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

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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Arabidopsis thaliana CBF1 encodes an AP2 domain-containing transcriptional activator that binds to the C-repeat/DRE, a cis-acting DNA regulatory element that stimulates transcription in response to low temperature and water deficit

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.94.3.1035 ◽

1997 ◽

Vol 94 (3) ◽

pp. 1035-1040 ◽

Cited By ~ 1014

Author(s):

E. J. Stockinger ◽

S. J. Gilmour ◽

M. F. Thomashow

Keyword(s):

Arabidopsis Thaliana ◽

Low Temperature ◽

Water Deficit ◽

Regulatory Element ◽

Transcriptional Activator ◽

Cis Acting ◽

Ap2 Domain

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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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