Biology subjects

Taylor, I. W.

Publications and source records attributed to Taylor, I. W..

3 recordsLinked to original sources

bioRxiv2020

A single cell Arabidopsis root atlas reveals developmental trajectories in wild type and cell identity mutants

SummaryCell fate acquisition is a fundamental developmental process in all multicellular organisms. Yet, much is unknown regarding how a cell traverses the pathway from stem cell to terminal differentiation. Advances in single cell genomics1 hold promise for unraveling developmental mechanisms2–3 in tissues4, organs5–6, and organisms7–8. However, lineage tracing can be challenging for some tissues9 and integration of high-quality datasets is often necessary to detect rare cell populations and developmental states10,11. Here, we harmonized single cell mRNA sequencing data from over 110,000 cells to construct a comprehensive atlas for a stereotypically developing organ with indeterminate growth, the Arabidopsis root. To test the utility of the atlas to interpret new datasets, we profiled mutants for two key transcriptional regulators at single cell resolution, shortroot and scarecrow. Although both transcription factors are required for early specification of cell identity12, our results suggest the existence of an alternative pathway acting in mature cells to specify endodermal identity, for which SHORTROOT is required. Uncovering the architecture of this pathway will provide insight into specification and stabilization of the endodermis, a tissue analogous to the mammalian epithelium. Thus, the atlas is a pivotal advance for unraveling the transcriptional programs that specify and maintain cell identity to regulate organ development in space and time.Competing Interest StatementPNB is the co-founder and Chair of the Scientific Advisory Board of Hi Fidelity Genetics, Inc, a company that works on crop root growth.View Full Text

plant biology↗

bioRxiv2020

VST Family Proteins are Regulators of Root System Architecture in Rice and Arabidopsis

Root System Architecture (RSA) is a key factor in the efficiency of nutrient capture and water uptake in plants. Understanding the genetic control of RSA will be useful in minimizing fertilizer and water usage in agricultural cropping systems. Using a hydroponic screen and a gel-based imaging system we identified a rice gene, OsVST1, which plays a key role in controlling RSA. This gene encodes a homolog of the Arabidopsis VAP-RELATED SUPPRESSORS OF TMM (VSTs), a class of proteins that promote signaling in stomata by mediating plasma membrane-endoplasmic reticulum contacts. OsVST1 mutants have shorter primary roots, decreased root meristem size, and a more compact root system architecture. We show that the Arabidopsis VST triple mutants have similar phenotypes, with reduced primary root growth and smaller root meristems. Expression of OsVST1 largely complements the short root length and reduced plant height in the Arabidopsis triple mutant, supporting conservation of function between rice and Arabidopsis VST proteins. In a field trial, mutations in OsVST1 do not adversely affect grain yield, suggesting that modulation of this gene could be used as a way to optimize RSA without an inherent yield penalty.

plant biology↗

bioRxiv2020

Mechanism and function of root circumnutation

AbstractEarly root growth is critical for plant establishment and survival. We have identified a molecular pathway required for oscillatory root tip movement known as circumnutation. Here we report a multiscale investigation of the regulation and function of this phenomenon. We identify key cell signaling events comprising interaction of the ethylene, cytokinin, and auxin hormone signaling pathways. We identify the gene Oryza sativa Histidine Kinase-1/OsHK1, as well as the auxin influx carrier gene OsAUX1, as essential regulators of this process in rice. Robophysical modelling demonstrated the benefits of tip movement for navigating past obstacles, prompting us to challenge mutant and wild-type plants with different substrates. Consistent with model behavior, root circumnutation facilitated exploration of a solid surface and promoted seedling establishment in rocky soil. Thus, the integration of robotics, physics and biology elucidated the functional importance of root circumnutation and uncovered the molecular mechanisms underlying its regulation. One sentence summaryCircumnutation facilitates root exploration.

plant biology↗