scholarly journals The PINOID protein kinase regulates organ development in Arabidopsis by enhancing polar auxin transport

Development ◽  
2001 ◽  
Vol 128 (20) ◽  
pp. 4057-4067 ◽  
Author(s):  
René Benjamins ◽  
Ab Quint ◽  
Dolf Weijers ◽  
Paul Hooykaas ◽  
Remko Offringa
Keyword(s):  
Protein Kinase ◽  
Auxin Transport ◽  
Vascular Tissue ◽  
Primary Root ◽  
Ectopic Expression ◽  
Polar Auxin Transport ◽  
Fine Tuning ◽  
35S Promoter ◽  
Serine Threonine Kinase ◽  
Transport Inhibitors

Arabidopsis pinoid mutants show a strong phenotypic resemblance to the pin-formed mutant that is disrupted in polar auxin transport. The PINOID gene was recently cloned and found to encode a protein-serine/threonine kinase. Here we show that the PINOID gene is inducible by auxin and that the protein kinase is present in the primordia of cotyledons, leaves and floral organs and in vascular tissue in developing organs or proximal to meristems. Overexpression of PINOID under the control of the constitutive CaMV 35S promoter (35S::PID) resulted in phenotypes also observed in mutants with altered sensitivity to or transport of auxin. A remarkable characteristic of high expressing 35S::PID seedlings was a frequent collapse of the primary root meristem. This event triggered lateral root formation, a process that was initially inhibited in these seedlings. Both meristem organisation and growth of the primary root were rescued when seedlings were grown in the presence of polar auxin transport inhibitors, such as naphthylphtalamic acid (NPA). Moreover, ectopic expression of PINOID cDNA under control of the epidermis-specific LTP1 promoter provided further evidence for the NPA-sensitive action of PINOID. The results presented here indicate that PINOID functions as a positive regulator of polar auxin transport. We propose that PINOID is involved in the fine-tuning of polar auxin transport during organ formation in response to local auxin concentrations.

scholarly journals AtCRK5 Protein Kinase Exhibits a Regulatory Role in Hypocotyl Hook Development during Skotomorphogenesis

2019 ◽  
Vol 20 (14) ◽  
pp. 3432 ◽  
Author(s):  
Abu Imran Baba ◽  
Norbert Andrási ◽  
Ildikó Valkai ◽  
Teréz Gorcsa ◽  
Lilla Koczka ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Protein Kinase ◽  
Auxin Transport ◽  
Polar Auxin Transport ◽  
Fine Tuning ◽  
Regulatory Role ◽  
Protein Activity ◽  
Directional Movement ◽  
Pat Proteins

Seedling establishment following germination requires the fine tuning of plant hormone levels including that of auxin. Directional movement of auxin has a central role in the associated processes, among others, in hypocotyl hook development. Regulated auxin transport is ensured by several transporters (PINs, AUX1, ABCB) and their tight cooperation. Here we describe the regulatory role of the Arabidopsis thaliana CRK5 protein kinase during hypocotyl hook formation/opening influencing auxin transport and the auxin-ethylene-GA hormonal crosstalk. It was found that the Atcrk5-1 mutant exhibits an impaired hypocotyl hook establishment phenotype resulting only in limited bending in the dark. The Atcrk5-1 mutant proved to be deficient in the maintenance of local auxin accumulation at the concave side of the hypocotyl hook as demonstrated by decreased fluorescence of the auxin sensor DR5::GFP. Abundance of the polar auxin transport (PAT) proteins PIN3, PIN7, and AUX1 were also decreased in the Atcrk5-1 hypocotyl hook. The AtCRK5 protein kinase was reported to regulate PIN2 protein activity by phosphorylation during the root gravitropic response. Here it is shown that AtCRK5 can also phosphorylate in vitro the hydrophilic loops of PIN3. We propose that AtCRK5 may regulate hypocotyl hook formation in Arabidopsis thaliana through the phosphorylation of polar auxin transport (PAT) proteins, the fine tuning of auxin transport, and consequently the coordination of auxin-ethylene-GA levels.

scholarly journals CRK5 Protein Kinase Contributes to the Progression of Embryogenesis of Arabidopsis thaliana

2019 ◽  
Vol 20 (24) ◽  
pp. 6120 ◽  
Author(s):  
Baba ◽  
Valkai ◽  
Labhane ◽  
Koczka ◽  
Andrási ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Protein Kinase ◽  
Embryo Development ◽  
Auxin Transport ◽  
Polar Auxin Transport ◽  
Fine Tuning ◽  
Calcium Dependent ◽  
Directional Movement ◽  
Pat Proteins

The fine tuning of hormone (e.g., auxin and gibberellin) levels and hormone signaling is required for maintaining normal embryogenesis. Embryo polarity, for example, is ensured by the directional movement of auxin that is controlled by various types of auxin transporters. Here, we present pieces of evidence for the auxin-gibberellic acid (GA) hormonal crosstalk during embryo development and the regulatory role of the Arabidopsis thaliana Calcium-Dependent Protein Kinase-Related Kinase 5 (AtCRK5) in this regard. It is pointed out that the embryogenesis of the Atcrk5-1 mutant is delayed in comparison to the wild type. This delay is accompanied with a decrease in the levels of GA and auxin, as well as the abundance of the polar auxin transport (PAT) proteins PIN1, PIN4, and PIN7 in the mutant embryos. We have previously showed that AtCRK5 can regulate the PIN2 and PIN3 proteins either directly by phosphorylation or indirectly affecting the GA level during the root gravitropic and hypocotyl hook bending responses. In this manuscript, we provide evidence that the AtCRK5 protein kinase can in vitro phosphorylate the hydrophilic loops of additional PIN proteins that are important for embryogenesis. We propose that AtCRK5 can govern embryo development in Arabidopsis through the fine tuning of auxin-GA level and the accumulation of certain polar auxin transport proteins.

scholarly journals Molecular Basis for Natural Vegetative Propagation via Regeneration in North American Lake Cress, Rorippa aquatica (Brassicaceae)

2019 ◽  
Vol 61 (2) ◽  
pp. 353-369 ◽  
Author(s):  
Rumi Amano ◽  
Hokuto Nakayama ◽  
Risa Momoi ◽  
Emi Omata ◽  
Shizuka Gunji ◽  
...  
Keyword(s):  
Shoot Regeneration ◽  
Vegetative Propagation ◽  
Molecular Basis ◽  
Auxin Transport ◽  
Vascular Tissue ◽  
De Novo ◽  
Leaf Explants ◽  
Experimental Models ◽  
Polar Auxin Transport ◽  
Proximal Side

Abstract Some plant species have a striking capacity for regeneration in nature, including regeneration of the entire individual from explants. However, due to the lack of suitable experimental models, the regulatory mechanisms of spontaneous whole plant regeneration are mostly unknown. In this study, we established a novel model system to study these mechanisms using an amphibious plant within Brassicaceae, Rorippa aquatica, which naturally undergoes vegetative propagation via regeneration from leaf fragments. Morphological and anatomical observation showed that both de novo root and shoot organogenesis occurred from the proximal side of the cut edge transversely with leaf vascular tissue. Time-series RNA-seq analysis revealed that auxin and cytokinin responses were activated after leaf amputation and that regeneration-related genes were upregulated mainly on the proximal side of the leaf explants. Accordingly, we found that both auxin and cytokinin accumulated on the proximal side. Application of a polar auxin transport inhibitor retarded root and shoot regeneration, suggesting that the enhancement of auxin responses caused by polar auxin transport enhanced de novo organogenesis at the proximal wound site. Exogenous phytohormone and inhibitor applications further demonstrated that, in R. aquatica, both auxin and gibberellin are required for root regeneration, whereas cytokinin is important for shoot regeneration. Our results provide a molecular basis for vegetative propagation via de novo organogenesis.

scholarly journals Isolation and identification of polar auxin transport inhibitors from Saussurea costus and Atractylodes japonica

2017 ◽  
Vol 70 (3) ◽  
Author(s):  
Yuta Toda ◽  
Hideyuki Shigemori ◽  
Junichi Ueda ◽  
Kensuke Miyamoto
Keyword(s):  
Auxin Transport ◽  
Polar Auxin Transport ◽  
Inhibitory Effects ◽  
Medicinal Species ◽  
Isolation And Identification ◽  
Naturally Occurring ◽  
Structure Activity ◽  
Atractylodes Japonica ◽  
Transport Inhibitors ◽  
Dehydrocostus Lactone

An intensive survey of naturally-occurring regulators of polar auxin transport (PAT) was conducted in two oriental medicinal species from the Asteraceae, <em>Saussurea costus</em> and <em>Atractylodes japonica</em>, using the radish hypocotyl bioassay system and physicochemical analyses. Costunolide and santamarine were identified as well as dehydrocostus lactone from <em>S. costus</em> roots, and atractylenolide II and (+)-eudesma-4(14),7(11)-dien-8-one from <em>Atractylodes japonica</em> rhizomes as physiologically novel compounds possessing inhibitory activities of PAT. Costunolide and santamarine showed ca. 40% inhibition of PAT in the radish hypocotyl segments at a dose of 2.5 μg/plant and 1 μg/plant, respectively. Inhibitory effects of atractylenolide II and (+)-eudesma-4(14),7(11)-dien-8-one were ca. 10 times lower than those of costunolide and santamarine. Structure–activity relationships and possible mechanisms to inhibit PAT are also discussed.

scholarly journals Ethylene Does Not Promote Adventitious Root Initiation on Apple Microcuttings

1996 ◽  
Vol 121 (5) ◽  
pp. 880-885 ◽  
Author(s):  
James F. Harbage ◽  
Dennis P. Stimart
Keyword(s):  
Carboxylic Acid ◽  
Auxin Transport ◽  
Adventitious Rooting ◽  
Polar Auxin Transport ◽  
Root Initiation ◽  
Ethylene Evolution ◽  
Basal Section ◽  
Naphthylphthalamic Acid ◽  
Transport Inhibitors

We investigated the role of ethylene on adventitious rooting of `Gala' (easy-to-root) and `Triple Red Delicious' (difficult-to-root) apple (Malus domestica Borkh.) microcuttings. Root count increased significantly as IBA level increased, with highest root counts on `Gala'. Ethylene evolution increased significantly with IBA level without significant differences between cultivars. Basal section removal of microcuttings in the area of root origin reduced root count without changing ethylene evolution. Ethylene treatment of proliferated shoots before microcutting excision failed to enhance rooting. IBA-induced ethylene evolution was eliminated nearly by AVG, but root count remained IBA dependent. ACC reversed IBA plus AVG rooting inhibition, but ACC alone failed to influence root count. Polar auxin transport inhibitors NPA and TIBA stimulated ethylene evolution without increasing root count. Adventitious rooting of apple microcuttings was not associated with ethylene. Chemical names used: 1-H-indole-3-butyric acid (IBA); aminoethoxyvinylglycine (AVG); 1-aminocyclopropane-1-carboxylic acid (ACC); 2,3,5-triiodobenzoic acid (TIBA); N-1-naphthylphthalamic acid (NPA).

Auxin Transport Inhibitors. II. 2-(1-Pyrenol)Benzoic Acid, a Potent Inhibitor of Polar Auxin Transport

1977 ◽  
Vol 4 (3) ◽  
pp. 321 ◽  
Author(s):  
GF Katekar ◽  
AE Geissler
Keyword(s):  
Benzoic Acid ◽  
Auxin Transport ◽  
Indoleacetic Acid ◽  
Potent Inhibitor ◽  
Polar Auxin Transport ◽  
Active Inhibitor ◽  
Polar Transport ◽  
Highly Active ◽  
Transport Inhibitors ◽  
Auxin Transport Inhibitors

2-(1-Pyrenoyl)benzoic acid is shown to be a highly active inhibitor of auxin transport by its ability to prevent the polar transport of indoleacetic acid in bean petioles. It is comparable in activity to other known auxin transport inhibitors, and also affects apical dominance and the geotropic and phototropic responses.

scholarly journals Coumarin Interferes with Polar Auxin Transport Altering Microtubule Cortical Array Organization in Arabidopsis thaliana (L.) Heynh. Root Apical Meristem

2021 ◽  
Vol 22 (14) ◽  
pp. 7305
Author(s):  
Leonardo Bruno ◽  
Emanuela Talarico ◽  
Luz Cabeiras-Freijanes ◽  
Maria Letizia Madeo ◽  
Antonella Muto ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Lateral Root ◽  
Apical Meristem ◽  
Root Formation ◽  
Auxin Transport ◽  
Primary Root ◽  
Polar Auxin Transport ◽  
Root Apical Meristem ◽  
Lateral Root Formation ◽  
Cortical Array

Coumarin is a phytotoxic natural compound able to affect plant growth and development. Previous studies have demonstrated that this molecule at low concentrations (100 µM) can reduce primary root growth and stimulate lateral root formation, suggesting an auxin-like activity. In the present study, we evaluated coumarin’s effects (used at lateral root-stimulating concentrations) on the root apical meristem and polar auxin transport to identify its potential mode of action through a confocal microscopy approach. To achieve this goal, we used several Arabidopsis thaliana GFP transgenic lines (for polar auxin transport evaluation), immunolabeling techniques (for imaging cortical microtubules), and GC-MS analysis (for auxin quantification). The results highlighted that coumarin induced cyclin B accumulation, which altered the microtubule cortical array organization and, consequently, the root apical meristem architecture. Such alterations reduced the basipetal transport of auxin to the apical root apical meristem, inducing its accumulation in the maturation zone and stimulating lateral root formation.

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