Plants

Journal Browser

► Journal Browser

Molecular Mechanisms Underlying Root Growth Behavior

Share This Special Issue

Special Issue Editors

Prof. Dr. Patrick Masson

Department of Genetics, College of Agriculture and Life Sciences, University of Wisconsin-Madison, 425G Henry Mall, Madison, WI 53706, USA
Interests: molecular genetics of root growth behavior and root responses to environmental stressors; role of polyamines in plant stress response

Dr. Shih-Heng Su

E-Mail Website
Guest Editor

Department of Genetics, College of Agriculture and Life Sciences, University of Wisconsin-Madison, 425G Henry Mall, Madison, WI 53706, USA
Interests: molecular mechanism of gravitropism; root growth behavior; polyamine function in stress response

Special Issue Information

Dear Colleagues,

Root system architecture is a dynamic trait that contributes to plant survival and productivity. Its ability to adapt to varying environmental conditions within the constraints dictated by a plant’s genotype allows the efficient capture of soil water and nutrients while also permitting adequate plant anchorage to the soil substrate. As such, root system architecture contributes to crop productivity and plant adaptability to environmental changes, including those associated with climate change, the agricultural encroachment of marginal lands, space travel and/or extraterrestrial outposts. It is therefore not surprising that modern crop breeding programs target root system architecture traits that favor the better acquisition of water, nitrogen and phosphorus under stressful conditions, with the hope of developing crops that better tolerate suboptimal environments and require lower quantities of expensive and polluting fertilizers.

Root system architecture is a consequence of multiple and integrated growth behaviors that are genetically encoded, but also highly tunable via environmental parameters and resources. These include soil penetration, directional growth responses to vectorial signals such as gravity, light, touch, water, salt, oxygen, ions and/or chemical gradients (tropisms), and/or endogenous cues (autotropism; auto-straightening / proprioception), multileveled root branching, responses to symbiotic and/or pathogenic microbes and parasites, and circumnutation processes. Similarly, root hair formation and lateral root density vary depending on water and nutrient availability (hydro- and chemo-patterning).

In recent years, we have witnessed amazing new developments in our understanding of root growth behavior, in part due to new technological innovations in time-lapse imaging and phenotyping, computer-driven image analysis platforms, molecular genetics, population and quantitative genetics, genome editing, systems biology including single-cell transcriptomic, proteomic and metabolomic approaches, cell biology, biochemistry, physiology and biophysical modeling. The adoption of integrated approaches in studies of root growth behavior and root system architecture promises to yield a greater understanding of root system adaptive responses to their environment, thereby offering the tools needed to develop novel crop cultivars that are better equipped to respond more effectively to suboptimal environments and require less fertilizers. This Special Issue of Plants will gather research articles, review papers and short communications that improve our understanding of the molecular, biophysical, cell biological, physiological and/or morphological mechanisms underlying root growth behavior in the broadest sense of the term, and/or their potential applications in agriculture, horticulture, forestry and/or space biology.

Prof. Dr. Patrick Masson
Dr. Shih-Heng Su
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Plants is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

circumnutation
hydropatterning
root branching
root hair
root system architecture
root tropisms
skewing
soil penetration
thigmomorphogenesis
waving

Published Papers (2 papers)

Download All Papers

Research

Jump to: Review

15 pages, 4177 KiB

Open AccessArticle

QTL for the Kinematic Traits That Define the Arabidopsis Root Elongation Zone and Their Relationship to Gravitropism

by Ashley R. Henry, Nathan D. Miller and Edgar P. Spalding

Plants 2024, 13(9), 1189; https://doi.org/10.3390/plants13091189 - 25 Apr 2024

Viewed by 302

Abstract

Cell expansion in a discrete region called the elongation zone drives root elongation. Analyzing time lapse images can quantify the expansion in kinematic terms as if it were fluid flow. We used horizontal microscopes to collect images from which custom software extracted the length of the elongation zone, the peak relative elemental growth rate (REGR) within it, the axial position of the REGR peak, and the root elongation rate. Automation enabled these kinematic traits to be measured in 1575 Arabidopsis seedlings representing 162 recombinant inbred lines (RILs) derived from a cross of Cvi and Ler ecotypes. We mapped ten quantitative trait loci (QTL), affecting the four kinematic traits. Three QTL affected two or more traits in these vertically oriented seedlings. We compared this genetic architecture with that previously determined for gravitropism using the same RIL population. The major QTL peaks for the kinematic traits did not overlap with the gravitropism QTL. Furthermore, no single kinematic trait correlated with quantitative descriptors of the gravitropism response curve across this population. In addition to mapping QTL for growth zone traits, this study showed that the size and shape of the elongation zone may vary widely without affecting the differential growth induced by gravity. Full article

(This article belongs to the Special Issue Molecular Mechanisms Underlying Root Growth Behavior)

► Show Figures

Figure 1

Review

Jump to: Research

16 pages, 3463 KiB

Open AccessReview

Role of Abscisic Acid, Reactive Oxygen Species, and Ca²⁺ Signaling in Hydrotropism—Drought Avoidance-Associated Response of Roots

by Baris Uzilday, Kaori Takahashi, Akie Kobayashi, Rengin Ozgur Uzilday, Nobuharu Fujii, Hideyuki Takahashi and Ismail Turkan

Plants 2024, 13(9), 1220; https://doi.org/10.3390/plants13091220 - 28 Apr 2024

Viewed by 331

Abstract

Plant roots exert hydrotropism in response to moisture gradients to avoid drought stress. The regulatory mechanism underlying hydrotropism involves novel regulators such as MIZ1 and GNOM/MIZ2 as well as abscisic acid (ABA), reactive oxygen species (ROS), and Ca²⁺ signaling. ABA, ROS, and Ca²⁺ signaling are also involved in plant responses to drought stress. Although the mechanism of moisture gradient perception remains largely unknown, the sensory apparatus has been reported to reside in the root elongation zone rather than in the root cap. In Arabidopsis roots, hydrotropism is mediated by the action of MIZ1 and ABA in the cortex of the elongation zone, the accumulation of ROS at the root curvature, and the variation in the cytosolic Ca²⁺ concentration in the entire root tip including the root cap and stele of the elongation zone. Moreover, root exposure to moisture gradients has been proposed to cause asymmetric ABA distribution or Ca²⁺ signaling, leading to the induction of the hydrotropic response. A comprehensive and detailed analysis of hydrotropism regulators and their signaling network in relation to the tissues required for their function is apparently crucial for understanding the mechanisms unique to root hydrotropism. Here, referring to studies on plant responses to drought stress, we summarize the recent findings relating to the role of ABA, ROS, and Ca²⁺ signaling in hydrotropism, discuss their functional sites and plausible networks, and raise some questions that need to be answered in future studies. Full article

(This article belongs to the Special Issue Molecular Mechanisms Underlying Root Growth Behavior)

► Show Figures