Potassium transporter TRH1/KUP4 contributes to distinct auxin-mediated root system architecture responses

2021 ◽  
Author(s):  
Dimitris Templalexis ◽  
Dikran Tsitsekian ◽  
Chen Liu ◽  
Gerasimos Daras ◽  
Jan Šimura ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Root System ◽  
Root Hair ◽  
System Architecture ◽  
Auxin Transport ◽  
Root System Architecture ◽  
Growth Responses ◽  
Specific Expression ◽  
Peripheral Cell ◽  
Root Gravitropism

Abstract In plants, auxin transport and development are tightly coupled, just as hormone and growth responses are intimately linked in multicellular systems. Here we provide insights into uncoupling this tight control by specifically targeting the expression of TINY ROOT HAIR 1 (TRH1), a member of plant HAK/KUP/KT transporters that facilitate potassium uptake by co-transporting protons, in Arabidopsis root cell files. Use of this system pinpointed specific root developmental responses to acropetal versus basipetal auxin transport. Loss of TRH1 function shows tiny root hairs and defective root gravitropism, associated with auxin imbalance in the root apex. Cell file-specific expression of TRH1 in the central cylinder rescued trh1 root agravitropism, whereas positional TRH1 expression in peripheral cell layers, including epidermis and cortex, restored trh1 root hair defects. Applying a systems-level approach, the role of RAP2.11 and RSL5 transcription factors in root hair development was verified. Furthermore, ERF53 and WRKY51 transcription factors were overrepresented upon restoration of root gravitropism supporting involvement in gravitropic control. Auxin has a central role in shaping root system architecture by regulating multiple developmental processes. We reveal that TRH1 jointly modulates intracellular ionic gradients and cell-to-cell polar auxin transport to drive root epidermal cell differentiation and gravitropic response. Our results indicate the developmental importance of HAK/KUP/KT proton-coupled K+ transporters.

Does the lack of root hairs alter root system architecture of Zea mays?

2021 ◽  
Author(s):  
Steffen Schlüter ◽  
Eva Lippold ◽  
Maxime Phalempin ◽  
Doris Vetterlein
Keyword(s):  
Zea Mays ◽  
Root System ◽  
Root Hair ◽  
System Architecture ◽  
Volume Fraction ◽  
Root Hairs ◽  
Root System Architecture ◽  
Root Diameter ◽  
Wild Type ◽  
Defective Mutant

<p>Root hairs are one root trait among many which enables plants to adapt to environmental conditions. How different traits are coordinated and whether some are mutually exclusive is currently poorly understood. Comparing a root hair defective mutant with its corresponding wild-type we explored if and how the mutant exhibited root growth adaption strategies and as to how far this depended on the substrate.</p><p>Zea mays root hair defective mutant (rth3) and the corresponding wild-type siblings were grown on two substrates with contrasting texture and hence nutrient mobility. Root system architecture was investigated over time using repeated X-ray computed tomography.</p><p>There was no plastic adaption of root system architecture to the lack of root hairs, which resulted in lower uptake in particular in the substrate with low P mobility. The function of the root hairs for anchoring did not result in different depth profiles of the root length density between genotypes. Both maize genotypes showed a marked response to substrate. This was well reflected in the spatiotemporal development of rhizosphere volume fraction but especially in the strong response of root diameter to substrate, irrespective of genotype.</p><p>The most salient root plasticity trait was root diameter in response to substrate, whereas coping mechanisms for missing root hairs were less evident. Further experiments are required to elucidate whether observed differences can be explained by mechanical properties beyond mechanical impedance, root or microbiome ethylene production or differences in diffusion processes within the root or the rhizosphere.</p>

scholarly journals Root System Architecture from Coupling Cell Shape to Auxin Transport

PLoS Biology ◽  
2008 ◽  
Vol 6 (12) ◽  
pp. e307 ◽  
Author(s):  
Marta Laskowski ◽  
Verônica A Grieneisen ◽  
Hugo Hofhuis ◽  
Colette A. ten Hove ◽  
Paulien Hogeweg ◽  
...  
Keyword(s):  
Root System ◽  
System Architecture ◽  
Cell Shape ◽  
Auxin Transport ◽  
Root System Architecture ◽  
Coupling Cell

scholarly journals Signalling Overlaps between Nitrate and Auxin in Regulation of The Root System Architecture: Insights from the Arabidopsis thaliana

2020 ◽  
Vol 21 (8) ◽  
pp. 2880
Author(s):  
Muhammad Asim ◽  
Zia Ullah ◽  
Aluko Oluwaseun ◽  
Qian Wang ◽  
Haobao Liu
Keyword(s):  
Arabidopsis Thaliana ◽  
Transcription Factors ◽  
Root System ◽  
System Architecture ◽  
Lateral Roots ◽  
Root System Architecture ◽  
Auxin Biosynthesis ◽  
Regulatory Module ◽  
Model Plant Arabidopsis Thaliana ◽  
Nitrate Supply

Nitrate (NO3–) and auxin are key regulators of root growth and development, modulating the signalling cascades in auxin-induced lateral root formation. Auxin biosynthesis, transport, and transduction are significantly altered by nitrate. A decrease in nitrate (NO3–) supply tends to promote auxin translocation from shoots to roots and vice-versa. This nitrate mediated auxin biosynthesis regulating lateral roots growth is induced by the nitrate transporters and its downstream transcription factors. Most nitrate responsive genes (short-term and long-term) are involved in signalling overlap between nitrate and auxin, thereby inducing lateral roots initiation, emergence, and development. Moreover, in the auxin signalling pathway, the varying nitrate supply regulates lateral roots development by modulating the auxin accumulation in the roots. Here, we focus on the roles of nitrate responsive genes in mediating auxin biosynthesis in Arabidopsis root, and the mechanism involved in the transport of auxin at different nitrate levels. In addition, this review also provides an insight into the significance of nitrate responsive regulatory module and their downstream transcription factors in root system architecture in the model plant Arabidopsis thaliana.

scholarly journals Does the lack of root hairs alter root system architecture of Zea mays?

2021 ◽  
Author(s):  
Eva Lippold ◽  
Maxime Phalempin ◽  
Steffen Schlüter ◽  
Doris Vetterlein
Keyword(s):  
Zea Mays ◽  
Root System ◽  
Root Hair ◽  
System Architecture ◽  
Volume Fraction ◽  
Root Hairs ◽  
Root System Architecture ◽  
Root Diameter ◽  
Wild Type ◽  
Defective Mutant

Abstract Aims Root hairs are one root trait among many which enables plants to adapt to environmental conditions. How different traits are coordinated and whether some are mutually exclusive is currently poorly understood. Comparing a root hair defective mutant with its corresponding wild-type, we explored if and how the mutant exhibited root growth adaptation strategies and how dependent this was on substrate. Methods Zea mays root hair defective mutant (rth3) and the corresponding wild-type siblings were grown under well-watered conditions on two substrates with contrasting texture and hence nutrient mobility. Root system architecture was investigated over time using repeated X-ray computed tomography. Results There was no plastic adaptation of root system architecture to the lack of root hairs, which resulted in lower uptake of nutrients especially in the substrate with high sorption capacity. The function of the root hairs for anchoring did not result in different root length density profiles between genotypes. Both maize genotypes showed a marked response to substrate. This was well reflected in the spatiotemporal development of rhizosphere volume fraction but especially in the highly significant response of root diameter to substrate, irrespective of genotype. Conclusions The most salient root plasticity trait was root diameter in response to substrate. Coping mechanisms for missing root hairs were limited to a shift in root-shoot ratio in loam. Further experiments are required, to elucidate whether observed differences can be explained by mechanical properties beyond mechanical impedance, root or microbiome ethylene production or differences in diffusion processes within the root or the rhizosphere.

scholarly journals Comprehensive Genome-Wide Association Analysis Reveals the Genetic Basis of Root System Architecture in Soybean

2020 ◽  
Vol 11 ◽  
Author(s):  
Waldiodio Seck ◽  
Davoud Torkamaneh ◽  
François Belzile
Keyword(s):  
Root System ◽  
System Architecture ◽  
Phenotypic Variation ◽  
Genetic Basis ◽  
Genome Wide Association Study ◽  
Primary Root ◽  
Root System Architecture ◽  
Genome Wide Association ◽  
Nucleotide Polymorphisms ◽  
Genome Wide

Increasing the understanding genetic basis of the variability in root system architecture (RSA) is essential to improve resource-use efficiency in agriculture systems and to develop climate-resilient crop cultivars. Roots being underground, their direct observation and detailed characterization are challenging. Here, were characterized twelve RSA-related traits in a panel of 137 early maturing soybean lines (Canadian soybean core collection) using rhizoboxes and two-dimensional imaging. Significant phenotypic variation (P < 0.001) was observed among these lines for different RSA-related traits. This panel was genotyped with 2.18 million genome-wide single-nucleotide polymorphisms (SNPs) using a combination of genotyping-by-sequencing and whole-genome sequencing. A total of 10 quantitative trait locus (QTL) regions were detected for root total length and primary root diameter through a comprehensive genome-wide association study. These QTL regions explained from 15 to 25% of the phenotypic variation and contained two putative candidate genes with homology to genes previously reported to play a role in RSA in other species. These genes can serve to accelerate future efforts aimed to dissect genetic architecture of RSA and breed more resilient varieties.

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.

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