Skewing in Arabidopsis roots involves disparate environmental signaling pathways

Eric R. Schultz,Natasha J. Sng,Agata K. Zupanska,Robert J. Ferl,Anna-Lisa Paul

doi:10.1186/s12870-017-0975-9

Eric R. Schultz, Natasha J. Sng + Show 3 more

Open Access

https://doi.org/10.1186/s12870-017-0975-9

Copy DOI

Abstract

BackgroundSkewing root patterns provide key insights into root growth strategies and mechanisms that produce root architectures. Roots exhibit skewing and waving when grown on a tilted, impenetrable surface. The genetics guiding these morphologies have been examined, revealing that some Arabidopsis ecotypes skew and wave (e.g. WS), while others skew insignificantly but still wave (e.g. Col-0). The underlying molecular mechanisms of skewing and waving remain unclear. In this study, transcriptome data were derived from two Arabidopsis ecotypes, WS and Col-0, under three tilted growth conditions in order to identify candidate genes involved in skewing.ResultsThis work identifies a number of genes that are likely involved in skewing, using growth conditions that differentially affect skewing and waving. Comparing the gene expression profiles of WS and Col-0 in different tilted growth conditions identified 11 candidate genes as potentially involved in the control of skewing. These 11 genes are involved in several different cellular processes, including sugar transport, salt signaling, cell wall organization, and hormone signaling.ConclusionsThis study identified 11 genes whose change in expression level is associated with root skewing behavior. These genes are involved in signaling and perception, rather than the physical restructuring of root. Future work is needed to elucidate the potential role of these candidate genes during root skewing.

Highlights

Skewing root patterns provide key insights into root growth strategies and mechanisms that produce root architectures
The first analysis compared transcriptional differences within a ecotype caused by the environmental condition of Angle of the growth plate (Agp), differences between WS roots grown at Agp 90° and WS roots grown at Agp 45° or 135°, and the differences between Col-0 roots grown at Agp 90° and Col-0 roots grown at Agp 45° or 135°
The genes with altered transcription identified in this comparison of Agp 135° to Agp 90° represent the pool of genes likely involved in root skewing and not waving, since they were altered in a condition that induces root skewing independent of the classical root waving patterns

Summary

Introduction

Skewing root patterns provide key insights into root growth strategies and mechanisms that produce root architectures. Thigmotropism, involves many genes that interact with auxin and can subsequently alter growth patterns [11, 19,20,21,22,23,24,25,26,27,28]. Plants determine their growth in relation to the gravity vector, resulting in a gravitropic set-point angle (GSA), which is most commonly associated with lateral organ growth relative to the primary organ [29]. Additional tropisms include halotropism [39, 43, 44], chemotropism [45], hydrotropism [46], all of which can alter root growth response (reviewed in [3])

Objectives

Methods

Results

Discussion

Conclusion