scholarly journals EXOCYST70A3 controls root system depth in Arabidopsis via the dynamic modulation of auxin transport

2019 ◽  
Author(s):  
Takehiko Ogura ◽  
Christian Goeschl ◽  
Daniele Filiault ◽  
Madalina Mirea ◽  
Radka Slovak ◽  
...  
Keyword(s):  
Root System ◽  
Natural Variation ◽  
Molecular Mechanisms ◽  
Allelic Variation ◽  
Root System Architecture ◽  
Protein Distribution ◽  
System Architectures ◽  
Dynamic Modulation ◽  
Distribution Of Roots ◽  
Local Modulation

SUMMARYRoot system architecture (RSA), the distribution of roots in soil, plays a major role in plant survival. RSA is shaped by multiple developmental processes that are largely governed by the phytohormone auxin, suggesting that auxin regulates responses of roots that are important for local adaptation. However, auxin has a central role in numerous processes and it is unclear which molecular mechanisms contribute to the variation in RSA for environmental adaptation. Using natural variation in Arabidopsis, we identify EXOCYST70A3 as a modulator of the auxin system that causes variation in RSA by acting on PIN4 protein distribution. Allelic variation and genetic perturbation of EXOCYST70A3 leads to alteration of root gravitropic responses, resulting in a different RSA depth profile and drought resistance. Overall our findings suggest that the local modulation of the pleiotropic auxin pathway can gives rise to distinct root system architectures that can be adaptive in specific environments.

scholarly journals Controlling The Root System Architecture In Rice: Impact of Genes, Phytohormones And Root Microbiota

2021 ◽  
Author(s):  
Pankaj K Verma ◽  
Shikha Verma ◽  
Nalini Pandey
Keyword(s):  
Root System ◽  
System Architecture ◽  
Hormonal Regulation ◽  
Molecular Mechanisms ◽  
Environmental Changes ◽  
Root Systems ◽  
Root System Architecture ◽  
World Food Security ◽  
The Impact ◽  
Root Microbiota

Abstract BackgroundIn order to feed expanding population, new crop varieties were generated which significantly contribute to world food security. However, the growth of these improved plants varieties relied primarily on synthetic fertilizers, which negatively affect the environment as well as human health. Plants adapt to adverse environmental changes by adopting root systems through architectural changes at the root-type and tissue-specific changes and nutrient uptake efficiency. ScopePlants adapt and operate distinct pathways at various stages of development in order to optimally establish their root systems, such as change in the expression profile of genes, changes in phytohormone level and microbiome induced Root System Architecture (RSA) modification. Many scientific studies have been carried out to understand plant response to microbial colonization and how microbes involved in RSA improvement through phytohormone level and transcriptomic changes.ConclusionIn this review, we spotlight the impact of genes, phytohormones and root microbiota on RSA and provide specific, critical new insights that have been resulted from recent studies on rice root as a model. First, we discuss new insights into the genetic regulation of RSA. Next, hormonal regulation of root architecture and the impact of phytohormones in crown root and root branching is discussed. Finally, we discussed the impact of root microbiota in RSA modification and summarized the current knowledge about the biochemical and central molecular mechanisms involved.

scholarly journals 265 Root Architecture in Quercus falcata after Physical Removal of the Radicle Tip or Copper Treatment

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 488A-488
Author(s):  
Gisele G. Martins ◽  
Robert Geneve ◽  
Sharon Kester
Keyword(s):  
Root System ◽  
Dry Weight ◽  
Root System Architecture ◽  
Root Tip ◽  
Link Length ◽  
System Architectures ◽  
Root Shoot Ratio ◽  
Internal Link ◽  
Intact Root ◽  
Root Box

Quercus falcata acorns were cold-stratified for 120 days and then sown in vermiculite under greenhouse conditions. When radicles were 7 cm long, the root tip was either removed (physically pruned) or dipped in a copper hydroxide solution (copper-treated). Intact root systems were used as control. Seedlings were then moved to a root box to observe root system architectures. The box was built of clear plexiglass 2.5 mm thick, and each face was 25.7 × 35.7 cm. Styrofoam spacers were used to separate faces, and nuts and bolts were placed along edges to hold the root box together. To permit observation of the entire root system, plants were grown in a plane between the plexiglass surface and a nylon sheet that separated roots from the medium (MetroMix 510). At 7, 9, and 11 days after treatment, the entire root system was traced on an acetate sheet, and number of internal and external links and number of secondary and tertiary roots were recorded. Total length, internal and external root links length, were obtained using digital analysis (MacRhizo). Dry weight of roots and shoots was collected at the end of this experiment (day 11). Treatment effects were evident 11 days after treatment. Copper-treated plants had statistically more secondary roots and larger internal link length than control or physically pruned plants. Also, copper-treated plants had smaller mean external link length, showing a more branched root system. Root biomass was similar for all treatments; however, copper-treated plants had smaller root: shoot ratio. This suggests that copper was acting as more than a pruning agent because copper-treated plants showed a different root system architecture compared to physically pruned plants.

scholarly journals Signaling pathways underlying nitrogen-dependent changes in root system architecture: from model to crop species

2020 ◽  
Vol 71 (15) ◽  
pp. 4393-4404 ◽  
Author(s):  
Zhongtao Jia ◽  
Nicolaus von Wirén
Keyword(s):  
Nutritional Status ◽  
Root System ◽  
System Architecture ◽  
Molecular Mechanisms ◽  
N Uptake ◽  
Root System Architecture ◽  
Water Soluble ◽  
Organic N ◽  
Limiting Factor ◽  
Crop Species

Abstract Among all essential mineral elements, nitrogen (N) is required in the largest amounts and thus is often a limiting factor for plant growth. N is taken up by plant roots in the form of water-soluble nitrate, ammonium, and, depending on abundance, low-molecular weight organic N. In soils, the availability and composition of these N forms can vary over space and time, which exposes roots to various local N signals that regulate root system architecture in combination with systemic signals reflecting the N nutritional status of the shoot. Uncovering the molecular mechanisms underlying N-dependent signaling provides great potential to optimize root system architecture for the sake of higher N uptake efficiency in crop breeding. In this review, we summarize prominent signaling mechanisms and their underlying molecular players that derive from external N forms or the internal N nutritional status and modulate root development including root hair formation and gravitropism. We also compare the current state of knowledge of these pathways between Arabidopsis and graminaceous plant species.

scholarly journals Natural genetic variation of root system architecture from Arabidopsis to Brachypodium : towards adaptive value

2012 ◽  
Vol 367 (1595) ◽  
pp. 1552-1558 ◽  
Author(s):  
David Pacheco-Villalobos ◽  
Christian S. Hardtke
Keyword(s):  
Genetic Variation ◽  
Root System ◽  
System Architecture ◽  
Allelic Variation ◽  
Molecular Model ◽  
Significant Degree ◽  
Root System Architecture ◽  
Natural Genetic Variation ◽  
Adaptive Value ◽  
System Physiology

Root system architecture is a trait that displays considerable plasticity because of its sensitivity to environmental stimuli. Nevertheless, to a significant degree it is genetically constrained as suggested by surveys of its natural genetic variation. A few regulators of root system architecture have been isolated as quantitative trait loci through the natural variation approach in the dicotyledon model, Arabidopsis . This provides proof of principle that allelic variation for root system architecture traits exists, is genetically tractable, and might be exploited for crop breeding. Beyond Arabidopsis , Brachypodium could serve as both a credible and experimentally accessible model for root system architecture variation in monocotyledons, as suggested by first glimpses of the different root morphologies of Brachypodium accessions. Whether a direct knowledge transfer gained from molecular model system studies will work in practice remains unclear however, because of a lack of comprehensive understanding of root system physiology in the native context. For instance, apart from a few notable exceptions, the adaptive value of genetic variation in root system modulators is unknown. Future studies should thus aim at comprehensive characterization of the role of genetic players in root system architecture variation by taking into account the native environmental conditions, in particular soil characteristics.

scholarly journals Uncovering natural variation in root system architecture and growth dynamics using a robotics-assisted phenomics platform

2021 ◽  
Author(s):  
Therese LaRue ◽  
Heike Lindner ◽  
Ankit Srinivas ◽  
Moises Exposito-Alonso ◽  
Guillaume Ramon Lobet ◽  
...  
Keyword(s):  
Root System ◽  
System Architecture ◽  
Natural Variation ◽  
Growth Dynamics ◽  
Root System Architecture ◽  
Climate Variables ◽  
Soil Environment ◽  
Local Environments ◽  
Below Ground ◽  
Developmental Dynamics

The plant kingdom contains a stunning array of complex morphologies easily observed above ground, but largely unexplored below-ground. Understanding the magnitude of diversity in root distribution within the soil, termed root system architecture (RSA), is fundamental to determining how this trait contributes to species adaptation in local environments. Roots are the interface between the soil environment and the shoot system and therefore play a key role in anchorage, resource uptake, and stress resilience. Previously, we presented the GLO-Roots (Growth and Luminescence Observatory for Roots) system to study the RSA of soil-grown Arabidopsis thaliana plants from germination to maturity. In this study, we present the automation of GLO-Roots using robotics and the development of image analysis pipelines in order to examine the natural variation of RSA in Arabidopsis over time. This dataset describes the developmental dynamics of 93 accessions and reveals highly complex and polygenic RSA traits that show significant correlation with climate variables.

scholarly journals Control of root system architecture by phytohormones and environmental signals in rice

2020 ◽  
Vol 67 (1-2) ◽  
pp. 98-109
Author(s):  
Chen Lin ◽  
Margret Sauter
Keyword(s):  
Root System ◽  
System Architecture ◽  
Crop Production ◽  
Molecular Mechanisms ◽  
Extreme Environments ◽  
Root System Architecture ◽  
Environmental Signals ◽  
Production Water ◽  
Environmental Extremes ◽  
Crown Roots

Drought and flooding are environmental extremes and major threats to crop production. Water uptake is achieved by plant roots which have to explore new soil spaces to alleviate water deficit during drought or to cope with water excess during flooding. Adaptation of the root system architecture helps plants cope with such extreme conditions and is crucial for plant health and survival. While for dicot plants the well studied model plant Arabidopsis thaliana has provided insight into the genetic and molecular regulation of the root system, less information is available for monocot species, which include the agronomically important cereal crops. Rice (Oryza sativa L.) is a semi-aquatic monocot plant that develops strong tolerance to flooding. Flooding tolerance of rice is closely linked to its adaptive root system. The functional root system of rice is mainly composed of crown roots and is shifted to nodal adventitious roots during flooding which allows rice to maintain oxygen supply to the roots and to survive longer periods of partial submergence as compared with other crops. Likewise, a number of drought-tolerance traits of rice are the result of an altered root system architecture. Hence, the structure of the root system adapts to, both, flooding and drought. Understanding the regulatory mechanisms that control root system adaptation to extreme environments is a key task for scientists to accelerate the breeding efforts for stress-tolerant crops. This review summarizes recently identified genes and molecular mechanisms that regulate root system architecture in rice in response to drought and flooding.

scholarly journals Spatial and Texture Analysis of Root System Architecture with Earth Mover's Distance (STARSEED)

2021 ◽  
Author(s):  
Joshua Peeples ◽  
Weihuang Xu ◽  
Romain Gloaguen ◽  
Diane Rowland ◽  
Alina Zare ◽  
...  
Keyword(s):  
Root System ◽  
Texture Analysis ◽  
System Architecture ◽  
Spatial Information ◽  
Growth Conditions ◽  
Root System Architecture ◽  
Earth Mover’S Distance ◽  
System Architectures ◽  
Earth Mover's Distance ◽  
Architecture Development

Abstract Root system architectures are complex, multidimensional, and challenging to characterize effectively for agronomic and ecological discovery. We propose a new method, Spatial and Texture Analysis of Root System architEcture with Earth mover's Distance (STARSEED), for comparing root architectures that incorporate spatial information through a novel application of the Earth Mover's Distance (EMD).We illustrate that the approach captures the response of sesame root systems for different genotypes and soil moisture levels. STARSEED provides quantitative and visual insights into changes that occur in root architectures across experimental treatments.STARSEED can be easily generalized to other plants and provides insight into root system architecture development and response to varying growth conditions not captured by existing root architecture metrics and models. The code and data for our experiments are publicly available: https://github.com/GatorSense/STARSEED.

scholarly journals The impact of the rhizobia–legume symbiosis on host root system architecture

2020 ◽  
Vol 71 (13) ◽  
pp. 3902-3921 ◽  
Author(s):  
Cristobal Concha ◽  
Peter Doerner
Keyword(s):  
Root System ◽  
System Architecture ◽  
Root Nodules ◽  
Root System Architecture ◽  
Resource Acquisition ◽  
Legume Symbiosis ◽  
Below Ground ◽  
Distribution Of Roots ◽  
The Impact ◽  
Host Resource

Abstract Legumes form symbioses with rhizobia to fix N2 in root nodules to supplement their nitrogen (N) requirements. Many studies have shown how symbioses affect the shoot, but far less is understood about how they modify root development and root system architecture (RSA). RSA is the distribution of roots in space and over time. RSA reflects host resource allocation into below-ground organs and patterns of host resource foraging underpinning its resource acquisition capacity. Recent studies have revealed a more comprehensive relationship between hosts and symbionts: the latter can affect host resource acquisition for phosphate and iron, and the symbiont’s production of plant growth regulators can enhance host resource flux and abundance. We review the current understanding of the effects of rhizobia–legume symbioses on legume root systems. We focus on resource acquisition and allocation within the host to conceptualize the effect of symbioses on RSA, and highlight opportunities for new directions of research.

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