Naturally coloured roots as a tool for studying root interactions in mixed cropping

The objective of this study was to evaluate the usage of species with coloured roots to study root growth patterns during intercropping. Red beet (Beta vulgaris L. cv. Detroit), having clear red roots, was used in a semi-field and field experiment to allow identification and quantification of roots of the individual species in the mixture. In the field experiment, red beet was strip intercropped with lucerne (Medicago sativa L. cv. Creno) and kale (Brassica oleracea L. var. Sabellica), respectively while the red beet-lucerne intercropping was conducted in large rhizoboxes where root growth distribution and <sup>15</sup>N isotope uptake was determined. The study confirmed that the direct visual measurement of root growth using species with coloured roots and indirect tracer uptake measurements contributed to the success of studying root growth dynamics in intercropping systems. Red beet root intensity was not considerably affected by the strip intercropping when the crops were established at the same time, but when established between existing lucerne strips, a reduction in roots at the border row was shown. Lucerne and kale were both observed to be able to exploit the deep soil layers beneath the red beet border row.

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High-resolution 4D spatiotemporal analysis reveals the contributions of local growth dynamics to contrasting maize root architectures

10.1101/381046 ◽

2018 ◽

Cited By ~ 1

Author(s):

Ni Jiang ◽

Eric Floro ◽

Adam L. Bray ◽

Benjamin Laws ◽

Keith E. Duncan ◽

...

Keyword(s):

Root Growth ◽

Root System ◽

Growth Dynamics ◽

Root Systems ◽

Growth Patterns ◽

Maize Root ◽

Global Features ◽

Long Distance ◽

Local Root ◽

The Many

ABSTRACTRoot systems are branched networks that develop from simple growth properties of their individual roots. Yet a mature maize root system has many thousands of roots that each interact with soil structures, water and nutrient patches, and microbial ecologies in the micro-environments surrounding each root tip. Although the plasticity of root growth to these and other environmental factors is well known, how the many local processes contribute over time to global features of root system architecture is hardly understood. We employ an automated 3D root imaging pipeline to capture the growth of maize roots every four hours throughout seven days of seedling development. We model the contrasting architectures of two maize inbred genotypes and their hybrid to derive key parameters that distinguish complex growth patterns as a function of time. The statistical characteristics of local root growth defined the global system properties despite a large range of trait values. “Computational dissection” of a single root from each root system identified differences in the size of the root branching zone and lateral branching densities, but not radial patterns, that drove the contrasting root architectures from seedling to maturity. X-ray imaging of mature field-grown root crowns showed that seedling growth trajectories persisted throughout development and could predict eventual architectures, suggesting a strong genetic basis. The work connects individual and systemwide scales of root growth dynamics, providing the means for a function-valued approach to understanding the genetic and genetic x environment conditioning of root growth that will enable breeding for enhanced root traits.SIGNIFICANCE STATEMENTWhen and where roots grow determines their ability to capture short-lived and patchy water and nutrient resources to support the aboveground organs of the plant. Roots have no known long-distance external sensing mechanisms, but form branched networks that blindly explore the soil and respond to encountered local stimuli. How global architectures form from the many thousands of these local responses, and how they are controlled genetically are major open questions. Here we quantify differences in local root growth patterns of two inbred genotypes of maize that control contrasting systemwide properties. Measurements at the seedling stage were highly correlated with the complex architectures of mature root systems, paving the way for the development of crops with greater resource uptake capacity.

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ALCOHOL DEHYDROGENASE ACTIVITY IN ISOLATED VACUOLES OF RED BEET ROOT CELLS

Tsitologiya ◽

10.31116/tsitol.2018.06-08 ◽

2018 ◽

Vol 60 (6) ◽

pp. 469-475

Author(s):

O. D. Nimaeva ◽

◽

E. V. Pradedova ◽

A. B. Karpova ◽

R. K. Salyaev ◽

...

Keyword(s):

Alcohol Dehydrogenase ◽

Dehydrogenase Activity ◽

Root Cells ◽

Beet Root ◽

Red Beet ◽

Alcohol Dehydrogenase Activity

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Root and Stem Growth Patterns of Young `Mauritius' Lychee Trees

HortScience ◽

10.21273/hortsci.31.5.815 ◽

1996 ◽

Vol 31 (5) ◽

pp. 815-818 ◽

Cited By ~ 5

Author(s):

Thomas E. Marler ◽

Leah E. Willis

Keyword(s):

Root Growth ◽

Stem Growth ◽

Growth Patterns ◽

Extension Growth ◽

Glass Wall ◽

Litchi Chinensis ◽

Root Extension ◽

Stem Extension ◽

Root Observation

`Mauritius' lychee (Litchi chinensis Sonn.) trees were planted in root observation chambers in July 1990 to determine the pattern of root and stem extension growth during 12 months. Root and stem lengths were measured at intervals ranging from 7 to 18 days from Aug. 1990 until Aug. 1991. During each period of active canopy growth, up to six stem tips were tagged and measured. Root growth was determined by measuring tracings of the extension of each root in a visible plane of the glass wall of the observation chambers. Stem growth was cyclic, with distinct periods of rapid extension followed by periods with no extension. In contrast, root growth was fairly continuous with only three periods of no visible root extension. Mean absolute extension rates were higher for stems than for roots. There were no consistent relationships between the timing of root and stem extension growth.

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Opening of Ca2+ channels in isolated red beet root vacuole membrane by inositol 1,4,5-trisphosphate

Nature ◽

10.1038/343567a0 ◽

1990 ◽

Vol 343 (6258) ◽

pp. 567-570 ◽

Cited By ~ 163

Author(s):

J. Alexandra ◽

J. P. Lassalles ◽

R. T. Kado

Keyword(s):

Vacuole Membrane ◽

Beet Root ◽

Red Beet ◽

Inositol 1,4,5 Trisphosphate ◽

Ca2 Channels

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Contemporary Concepts of Root System Architecture of Urban Trees

Arboriculture & Urban Forestry ◽

10.48044/jauf.2010.020 ◽

2010 ◽

Vol 36 (4) ◽

pp. 149-159

Author(s):

Susan Day ◽

P. Eric Wiseman ◽

Sarah Dickinson ◽

J. Roger Harris

Keyword(s):

Built Environment ◽

Root Growth ◽

Root System ◽

Root Architecture ◽

Root Systems ◽

Growth Patterns ◽

Urban Trees ◽

Rooting Depth ◽

Similar Species ◽

Urban Settings

Knowledge of the extent and distribution of tree root systems is essential for managing trees in the built environment. Despite recent advances in root detection tools, published research on tree root architecture in urban settings has been limited and only partially synthesized. Root growth patterns of urban trees may differ considerably from similar species in forested or agricultural environments. This paper reviews literature documenting tree root growth in urban settings as well as literature addressing root architecture in nonurban settings that may contribute to present understanding of tree roots in built environments. Although tree species may have the genetic potential for generating deep root systems (>2 m), rooting depth in urban situations is frequently restricted by impenetrable or inhospitable soil layers or by underground infrastructure. Lateral root extent is likewise subject to restriction by dense soils under hardscape or by absence of irrigation in dry areas. By combining results of numerous studies, the authors of this paper estimated the radius of an unrestricted root system initially increases at a rate of approximately 38 to 1, compared to trunk diameter; however, this ratio likely considerably declines as trees mature. Roots are often irregularly distributed around the tree and may be influenced by cardinal direction, terrain, tree lean, or obstacles in the built environment. Buttress roots, tap roots, and other root types are also discussed.

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Root and Shoot Growth Periodicity of Green Ash, Scarlet Oak, Turkish Hazelnut, and Tree Lilac

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.120.2.211 ◽

1995 ◽

Vol 120 (2) ◽

pp. 211-216 ◽

Cited By ~ 22

Author(s):

J. Roger Harris ◽

Nina L. Bassuk ◽

Richard W. Zobel ◽

Thomas H. Whitlow

Keyword(s):

Root Growth ◽

Root Length ◽

Shoot Growth ◽

Lateral Roots ◽

Growth Patterns ◽

Extension Rate ◽

Green Ash ◽

Growth Measurement ◽

Root And Shoot Growth ◽

Growth Periodicity

The objectives of this study were to determine root and shoot growth periodicity for established Fraxinus pennsylvanica Marsh. (green ash), Quercus coccinea Muenchh. (scarlet oak), Corylus colurna L. (Turkish hazelnut), and Syringa reticulata (Blume) Hara `Ivory Silk' (tree lilac) trees and to evaluate three methods of root growth periodicity measurement. Two methods were evaluated using a rhizotron. One method measured the extension rate (RE) ofindividual roots, and the second method measured change in root length (RL) against an observation grid. A third method, using periodic counts of new roots present on minirhizotrons (MR), was also evaluated. RE showed the least variability among individual trees. Shoot growth began before or simultaneously with the beginning of root growth for all species with all root growth measurement methods. All species had concurrent shoot and root growth, and no distinct alternating growth patterns were evident when root growth was measured by RE. Alternating root and shoot growth was evident, however, when root growth was measured by RL and MR. RE measured extension rate of larger diameter lateral roots, RL measured increase in root length of all diameter lateral roots and MR measured new root count of all sizes of lateral and vertical roots. Root growth periodicity patterns differed with the measurement method and the types of roots measured.

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Lateral Root Priming Synergystically Arises from Root Growth and Auxin Transport Dynamics

10.1101/361709 ◽

2018 ◽

Cited By ~ 2

Author(s):

Thea van den Berg ◽

Kirsten H. ten Tusscher

Keyword(s):

Cell Cycle ◽

Root Growth ◽

Lateral Root ◽

Root Formation ◽

Growth Dynamics ◽

Root Tip ◽

Cycle Duration ◽

Elongation Zone ◽

Lateral Root Formation ◽

Cell Cycle Duration

AbstractThe root system is a major determinant of plant fitness. Its capacity to supply the plant with sufficient water and nutrients strongly depends on root system architecture, which arises from the repeated branching off of lateral roots. A critical first step in lateral root formation is priming, which prepatterns sites competent of forming a lateral root. Priming is characterized by temporal oscillations in auxin, auxin signalling and gene expression in the root meristem, which through growth become transformed into a spatially repetitive pattern of competent sites. Previous studies have demonstrated the importance of auxin synthesis, transport and perception for the amplitude of these oscillations and their chances of producing an actual competent site. Additionally, repeated lateral root cap apoptosis was demonstrated to be strongly correlated with repetitive lateral root priming. Intriguingly, no single mutation has been identified that fully abolishes lateral root formation, and thusfar the mechanism underlying oscillations has remained unknown. In this study, we investigated the impact of auxin reflux loop properties combined with root growth dynamics on priming, using a computational approach. To this end we developed a novel multi-scale root model incorporating a realistic root tip architecture and reflux loop properties as well as root growth dynamics. Excitingly, in this model, repetitive auxin elevations automatically emerge. First, we show that root tip architecture and reflux loop properties result in an auxin loading zone at the start of the elongation zone, with preferential auxin loading in narrow vasculature cells. Second, we demonstrate how meristematic root growth dynamics causes regular alternations in the sizes of cells arriving at the elongation zone, which subsequently become amplified during cell expansion. These cell size differences translate into differences in cellular auxin loading potential. Combined, these properties result in temporal and spatial fluctuations in auxin levels in vasculature and pericycle cells. Our model predicts that temporal priming frequency predominantly depends on cell cycle duration, while cell cycle duration together with meristem size control lateral root spacing.

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Genetic variability for root morph-architecture traits and root growth dynamics as related to phosphorus efficiency in soybean

Functional Plant Biology ◽

10.1071/fp09215 ◽

2010 ◽

Vol 37 (4) ◽

pp. 304 ◽

Cited By ~ 49

Author(s):

Junhua Ao ◽

Jiabing Fu ◽

Jiang Tian ◽

Xiaolong Yan ◽

Hong Liao

Keyword(s):

Genetic Variability ◽

Root Growth ◽

Recombinant Inbred Lines ◽

Growth Dynamics ◽

Root Traits ◽

Phosphorus Efficiency ◽

P Efficiency ◽

Glycine Max L ◽

Positive Correlations

Root morphology and architecture are believed to be important for plant phosphorus (P) efficiency, but their genetic information is relatively scarce. In the present study, a field and a specially designed minirhizotron experiments were conducted using two soybean (Glycine max L. Merr.) genotypes and their 88 recombinant inbred lines (RILs) to elucidate the genetic variability for root morph-architecture traits and root growth dynamics as related to P efficiency in soybean. The results indicated that the root morph-architecture traits were continually segregated in the RILs with a normal distribution, indicating which are possibly controlled by quantitative trait loci. Significantly positive correlations were found between root and P traits, suggesting feasibility of screening P efficient genotype through simple selection of root traits in field. Most root morph-architecture traits were closely correlated, showing a coordinating contribution to P efficiency. Furthermore, root morphological traits always had higher heritability than architecture traits, thus, could serve as more reliable index in field selection. The dynamic parameters of root growth from the minirhizotron experiment showed that the P efficient genotype established longer and larger root system with preferring distribution in surface layer and also kept more active roots, therefore, had a better growth performance in field, than the P-inefficient genotype. Taken together, this is the first report on in situ root growth dynamics and its relation to P efficiency using minirhizotron systems in crops. Our findings help to better understand the relationships between P efficiency and root traits and, thus, facilitate development of P efficient genotypes in crops.

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