Polar auxin transport: models and mechanisms

Berkel, Klaartje van; Boer, Rob J. de; Scheres, Ben; Tusscher, Kirsten ten

doi:10.1242/dev.079111

Cited by 117 publications

(109 citation statements)

References 48 publications

Supporting

Mentioning

104

Contrasting

Order By: Relevance

“…Auxin patterning and how this influences plant growth and development is still controversial (Van Berkel et al, 2013). The cycling of proteins that act as efflux carriers can influence auxin fluxes or levels.…”

Section: Effects Of Growth Regulators On In Vitro Morphogenesismentioning

confidence: 99%

“…The cycling of proteins that act as efflux carriers can influence auxin fluxes or levels. Models for differential source or tissue-specific requirements for flux orientations of auxin include regulation by gene expression; and models of auxin action nowadays combine the sink behavior of an auxin maximum for different tissue layers with a flux-based model (Van Berkel et al, 2013). It is possible that TIBA-induced root formation in the current investigation could have resulted from changes in auxin transport with a certain pattern of accumulation and conjugation (Guerrero et al, 1999;Muday, 2001;LudwigMüller, 2011;Dong et al, 2012), which could induce changes at the different levels of auxin patterning mentioned above.…”

Section: Effects Of Growth Regulators On In Vitro Morphogenesismentioning

confidence: 99%

See 1 more Smart Citation

Effects of explant, media and growth regulators on in vitro regeneration and antioxidant activity of Juniperus phoenicea

Al-Ramamneh¹,

Daradkeh²,

Rababah³

et al. 2017

Aust J Crop Sci

View full text Add to dashboard Cite

Juniperus phoenicea is an ornamental shrub that is also used to flavor food and to supply medicines and timber. Its micropropagation is of industrial concern and can occur by axillary shoot multiplication. Microcuttings of J. phoenicia were established in vitro on Murashige and Skoog (MS) and Rugini Olive (OM) media in glass tubes (25 mm x 150 mm). Factors studied were explant length (0.5 or 1.5 cm) and orientation (horizontal or vertical), media strength (OM, ½OM, MS, ½MS) and the following growth regulators: the anti-auxin 2,3,5-triiodobenzoic acid (TIBA), the cytokinins 6-benzyladenine (BA) and thidiazuron (TDZ), and the growth retardant daminozide (DM). Microcuttings placed vertically on the surface of OM, ½OM and ½MS media without hormones exhibited axillary bud differentiation, but they were swollen and turned brown one month later when placed horizontally on the medium surface. The number of shoots, averaged across OM, ½OM and ½MS media, was significantly higher from longer (1.5 cm) than shorter (0.5 cm) microcuttings (4.11 versus 1.57 shoots microcutting -1 ) after 60 days of culture. TIBA or DM at 0.1 mg l -1 included in OM medium enhanced leaf differentiation, callus induction and formation of adventitious shoots over three months from 0.5 cm long microcuttings taken from in vitro shoots. The formation of adventitious shoots was sporadic and occurred at a rate of 1 shoot microcutting -1 in the presence of 0.1 mg l -1 DM. OM supplemented with 0.1 mg l -1 TIBA resulted in significantly the highest leaf differentiation (55 leaves microcutting -1 ), with a rooting rate of 40%. Contents of phenols, flavonoids and antioxidants were compared for cuttings from young seedlings, callus, in vitro shoots, and seeds. Antioxidant activity was significantly the highest for shoots grown on hormone-free OM medium and callus maintained on OM medium containing 0.1 mg l -1 2,4-D (94.7 and 94.3% inhibition of DPPH free radicals, respectively). Thus, different routes for in vitro regeneration of J. phoenicea can be of potential use for many biotechnological, pharmaceutical and food industry applications.

show abstract

Section: Effects Of Growth Regulators On In Vitro Morphogenesismentioning

confidence: 99%

Section: Effects Of Growth Regulators On In Vitro Morphogenesismentioning

confidence: 99%

Effects of explant, media and growth regulators on in vitro regeneration and antioxidant activity of Juniperus phoenicea

Al-Ramamneh¹,

Daradkeh²,

Rababah³

et al. 2017

Aust J Crop Sci

View full text Add to dashboard Cite

show abstract

“…Many other modelling efforts have focused on the mechanisms of polar auxin transport. A recent excellent review has discussed those models and mechanisms (van Berkel et al, 2013). These models can be divided into two main classes: flux-based and concentration-based models, and they can be used to study the mechanisms of polar auxin transport (van Berkel et al, 2013).…”

Section: Other Important Aspects Of Modelling Hormone Gradients a Mementioning

confidence: 99%

“…A recent excellent review has discussed those models and mechanisms (van Berkel et al, 2013). These models can be divided into two main classes: flux-based and concentration-based models, and they can be used to study the mechanisms of polar auxin transport (van Berkel et al, 2013). In general, these models are based on the assumptions that cells can sense the auxin of their neighbouring cells.…”

Section: Other Important Aspects Of Modelling Hormone Gradients a Mementioning

confidence: 99%

“…Although the study of mechanisms of polar auxin transport has predominantly focused on the relationship between auxin patterning and the localisation of PIN proteins (van Berkel et al, 2013;Bennett et al, 2014), it is evident that auxin influx carriers are also important for auxin patterning (Band et al, 2014;Moore et al, 2015a). The mechanistic roles of auxin influx carriers in polar auxin transport should therefore be further examined, as experimental evidence shows that the distribution of AUX1 protein in the root is not uniform (Band et al, 2014) and influx carriers contribute to the shoot vasculature (Fàbregas et al, 2015).…”

Section: Other Important Aspects Of Modelling Hormone Gradients a Mementioning

confidence: 99%

See 1 more Smart Citation

Modelling Plant Hormone Gradients

Moore

Zhang

Lindsey

2015

Encyclopedia of Life Sciences

View full text Add to dashboard Cite

Cellular patterning in the Arabidopsis root is coordinated via a localised auxin concentration maximum in the root tip, requiring the regulated expression of specific genes. The activities of plant hormones such as auxin, ethylene and cytokinin depend on cellular context and exhibit either synergistic or antagonistic interactions. Due to the complexity and nonlinearity of spatiotemporal interactions between both hormones and gene expression in root development, modelling plant hormone gradients requires a systems approach in which experimental data and modelling analysis are closely combined. Modelling therefore allows a predictive interrogation of highly complex and nonintuitive interactions between components in the system. Important factors to be considered when modelling hormone gradients include the construction of a hormonal crosstalk network, the formulation of kinetic equations and the construction of an in silico root map. A modelling approach enables the analysis of relationships between multiple hormone gradients, predictions on how hormone gradients emerge under the action of hormonal crosstalk, and the prediction and elucidation of experimental results from mutant roots. Key Concepts Patterning in Arabidopsis root development is coordinated via a localised auxin concentration maximum in the root tip, requiring the regulated expression of specific genes. The activities of plant hormones such as auxin, ethylene, cytokinin, abscisic acid, gibberellin and brassinosteroids depend on cellular context and exhibit either synergistic or antagonistic interactions. Auxin concentration and the associated regulatory and target genes are regulated by diverse interacting hormones and gene expression and therefore cannot change independently of the various crosstalk components in space and time. Other hormone concentrations, such as ethylene and cytokinin concentrations, and expression of the associated regulatory and target genes are also interlinked. Modelling plant hormone gradients requires a systems approach where experimental data and modelling analysis are closely combined. A hormonal crosstalk network describes the regulatory relationships between hormones and their associated genes. A kinetic equation can be formulated for any regulatory relationship following thermodynamic and kinetic principles. Construction of an in silico root map enables the study of multicellular cell–cell communications in Arabidopsis root development. Modelling hormone gradients enables the analysis of relationships between multiple hormone gradients, predictions on how hormone gradients emerge under the action of hormonal crosstalk, and the prediction and elucidation of experimental results from mutant roots. Modelling auxin gradients can also incorporate different mechanisms of polar auxin transport and the interaction of hormone gradients and root growth.

show abstract

Electrophysiological study of Arabidopsis ABCB4 and PIN2 auxin transporters: Evidence of auxin activation and interaction enhancing auxin selectivity

Deslauriers

Spalding

2021

Plant Direct

View full text Add to dashboard Cite

Polar auxin transport through plant tissue strictly requires polarly localized PIN proteins and uniformly distributed ABCB proteins. A functional synergy between the two types of membrane protein where their localizations overlap may create the degree of asymmetric auxin efflux required to produce polar auxin transport. We investigated this possibility by expressing ABCB4 and PIN2 in human embryonic kidney cells and measuring whole‐cell ionic currents with the patch‐clamp technique and CsCl‐based electrolytes. ABCB4 activity was 1.81‐fold more selective for Cl− over Cs+ and for PIN2 the value was 2.95. We imposed auxin gradients and determined that ABCB4 and PIN2 were 12‐fold more permeable to the auxin anion (IAA−) than Cl−. This measure of the intrinsic selectivity of the transport pathway was 21‐fold when ABCB4 and PIN2 were co‐expressed. If this increase occurs in plants, it could explain why asymmetric PIN localization is not sufficient to create polar auxin flow. Some form of co‐action or synergy between ABCB4 and PIN2 that increases IAA− selectivity at the cell face where both occur may be important. We also found that auxin stimulated ABCB4 activity, which may contribute to a self‐reinforcement of auxin transport known as canalization.

show abstract

Polar auxin transport: models and mechanisms

Cited by 117 publications

References 48 publications

Effects of explant, media and growth regulators on in vitro regeneration and antioxidant activity of Juniperus phoenicea

Effects of explant, media and growth regulators on in vitro regeneration and antioxidant activity of Juniperus phoenicea

Modelling Plant Hormone Gradients

Electrophysiological study of Arabidopsis ABCB4 and PIN2 auxin transporters: Evidence of auxin activation and interaction enhancing auxin selectivity

Contact Info

Product

Resources

About