scholarly journals A Linear Model to Describe Branching and Allometry in Root Architecture

Plants ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 218
Author(s):  
Joel Colchado-López ◽  
R. Cristian Cervantes ◽  
Ulises Rosas
Keyword(s):  
Root Development ◽  
Lateral Root ◽  
Root Architecture ◽  
Complex Structure ◽  
Primary Root ◽  
Allometric Model ◽  
Multiple Traits ◽  
Three Stages ◽  
Natural Variations ◽  
New Feature

Root architecture is a complex structure that comprises multiple traits of the root phenotype. Novel platforms and models have been developed to better understand root architecture. In this methods paper, we introduce a novel allometric model, named rhizochron index (m), which describes lateral root (LR) branching and elongation patterns across the primary root (PR). To test our model, we obtained data from 16 natural accessions of Arabidopsis thaliana at three stages of early root development to measure conventional traits of root architecture (e.g., PR and LR length), and extracted the rhizochron index (m). In addition, we tested previously published datasets to assess the utility of the rhizochron index (m) to distinguish mutants and environmental effects on root architecture. Our results indicate that rhizochron index (m) is useful to distinguish the natural variations of root architecture between A. thaliana accessions, but not across early stages of root development. Correlation analyses in these accessions showed that m is a novel trait that partially captures information from other root architecture traits such as total lateral root length, and the ratio between lateral root and primary root lengths. Moreover, we found that the rhizochron index was useful to distinguish ABA effect on root architecture, as well as the mutant pho1 phenotype. We propose the rhizochron index (m) as a new feature of the root architectural system to be considered, in addition to conventional traits in future investigations.

scholarly journals High throughput phenotyping of root growth dynamics, lateral root formation, root architecture and root hair development enabled by PlaRoM

2009 ◽  
Vol 36 (11) ◽  
pp. 938 ◽  
Author(s):  
Nima Yazdanbakhsh ◽  
Joachim Fisahn
Keyword(s):  
Root Growth ◽  
Growth Kinetics ◽  
Lateral Root ◽  
Root Architecture ◽  
Imaging Techniques ◽  
Plant Root ◽  
Primary Root ◽  
Growth Media ◽  
Root Extension ◽  
Lateral Root Development

Plant organ phenotyping by non-invasive video imaging techniques provides a powerful tool to assess physiological traits and biomass production. We describe here a range of applications of a recently developed plant root monitoring platform (PlaRoM). PlaRoM consists of an imaging platform and a root extension profiling software application. This platform has been developed for multi parallel recordings of root growth phenotypes of up to 50 individual seedlings over several days, with high spatial and temporal resolution. PlaRoM can investigate root extension profiles of different genotypes in various growth conditions (e.g. light protocol, temperature, growth media). In particular, we present primary root growth kinetics that was collected over several days. Furthermore, addition of 0.01% sucrose to the growth medium provided sufficient carbohydrates to maintain reduced growth rates in extended nights. Further analysis of records obtained from the imaging platform revealed that lateral root development exhibits similar growth kinetics to the primary root, but that root hairs develop in a faster rate. The compatibility of PlaRoM with currently accessible software packages for studying root architecture will be discussed. We are aiming for a global application of our collected root images to analytical tools provided in remote locations.

FERONIAregulates auxin‐mediated lateral root development and primary root gravitropism

FEBS Letters ◽  
2018 ◽  
Vol 593 (1) ◽  
pp. 97-106 ◽  
Author(s):  
QingKun Dong ◽  
ZhiWei Zhang ◽  
YuTing Liu ◽  
Li‐Zhen Tao ◽  
HuiLi Liu
Keyword(s):  
Root Development ◽  
Lateral Root ◽  
Primary Root ◽  
Lateral Root Development ◽  
Root Gravitropism

scholarly journals Bradyrhizobium japonicum IRAT FA3 alters Arabidopsis thaliana root architecture via regulation of auxin efflux transporters PIN2, PIN3, PIN7 and ABCB19

2021 ◽  
Author(s):  
Mercedes Schroeder ◽  
Melissa Y. Gomez ◽  
Nathan K. McLain ◽  
Emma Gachomo
Keyword(s):  
Arabidopsis Thaliana ◽  
Root System ◽  
Root Development ◽  
Bradyrhizobium Japonicum ◽  
Lateral Root ◽  
Plant Root ◽  
Primary Root ◽  
Efflux Transporters ◽  
Loss Of Function ◽  
Lateral Root Primordia

Beneficial rhizobacteria can stimulate changes in plant root development. While root system growth is mediated by multiple factors, the regulated distribution of the phytohormone auxin within root tissues plays a principal role. Auxin transport facilitators help to generate the auxin gradients and maxima that determine root structure. Here, we show that the plant growth-promoting rhizobacterial strain Bradyrhizobium japonicum IRAT FA3 influences specific auxin efflux transporters to alter Arabidopsis thaliana root morphology. Gene expression profiling of host transcripts in control and B. japonicum-inoculated roots of the wild type A. thaliana accession Col-0 confirmed upregulation of PIN2, PIN3, PIN7 and ABCB19 with B. japonicum and identified genes potentially contributing to a diverse array of auxin-related responses. Co-cultivation of the bacterium with loss-of-function auxin efflux transport mutants revealed that B. japonicum requires PIN3, PIN7 and ABCB19 to increase lateral root development and utilizes PIN2 to reduce primary root length. Accelerated lateral root primordia production due to B. japonicum was not observed in single pin3, pin7 or abcb19 mutants, suggesting independent roles for PIN3, PIN7 and ABCB19 during the plant-microbe interaction. Our work demonstrates B. japonicum’s influence over host transcriptional reprogramming during plant interaction with this beneficial microbe and the subsequent alterations to root system architecture.

scholarly journals Development of Root Architecture in Thirty-seven Tree Species of Field Grown Nursery Stock1

2020 ◽  
Vol 38 (4) ◽  
pp. 143-148
Author(s):  
G. W. Watson ◽  
A.M. Hewitt
Keyword(s):  
Root System ◽  
Root Development ◽  
Lateral Root ◽  
Root Architecture ◽  
Lateral Roots ◽  
Acer Rubrum ◽  
Acer Pseudoplatanus ◽  
Lateral Root Development ◽  
Nursery Production ◽  
One Year

Abstract The number and size of lateral roots of a tree seedling can be evaluated visually, and could potentially be used to select plants with better root systems early in nursery production. To evaluate how root architecture develops in young trees, root architecture of 37 species of trees was compared at two stages of development: as harvested seedlings, and then one year after replanting. The total number of lateral roots and the number of roots >2mm (0.08 in) diameter that were present on the portion of the taproot remaining on seedlings after standard root pruning were recorded. Neither could consistently predict the number of lateral roots on the root system one year after replanting. Development of roots (sum of diameters) regenerated from the cut end of the seedling taproot was equal or greater than lateral root development in 84 percent of evaluated species. Even when regenerated root development was significantly less than lateral root development, the regenerated roots still comprised up to 44 percent of the root system. Regenerated roots from the cut end of the taproot can become a major component of the architecture of the structural root system in nursery stock. Index words: structural roots, nursery production, root regeneration. Species used in this study: European black alder (Alnus glutinosa Gaertn.), green ash (Fraxinus pennsylvanica Marshall), quaking aspen (Populus tremuloides Michx.), European white birch. (Betula pendula Roth), river birch (Betula nigra L.), black locust (Robinia pseudoacacia L.), northern catalpa (Catalpa speciosa (Warder) Warder ex Engelm.), Mazzard cherry [Prunus avium [L.) L.], chokecherry (Prunus virginiana L.), American elm (Ulmus americana L.), Siberian elm (Ulmus pumilia L.), goldenchain tree (Laburnum anagyroides Medik.), northern hackberry (Celtis occidentalis L.), Cockspur hawthorn (Crateagus crus-galli L.), single seed hawthorn (Crateagus monogyna Jacq.), honeylocust (Gleditsia tricanthos L.), Japanese pagodatree [Sophora japonica (L.) Schott], Katsura tree (Cercidiphyllum japonicum Siebold & Zucc.), Kentucky coffee tree [Gymnocladus dioicus (L.) K. Koch], littleleaf linden (Tilia cordata Mill.), boxelder (Acer negundo L.), hedge maple (Acer campestre L.), Norway maple (Acer platanoides L.), red maple (Acer rubrum L.), silver maple (Acer saccharinum L.), sugar maple (Acer saccharum Marshall), sycamore maple (Acer pseudoplatanus L.), English Oak (Quercus robur L.), northern red oak (Quercus rubra L.), Siberian peashrub (Caragana arborescens Lam.), American plum (Prunus Americana Marshall ), Myrobalan plum (Prunus cerasifera Ehrh.), redbud (Cercis Canadensis L.), Russian olive (Elaeagnus angustifoliaI L.), tuliptree (Liriodendron tulipifera L.), black walnut (Juglans nigra L.), Japanese zelkova (Zelkova serrata (Thunb.) Makino).

scholarly journals A single cell view of the transcriptome during lateral root initiation in Arabidopsis thaliana

2020 ◽  
Author(s):  
Hardik P. Gala ◽  
Amy Lanctot ◽  
Ken Jean-Baptiste ◽  
Sarah Guiziou ◽  
Jonah C. Chu ◽  
...  
Keyword(s):  
Single Cell ◽  
Root Development ◽  
Lateral Root ◽  
Lateral Roots ◽  
Primary Root ◽  
Root Initiation ◽  
Lateral Root Primordia ◽  
Lateral Root Development ◽  
Lateral Root Initiation ◽  
Molecular Events

AbstractRoot architecture is a major determinant of fitness, and is under constant modification in response to favorable and unfavorable environmental stimuli. Beyond impacts on the primary root, the environment can alter the position, spacing, density and length of secondary or lateral roots. Lateral root development is among the best-studied examples of plant organogenesis, yet there are still many unanswered questions about its earliest steps. Among the challenges faced in capturing these first molecular events is the fact that this process occurs in a small number of cells with unpredictable timing. Single-cell sequencing methods afford the opportunity to isolate the specific transcriptional changes occurring in cells undergoing this fate transition. Using this approach, we successfully captured the transcriptomes of initiating lateral root primordia, and discovered many previously unreported upregulated genes associated with this process. We developed a method to selectively repress target gene transcription in the xylem pole pericycle cells where lateral roots originate, and demonstrated that expression of several of these targets was required for normal root development. We also discovered novel subpopulations of cells in the pericycle and endodermal cell files that respond to lateral root initiation, highlighting the coordination across cell files required for this fate transition.One sentence summarySingle cell RNA sequencing reveals new molecular details about lateral root initiation, including the transcriptional impacts of the primordia on bordering cells.

scholarly journals Oak Taproot Growth Disruption Differentially Impacts Root Architecture during Nursery Production

Forests ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 798
Author(s):  
Shanon Hankin ◽  
Gary Watson
Keyword(s):  
Root Development ◽  
Lateral Root ◽  
Root Architecture ◽  
Lateral Roots ◽  
Production Methods ◽  
Lateral Root Development ◽  
Root Regeneration ◽  
Nursery Production ◽  
Growth Disruption ◽  
Taproot Pruning

For urban trees with strong taproots, a shift in root growth towards increased lateral root development could improve tree performance in compacted, poorly drained urban soils. In effort to achieve this desired shift, various propagation and production practices exist within the nursery industry. However, the effectiveness of practices used to disrupt taproot development, as well as their impact on root architecture, has been largely undocumented. To determine how seedling root systems respond to taproot growth disruption, we pruned oak seedling taproots either mechanically at 5 and/or 15 cm, or via air pruning at 15 cm. Taproot regeneration and lateral root development were evaluated after two years. Taproot pruning resulted in multiple regenerated taproots. The location and number of times the taproot(s) was pruned did not appear to alter the ultimate number. Mechanical taproot pruning did not affect lateral root development above the first pruning cut location at 5 or 15 cm, but generally increased the density of lateral roots below the pruning cut, likely due to the multiple taproots present. Most lateral roots were fine roots less than 1 mm in diameter (fine roots), being unlikely to become long-lived components of the root system architecture. The average number of lateral roots on air pruned (AP) seedlings was generally greater than on the same taproot segment of control (C) seedlings. To determine how these seedling changes impact the root regeneration of liner stock, we planted both taproot pruned and taproot air pruned seedlings in in-ground fabric bags filled with field soil (B) or directly into the field without bags (F). Root regeneration potential (RRP) at the bottom and lateral surfaces of the root ball were evaluated. There was less RRP on the lateral surface of the root ball in taproot air pruned, container-grown (CG) compared to taproot pruned, bare root (BR) bur oak liners, and there was no difference in red oak liners. The multiple taproots of mechanically pruned BR seedlings did not result in excessive taproot development as liners. In contrast, CG seedling taproots restricted by air pruning produced more regenerated taproots after transplanting. While seedling taproot growth disruption does disrupt the growth of a dominant single taproot and alters the architecture toward increasing the number of lateral roots, these practices do not result in laterally dominated root architecture at the liner stage of nursery production. Future research should determine how these production methods effect lateral root growth after a tree is established in the landscape and determine appropriate combinations of production methods for different species.

Effects of IAA, Kinetin, and Trifluralin on Cotton Seedlings

Weed Science ◽  
1971 ◽  
Vol 19 (3) ◽  
pp. 265-268 ◽  
Author(s):  
Ghanem S. Hassawy ◽  
K. C. Hamilton
Keyword(s):  
Gossypium Hirsutum ◽  
Root Development ◽  
Lateral Root ◽  
Indoleacetic Acid ◽  
Lateral Roots ◽  
Primary Root ◽  
Lateral Root Development

Trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine), IAA (indoleacetic acid), kinetin (6-furfurylamino purine), and their combinations in culture solutions did not affect cotton (Gossypium hirsutumL., var. Deltapine Smooth Leaf) germination but reduced primary root and shoot lengths of seedlings. Trifluralin alone and in combination with IAA or kinetin inhibited lateral root development. When IAA and kinetin were both applied with 5 ppmw trifluralin, lateral roots developed.

scholarly journals Nitrate Signaling, Functions, and Regulation of Root System Architecture: Insights from Arabidopsis thaliana

Genes ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 633 ◽  
Author(s):  
Muhammad Asim ◽  
Zia Ullah ◽  
Fangzheng Xu ◽  
Lulu An ◽  
Oluwaseun Olayemi Aluko ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Root System ◽  
Root Development ◽  
System Architecture ◽  
Lateral Root ◽  
Transcriptional Regulatory Network ◽  
Primary Root ◽  
Root System Architecture ◽  
Nitrate Transporter ◽  
Nitrate Transporters

Root system architecture (RSA) is required for the acquisition of water and mineral nutrients from the soil. One of the essential nutrients, nitrate (NO3−), is sensed and transported by nitrate transporters NRT1.1 and NRT2.1 in the plants. Nitrate transporter 1.1 (NRT1.1) is a dual-affinity nitrate transporter phosphorylated at the T101 residue by calcineurin B-like interacting protein kinase (CIPKs); it also regulates the expression of other key nitrate assimilatory genes. The differential phosphorylation (phosphorylation and dephosphorylation) strategies and underlying Ca2+ signaling mechanism of NRT1.1 stimulate lateral root growth by activating the auxin transport activity and Ca2+-ANR1 signaling at the plasma membrane and the endosomes, respectively. NO3− additionally functions as a signal molecule that forms a signaling system, which consists of a vast array of transcription factors that control root system architecture that either stimulate or inhibit lateral and primary root development in response to localized and high nitrate (NO3−), respectively. This review elucidates the so-far identified nitrate transporters, nitrate sensing, signal transduction, and the key roles of nitrate transporters and its downstream transcriptional regulatory network in the primary and lateral root development in Arabidopsis thaliana under stress conditions.

scholarly journals Reactive oxygen species signalling is involved in alkamide-induced altered root development.

2021 ◽  
Author(s):  
Tonatiu Campos García ◽  
Jorge Molina-Torres ◽  
Kirk L Overmyer
Keyword(s):  
Root Hair ◽  
Lateral Root ◽  
Root Architecture ◽  
Primary Root ◽  
Heterotrimeric G Proteins ◽  
Reverse Genetic ◽  
Transcriptional Reprogramming ◽  
Protein Mutants ◽  
Induced Changes

Alkamides are alpha unsaturated N-acylamides structurally related to N-acyl ethanolamides (NAEs) and N-acyl-L-homoserine lactones (AHLs). Studies have shown that alkamides induce prominent changes in root architecture, a significant metabolic readjustment, and transcriptional reprogramming. Some alkamide responses have been associated with redox signalling; however, this involvement and ROS sources have not been fully described. We utilized a genetic approach to address ROS signalling in alkamide-induced processes and found that in Arabidopsis, treatment with the alkamide affinin (50μM) increased the in-situ accumulation of H2O2 in lateral root emergence sites and reduced H2O2 accumulation in primary root meristems implying that altered root growth was dependent on endogenous H2O2. Results show that ROS sourced from PRX34, RBOHC and RBOHD were involved in promotion of lateral root emergence by alkamides. RBOHC was required for affinin-induced enhanced root hair expansion. Furthermore, affinin-induced changes in lateral root emergence, but not root hair length, were dependent on a change in extracellular pH. Finally, reverse genetic experiments suggest heterotrimeric G-proteins were involved in plant response to alkamides; nevertheless, further studies with additional higher order G-protein mutants will be required to resolve this question. These results support that alkamides recruit specific ROS signaling programs to mediate alterations in root architecture.

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