Decision Making within Plant Root Systems

1996 ◽  
Author(s):  
Yoav Waisel ◽  
Bobbie McMichael ◽  
Amram Eshel
Keyword(s):  
Root System ◽  
System Architecture ◽  
Plant Root ◽  
Lateral Roots ◽  
Root Systems ◽  
Root System Architecture ◽  
Growth Patterns ◽  
Soil Conditions ◽  
Stage Of Development ◽  
Root Types

Architecture of a root system is the expression of the potential of various root types to branch, to grow and to coordinate with other plant organs, under the specific limitations of the environmental conditions. The present investigation has proven the following points. 1) Genotypes with different types of root systems were identified. The growth patterns of their roots and the distribution of laterals along their main axes were recorded. 2) The patterns of development of the root systems of four cotton genotypes, throughout the entire life cycle of the plants, were described, even at such a late stage of development when the total length of the roots exceeded two kilometers. To the best of our knowledge, this is the first time that an analysis of this type is accomplished. 3) The development of root systems under restrictive soil conditions were compared with those that have developed under the non-restrictive conditions of aeroponics. Results indicate that in the absence of the mechanical impedance of the soil, cotton plants develop single roots that reach the length of 6 m, and have a total root length of 2000 m. Thus, root growth is strongly inhibited by the soil, with some root types being inhibited more than others. 4) One of the important decisions, in constructing an operational root system architecture of mature plants, is the shift of the balance between various root fractions in favor of the very fine roots. 5) Root system architecture is determined, in part, by the sites of initiation of the lateral roots. This is determined genetically by the number of xylem archs and by the totuosity of the stele. Selection for such traits should be sought.

scholarly journals 285 Some Polyethylene Mulches Increase Root Numbers in Peppers

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 440D-440
Author(s):  
R.E. Gough
Keyword(s):  
Root System ◽  
System Architecture ◽  
Adventitious Roots ◽  
Lateral Roots ◽  
Root Systems ◽  
Root System Architecture ◽  
Root Numbers ◽  
Plant Stem ◽  
Pepper Plants

In 1999, `Sweet Banana' pepper plants were grown under clean cultivation or SMR—red, silver, or black polyethylene mulches. Plants in each of three replications per treatment were field-set on 15 June. On 22 Sept., plants were excavated, and their root systems were examined. The total number of roots per plant at 5-, 10-, 15-, 20-, and 25-cm depths and 10-, 20-, 30-, 40-, 50-, and 60-cm distances from plant stems were recorded. Distribution and architecture of the root systems also were examined. Plants grown under clean cultivation developed 50 to 60 adventitious roots each, while those grown under red mulch developed about 20, and those under black and silver mulch about nine adventitious roots each. In all treatments, the adventitious roots radiated from the stem at an oblique, downward 35° angle. No plants had vertical roots. Root system architecture was similar among treatments, with 40% of the roots in the upper 5 cm of soil and 70% in the upper 10 cm. Thirty percent of roots were within 10 cm of the plant stem, and 50% were within 20 cm. Nearly 100% of the roots were located within 40 cm of the plant stem. Root count decreased with increasing depth and distance from the plant stem. Plants grown beneath the silver mulch produced the greatest number of lateral roots, followed by plants grown in clean cultivation and under black mulch. Plants grown under red mulch produced the fewest roots. Differences among treatments were significant. Colored mulches influence the total number of adventitious and lateral roots but not the root system architecture of pepper plants.

scholarly journals Transcriptome diversity among rice root types during asymbiosis and interaction with arbuscular mycorrhizal fungi

2015 ◽  
Vol 112 (21) ◽  
pp. 6754-6759 ◽  
Author(s):  
Caroline Gutjahr ◽  
Ruairidh J. H. Sawers ◽  
Guillaume Marti ◽  
Liliana Andrés-Hernández ◽  
Shu-Yi Yang ◽  
...  
Keyword(s):  
Root System ◽  
System Architecture ◽  
Arbuscular Mycorrhizal ◽  
Root Systems ◽  
Root System Architecture ◽  
Adaptive Plasticity ◽  
Functional Relationships ◽  
Am Symbiosis ◽  
Crown Roots ◽  
Root Types

Root systems consist of different root types (RTs) with distinct developmental and functional characteristics. RTs may be individually reprogrammed in response to their microenvironment to maximize adaptive plasticity. Molecular understanding of such specific remodeling—although crucial for crop improvement—is limited. Here, RT-specific transcriptomes of adult rice crown, large and fine lateral roots were assessed, revealing molecular evidence for functional diversity among individual RTs. Of the three rice RTs, crown roots displayed a significant enrichment of transcripts associated with phytohormones and secondary cell wall (SCW) metabolism, whereas lateral RTs showed a greater accumulation of transcripts related to mineral transport. In nature, arbuscular mycorrhizal (AM) symbiosis represents the default state of most root systems and is known to modify root system architecture. Rice RTs become heterogeneously colonized by AM fungi, with large laterals preferentially entering into the association. However, RT-specific transcriptional responses to AM symbiosis were quantitatively most pronounced for crown roots despite their modest physical engagement in the interaction. Furthermore, colonized crown roots adopted an expression profile more related to mycorrhizal large lateral than to noncolonized crown roots, suggesting a fundamental reprogramming of crown root character. Among these changes, a significant reduction in SCW transcripts was observed that was correlated with an alteration of SCW composition as determined by mass spectrometry. The combined change in SCW, hormone- and transport-related transcript profiles across the RTs indicates a previously overlooked switch of functional relationships among RTs during AM symbiosis, with a potential impact on root system architecture and functioning.

scholarly journals Color of Plastic Mulch Affects Lateral Root Development But Not Root System Architecture in Pepper

HortScience ◽  
2001 ◽  
Vol 36 (1) ◽  
pp. 66-68 ◽  
Author(s):  
R.E. Gough
Keyword(s):  
Root System ◽  
System Architecture ◽  
Adventitious Roots ◽  
Lateral Roots ◽  
Soil Surface ◽  
Root Systems ◽  
Root System Architecture ◽  
Plastic Mulch ◽  
Lateral Root Development ◽  
Root Numbers

In 1999, `Sweet Banana' pepper [Capsicum annuum L. (Grossum Group)] plants were grown under clean cultivation or with red, silver, or black polyethylene selective reflecting (SMR) mulches over the soil surface. Plants in each of three replications per treatment were field-set on 15 June. On 22 Sept., the plants were excavated and their root systems examined using a trench profile method and a succession of trench wall slices. The total numbers of roots of each plant at depths of 5, 10, 15, 20, and 25 cm and 10, 20, 30, 40, 50, and 60 cm from the plant stem were recorded. Distribution and architecture of the root systems were also examined. Plants grown under clean cultivation developed 50 to 60 adventitious roots each, while those grown under red mulch developed ≈20 and those under black and silver mulch about nine adventitious roots each. In all treatments, the adventitious roots radiated downward from the stem at an angle of 35° from the horizontal. No plants had vertical roots. Root system architecture was similar among treatments, with 40% of the roots in the upper 5 cm of soil and 70% in the upper 10 cm. Thirty percent of the roots were within 10 cm, 50% within 20 cm, and nearly 100% within 40 cm of the stem. Root numbers decreased with increasing depth and distance from the stem. The greatest number of lateral roots were produced under silver mulch, intermediate numbers under clean cultivation and black mulch, and the fewest roots under red mulch. Colored mulches influenced the total number of adventitious and lateral roots but not the root system architecture of pepper plants.

scholarly journals Genome-wide association analysis unveils novel QTLs for seminal root system architecture traits in Ethiopian durum wheat

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Admas Alemu ◽  
Tileye Feyissa ◽  
Marco Maccaferri ◽  
Giuseppe Sciara ◽  
Roberto Tuberosa ◽  
...  
Keyword(s):  
Durum Wheat ◽  
Root System ◽  
System Architecture ◽  
Root Length ◽  
Dry Weight ◽  
Root System Architecture ◽  
High Density ◽  
Soil Conditions ◽  
Root Dry Weight ◽  
Seminal Roots

Abstract Background Genetic improvement of root system architecture is essential to improve water and nutrient use efficiency of crops or to boost their productivity under stress or non-optimal soil conditions. One hundred ninety-two Ethiopian durum wheat accessions comprising 167 historical landraces and 25 modern cultivars were assembled for GWAS analysis to identify QTLs for root system architecture (RSA) traits and genotyped with a high-density 90 K wheat SNP array by Illumina. Results Using a non-roll, paper-based root phenotyping platform, a total of 2880 seedlings and 14,947 seminal roots were measured at the three-leaf stage to collect data for total root length (TRL), total root number (TRN), root growth angle (RGA), average root length (ARL), bulk root dry weight (RDW), individual root dry weight (IRW), bulk shoot dry weight (SDW), presence of six seminal roots per seedling (RT6) and root shoot ratio (RSR). Analysis of variance revealed highly significant differences between accessions for all RSA traits. Four major (− log10P ≥ 4) and 34 nominal (− log10P ≥ 3) QTLs were identified and grouped in 16 RSA QTL clusters across chromosomes. A higher number of significant RSA QTL were identified on chromosome 4B particularly for root vigor traits (root length, number and/or weight). Conclusions After projecting the identified QTLs on to a high-density tetraploid consensus map along with previously reported RSA QTL in both durum and bread wheat, fourteen nominal QTLs were found to be novel and could potentially be used to tailor RSA in elite lines. The major RGA QTLs on chromosome 6AL detected in the current study and reported in previous studies is a good candidate for cloning the causative underlining sequence and identifying the beneficial haplotypes able to positively affect yield under water- or nutrient-limited conditions.

scholarly journals Morphological Characterization of Root System Architecture in Diverse Tomato Genotypes during Early Growth

2018 ◽  
Vol 19 (12) ◽  
pp. 3888 ◽  
Author(s):  
Aurora Alaguero-Cordovilla ◽  
Francisco Gran-Gómez ◽  
Sergio Tormos-Moltó ◽  
José Pérez-Pérez
Keyword(s):  
Root System ◽  
System Architecture ◽  
Lateral Root ◽  
Morphological Plasticity ◽  
Root System Architecture ◽  
Morphological Characterization ◽  
Early Growth ◽  
Soil Conditions ◽  
Wild Tomato Species ◽  
Local Soil

Plant roots exploit morphological plasticity to adapt and respond to different soil environments. We characterized the root system architecture of nine wild tomato species and four cultivated tomato (Solanum lycopersicum L.) varieties during early growth in a controlled environment. Additionally, the root system architecture of six near-isogenic lines from the tomato ‘Micro-Tom’ mutant collection was also studied. These lines were affected in key genes of ethylene, abscisic acid, and anthocyanin pathways. We found extensive differences between the studied lines for a number of meaningful morphological traits, such as lateral root distribution, lateral root length or adventitious root development, which might represent adaptations to local soil conditions during speciation and subsequent domestication. Taken together, our results provide a general quantitative framework for comparing root system architecture in tomato seedlings and other related species.

scholarly journals AT-HOOK MOTIF NUCLEAR LOCALISED PROTEIN 18 as a Novel Modulator of Root System Architecture

2020 ◽  
Author(s):  
Marek Šírl ◽  
Tereza Šnajdrová ◽  
Dolores Gutiérrez-Alanís ◽  
Joseph G. Dubrovsky ◽  
Jean Phillipe Vielle-Calzada ◽  
...  
Keyword(s):  
Root System ◽  
System Architecture ◽  
Lateral Root ◽  
Apical Meristem ◽  
Lateral Roots ◽  
Primary Root ◽  
Root System Architecture ◽  
Root Apical Meristem ◽  
Root Initiation ◽  
Lateral Root Initiation

The AT-HOOK MOTIF NUCLEAR LOCALIZED PROTEIN (AHL) gene family encodes embryophyte-specific nuclear proteins with DNA binding activity. They modulate gene expression and affect various developmental processes in plants. We identify AHL18 (At3G60870) as a developmental modulator of root system architecture and growth. AHL18 regulates the length of the proliferation domain and number of dividing cells in the root apical meristem and thereby, cell production. Both primary root growth and lateral root development respond according to AHL18 transcription level. The ahl18 knock-out plants show reduced root systems due to a shorter primary root and a lower number of lateral roots. This change results from a higher number of arrested and non-developing lateral root primordia (LRP) rather than from decreased initiation. Overexpression of AHL18 results in a more extensive root system, longer primary roots, and increased density of lateral root initiation events. Formation of lateral roots is affected during the initiation of LRP and later development. AHL18 regulate root apical meristem activity, lateral root initiation and emergence, which is in accord with localization of its expression.

scholarly journals Response of Mungbean Root System Architecture to Phosphorus Application Methods

Proceedings ◽  
2020 ◽  
Vol 36 (1) ◽  
pp. 173
Author(s):  
Vijaya Singh ◽  
Marisa Collins ◽  
Colin Andrew Douglas ◽  
Michael Bell
Keyword(s):  
Root System ◽  
System Architecture ◽  
Root Systems ◽  
Root System Architecture ◽  
Grain Legumes ◽  
Coarse Root ◽  
Root Parameters ◽  
P Application ◽  
Application Methods ◽  
Phosphorus Application

In recent years phosphorus application methods have become an important management strategy for optimising the uptake of the immobile nutrient phosphorus (P). Root system architecture (RSA) could play a particularly important role in the uptake of P by grain legumes, due to their relatively coarse root systems. The objective of this study was to understand the response of mungbean root systems to P application methods. Four mungbean varieties were grown in purpose-built soil filled root chambers that received five P application methods. Phosphorus treatments consisted of a control (no application of P) compared with 30 mg P/kg soil throughout the soil volume (high P treatment) or restricted to 10cm deep layers in the topsoil or in a layer from 20-30cm deep. A fifth treatment consisted of the same amount of P as applied in deeper dispersed layer applied in a concentrated band at 25cm depth. After 50 days of growth, plant were destructively harvested and shoot and root parameters were measured. Mungbean varieties responded differently to P application methods, with Jade and Berken varieties showing greater root proliferation at depth and greater shoot growth in response to banded and deeper dispersed P applications, relative to the late maturing variety Putland. Shallow dispersed P and the no-P control both resulted in poor root growth in all the genotypes except Celera II, which did not respond to P application from any placement strategy. Results suggest that P application strategies may need to vary with variety to maximize the uptake of P.

scholarly journals Root biomass of beech as a factor influencing the wind tree stability 

2019 ◽  
Vol 48 (No. 12) ◽  
pp. 549-564 ◽  
Author(s):  
J. Kodrík ◽  
M. Kodrík
Keyword(s):  
Root System ◽  
Groundwater Level ◽  
Negative Impact ◽  
Lateral Roots ◽  
Root Systems ◽  
Static Stability ◽  
Soil Conditions ◽  
Tree Stability ◽  
Ground Biomass ◽  
Below Ground

Beech is, thanks to its root system, in general considered to be a wind-resistant woody plant species. Nevertheless, the research on beech root systems has revealed that it is not possible to mechanically divide the woody plants into deep rooted and shallow rooted, because their root systems are modified according to various stand conditions. The root system shape, growth and development are mostly influenced by soil conditions and groundwater level. In the case of a high groundwater level beech root systems do not form tap roots and the lateral roots are rather thin and weak. Important factor for the tree static stability is number of roots with diameter 3–10 cm. The most important for the tree stability are roots with diameter over 10 cm. Wood-destroying fungi have strong negative impact on tree static stability. There are differences between beech below-ground biomass growing in soils rich in nutrients and poor in nutrients. The total below-ground biomass of the beech stands poor in nutrients is higher.

scholarly journals Plasticity of the Root System Architecture and Leaf Gas Exchange Parameters Are Important for Maintaining Bottle Gourd Responses under Water Deficit

Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1697
Author(s):  
Dinoclaudio Zacarias Rafael ◽  
Osvin Arriagada ◽  
Guillermo Toro ◽  
Jacob Mashilo ◽  
Freddy Mora-Poblete ◽  
...  
Keyword(s):  
Root System ◽  
Water Deficit ◽  
System Architecture ◽  
Root Length ◽  
Leaf Gas Exchange ◽  
Lateral Roots ◽  
Physiological Responses ◽  
Root System Architecture ◽  
Second Order ◽  
Bottle Gourd

The evaluation of root system architecture (RSA) development and the physiological responses of crop plants grown under water-limited conditions are of great importance. The purpose of this study was to examine the short-term variation of the morphological and physiological plasticity of Lagenaria siceraria genotypes under water deficit, evaluating the changes in the relationship between the root system architecture and leaf physiological responses. Bottle gourd genotypes were grown in rhizoboxes under well-watered and water deficit conditions. Significant genotype-water regime interactions were observed for several RSA traits and physiological parameters. Biplot analyses confirmed that the drought-tolerant genotypes (BG-48 and GC) showed a high net CO2 assimilation rate, stomatal conductance, transpiration rates with a smaller length, and a reduced root length density of second-order lateral roots, whereas the genotypes BG-67 and Osorno were identified as drought-sensitive and showed greater values for average root length and the density of second-order lateral roots. Consequently, a reduced length and density of lateral roots in bottle gourd should constitute a response to water deficit. The root traits studied here can be used to evaluate bottle gourd performance under novel water management strategies and as criteria for breeding selection.

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