Biology subjects

Wolverton, C.

Publications and source records attributed to Wolverton, C..

3 recordsLinked to original sources

bioRxiv2022

Angle-dependence and auxin asymmetry: towards the formulation of a universal theory of root gravitropism

Gravitropism has been conceptualized through three main theories: the starch-statolith model for sensing, the Cholodny-Went model of growth control via auxin asymmetry, and the law of angle-dependence for behavior, in which the magnitude of gravitropic response increases with displacement from the vertical. While experimental data show that the generation of both Cholodny-Went-type auxin gradients and angle-dependent behavior requires statolith sedimentation, a link between auxin asymmetry and angle-dependence has not been demonstrated. Here, we use large scale reorientation assays of Arabidopsis roots, epidermal length measurements, and confocal microscopy to quantify auxin distribution and PIN localization during graviresponse. We show angle-dependence in auxin asymmetry and growth response, even at low stimulation angles. As such, our work integrates the three theories sensing, signal transduction and behavior into a single unified model of gravitropism and provides an important framework for exploring major outstanding questions in the field.

plant biology↗

bioRxiv2020

NASA GeneLab RNA-Seq Consensus Pipeline: Standardized Processing of Short-Read RNA-Seq Data

With the development of transcriptomic technologies, we are able to quantify precise changes in gene expression profiles from astronauts and other organisms exposed to spaceflight. Members of NASA GeneLab and GeneLab-associated analysis working groups (AWGs) have developed a consensus pipeline for analyzing short-read RNA-sequencing data from spaceflight-associated experiments. The pipeline includes quality control, read trimming, mapping, and gene quantification steps, culminating in the detection of differentially expressed genes. This data analysis pipeline and the results of its execution using data submitted to GeneLab are now all publicly available through the GeneLab database. We present here the full details and rationale for the construction of this pipeline in order to promote transparency, reproducibility and reusability of pipeline data, to provide a template for data processing of future spaceflight-relevant datasets, and to encourage cross-analysis of data from other databases with the data available in GeneLab.

bioinformatics↗

bioRxiv2019

Antagonistic and auxin-dependent phosphoregulation of columella PIN proteins controls lateral root gravitropic setpoint angle in Arabidopsis

Lateral roots of many species are maintained at non-vertical angles with respect to gravity. These gravitropic setpoint angles (GSAs) are intriguing because their maintenance requires that roots are able to effect gravitropic response both with and against the gravity vector. Here we have used the Arabidopsis lateral root in order to investigate the molecular basis of the maintenance of non-vertical GSAs. We show that gravitropism in the lateral root is angle-dependent and that both upward and downward graviresponse requires auxin transport and the generation of auxin asymmetries consistent with the Cholodny-Went model. We show that the symmetry in auxin distribution in lateral roots growing at GSA can be traced back to a net, balanced polarization of PIN3 and PIN7 auxin transporters in the columella cells. Further, upward and downward graviresponse in lateral roots correlates with corresponding changes in PIN3 and PIN7 polar localisation. Finally, we show that auxin, in addition to driving tropic growth in the lateral root, acts within the columella to regulate GSA via the PIN phosphatase subunit RCN1 in a PIN3-dependent and PIN7-independent manner. Together, these findings provide a molecular framework for understanding gravity-dependent nonvertical growth in Arabidopsis lateral roots.

plant biology↗