Keeping the gate closed: WOX5 supports the balance between the proximal and distal root meristems via auxin biosynthesis in Arabidopsis thaliana L.

Abstract Nitrilases are versatile enzymes that hydrolyze nitriles to carboxylic acids and ammonia, but many members of this family lack defined biological functions. In plants, nitrilases have been associated with detoxification of cyanide-containing compounds and auxin biosynthesis; however, recent work suggests that the chemical versatility of these proteins contributes to metabolite repair. In this issue of the Biochemical Journal, Niehaus et al. demonstrate that the Nit1 nitrilase from Arabidopsis thaliana functions as a metabolite repair enzyme that removes deaminated glutathione from the cytoplasm and plastids.

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Cadmium and arsenic affect quiescent centre formation and maintenance in Arabidopsis thaliana post-embryonic roots disrupting auxin biosynthesis and transport

Environmental and Experimental Botany ◽

10.1016/j.envexpbot.2017.10.005 ◽

2017 ◽

Vol 144 ◽

pp. 37-48 ◽

Cited By ~ 19

Author(s):

L. Fattorini ◽

M. Ronzan ◽

D. Piacentini ◽

F. Della Rovere ◽

C. De Virgilio ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Auxin Biosynthesis ◽

Quiescent Centre

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The Arabidopsis thaliana STYLISH1 Protein Acts as a Transcriptional Activator Regulating Auxin Biosynthesis

The Plant Cell ◽

10.1105/tpc.108.064816 ◽

2010 ◽

Vol 22 (2) ◽

pp. 349-363 ◽

Cited By ~ 109

Author(s):

D. Magnus Eklund ◽

Veronika Ståldal ◽

Isabel Valsecchi ◽

Izabela Cierlik ◽

Caitriona Eriksson ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Transcriptional Activator ◽

Auxin Biosynthesis

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A network of phosphate starvation and immune-related signaling and metabolic pathways controls the interaction between Arabidopsis thaliana and the beneficial fungus Colletotrichum tofieldiae.

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-08-20-0233-r ◽

2020 ◽

Author(s):

Henning Frerigmann ◽

Markus Piotrowski ◽

René Lemke ◽

Paweł Bednarek ◽

Paul Schulze-Lefert

Keyword(s):

Arabidopsis Thaliana ◽

Growth Promotion ◽

Auxin Biosynthesis ◽

Auxin Signaling ◽

Ethylene Signaling ◽

In Planta ◽

Triple Mutant ◽

Hydrolysis Products ◽

Pi Starvation ◽

Pi Deficiency

The beneficial root-colonizing fungus Colletotrichum tofieldiae (Ct) mediates plant growth promotion (PGP) upon phosphate (Pi) starvation in Arabidopsis thaliana (Arabidopsis). This activity is dependent on the Trp-metabolism of the host, including indole glucosinolate (IG) hydrolysis. Here we show that Ct resolves several Pi starvation-induced molecular processes in the host, one of which is the downregulation of auxin signaling in germ-free plants, which is restored in the presence of the fungus. Using CRISPR/Cas9 genome editing, we generated an Arabidopsis triple mutant lacking three homologous nitrilases (NIT1-3) that are thought to link IG-hydrolysis products with auxin biosynthesis. Retained Ct-induced PGP in nit1;2;3 mutant plants demonstrated that this metabolic connection is dispensable for the beneficial activity of the fungus. This suggests that either there is an alternative metabolic link between IG-hydrolysis products and auxin biosynthesis, or that Ct restores auxin signaling independently of IG metabolism. We show that Ct, similar to pathogenic microorganisms, triggers Arabidopsis immune pathways that rely on IG metabolism as well as salicylic acid and ethylene signaling. Analysis of IG-deficient myb mutants revealed that these metabolites are indeed important for control of in planta Ct growth: however, enhanced Ct biomass does not necessarily negatively correlate with PGP. We show that Pi deficiency enables more efficient colonization of Arabidopsis by Ct, possibly due to the MYC2-mediated repression of ethylene signaling and changes in the constitutive IG composition in roots.

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The Molecular Basis of Age-Modulated Plant De Novo Root Regeneration Decline in Arabidopsis thaliana

Plant and Cell Physiology ◽

10.1093/pcp/pcaa134 ◽

2020 ◽

Author(s):

Lili Sun ◽

Ziqiang Zhu

Keyword(s):

Arabidopsis Thaliana ◽

Cell Fate ◽

Adventitious Roots ◽

De Novo ◽

Leaf Explants ◽

Auxin Biosynthesis ◽

Regeneration Capacity ◽

Exogenous Hormone ◽

Root Regeneration ◽

Wox Genes

Abstract Plants possess a regeneration capacity that enables them to survive after wounding. For example, detached Arabidopsis thaliana leaves are able to form adventitious roots from their cutting sites even in the absence of exogenous hormone supplements, as process termed de novo root regeneration (DNRR). Wounding rapidly induces auxin biosynthesis at the cutting sites and then elicits a signaling cascade to promote cell fate transitions and finally generate the adventitious roots. However, rooting rates in older plants are much lower than in younger leaf explants. In this review, we highlight the recent breakthroughs in the understanding of DNRR decay in older plants from at least two independent signaling routes: (i) via the accumulation of EIN3 protein in older plants, which directly suppresses expression of WUSCHEL RELATED HOMEOBOX (WOX) genes to inhibit rooting; (ii) the miR156-SPLs-AP2/ERFs pathway, which modulates root regeneration by reducing auxin biosynthesis.

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High ammonium inhibits root growth in Arabidopsis thaliana by promoting auxin conjugation rather than inhibiting auxin biosynthesis

Journal of Plant Physiology ◽

10.1016/j.jplph.2021.153415 ◽

2021 ◽

pp. 153415

Author(s):

Dong-Wei Di ◽

Guangjie Li ◽

Li Sun ◽

Jingjing Wu ◽

Meng Wang ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Root Growth ◽

Auxin Biosynthesis

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

International Journal of Molecular Sciences ◽

10.3390/ijms21082880 ◽

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.

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