scholarly journals SpARF4 reduces cadmium accumulation by negatively regulating SpABCG14 and SpACO4 in the cadmium/zinc hyperaccumulator Sedum plumbizincicola

2021 ◽  
Author(s):  
Dong Xu ◽  
Zhuchou Lu ◽  
Longhua Wu ◽  
Guirong Qiao ◽  
Wenmin Qiu ◽  
...  
Keyword(s):  
Root Development ◽  
Ethylene Production ◽  
Molecular Mechanisms ◽  
Lignin Content ◽  
Accumulation Rate ◽  
Cadmium Accumulation ◽  
Negative Regulator ◽  
Lateral Root Development ◽  
Vessel Area ◽  
Sedum Plumbizincicola

Root development and apoplastic transport are respectively important for cadmium (Cd) absorption and transportation, which profoundly influence Cd bioremediation. However, molecular mechanisms underlying the two processes are not completely understood. In this study, we demonstrated that auxin response factor 4 (SpARF4) from a Cd hyperaccumulator Sedum plumbizincicola was a negative regulator for these processes. SpARF4 positively regulated by auxin was highly expressed in xylem. Overexpression of SpARF4 significantly decreased vessel area and declined lignin content of S. plumbizincicola. Meanwhile, less adventitious roots were found, and lateral root development was delayed in transgenic plants. Furthermore, ethylene production and auxin transportation were impaired. More importantly, SpARF4 negatively regulated Cd content of xylem saps and aerial tissues. Combining dual-LUC reporter, Y1H and qRT-PCR assays, SpARF4 was a repressor for two downstream genes (SpABCG14 and SpACO4) which influenced vascular bundle development and ethylene production, respectively. PIN1, 2, 3, 7 were downregulated and slowed down local auxin accumulation rate, which suspended root development. These results indicate that SpARF4 can decelerate Cd transportation rate from roots to aerial parts and reduce Cd content of aboveground tissues by delaying the root development and decreasing vessel area.

Lateral root formation and nutrients: nitrogen in the spotlight

2021 ◽  
Author(s):  
Pierre-Mathieu Pélissier ◽  
Hans Motte ◽  
Tom Beeckman
Keyword(s):  
Signaling Pathways ◽  
Root System ◽  
Root Development ◽  
Lateral Root ◽  
Molecular Mechanisms ◽  
Root Formation ◽  
Lateral Roots ◽  
Nutrient Use Efficiency ◽  
Lateral Root Formation ◽  
Lateral Root Development

Abstract Lateral roots are important to forage for nutrients due to their ability to increase the uptake area of a root system. Hence, it comes as no surprise that lateral root formation is affected by nutrients or nutrient starvation, and as such contributes to the root system plasticity. Understanding the molecular mechanisms regulating root adaptation dynamics towards nutrient availability is useful to optimize plant nutrient use efficiency. There is at present a profound, though still evolving, knowledge on lateral root pathways. Here, we aimed to review the intersection with nutrient signaling pathways to give an update on the regulation of lateral root development by nutrients, with a particular focus on nitrogen. Remarkably, it is for most nutrients not clear how lateral root formation is controlled. Only for nitrogen, one of the most dominant nutrients in the control of lateral root formation, the crosstalk with multiple key signals determining lateral root development is clearly shown. In this update, we first present a general overview of the current knowledge of how nutrients affect lateral root formation, followed by a deeper discussion on how nitrogen signaling pathways act on different lateral root-mediating mechanisms for which multiple recent studies yield insights.

scholarly journals Novel Regulators of Sugar-Mediated Lateral Root Development in Arabidopsis thaliana

Genes ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1257
Author(s):  
Jinzhu Li ◽  
Bingxin Wang ◽  
Xinxing Zhu ◽  
Rong Li ◽  
Jing Fu ◽  
...  
Keyword(s):  
Root Development ◽  
Molecular Basis ◽  
Lateral Root ◽  
Glucose Sensor ◽  
Negative Regulator ◽  
Chromosome 2 ◽  
Altered Level ◽  
Lateral Root Development ◽  
Recessive Mutations ◽  
Complex Process

Lateral root development is a complex process regulated by numerous factors. An important role for sugar in lateral root development has been known for a while, but the underlying molecular basis still remains unclear. In this study, we first showed that WOX7, a sugar-inducible negative regulator of lateral root development, acts downstream of the glucose sensor HXK1. Using a transgenic line homozygous for a transgene expressing GFP under the control of the WOX7 promoter, we next performed a genetic screen to identify additional genes in this development pathway. A number of mutants with altered level of WOX7 expression were recovered, and two with increased WOX7 expression, named ewe-1 and ewe-2 (for Enhanced WOX7 Expression), were further characterized. Both mutants manifest delayed lateral root development, and genetic analysis indicates that single recessive mutations are responsible for the observed phenotypes. The mutations were then located to similar regions on chromosome 2 by marker-assisted analyses, and candidate genes were identified through whole genome sequencing. The significance and limitations of this work are discussed.

scholarly journals CLE-CLAVATA1 Signaling Pathway Modulates Lateral Root Development under Sulfur Deficiency

Plants ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 103 ◽  
Author(s):  
Wei Dong ◽  
Yinghua Wang ◽  
Hideki Takahashi
Keyword(s):  
Root Development ◽  
Lateral Root ◽  
Molecular Mechanisms ◽  
Plant Root ◽  
Root System Architecture ◽  
Wild Type ◽  
Lateral Root Development ◽  
S Deficiency ◽  
Cle Peptide ◽  
Plant Root System

Plant root system architecture changes drastically in response to availability of macronutrients in the soil environment. Despite the importance of root sulfur (S) uptake in plant growth and reproduction, molecular mechanisms underlying root development in response to S availability have not been fully characterized. We report here on the signaling module composed of the CLAVATA3 (CLV3)/EMBRYO SURROUNDING REGION (CLE) peptide and CLAVATA1 (CLV1) leucine-rich repeat receptor kinase, which regulate lateral root (LR) development in Arabidopsis thaliana upon changes in S availability. The wild-type seedlings exposed to prolonged S deficiency showed a phenotype with low LR density, which was restored upon sulfate supply. In contrast, the clv1 mutant showed a higher daily increase rate of LR density relative to the wild-type under prolonged S deficiency, which was diminished to the wild-type level upon sulfate supply, suggesting that CLV1 directs a signal to inhibit LR development under S-deficient conditions. CLE2 and CLE3 transcript levels decreased under S deficiency and through CLV1-mediated feedback regulations, suggesting the levels of CLE peptide signals are adjusted during the course of LR development. This study demonstrates a fine-tuned mechanism for LR development coordinately regulated by CLE-CLV1 signaling and in response to changes in S availability.

scholarly journals AtMYB93 is a novel negative regulator of lateral root development in Arabidopsis

2014 ◽  
Vol 203 (4) ◽  
pp. 1194-1207 ◽  
Author(s):  
Daniel J. Gibbs ◽  
Ute Voß ◽  
Susan A. Harding ◽  
Jessica Fannon ◽  
Laura A. Moody ◽  
...  
Keyword(s):  
Root Development ◽  
Lateral Root ◽  
Negative Regulator ◽  
Lateral Root Development

scholarly journals Flavonols modulate lateral root emergence by scavenging reactive oxygen species in Arabidopsis thaliana

2020 ◽  
pp. jbc.RA120.014543
Author(s):  
Jordan M. Chapman ◽  
Gloria K. Muday
Keyword(s):  
Arabidopsis Thaliana ◽  
Root Development ◽  
Lateral Root ◽  
Lateral Roots ◽  
Negative Regulator ◽  
Wild Type ◽  
Root Primordia ◽  
Lateral Root Primordia ◽  
Lateral Root Development ◽  
Genes Encoding

Flavonoids are a class of specialized metabolites with subclasses including flavonols and anthocyanins, which have unique properties as antioxidants. Flavonoids modulate plant development, but whether and how they impact lateral root development is unclear. We examined potential roles for flavonols in this process using Arabidopsis thaliana mutants with defects in genes encoding key enzymes in flavonoid biosynthesis. We observed the tt4 and fls1 mutants, which produce no flavonols, have increased lateral root emergence. The tt4 root phenotype was reversed by genetic and chemical complementation. To more specifically define the flavonoids involved, we tested an array of flavonoid biosynthetic mutants, eliminating roles for anthocyanins and the flavonols quercetin and isorhamnetin in modulating root development. Instead, two tt7 mutant alleles, with defects in a branchpoint enzyme blocking quercetin biosynthesis, formed reduced numbers of lateral roots, and tt7-2 had elevated levels of kaempferol. Using a flavonol-specific dye, we observed that in the tt7-2 mutant, kaempferol accumulated within lateral root primordia at higher levels than wild-type. These data are consistent with kaempferol, or downstream derivatives, acting as a negative regulator of lateral root emergence. We examined ROS accumulation using ROS-responsive probes and found reduced fluorescence of a superoxide-selective probe within the primordia of tt7-2 compared to wild type, but not in the tt4 mutant, consistent with opposite effects of these mutants on lateral root emergence. These results support a model in which increased level of kaempferol in the lateral root primordia of tt7-2 reduces superoxide concentration and ROS-stimulated lateral root emergence.

scholarly journals Cryptic variation in RNA-directed DNA-methylation controls lateral root development when auxin signalling is perturbed

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Zaigham Shahzad ◽  
Ross Eaglesfield ◽  
Craig Carr ◽  
Anna Amtmann
Keyword(s):  
Dna Methylation ◽  
Root Development ◽  
Transcriptional Repression ◽  
Lateral Root ◽  
Developmental Plasticity ◽  
Plant Root ◽  
Negative Regulator ◽  
Lateral Root Primordia ◽  
Lateral Root Development ◽  
Cryptic Variation

AbstractMaintaining the right balance between plasticity and robustness in biological systems is important to allow adaptation while maintaining essential functions. Developmental plasticity of plant root systems has been the subject of intensive research, but the mechanisms underpinning robustness remain unclear. Here, we show that potassium deficiency inhibits lateral root organogenesis by delaying early stages in the formation of lateral root primordia. However, the severity of the symptoms arising from this perturbation varies within a natural population of Arabidopsis and is associated with the genetic variation in CLSY1, a key component of the RNA-directed DNA-methylation machinery. Mechanistically, CLSY1 mediates the transcriptional repression of a negative regulator of root branching, IAA27, and promotes lateral root development when the auxin-dependent proteolysis pathway fails. Our study identifies DNA-methylation-mediated transcriptional repression as a backup system for post-translational protein degradation which ensures robust development and performance of plants in a challenging environment.

scholarly journals Mepiquat chloride promotes cotton lateral root formation by modulating plant hormone homeostasis

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Qian Wu ◽  
Mingwei Du ◽  
Jie Wu ◽  
Ning Wang ◽  
Baomin Wang ◽  
...  
Keyword(s):  
Root Growth ◽  
Root Development ◽  
Lateral Root ◽  
Seed Treatment ◽  
Molecular Mechanisms ◽  
Root Formation ◽  
Lateral Root Formation ◽  
Mepiquat Chloride ◽  
Auxin Level ◽  
Lateral Root Development

Abstract Background Mepiquat chloride (MC), a plant growth regulator, enhances root growth by promoting lateral root formation in cotton. However, the underlying molecular mechanisms of this phenomenon is still unknown. Methods In this study, we used 10 cotton (Gossypium hirsutum Linn.) cultivars to perform a seed treatment with MC to investigate lateral root formation, and selected a MC sensitive cotton cultivar for dynamic monitor of root growth and transcriptome analysis during lateral root development upon MC seed treatment. Results The results showed that MC treated seeds promotes the lateral root formation in a dosage-depended manner and the effective promotion region is within 5 cm from the base of primary root. MC treated seeds induce endogenous auxin level by altering gene expression of both gibberellin (GA) biosynthesis and signaling and abscisic acid (ABA) signaling. Meanwhile, MC treated seeds differentially express genes involved in indole acetic acid (IAA) synthesis and transport. Furthermore, MC-induced IAA regulates the expression of genes related to cell cycle and division for lateral root development. Conclusions Our data suggest that MC orchestrates GA and ABA metabolism and signaling, which further regulates auxin biosynthesis, transport, and signaling to promote the cell division responsible for lateral root formation.

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