characterize root meristems and mature root segments of brassinosteroid-blind mutants and wildtype. These data demonstrate that brassinosteroid signaling neither affects cell volume nor cell proliferation capacity. Instead, brassinosteroid signaling is essential for the precise orientation of cell division planes and the extent and timing of anisotropic cell expansion. Moreover, we found that the cell-aligning effects of brassinosteroid signaling can propagate to normalize the anatomy of both adjacent and distant brassinosteroid-blind cells through non-cell-autonomous functions, which are sufficient to restore overall root growth vigor. Finally, single-cell transcriptome data discern directly brassinosteroid-responsive genes from genes that can react to non-cell-autonomous brassinosteroid-dependent signals and highlight arabinogalactans as sentinels of brassinosteroid-dependent anisotropic cell expansion.

plant biology↗

bioRxiv2018

OsIQD14 regulates rice grain shape through modulating the microtubule cytoskeleton

Cortical microtubule (MT) arrays play a critical role in plant cell shape determination by defining the direction of cell expansion1-3. The control of plant organ shape and architecture is a major target of cereal crop improvement. Given the pleiotropic effects of MT modification, however, it is challenging to exploiting MT array organization for crop improvement. Moreover, as plants continuously adapt cell growth and expansion to ever-changing environmental conditions, multiple environmental (e.g. light4) and developmental (e.g. hormones5,6) inputs need to be translated into changes of the MT cytoskeleton. Here, we identify and functionally characterize an auxin-inducible and MT-localized protein OsIQ67-DOMAIN14 (OsIQD14), which is highly expressed in rice seed hull cells. While deficiency of OsIQD14 results in short and wide seeds and increases overall yield, overexpression leads to narrow and long seeds, caused by changes in the direction of MT arrangement. We further show that OsIQD14-mediated MT reordering is regulated through interacting with SPIRAL2, a MT-binding protein involved in KATANIN1-mediated MT rearrangement7,8, and with calmodulin proteins. As such, OsIQD14 acts as an integrator of auxin and calcium inputs into MT rearrangements, and allows effective local cell shape manipulation to improve a key rice yield trait.

plant biology↗