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Lv Z, Yu L, Zhan H, Li J, Wang C, Huang L, Wang S. Shoot differentiation from Dendrocalamus brandisii callus and the related physiological roles of sugar and hormones during shoot differentiation. TREE PHYSIOLOGY 2023:tpad039. [PMID: 36988419 DOI: 10.1093/treephys/tpad039] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/20/2023] [Indexed: 06/19/2023]
Abstract
Only a few calli regeneration systems of bamboos were successfully established, which limited the research on physiological mechanism of callus differentiation. In this study, we successfully established the callus differentiation systems of Dendrocalamus brandisii via seeds. The results showed that the best medium for callus induction of D. brandisii seeds was basal MS media amended with 5.0 mg L-1 2,4-D and 0.5 mg L-1 KT, and the optimal medium for shoot differentiation was the basal MS media supplemented with 4.0 mg L-1 BA and 0.5 mg L-1 NAA. Callus tissues had apparent polarity in cell arrangement, and developed their own meristematic cell layers. α-amylase, STP and SUSY played a dominant role in carbohydrates degradation in callus during shoot differentiation. PPP and TCA pathways up-regulated in the shoot-differentiated calli. The dynamics of BA and KT contents in calli was consistent with their concentrations applied in medium. IAA synthesis and the related signal transduction were down-regulated, while the endogenous CTKs contents were up-regulated by the exogenous CTKs application in shoot-differentiated calli, and their related synthesis, transport and signal transduction pathways were also up-regulated. The downregulated signal transduction pathways of IAA and ABA revealed that they did not play the key role in shoot differentiation of bamboos. GAs also played a role in shoot differentiation based on the down-regulation of DELLA and the up-regulation of PIF4 genes. The overexpression of DbSNRK2 and DbFIF4 genes further confirmed the negative role of ABA and the positive role of GAs in shoot differentiation.
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Affiliation(s)
- Zhuo Lv
- Faculty of Life Sciences, Southwest Forestry University, Kunming, China
- Bamboo Research Institute, Nanjing Forestry University, Nanjing, China
| | - Lixia Yu
- Faculty of Life Sciences, Southwest Forestry University, Kunming, China
- Faculty of Bamboo and Rattan, Southwest Forestry University, Kunming, China
| | - Hui Zhan
- Faculty of Life Sciences, Southwest Forestry University, Kunming, China
- Faculty of Bamboo and Rattan, Southwest Forestry University, Kunming, China
| | - Juan Li
- Faculty of Life Sciences, Southwest Forestry University, Kunming, China
- Faculty of Bamboo and Rattan, Southwest Forestry University, Kunming, China
| | - Changming Wang
- Faculty of Life Sciences, Southwest Forestry University, Kunming, China
- Faculty of Bamboo and Rattan, Southwest Forestry University, Kunming, China
| | - Ling Huang
- Faculty of Life Sciences, Southwest Forestry University, Kunming, China
| | - Shuguang Wang
- Faculty of Life Sciences, Southwest Forestry University, Kunming, China
- Faculty of Bamboo and Rattan, Southwest Forestry University, Kunming, China
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Rigal A, Doyle SM, Ritter A, Raggi S, Vain T, O’Brien JA, Goossens A, Pauwels L, Robert S. A network of stress-related genes regulates hypocotyl elongation downstream of selective auxin perception. PLANT PHYSIOLOGY 2021; 187:430-445. [PMID: 34618142 PMCID: PMC8418399 DOI: 10.1093/plphys/kiab269] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 05/06/2021] [Indexed: 06/13/2023]
Abstract
The plant hormone auxin, a master coordinator of development, regulates hypocotyl elongation during seedling growth. We previously identified the synthetic molecule RubNeddin 1 (RN1), which induces degradation of the AUXIN/INDOLE-3-ACETIC ACID (AUX/IAA) transcriptional repressors INDOLE-3-ACETIC ACID-INDUCIBLE3 (IAA3) and IAA7 in planta and strongly promotes hypocotyl elongation. In the present study, we show that despite the structural similarity of RN1 to the synthetic auxin 2,4-dichlorophenoxyacetic-acid (2,4-D), direct treatments with these compounds in Arabidopsis (Arabidopsis thaliana) result in distinct effects, possibly due to enhanced uptake of RN1 and low-level, chronic release of 2,4-D from RN1 in planta. We confirm RN1-induced hypocotyl elongation occurs via specific TRANSPORT INHIBITOR RESISTANT1 (TIR1)/AUXIN SIGNALING F-BOX (AFB) receptor-mediated auxin signaling involving TIR1, AFB2, and AFB5. Using a transcriptome profiling strategy and candidate gene approach, we identify the genes ZINC FINGER OF ARABIDOPSIS THALIANA10 (ZAT10), ARABIDOPSIS TOXICOS EN LEVADURA31 (ATL31), and WRKY DNA-BINDING PROTEIN33 (WRKY33) as being rapidly upregulated by RN1, despite being downregulated by 2,4-D treatment. RN1-induced expression of these genes also occurs via TIR1/AFB-mediated auxin signaling. Our results suggest both hypocotyl elongation and transcription of these genes are induced by RN1 via the promoted degradation of the AUX/IAA transcriptional repressor IAA7. Moreover, these three genes, which are known to be stress-related, act in an inter-dependent transcriptional regulatory network controlling hypocotyl elongation. Together, our results suggest ZAT10, ATL31, and WRKY33 take part in a common gene network regulating hypocotyl elongation in Arabidopsis downstream of a selective auxin perception module likely involving TIR1, AFB2, and AFB5 and inducing the degradation of IAA7.
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Affiliation(s)
- Adeline Rigal
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 90183 Umeå, Sweden
| | - Siamsa M. Doyle
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 90183 Umeå, Sweden
| | - Andrés Ritter
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, 9052 Ghent, Belgium
| | - Sara Raggi
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 90183 Umeå, Sweden
| | - Thomas Vain
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 90183 Umeå, Sweden
| | - José Antonio O’Brien
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Santiago, 8331150, Chile
- Departamento de Fruticultura y Enología, Facultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O’Higgins 340, Santiago, 8331150, Chile
| | - Alain Goossens
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, 9052 Ghent, Belgium
| | - Laurens Pauwels
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, 9052 Ghent, Belgium
| | - Stéphanie Robert
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 90183 Umeå, Sweden
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Abstract
As the outermost cell layer of an organism, the epidermis plays a key role in controlling morphogenesis. In this work, we investigated cell-shape regulation in young, lobing pavement cells of the Arabidopsis leaf epidermis. By taking advantage of their developmental synchrony, we showed that the establishment of a local auxin gradient is necessary for the initiation of first-lobe formation. However, the auxin gradient is not stable over time but rather fluctuates according to the particular developmental stage of the cells. These changes are established by the specific distribution of auxin transporters at the different membranes of these young pavement cells. This work reports an observation of auxin fluctuation during cell-shape determination in plants. Puzzle-shaped pavement cells provide a powerful model system to investigate the cellular and subcellular processes underlying complex cell-shape determination in plants. To better understand pavement cell-shape acquisition and the role of auxin in this process, we focused on the spirals of young stomatal lineage ground cells of Arabidopsis leaf epidermis. The predictability of lobe formation in these cells allowed us to demonstrate that the auxin response gradient forms within the cells of the spiral and fluctuates based on the particular stage of lobe development. We revealed that specific localization of auxin transporters at the different membranes of these young cells changes during the course of lobe formation, suggesting that these fluctuating auxin response gradients are orchestrated via auxin transport to control lobe formation and determine pavement cell shape.
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True JH, Shaw SL. Exogenous Auxin Induces Transverse Microtubule Arrays Through TRANSPORT INHIBITOR RESPONSE1/AUXIN SIGNALING F-BOX Receptors. PLANT PHYSIOLOGY 2020; 182:892-907. [PMID: 31767691 PMCID: PMC6997688 DOI: 10.1104/pp.19.00928] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 11/10/2019] [Indexed: 05/12/2023]
Abstract
Auxin plays a central role in controlling plant cell growth and morphogenesis. Application of auxin to light-grown seedlings elicits both axial growth and transverse patterning of the cortical microtubule cytoskeleton in hypocotyl cells. Microtubules respond to exogenous auxin within 5 min, although repatterning of the array does not initiate until 30 min after application and is complete by 2 h. To examine the requirements for auxin-induced microtubule array patterning, we used an Arabidopsis (Arabidopsis thaliana) double auxin f-box (afb) receptor mutant, afb4-8 afb5-5, that responds to conventional auxin (indole-3-acetic acid) but has a strongly diminished response to the auxin analog, picloram. We show that 5 µm picloram induces immediate changes to microtubule density and later transverse microtubule patterning in wild-type plants, but does not cause microtubule array reorganization in the afb4-8 afb5-5 mutant. Additionally, a dominant mutant (axr2-1) for the auxin coreceptor AUXIN RESPONSIVE2 (AXR2) was strongly suppressed for auxin-induced microtubule array reorganization, providing additional evidence that auxin functions through a transcriptional pathway for transverse patterning. We observed that brassinosteroid application mimicked the auxin response, showing both early and late microtubule array effects, and induced transverse patterning in the axr2-1 mutant. Application of auxin to the brassinosteroid synthesis mutant, diminuto1, induced transverse array patterning but did not produce significant axial growth. Thus, exogenous auxin induces transverse microtubule patterning through the TRANSPORT INHIBITOR 1/AUXIN F-BOX (TIR1/AFB) transcriptional pathway and can act independently of brassinosteroids.
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Affiliation(s)
- Jillian H True
- Department of Biology, Indiana University, Bloomington, Indiana 47405
| | - Sidney L Shaw
- Department of Biology, Indiana University, Bloomington, Indiana 47405
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Sun J, Wang L, Li S, Yin L, Huang J, Chen C. Toxicity of silver nanoparticles to Arabidopsis: Inhibition of root gravitropism by interfering with auxin pathway. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2017; 36:2773-2780. [PMID: 28440569 DOI: 10.1002/etc.3833] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 02/03/2017] [Accepted: 04/24/2017] [Indexed: 05/25/2023]
Abstract
Impacts of polyvinylpyrrolidine-coated silver nanoparticles (AgNPs) on root gravitropism in Arabidopsis thaliana were investigated at the physiological, cellular, and molecular levels. Our results showed that AgNPs were taken up by the root and primarily localized at the cell wall and intercellular spaces. Root gravitropism was inhibited by exposure to AgNPs, and the inhibition in root gravitropism caused by exposure to AgNPs exhibited a dose-response relationship. Auxin accumulation was reduced in the root tips because of exposure to AgNPs. However, increased indole-3-acetic acid level could not rescue the inhibition of root gravitropism. Real-time polymerase chain reaction showed significant downregulation of expression of auxin receptor-related genes, which is the TIR1/AFB family of F-box proteins including AFB1, AFB2, AFB3, AFB5, and TIR1. Therefore, the present study suggests that AgNPs have toxicity to the model plant A. thaliana as shown by inhibition of root gravitropism along with a reduction in auxin accumulation and expression of auxin receptors. Environ Toxicol Chem 2017;36:2773-2780. © 2017 SETAC.
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Affiliation(s)
- Juzhi Sun
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Likai Wang
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Shuang Li
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Liyan Yin
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, Agricultural College, Hainan University, Haikou, China
| | - Jin Huang
- School of Chemistry and Chemical Engineering, Southwest University, Chongqing, China
| | - Chunli Chen
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
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Fu S, Shao J, Zhou C, Hartung JS. Co-infection of Sweet Orange with Severe and Mild Strains of Citrus tristeza virus Is Overwhelmingly Dominated by the Severe Strain on Both the Transcriptional and Biological Levels. FRONTIERS IN PLANT SCIENCE 2017; 8:1419. [PMID: 28912786 PMCID: PMC5583216 DOI: 10.3389/fpls.2017.01419] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 07/31/2017] [Indexed: 05/18/2023]
Abstract
Citrus tristeza is one of the most destructive citrus diseases and is caused by the phloem-restricted Closterovirus, Citrus tristeza virus. Mild strain CTV-B2 does not cause obvious symptoms on indicators whereas severe strain CTV-B6 causes symptoms, including stem pitting, cupping, yellowing, and stiffening of leaves, and vein corking. Our laboratory has previously characterized changes in transcription in sweet orange separately infected with CTV-B2 and CTV-B6. In the present study, transcriptome analysis of Citrus sinensis in response to double infection by CTV-B2 and CTV-B6 was carried out. Four hundred and eleven transcripts were up-regulated and 356 transcripts were down-regulated prior to the onset of symptoms. Repressed genes were overwhelmingly associated with photosynthesis, and carbon and nucleic acid metabolism. Expression of genes related to the glycolytic, oxidative pentose phosphate (OPP), tricarboxylic acid cycle (TCA) pathways, tetrapyrrole synthesis, redox homeostasis, nucleotide metabolism, protein synthesis and post translational protein modification and folding, and cell organization were all reduced. Ribosomal composition was also greatly altered in response to infection by CTV-B2/CTV-B6. Genes that were induced were related to cell wall structure, secondary and hormone metabolism, responses to biotic stress, regulation of transcription, signaling, and secondary metabolism. Transport systems dedicated to metal ions were especially disturbed and ZIPs (Zinc Transporter Precursors) showed different expression patterns in response to co-infection by CTV-B2/CTV-B6 and single infection by CTV-B2. Host plants experienced root decline that may have contributed to Zn, Fe, and other nutrient deficiencies. Though defense responses, such as, strengthening of the cell wall, alteration of hormone metabolism, secondary metabolites, and signaling pathways, were activated, these defense responses did not suppress the spread of the pathogens and the development of symptoms. The mild strain CTV-B2 did not provide a useful level of cross-protection to citrus against the severe strain CTV-B6.
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Affiliation(s)
- Shimin Fu
- Citrus Research Institute, Southwest UniversityChongqing, China
- Molecular Plant Pathology Laboratory, United States Department of Agriculture-Agricultural Research ServiceBeltsville, MD, United States
| | - Jonathan Shao
- Molecular Plant Pathology Laboratory, United States Department of Agriculture-Agricultural Research ServiceBeltsville, MD, United States
| | - Changyong Zhou
- Citrus Research Institute, Southwest UniversityChongqing, China
| | - John S. Hartung
- Molecular Plant Pathology Laboratory, United States Department of Agriculture-Agricultural Research ServiceBeltsville, MD, United States
- *Correspondence: John S. Hartung
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7
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Abstract
The plant hormone auxin (indole-3-acetic acid, IAA) controls growth and developmental responses throughout the life of a plant. A combination of molecular, genetic and biochemical approaches has identified several key components involved in auxin signal transduction. Rapid auxin responses in the nucleus include transcriptional activation of auxin-regulated genes and degradation of transcriptional repressor proteins. The nuclear auxin receptor is an integral component of the protein degradation machinery. Although auxin signalling in the nucleus appears to be short and simple, recent studies indicate that there is a high degree of diversity and complexity, largely due to the existence of multigene families for each of the major molecular components. Current studies are attempting to identify interacting partners among these families, and to define the molecular mechanisms involved in the interactions. Future goals are to determine the levels of regulation of the key components of the transcriptional complex, to identify higher-order complexes and to integrate this pathway with other auxin signal transduction pathways, such as the pathway that is activated by auxin binding to a different receptor at the outer surface of the plasma membrane. In this case, auxin binding triggers a signal cascade that affects a number of rapid cytoplasmic responses. Details of this pathway are currently under investigation.
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8
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The Arabidopsis Auxin Receptor F-Box Proteins AFB4 and AFB5 Are Required for Response to the Synthetic Auxin Picloram. G3-GENES GENOMES GENETICS 2016; 6:1383-90. [PMID: 26976444 PMCID: PMC4856089 DOI: 10.1534/g3.115.025585] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The plant hormone auxin is perceived by a family of F-box proteins called the TIR1/AFBs. Phylogenetic studies reveal that these proteins fall into four clades in flowering plants called TIR1, AFB2, AFB4, and AFB6. Genetic studies indicate that members of the TIR1 and AFB2 groups act as positive regulators of auxin signaling by promoting the degradation of the Aux/IAA transcriptional repressors. In this report, we demonstrate that both AFB4 and AFB5 also function as auxin receptors based on in vitro assays. We also provide genetic evidence that AFB4 and AFB5 are targets of the picloram family of auxinic herbicides in addition to indole-3-acetic acid. In contrast to previous studies we find that null afb4 alleles do not exhibit obvious defects in seedling morphology or auxin hypersensitivity. We conclude that AFB4 and AFB5 act in a similar fashion to other members of the family but exhibit a distinct auxin specificity.
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El-Sharkawy I, Sherif S, El Kayal W, Jones B, Li Z, Sullivan AJ, Jayasankar S. Overexpression of plum auxin receptor PslTIR1 in tomato alters plant growth, fruit development and fruit shelf-life characteristics. BMC PLANT BIOLOGY 2016; 16:56. [PMID: 26927309 PMCID: PMC4772300 DOI: 10.1186/s12870-016-0746-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 02/26/2016] [Indexed: 05/20/2023]
Abstract
BACKGROUND TIR1-like proteins are F-box auxin receptors. Auxin binding to the F-box receptor proteins promotes the formation of SCF(TIR1) ubiquitin ligase complex that targets the auxin repressors, Aux/IAAs, for degradation via the ubiquitin/26S proteasome pathway. The release of auxin response factors (ARFs) from their Aux/IAA partners allows ARFs to mediate auxin-responsive changes in downstream gene transcription. In an attempt to understand the potential role of auxin during fruit development, a plum auxin receptor, PslTIR1, has previously been characterized at the cellular, biochemical and molecular levels, but the biological significance of this protein is still lacking. In the present study, tomato (Solanum lycopersicum) was used as a model to investigate the phenotypic and molecular changes associated with the overexpression of PslTIR1. RESULTS The findings of the present study highlighted the critical role of PslTIR1 as positive regulator of auxin-signalling in coordinating the development of leaves and fruits. This was manifested by the entire leaf morphology of transgenic tomato plants compared to the wild-type compound leaf patterning. Moreover, transgenic plants produced parthenocarpic fruits, a characteristic property of auxin hypersensitivity. The autocatalytic ethylene production associated with the ripening of climacteric fruits was not significantly altered in transgenic tomato fruits. Nevertheless, the fruit shelf-life characteristics were affected by transgene presence, mainly through enhancing fruit softening rate. The short shelf-life of transgenic tomatoes was associated with dramatic upregulation of several genes encoding proteins involved in cell-wall degradation, which determine fruit softening and subsequent fruit shelf-life. CONCLUSIONS The present study sheds light into the involvement of PslTIR1 in regulating leaf morphology, fruit development and fruit softening-associated ripening, but not autocatalytic ethylene production. The results demonstrate that auxin accelerates fruit softening independently of ethylene action and this is probably mediated through the upregulation of many cell-wall metabolism genes.
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Affiliation(s)
- I El-Sharkawy
- Department of Plant Agriculture, University of Guelph, Vineland Station, ON, Canada.
- Damanhour University, Faculty of Agriculture, Damanhour, Egypt.
| | - S Sherif
- Department of Plant Agriculture, University of Guelph, Vineland Station, ON, Canada.
- Damanhour University, Faculty of Agriculture, Damanhour, Egypt.
| | - W El Kayal
- Department of Plant Agriculture, University of Guelph, Vineland Station, ON, Canada.
| | - B Jones
- The University of Sydney, Faculty of Agriculture, Sydney, Australia.
| | - Z Li
- Chongqing University, Genetic Engineering Research Center, Bioengineering College, Chongqing, China.
| | - A J Sullivan
- Department of Plant Agriculture, University of Guelph, Guelph, ON, Canada.
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Cryptochrome 1 interacts with PIF4 to regulate high temperature-mediated hypocotyl elongation in response to blue light. Proc Natl Acad Sci U S A 2015; 113:224-9. [PMID: 26699514 DOI: 10.1073/pnas.1511437113] [Citation(s) in RCA: 293] [Impact Index Per Article: 32.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cryptochrome 1 (CRY1) is a blue light receptor that mediates primarily blue-light inhibition of hypocotyl elongation. Very little is known of the mechanisms by which CRY1 affects growth. Blue light and temperature are two key environmental signals that profoundly affect plant growth and development, but how these two abiotic factors integrate remains largely unknown. Here, we show that blue light represses high temperature-mediated hypocotyl elongation via CRY1. Furthermore, CRY1 interacts directly with PHYTOCHROME-INTERACTING FACTOR 4 (PIF4) in a blue light-dependent manner to repress the transcription activity of PIF4. CRY1 represses auxin biosynthesis in response to elevated temperature through PIF4. Our results indicate that CRY1 signal by modulating PIF4 activity, and that multiple plant photoreceptors [CRY1 and PHYTOCHROME B (PHYB)] and ambient temperature can mediate morphological responses through the same signaling component-PIF4.
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11
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Abstract
The plant hormone auxin is a key regulator of plant growth and development. Differences in auxin distribution within tissues are mediated by the polar auxin transport machinery, and cellular auxin responses occur depending on changes in cellular auxin levels. Multiple receptor systems at the cell surface and in the interior operate to sense and interpret fluctuations in auxin distribution that occur during plant development. Until now, three proteins or protein complexes that can bind auxin have been identified. SCF(TIR1) [a SKP1-cullin-1-F-box complex that contains transport inhibitor response 1 (TIR1) as the F-box protein] and S-phase-kinase-associated protein 2 (SKP2) localize to the nucleus, whereas auxin-binding protein 1 (ABP1), predominantly associates with the endoplasmic reticulum and cell surface. In this Cell Science at a Glance article, we summarize recent discoveries in the field of auxin transport and signaling that have led to the identification of new components of these pathways, as well as their mutual interaction.
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Affiliation(s)
- Peter Grones
- Institute of Science and Technology (IST) Austria, 3400 Klosterneuburg, Austria Department of Plant Systems Biology, Flanders Institute for Biotechnology (VIB) and Department of Plant Biotechnology and Bioinformatics, Ghent University, BE-9052 Gent, Belgium
| | - Jiří Friml
- Institute of Science and Technology (IST) Austria, 3400 Klosterneuburg, Austria Department of Plant Systems Biology, Flanders Institute for Biotechnology (VIB) and Department of Plant Biotechnology and Bioinformatics, Ghent University, BE-9052 Gent, Belgium Mendel Centre for Plant Genomics and Proteomics, Masaryk University, CEITEC MU, CZ-625 00 Brno, Czech Republic
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12
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Yu H, Zhang Y, Moss BL, Bargmann BOR, Wang R, Prigge M, Nemhauser JL, Estelle M. Untethering the TIR1 auxin receptor from the SCF complex increases its stability and inhibits auxin response. NATURE PLANTS 2015; 1:14030. [PMID: 26236497 PMCID: PMC4520256 DOI: 10.1038/nplants.2014.30] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Plant genomes encode large numbers of F-box proteins (FBPs), the substrate recognition subunit of SKP1-CULLIN-F-box (SCF) ubiquitin ligases. There are ~700 FBPs in Arabidopsis, most of which are uncharacterized. TIR1 is among the best-studied plant FBPs and functions as a receptor for the plant hormone auxin. Here we use a yeast two-hybrid system to identify novel TIR1 mutants with altered properties. The analysis of these mutants reveals that TIR1 associates with the CULLIN1 (CUL1) subunit of the SCF through the N-terminal H1 helix of the F-box domain. Mutations that untether TIR1 from CUL1 stabilize the FBP and cause auxin resistance and associated growth defects, probably by protecting TIR1 substrates from degradation. Based on these results we propose that TIR1 is subject to autocatalytic degradation when assembled into an SCF. Further, our results suggest a general method for determining the physiological function of uncharacterized FBPs. Finally, we show that a key amino acid variation in the F-box domain of auxin signalling F-box (AFB1), a closely related FBP, reduces its ability to form an SCF, resulting in an increase in AFB1 levels.
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Affiliation(s)
- Hong Yu
- Howard Hughes Medical Institute and Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California 92093, USA
| | - Yi Zhang
- Howard Hughes Medical Institute and Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California 92093, USA
| | - Britney L. Moss
- Department of Biology, University of Washington, Seattle, Washington 98195, USA
| | - Bastiaan O. R. Bargmann
- Howard Hughes Medical Institute and Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California 92093, USA
| | - Renhou Wang
- Howard Hughes Medical Institute and Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California 92093, USA
| | - Michael Prigge
- Howard Hughes Medical Institute and Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California 92093, USA
| | | | - Mark Estelle
- Howard Hughes Medical Institute and Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California 92093, USA
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Liu L, Zinkgraf M, Petzold HE, Beers EP, Filkov V, Groover A. The Populus ARBORKNOX1 homeodomain transcription factor regulates woody growth through binding to evolutionarily conserved target genes of diverse function. THE NEW PHYTOLOGIST 2015; 205:682-94. [PMID: 25377848 DOI: 10.1111/nph.13151] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2014] [Accepted: 10/01/2014] [Indexed: 05/28/2023]
Abstract
The class I KNOX homeodomain transcription factor ARBORKNOX1 (ARK1) is a key regulator of vascular cambium maintenance and cell differentiation in Populus. Currently, basic information is lacking concerning the distribution, functional characteristics, and evolution of ARK1 binding in the Populus genome. Here, we used chromatin immunoprecipitation sequencing (ChIP-seq) technology to identify ARK1 binding loci genome-wide in Populus. Computational analyses evaluated the distribution of ARK1 binding loci, the function of genes associated with bound loci, the effect of ARK1 binding on transcript levels, and evolutionary conservation of ARK1 binding loci. ARK1 binds to thousands of loci which are highly enriched proximal to the transcriptional start sites of genes of diverse functions. ARK1 target genes are significantly enriched in paralogs derived from the whole-genome salicoid duplication event. Both ARK1 and a maize (Zea mays) homolog, KNOTTED1, preferentially target evolutionarily conserved genes. However, only a small portion of ARK1 target genes are significantly differentially expressed in an ARK1 over-expression mutant. This study describes the functional characteristics and evolution of DNA binding by a transcription factor in an undomesticated tree, revealing complexities similar to those shown for transcription factors in model animal species.
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Affiliation(s)
- Lijun Liu
- Pacific Southwest Research Station, USDA Forest Service, Davis, CA, 95618, USA
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Shu W, Liu Y, Guo Y, Zhou H, Zhang J, Zhao S, Lu M. A Populus TIR1 gene family survey reveals differential expression patterns and responses to 1-naphthaleneacetic acid and stress treatments. FRONTIERS IN PLANT SCIENCE 2015; 6:719. [PMID: 26442033 PMCID: PMC4585115 DOI: 10.3389/fpls.2015.00719] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 08/20/2015] [Indexed: 05/03/2023]
Abstract
The plant hormone auxin is a central regulator of plant growth. TRANSPORT INHIBITOR RESPONSE 1/AUXIN SIGNALING F-BOX (TIR1/AFB) is a component of the E3 ubiquitin ligase complex SCF(TIR1/AFB) and acts as an auxin co-receptor for nuclear auxin signaling. The SCF(TIR1/AFB)-proteasome machinery plays a central regulatory role in development-related gene transcription. Populus trichocarpa, as a model tree, has a unique fast-growth trait to which auxin signaling may contribute. However, no systematic analyses of the genome organization, gene structure, and expression of TIR1-like genes have been undertaken in this woody model plant. In this study, we identified a total of eight TIR1 genes in the Populus genome that are phylogenetically clustered into four subgroups, PtrFBL1/PtrFBL2, PtrFBL3/PtrFBL4, PtrFBL5/PtrFBL6, and PtrFBL7/PtrFBL8, representing four paralogous pairs. In addition, the gene structure and motif composition were relatively conserved in each paralogous pair and all of the PtrFBL members were localized in the nucleus. Different sets of PtrFBLs were strongly expressed in the leaves, stems, roots, cambial zones, and immature xylem of Populus. Interestingly, PtrFBL1 and 7 were expressed mainly in vascular and cambial tissues, respectively, indicating their potential but different roles in wood formation. Furthermore, Populus FBLs responded differentially upon exposure to various stresses. Finally, over-expression studies indicated a role of FBL1 in poplar stem growth and response to drought stress. Collectively, these observations lay the foundation for further investigations into the potential roles of PtrFBL genes in tree growth and development.
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Affiliation(s)
- Wenbo Shu
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry UniversityNanjing, China
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of ForestryBeijing, China
| | - Yingli Liu
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of ForestryBeijing, China
| | - Yinghua Guo
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of ForestryBeijing, China
| | - Houjun Zhou
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of ForestryBeijing, China
| | - Jin Zhang
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of ForestryBeijing, China
| | - Shutang Zhao
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of ForestryBeijing, China
- *Correspondence: Shutang Zhao, State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Xiangshan Road, Beijing 100091, China
| | - Mengzhu Lu
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry UniversityNanjing, China
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of ForestryBeijing, China
- Mengzhu Lu, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, 159 Longpan Road, Nanjing, Jiangsu 210037, China
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15
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Salehin M, Bagchi R, Estelle M. SCFTIR1/AFB-based auxin perception: mechanism and role in plant growth and development. THE PLANT CELL 2015; 27:9-19. [PMID: 25604443 PMCID: PMC4330579 DOI: 10.1105/tpc.114.133744] [Citation(s) in RCA: 274] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 12/14/2014] [Accepted: 12/26/2014] [Indexed: 05/18/2023]
Abstract
Auxin regulates a vast array of growth and developmental processes throughout the life cycle of plants. Auxin responses are highly context dependent and can involve changes in cell division, cell expansion, and cell fate. The complexity of the auxin response is illustrated by the recent finding that the auxin-responsive gene set differs significantly between different cell types in the root. Auxin regulation of transcription involves a core pathway consisting of the TIR1/AFB F-box proteins, the Aux/IAA transcriptional repressors, and the ARF transcription factors. Auxin is perceived by a transient coreceptor complex consisting of a TIR1/AFB protein and an Aux/IAA protein. Auxin binding to the coreceptor results in degradation of the Aux/IAAs and derepression of ARF-based transcription. Although the basic outlines of this pathway are now well established, it remains unclear how specificity of the pathway is conferred. However, recent results, focusing on the ways that these three families of proteins interact, are starting to provide important clues.
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Affiliation(s)
- Mohammad Salehin
- Howard Hughes Medical Institute and Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California 92093
| | - Rammyani Bagchi
- Howard Hughes Medical Institute and Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California 92093
| | - Mark Estelle
- Howard Hughes Medical Institute and Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California 92093
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16
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Wang R, Estelle M. Diversity and specificity: auxin perception and signaling through the TIR1/AFB pathway. CURRENT OPINION IN PLANT BIOLOGY 2014; 21:51-58. [PMID: 25032902 PMCID: PMC4294414 DOI: 10.1016/j.pbi.2014.06.006] [Citation(s) in RCA: 165] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 06/15/2014] [Indexed: 05/19/2023]
Abstract
Auxin is a versatile plant hormone that plays an essential role in most aspects of plant growth and development. Auxin regulates various growth processes by modulating gene transcription through a SCF(TIR1/AFB)-Aux/IAA-ARF nuclear signaling module. Recent work has generated clues as to how multiple layers of regulation of the auxin signaling components may result in diverse and specific response outputs. In particular, interaction and structural studies of key auxin signaling proteins have produced novel insights into the molecular basis of auxin-regulated transcription and may lead to a refined auxin signaling model.
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Affiliation(s)
- Renhou Wang
- Section of Cell and Developmental Biology and Howard Hughes Medical Institute, UCSD, La Jolla, CA 92093, United States
| | - Mark Estelle
- Section of Cell and Developmental Biology and Howard Hughes Medical Institute, UCSD, La Jolla, CA 92093, United States.
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17
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El-Sharkawy I, Sherif SM, Jones B, Mila I, Kumar PP, Bouzayen M, Jayasankar S. TIR1-like auxin-receptors are involved in the regulation of plum fruit development. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:5205-15. [PMID: 24996652 PMCID: PMC4157706 DOI: 10.1093/jxb/eru279] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Ethylene has long been considered the key regulator of ripening in climacteric fruit. Recent evidence showed that auxin also plays an important role during fruit ripening, but the nature of the interaction between the two hormones has remained unclear. To understand the differences in ethylene- and auxin-related behaviours that might reveal how the two hormones interact, we compared two plum (Prunus salicina L.) cultivars with widely varying fruit development and ripening ontogeny. The early-ripening cultivar, Early Golden (EG), exhibited high endogenous auxin levels and auxin hypersensitivity during fruit development, while the late-ripening cultivar, V98041 (V9), displayed reduced auxin content and sensitivity. We show that exogenous auxin is capable of dramatically accelerating fruit development and ripening in plum, indicating that this hormone is actively involved in the ripening process. Further, we demonstrate that the variations in auxin sensitivity between plum cultivars could be partially due to PslAFB5, which encodes a TIR1-like auxin receptor. Two different PslAFB5 alleles were identified, one (Pslafb5) inactive due to substitution of the conserved F-box amino acid residue Pro61 to Ser. The early-ripening cultivar, EG, exhibited homozygosity for the inactive allele; however, the late cultivar, V9, displayed a PslAFB5/afb5 heterozygous genotype. Our results highlight the impact of auxin in stimulating fruit development, especially the ripening process and the potential for differential auxin sensitivity to alter important fruit developmental processes.
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Affiliation(s)
- Islam El-Sharkawy
- University of Guelph, Department of Plant Agriculture. 4890 Victoria Av. N., P.O. Box 7000 Vineland Station, ON, L0R 2E0 Canada Faculty of Agriculture, Damanhour University, Damanhour, Egypt
| | - Sherif M Sherif
- University of Guelph, Department of Plant Agriculture. 4890 Victoria Av. N., P.O. Box 7000 Vineland Station, ON, L0R 2E0 Canada Faculty of Agriculture, Damanhour University, Damanhour, Egypt
| | - Brian Jones
- The University of Sydney, Faculty of Agriculture, Australia
| | - Isabelle Mila
- Université de Toulouse, INP-ENSA Toulouse, Génomique et Biotechnologie des Fruits, Castanet-Tolosan F-31326, France
| | - Prakash P Kumar
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Mondher Bouzayen
- Université de Toulouse, INP-ENSA Toulouse, Génomique et Biotechnologie des Fruits, Castanet-Tolosan F-31326, France
| | - Subramanian Jayasankar
- University of Guelph, Department of Plant Agriculture. 4890 Victoria Av. N., P.O. Box 7000 Vineland Station, ON, L0R 2E0 Canada
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18
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Del Pozo JC, Manzano C. Auxin and the ubiquitin pathway. Two players-one target: the cell cycle in action. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:2617-2632. [PMID: 24215077 DOI: 10.1093/jxb/ert363] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Plants are sessile organisms that have to adapt their growth to the surrounding environment. Concomitant with this adaptation capability, they have adopted a post-embryonic development characterized by continuous growth and differentiation abilities. Constant growth is based on the potential of stem cells to divide almost incessantly and on a precise balance between cell division and cell differentiation. This balance is influenced by environmental conditions and by the genetic information of the cell. Among the internal cues, the cross-talk between different hormonal signalling pathways is essential to control this division/differentiation equilibrium. Auxin, one of the most important plant hormones, regulates cell division and differentiation, among many other processes. Amazing advances in auxin signal transduction at the molecular level have been reported, but how this signalling is connected to the cell cycle is, so far, not well known. Auxin signalling involves the auxin-dependent degradation of transcription repressors by F-box-containing E3 ligases of ubiquitin. Recently, SKP2A, another F-box protein, was shown to bind auxin and to target cell-cycle repressors for proteolysis, representing a novel mechanism that links auxin to cell division. In this review, a general vision of what is already known and the most recent advances on how auxin signalling connects to cell division and the role of the ubiquitin pathway in plant cell cycle will be covered.
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Affiliation(s)
- Juan C Del Pozo
- Centro de Biotecnología y Genómica de Plantas (CBGP) INIA-UPM. Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria. Campus de Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain
| | - Concepción Manzano
- Centro de Biotecnología y Genómica de Plantas (CBGP) INIA-UPM. Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria. Campus de Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain
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19
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Shimizu-Mitao Y, Kakimoto T. Auxin Sensitivities of All Arabidopsis Aux/IAAs for Degradation in the Presence of Every TIR1/AFB. ACTA ACUST UNITED AC 2014; 55:1450-9. [DOI: 10.1093/pcp/pcu077] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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20
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Abstract
Auxin signaling through the SCF(TIR1)-Aux/IAA-ARF pathway is one of the best-studied plant hormone response pathways. Components of this pathway, from receptors through to transcription factors, have been identified and analyzed in detail. Although we understand elementary aspects of how the auxin signal is perceived and leads to a transcriptional response, many questions remain about the in vivo function of the pathway. Two crucial issues are the tissue specificity of the response, i.e. how distinct cell types can interpret the same auxin signal differently, and the response to a signaling gradient, i.e. how a graded distribution of auxin can elicit distinct expression patterns along its range. Here, we speculate on how signaling through the canonical SCF(TIR1)-Aux/IAA-ARF pathway may achieve divergent responses.
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21
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Nan W, Wang X, Yang L, Hu Y, Wei Y, Liang X, Mao L, Bi Y. Cyclic GMP is involved in auxin signalling during Arabidopsis root growth and development. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:1571-83. [PMID: 24591051 PMCID: PMC3967089 DOI: 10.1093/jxb/eru019] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The second messenger cyclic guanosine 3',5'-monophosphate (cGMP) plays an important role in plant development and responses to stress. Recent studies indicated that cGMP is a secondary signal generated in response to auxin stimulation. cGMP also mediates auxin-induced adventitious root formation in mung bean and gravitropic bending in soybean. Nonetheless, the mechanism of the participation of cGMP in auxin signalling to affect these growth and developmental processes is largely unknown. In this report we provide evidence that indole-3-acetic acid (IAA) induces cGMP accumulation in Arabidopsis roots through modulation of the guanylate cyclase activity. Application of 8-bromo-cGMP (a cell-permeable cGMP derivative) increases auxin-dependent lateral root formation, root hair development, primary root growth, and gene expression. In contrast, inhibitors of endogenous cGMP synthesis block these processes induced by auxin. Data also showed that 8-bromo-cGMP enhances auxin-induced degradation of Aux/IAA protein modulated by the SCF(TIR1) ubiquitin-proteasome pathway. Furthermore, it was found that 8-bromo-cGMP is unable to directly influence the auxin-dependent TIR1-Aux/IAA interaction as evidenced by pull-down and yeast two-hybrid assays. In addition, we provide evidence for cGMP-mediated modulation of auxin signalling through cGMP-dependent protein kinase (PKG). Our results suggest that cGMP acts as a mediator to participate in auxin signalling and may govern this process by PKG activity via its influence on auxin-regulated gene expression and auxin/IAA degradation.
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Affiliation(s)
- Wenbin Nan
- * These authors contributed equally to this work
| | - Xiaomin Wang
- * These authors contributed equally to this work
| | | | | | | | | | | | - Yurong Bi
- † To whom correspondence should be addressed. E-mail:
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22
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Song Y. Insight into the mode of action of 2,4-dichlorophenoxyacetic acid (2,4-D) as an herbicide. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2014; 56:106-13. [PMID: 24237670 DOI: 10.1111/jipb.12131] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Accepted: 11/06/2013] [Indexed: 05/10/2023]
Abstract
2,4-Dichlorophenoxyacetic acid (2,4-D) was the first synthetic herbicide to be commercially developed and has commonly been used as a broadleaf herbicide for over 60 years. It is a selective herbicide that kills dicots without affecting monocots and mimics natural auxin at the molecular level. Physiological responses of dicots sensitive to auxinic herbicides include abnormal growth, senescence, and plant death. The identification of auxin receptors, auxin transport carriers, transcription factors response to auxin, and cross-talk among phytohormones have shed light on the molecular action mode of 2,4-D as a herbicide. Here, the molecular action mode of 2,4-D is highlighted according to the latest findings, emphasizing the physiological process, perception, and signal transduction under herbicide treatment.
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Affiliation(s)
- Yaling Song
- Key Laboratory of Tropical Plant Resource and Sustainable Use, Xishuangbanna Tropical Botanical Garden, the Chinese Academy of Sciences, Mengla, 666303, China
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23
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Motte H, Vereecke D, Geelen D, Werbrouck S. The molecular path to in vitro shoot regeneration. Biotechnol Adv 2014; 32:107-21. [DOI: 10.1016/j.biotechadv.2013.12.002] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 11/20/2013] [Accepted: 12/08/2013] [Indexed: 10/25/2022]
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24
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Choi CM, Gray WM, Mooney S, Hellmann H. Composition, roles, and regulation of cullin-based ubiquitin e3 ligases. THE ARABIDOPSIS BOOK 2014; 12:e0175. [PMID: 25505853 PMCID: PMC4262284 DOI: 10.1199/tab.0175] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Due to their sessile nature, plants depend on flexible regulatory systems that allow them to adequately regulate developmental and physiological processes in context with environmental cues. The ubiquitin proteasome pathway, which targets a great number of proteins for degradation, is cellular tool that provides the necessary flexibility to accomplish this task. Ubiquitin E3 ligases provide the needed specificity to the pathway by selectively binding to particular substrates and facilitating their ubiquitylation. The largest group of E3 ligases known in plants is represented by CULLIN-REALLY INTERESTING NEW GENE (RING) E3 ligases (CRLs). In recent years, a great amount of knowledge has been generated to reveal the critical roles of these enzymes across all aspects of plant life. This review provides an overview of the different classes of CRLs in plants, their specific complex compositions, the variety of biological processes they control, and the regulatory steps that can affect their activities.
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Affiliation(s)
| | | | | | - Hanjo Hellmann
- Washington State University, Pullman, Washington
- Address correspondence to
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25
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Rigal A, Ma Q, Robert S. Unraveling plant hormone signaling through the use of small molecules. FRONTIERS IN PLANT SCIENCE 2014; 5:373. [PMID: 25126092 PMCID: PMC4115670 DOI: 10.3389/fpls.2014.00373] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Accepted: 07/11/2014] [Indexed: 05/03/2023]
Abstract
Plants have acquired the capacity to grow continuously and adjust their morphology in response to endogenous and external signals, leading to a high architectural plasticity. The dynamic and differential distribution of phytohormones is an essential factor in these developmental changes. Phytohormone perception is a fast but complex process modulating specific developmental reprogramming. In recent years, chemical genomics or the use of small molecules to modulate target protein function has emerged as a powerful strategy to study complex biological processes in plants such as hormone signaling. Small molecules can be applied in a conditional, dose-dependent and reversible manner, with the advantage of circumventing the limitations of lethality and functional redundancy inherent to traditional mutant screens. High-throughput screening of diverse chemical libraries has led to the identification of bioactive molecules able to induce plant hormone-related phenotypes. Characterization of the cognate targets and pathways of those molecules has allowed the identification of novel regulatory components, providing new insights into the molecular mechanisms of plant hormone signaling. An extensive structure-activity relationship (SAR) analysis of the natural phytohormones, their designed synthetic analogs and newly identified bioactive molecules has led to the determination of the structural requirements essential for their bioactivity. In this review, we will summarize the so far identified small molecules and their structural variants targeting specific phytohormone signaling pathways. We will highlight how the SAR analyses have enabled better interrogation of the molecular mechanisms of phytohormone responses. Finally, we will discuss how labeled/tagged hormone analogs can be exploited, as compelling tools to better understand hormone signaling and transport mechanisms.
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Affiliation(s)
| | | | - Stéphanie Robert
- *Correspondence: Stéphanie Robert, Department of Forest Genetics and Plant Physiology, Umeå Plant Science Centre, Swedish University of Agricultural Sciences, 901 83 Umeå, Sweden e-mail:
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26
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Pérez AC, Goossens A. Jasmonate signalling: a copycat of auxin signalling? PLANT, CELL & ENVIRONMENT 2013; 36:2071-84. [PMID: 23611666 DOI: 10.1111/pce.12121] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 04/15/2013] [Indexed: 05/22/2023]
Abstract
Plant hormones regulate almost all aspects of plant growth and development. The past decade has provided breakthrough discoveries in phytohormone sensing and signal transduction, and highlighted the striking mechanistic similarities between the auxin and jasmonate (JA) signalling pathways. Perception of auxin and JA involves the formation of co-receptor complexes in which hormone-specific E3-ubiquitin ligases of the SKP1-Cullin-F-box protein (SCF) type interact with specific repressor proteins. Across the plant kingdom, the Aux/IAA and the JASMONATE-ZIM DOMAIN (JAZ) proteins correspond to the auxin- and JA-specific repressors, respectively. In the absence of the hormones, these repressors form a complex with transcription factors (TFs) specific for both pathways. They also recruit several proteins, among which the general co-repressor TOPLESS, and thereby prevent the TFs from activating gene expression. The hormone-mediated interaction between the SCF and the repressors targets the latter for 26S proteasome-mediated degradation, which, in turn, releases the TFs to allow modulating hormone-dependent gene expression. In this review, we describe the similarities and differences in the auxin and JA signalling cascades with respect to the protein families and the protein domains involved in the formation of the pathway-specific complexes.
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Affiliation(s)
- A Cuéllar Pérez
- Department of Plant Systems Biology, VIB, B-9052, Gent, Belgium; Department of Plant Biotechnology & Bioinformatics, Ghent University, B-9052, Gent, Belgium
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27
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Jahn L, Mucha S, Bergmann S, Horn C, Staswick P, Steffens B, Siemens J, Ludwig-Müller J. The Clubroot Pathogen (Plasmodiophora brassicae) Influences Auxin Signaling to Regulate Auxin Homeostasis in Arabidopsis. PLANTS 2013; 2:726-49. [PMID: 27137401 PMCID: PMC4844388 DOI: 10.3390/plants2040726] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 10/17/2013] [Accepted: 11/18/2013] [Indexed: 11/16/2022]
Abstract
The clubroot disease, caused by the obligate biotrophic protist Plasmodiophora brassicae, affects cruciferous crops worldwide. It is characterized by root swellings as symptoms, which are dependent on the alteration of auxin and cytokinin metabolism. Here, we describe that two different classes of auxin receptors, the TIR family and the auxin binding protein 1 (ABP1) in Arabidopsis thaliana are transcriptionally upregulated upon gall formation. Mutations in the TIR family resulted in more susceptible reactions to the root pathogen. As target genes for the different pathways we have investigated the transcriptional regulation of selected transcriptional repressors (Aux/IAA) and transcription factors (ARF). As the TIR pathway controls auxin homeostasis via the upregulation of some auxin conjugate synthetases (GH3), the expression of selected GH3 genes was also investigated, showing in most cases upregulation. A double gh3 mutant showed also slightly higher susceptibility to P. brassicae infection, while all tested single mutants did not show any alteration in the clubroot phenotype. As targets for the ABP1-induced cell elongation the effect of potassium channel blockers on clubroot formation was investigated. Treatment with tetraethylammonium (TEA) resulted in less severe clubroot symptoms. This research provides evidence for the involvement of two auxin signaling pathways in Arabidopsis needed for the establishment of the root galls by P. brassicae.
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Affiliation(s)
- Linda Jahn
- Institut für Botanik, Technische Universität Dresden, 01062 Dresden, Germany.
| | - Stefanie Mucha
- Institut für Botanik, Technische Universität Dresden, 01062 Dresden, Germany.
| | - Sabine Bergmann
- Institut für Botanik, Technische Universität Dresden, 01062 Dresden, Germany.
| | - Cornelia Horn
- Institut für Botanik, Technische Universität Dresden, 01062 Dresden, Germany.
| | - Paul Staswick
- Department of Agronomy and Horticulture, University of Nebraska, 379 Keim, Lincoln, NE 68521 USA.
| | - Bianka Steffens
- Botanisches Institut, Universität Kiel, Am Botanischen Garten 5, 24118 Kiel, Germany.
| | - Johannes Siemens
- Institut für Botanik, Technische Universität Dresden, 01062 Dresden, Germany.
| | - Jutta Ludwig-Müller
- Institut für Botanik, Technische Universität Dresden, 01062 Dresden, Germany.
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28
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Peer WA. From perception to attenuation: auxin signalling and responses. CURRENT OPINION IN PLANT BIOLOGY 2013; 16:561-8. [PMID: 24004572 DOI: 10.1016/j.pbi.2013.08.003] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 08/09/2013] [Accepted: 08/14/2013] [Indexed: 05/10/2023]
Abstract
The plant hormone auxin is essential for growth, development, and responses to environmental factors. Recently, Auxin Binding Protein 1 was shown to mediate non-transcriptional auxin signalling at the cell periphery. This has provoked reexamination of the paradigm that all auxin perception is intracellular and is mediated by the TIR1/AFB-Aux/IAA co-receptors for which auxin functions as a concentration-dependent molecular glue. Further, another F-box protein, SKP2a, was shown to bind auxin in the same way as TIR1/AFB, which provides a link to the role of auxin in the cell cycle. New work on auxin signalling and homeostasis include D6 PROTEIN KINASE activation of PINFORMED (PIN) auxin carriers, ROP-GTPase mediation of PIN localization, endoplasmic reticulum localization PIN and PIN-LIKES auxin carriers, and auxin biosynthesis and metabolism.
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Affiliation(s)
- Wendy Ann Peer
- Department of Environmental Science and Technology, University of Maryland, 5138 Plant Science Building, College Park, MD 20742, USA; Department of Plant Science and Landscape Architecture, University of Maryland, 5138 Plant Science Building, College Park, MD 20742, USA.
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29
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Hanzawa T, Shibasaki K, Numata T, Kawamura Y, Gaude T, Rahman A. Cellular auxin homeostasis under high temperature is regulated through a sorting NEXIN1-dependent endosomal trafficking pathway. THE PLANT CELL 2013; 25:3424-33. [PMID: 24003052 PMCID: PMC3809541 DOI: 10.1105/tpc.113.115881] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 08/11/2013] [Accepted: 08/19/2013] [Indexed: 05/19/2023]
Abstract
High-temperature-mediated adaptation in plant architecture is linked to the increased synthesis of the phytohormone auxin, which alters cellular auxin homeostasis. The auxin gradient, modulated by cellular auxin homeostasis, plays an important role in regulating the developmental fate of plant organs. Although the signaling mechanism that integrates auxin and high temperature is relatively well understood, the cellular auxin homeostasis mechanism under high temperature is largely unknown. Using the Arabidopsis thaliana root as a model, we demonstrate that under high temperature, roots counterbalance the elevated level of intracellular auxin by promoting shootward auxin efflux in a PIN-FORMED2 (PIN2)-dependent manner. Further analyses revealed that high temperature selectively promotes the retrieval of PIN2 from late endosomes and sorts them to the plasma membrane through an endosomal trafficking pathway dependent on SORTING NEXIN1. Our results demonstrate that recycling endosomal pathway plays an important role in facilitating plants adaptation to increased temperature.
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Affiliation(s)
- Taiki Hanzawa
- Cryobiofrontier Research Centre, Faculty of Agriculture, Iwate University, Morioka, Iwate 020-8550, Japan
| | - Kyohei Shibasaki
- Cryobiofrontier Research Centre, Faculty of Agriculture, Iwate University, Morioka, Iwate 020-8550, Japan
- Plant Biology Division, Samuel Roberts Noble Foundation, Ardmore, Oklahoma 73401
| | - Takahiro Numata
- Cryobiofrontier Research Centre, Faculty of Agriculture, Iwate University, Morioka, Iwate 020-8550, Japan
| | - Yukio Kawamura
- Cryobiofrontier Research Centre, Faculty of Agriculture, Iwate University, Morioka, Iwate 020-8550, Japan
| | - Thierry Gaude
- Reproduction et Développement des Plantes, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Structure Fédérative de Recherche BioSciences Gerland-Lyon Sud, Ecole Normale Supérieure Lyon, 69364 Lyon cedex 07, France
| | - Abidur Rahman
- Cryobiofrontier Research Centre, Faculty of Agriculture, Iwate University, Morioka, Iwate 020-8550, Japan
- Address correspondence to
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Abstract
E3 ligases comprise a highly diverse and important group of enzymes that act within the 26S ubiquitin proteasome pathway. They facilitate the transfer of ubiquitin moieties to substrate proteins which may be marked for degradation by this step. As such, they serve as central regulators in many cellular and physiological processes in plants. The review provides an update on the multitude of different E3 ligases currently known in plants, and illustrates the central role in plant biology of specific examples.
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Affiliation(s)
- Liyuan Chen
- Plant Stress Physiology, School of Biological Sciences, Abelson 435, PO Box 644236, Washington State University, Pullman, WA 99164-4236, USA
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Roychoudhry S, Del Bianco M, Kieffer M, Kepinski S. Auxin controls gravitropic setpoint angle in higher plant lateral branches. Curr Biol 2013; 23:1497-504. [PMID: 23891109 DOI: 10.1016/j.cub.2013.06.034] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 04/28/2013] [Accepted: 06/13/2013] [Indexed: 11/19/2022]
Abstract
Lateral branches in higher plants are often maintained at specific angles with respect to gravity, a quantity known as the gravitropic setpoint angle (GSA) [1]. Despite the importance of GSA control as a fundamental determinant of plant form, the mechanisms underlying gravity-dependent angled growth are not known. Here we address the central questions of how stable isotropic growth of a branch at a nonvertical angle is maintained and of how the value of that angle is set. We show that nonvertical lateral root and shoot branches are distinguished from the primary axis by the existence of an auxin-dependent antigravitropic offset mechanism that operates in tension with gravitropic response to generate angled isotropic growth. Further, we show that the GSA of lateral roots and shoots is dependent upon the magnitude of the antigravitropic offset component. Finally, we show that auxin specifies GSA values dynamically throughout development by regulating the magnitude of the antigravitropic offset component via TIR1/AFB-Aux/IAA-ARF-dependent auxin signaling within the gravity-sensing cells of the root and shoot. The involvement of auxin in controlling GSA is yet another example of auxin's remarkable capacity to self-organize in development [2] and provides a conceptual framework for understanding the specification of GSA throughout nature.
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32
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Abstract
Auxin is a plant hormone involved in an extraordinarily broad variety of biological mechanisms. These range from basic cellular processes, such as endocytosis, cell polarity, and cell cycle control over localized responses such as cell elongation and differential growth, to macroscopic phenomena such as embryogenesis, tissue patterning, and de novo formation of organs. Even though the history of auxin research reaches back more than a hundred years, we are still far from a comprehensive understanding of how auxin governs such a wide range of responses. Some answers to this question may lie in the auxin molecule itself. Naturally occurring auxin-like substances have been found and they may play roles in specific developmental and cellular processes. The molecular mode of auxin action can be further explored by the utilization of synthetic auxin-like molecules. A second area is the perception of auxin, where we know of three seemingly independent receptors and signalling systems, some better understood than others, but each of them probably involved in distinct physiological processes. Lastly, auxin is actively modified, metabolized, and intracellularly compartmentalized, which can have a great impact on its availability and activity. In this review, we will give an overview of these rather recent and emerging areas of auxin research and try to formulate some of the open questions. Without doubt, the manifold facets of auxin biology will not cease to amaze us for a long time to come.
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Affiliation(s)
- Michael Sauer
- Centro Nacional de Biotecnología-CNB-CSIC, Darwin 3, 28049 Madrid, Spain
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33
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Pierre-Jerome E, Moss BL, Nemhauser JL. Tuning the auxin transcriptional response. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:2557-63. [PMID: 23630231 DOI: 10.1093/jxb/ert100] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
How does auxin provoke such a diverse array of responses? This long-standing question is further complicated by a remarkably short nuclear auxin signalling pathway. To crack the auxin code, several potential sources of specificity need to be evaluated. These include: specificity of interactions among the core auxin response components, specificity resulting from higher order complex dynamics, and specificity in interactions with global factors controlling protein turnover and transcriptional repression. Here, we review recent progress towards characterizing and quantifying these interactions and highlight key gaps that remain.
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Yu H, Karampelias M, Robert S, Peer WA, Swarup R, Ye S, Ge L, Cohen J, Murphy A, Friml J, Estelle M. ROOT ULTRAVIOLET B-SENSITIVE1/weak auxin response3 is essential for polar auxin transport in Arabidopsis. PLANT PHYSIOLOGY 2013; 162:965-76. [PMID: 23580592 PMCID: PMC3668084 DOI: 10.1104/pp.113.217018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The phytohormone auxin regulates virtually every aspect of plant development. To identify new genes involved in auxin activity, a genetic screen was performed for Arabidopsis (Arabidopsis thaliana) mutants with altered expression of the auxin-responsive reporter DR5rev:GFP. One of the mutants recovered in the screen, designated as weak auxin response3 (wxr3), exhibits much lower DR5rev:GFP expression when treated with the synthetic auxin 2,4-dichlorophenoxyacetic acid and displays severe defects in root development. The wxr3 mutant decreases polar auxin transport and results in a disruption of the asymmetric auxin distribution. The levels of the auxin transporters AUXIN1 and PIN-FORMED are dramatically reduced in the wxr3 root tip. Molecular analyses demonstrate that WXR3 is ROOT ULTRAVIOLET B-SENSITIVE1 (RUS1), a member of the conserved Domain of Unknown Function647 protein family found in diverse eukaryotic organisms. Our data suggest that RUS1/WXR3 plays an essential role in the regulation of polar auxin transport by maintaining the proper level of auxin transporters on the plasma membrane.
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Yu H, Moss BL, Jang SS, Prigge M, Klavins E, Nemhauser JL, Estelle M. Mutations in the TIR1 auxin receptor that increase affinity for auxin/indole-3-acetic acid proteins result in auxin hypersensitivity. PLANT PHYSIOLOGY 2013; 162:295-303. [PMID: 23539280 PMCID: PMC3641209 DOI: 10.1104/pp.113.215582] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The phytohormone auxin regulates virtually every aspect of plant development. The hormone directly mediates the interaction between the two members of the auxin coreceptor complex, a TRANSPORT INHIBITOR RESPONSE (TIR1)/AUXIN SIGNALING F-BOX protein and an AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) transcriptional repressor. To learn more about the interaction between these proteins, a mutant screen was performed using the yeast (Saccharomyces cerevisiae) two-hybrid system in Arabidopsis (Arabidopsis thaliana). Two tir1 mutations were identified that increased interaction with Aux/IAAs. The D170E and M473L mutations increase affinity between TIR1 and the degron motif of Aux/IAAs and enhance the activity of the SCF(TIR1) complex. This resulted in faster degradation of Aux/IAAs and increased transcription of auxin-responsive genes in the plant. Plants carrying the pTIR1:tir1 D170E/M473L-Myc transgene exhibit diverse developmental defects during plant growth and display an auxin-hypersensitive phenotype. This work demonstrates that changes in the leucine-rich repeat domain of the TIR1 auxin coreceptor can alter the properties of SCF(TIR1).
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36
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Proveniers MCG, van Zanten M. High temperature acclimation through PIF4 signaling. TRENDS IN PLANT SCIENCE 2013; 18:59-64. [PMID: 23040086 DOI: 10.1016/j.tplants.2012.09.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Revised: 08/24/2012] [Accepted: 09/05/2012] [Indexed: 05/03/2023]
Abstract
Ambient temperature has direct consequences for plant functioning. Many plant species are able to adjust reproductive timing and development to optimize fitness to changes in ambient temperatures. Understanding the molecular networks of how plants cope with high temperatures is essential to counteract the effects of global warming and to secure future crop productivity. Several recent papers reported that Arabidopsis thaliana responses to changing light conditions and high temperature, and their underlying signaling mechanisms are highly similar and involve the basic helix-loop-helix (bHLH) transcription factor PHYTOCHROME INTERACTING FACTOR 4 (PIF4). In this opinion article we discuss the mechanisms of PIF4-mediated acclimation to increased ambient temperature with focus on timing of flowering and morphological acclimation.
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Affiliation(s)
- Marcel C G Proveniers
- Molecular Plant Physiology, Institute of Environmental Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
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37
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da Costa CT, de Almeida MR, Ruedell CM, Schwambach J, Maraschin FS, Fett-Neto AG. When stress and development go hand in hand: main hormonal controls of adventitious rooting in cuttings. FRONTIERS IN PLANT SCIENCE 2013; 4:133. [PMID: 23717317 PMCID: PMC3653114 DOI: 10.3389/fpls.2013.00133] [Citation(s) in RCA: 139] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Accepted: 04/21/2013] [Indexed: 05/18/2023]
Abstract
Adventitious rooting (AR) is a multifactorial response leading to new roots at the base of stem cuttings, and the establishment of a complete and autonomous plant. AR has two main phases: (a) induction, with a requirement for higher auxin concentration; (b) formation, inhibited by high auxin and in which anatomical changes take place. The first stages of this process in severed organs necessarily include wounding and water stress responses which may trigger hormonal changes that contribute to reprogram target cells that are competent to respond to rooting stimuli. At severance, the roles of jasmonate and abscisic acid are critical for wound response and perhaps sink strength establishment, although their negative roles on the cell cycle may inhibit root induction. Strigolactones may also inhibit AR. A reduced concentration of cytokinins in cuttings results from the separation of the root system, whose tips are a relevant source of these root induction inhibitors. The combined increased accumulation of basipetally transported auxins from the shoot apex at the cutting base is often sufficient for AR in easy-to-root species. The role of peroxidases and phenolic compounds in auxin catabolism may be critical at these early stages right after wounding. The events leading to AR strongly depend on mother plant nutritional status, both in terms of minerals and carbohydrates, as well as on sink establishment at cutting bases. Auxins play a central role in AR. Auxin transporters control auxin canalization to target cells. There, auxins act primarily through selective proteolysis and cell wall loosening, via their receptor proteins TIR1 (transport inhibitor response 1) and ABP1 (Auxin-Binding Protein 1). A complex microRNA circuitry is involved in the control of auxin response factors essential for gene expression in AR. After root establishment, new hormonal controls take place, with auxins being required at lower concentrations for root meristem maintenance and cytokinins needed for root tissue differentiation.
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Affiliation(s)
- Cibele T. da Costa
- Plant Physiology Laboratory, Center for Biotechnology and Department of Botany, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
- Cibele T. da Costa and Márcia R. de Almeida have contributed equally to this work
| | - Márcia R. de Almeida
- Plant Physiology Laboratory, Center for Biotechnology and Department of Botany, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
- Cibele T. da Costa and Márcia R. de Almeida have contributed equally to this work
| | - Carolina M. Ruedell
- Plant Physiology Laboratory, Center for Biotechnology and Department of Botany, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Joseli Schwambach
- Institute of Biotechnology, University of Caxias do Sul, Caxias do Sul, Rio Grande do Sul, Brazil
| | - Felipe S. Maraschin
- Plant Physiology Laboratory, Center for Biotechnology and Department of Botany, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Arthur G. Fett-Neto
- Plant Physiology Laboratory, Center for Biotechnology and Department of Botany, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
- *Correspondence: Arthur G. Fett-Neto, Plant Physiology Laboratory, Center for Biotechnology and Department of Botany, Federal University of Rio Grande do Sul, P.O. Box 15005, Porto Alegre 91501-970, Rio Grande do Sul, Brazil. e-mail:
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38
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Hohm T, Preuten T, Fankhauser C. Phototropism: translating light into directional growth. AMERICAN JOURNAL OF BOTANY 2013; 100:47-59. [PMID: 23152332 DOI: 10.3732/ajb.1200299] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Phototropism allows plants to align their photosynthetic tissues with incoming light. The direction of incident light is sensed by the phototropin family of blue light photoreceptors (phot1 and phot2 in Arabidopsis), which are light-activated protein kinases. The kinase activity of phototropins and phosphorylation of residues in the activation loop of their kinase domains are essential for the phototropic response. These initial steps trigger the formation of the auxin gradient across the hypocotyl that leads to asymmetric growth. The molecular events between photoreceptor activation and the growth response are only starting to be elucidated. In this review, we discuss the major steps leading from light perception to directional growth concentrating on Arabidopsis. In addition, we highlight links that connect these different steps enabling the phototropic response.
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Affiliation(s)
- Tim Hohm
- Department of Medical Genetics, Faculty of Biology and Medicine, University of Lausanne, Rue du Bugnon 27, CH-1005 Lausanne, Switzerland
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39
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Guo L, Nezames CD, Sheng L, Deng X, Wei N. Cullin-RING ubiquitin ligase family in plant abiotic stress pathways(F). JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2013; 55:21-30. [PMID: 23206256 DOI: 10.1111/jipb.12019] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The ubiquitin-proteasome system is a key mechanism that plants use to generate adaptive responses in coping with various environmental stresses. Cullin-RING (CRL) complexes represent a predominant group of ubiquitin E3 ligases in this system. In this review, we focus on the CRL E3s that have been implicated in abiotic stress signaling pathways in Arabidopsis. By comparing and analyzing these cases, we hope to gain a better understanding on how CRL complexes work under various settings in an attempt to decipher the clues about the regulatory mechanism of CRL E3s.
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Affiliation(s)
- Liquan Guo
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven 06520, Connecticut, USA
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40
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SCF(TIR1/AFB)-auxin signalling regulates PIN vacuolar trafficking and auxin fluxes during root gravitropism. EMBO J 2012; 32:260-74. [PMID: 23211744 PMCID: PMC3553380 DOI: 10.1038/emboj.2012.310] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Accepted: 10/19/2012] [Indexed: 01/31/2023] Open
Abstract
The distribution of the phytohormone auxin regulates many aspects of plant development including growth response to gravity. Gravitropic root curvature involves coordinated and asymmetric cell elongation between the lower and upper side of the root, mediated by differential cellular auxin levels. The asymmetry in the auxin distribution is established and maintained by a spatio-temporal regulation of the PIN-FORMED (PIN) auxin transporter activity. We provide novel insights into the complex regulation of PIN abundance and activity during root gravitropism. We show that PIN2 turnover is differentially regulated on the upper and lower side of gravistimulated roots by distinct but partially overlapping auxin feedback mechanisms. In addition to regulating transcription and clathrin-mediated internalization, auxin also controls PIN abundance at the plasma membrane by promoting their vacuolar targeting and degradation. This effect of elevated auxin levels requires the activity of SKP-Cullin-F-box(TIR1/AFB) (SCF(TIR1/AFB))-dependent pathway. Importantly, also suboptimal auxin levels mediate PIN degradation utilizing the same signalling pathway. These feedback mechanisms are functionally important during gravitropic response and ensure fine-tuning of auxin fluxes for maintaining as well as terminating asymmetric growth.
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41
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Sakai T, Haga K. Molecular genetic analysis of phototropism in Arabidopsis. PLANT & CELL PHYSIOLOGY 2012; 53:1517-34. [PMID: 22864452 PMCID: PMC3439871 DOI: 10.1093/pcp/pcs111] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Plant life is strongly dependent on the environment, and plants regulate their growth and development in response to many different environmental stimuli. One of the regulatory mechanisms involved in these responses is phototropism, which allows plants to change their growth direction in response to the location of the light source. Since the study of phototropism by Darwin, many physiological studies of this phenomenon have been published. Recently, molecular genetic analyses of Arabidopsis have begun to shed light on the molecular mechanisms underlying this response system, including phototropin blue light photoreceptors, phototropin signaling components, auxin transporters, auxin action mechanisms and others. This review highlights some of the recent progress that has been made in further elucidating the phototropic response, with particular emphasis on mutant phenotypes.
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Affiliation(s)
- Tatsuya Sakai
- Graduate School of Science and Technology, Niigata University, Nishi-ku, Niigata, 950-2181 Japan.
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42
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Kelley DR, Estelle M. Ubiquitin-mediated control of plant hormone signaling. PLANT PHYSIOLOGY 2012; 160:47-55. [PMID: 22723083 PMCID: PMC3440220 DOI: 10.1104/pp.112.200527] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 06/21/2012] [Indexed: 05/18/2023]
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43
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Arase F, Nishitani H, Egusa M, Nishimoto N, Sakurai S, Sakamoto N, Kaminaka H. IAA8 involved in lateral root formation interacts with the TIR1 auxin receptor and ARF transcription factors in Arabidopsis. PLoS One 2012; 7:e43414. [PMID: 22912871 PMCID: PMC3422273 DOI: 10.1371/journal.pone.0043414] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 07/20/2012] [Indexed: 11/18/2022] Open
Abstract
The expression of auxin-responsive genes is regulated by the TIR1/AFB auxin receptor-dependent degradation of Aux/IAA transcriptional repressors, which interact with auxin-responsive factors (ARFs). Most of the 29 Aux/IAA genes present in Arabidopsis have not been functionally characterized to date. IAA8 appears to have a distinct function from the other Aux/IAA genes, due to its unique transcriptional response to auxin and the stability of its encoded protein. In this study, we characterized the function of Arabidopsis IAA8 in various developmental processes governed by auxin and in the transcriptional regulation of the auxin response. Transgenic plants expressing estrogen-inducible IAA8 (XVE::IAA8) exhibited significantly fewer lateral roots than the wild type, and an IAA8 loss-of-function mutant exhibited significantly more. Ectopic overexpression of IAA8 resulted in abnormal gravitropism. The strong induction of early auxin-responsive marker genes by auxin treatment was delayed by IAA8 overexpression. GFP-fusion analysis revealed that IAA8 localized not only to the nucleus, but, in contrast to other Aux/IAAs, also to the cytosol. Furthermore, we demonstrated that IAA8 interacts with TIR1, in an auxin-dependent fashion, and with ARF proteins, both in yeast and in planta. Taken together, our results show that IAA8 is involved in lateral root formation, and that this process is regulated through the interaction with the TIR1 auxin receptor and ARF transcription factors in the nucleus.
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Affiliation(s)
- Fumi Arase
- Laboratory of Plant Molecular Biology, Faculty of Agriculture, Tottori University, Tottori, Japan
| | - Hiroko Nishitani
- Laboratory of Plant Molecular Biology, Faculty of Agriculture, Tottori University, Tottori, Japan
| | - Mayumi Egusa
- Laboratory of Plant Molecular Biology, Faculty of Agriculture, Tottori University, Tottori, Japan
| | - Nami Nishimoto
- Laboratory of Plant Molecular Biology, Faculty of Agriculture, Tottori University, Tottori, Japan
| | - Sumiko Sakurai
- Laboratory of Plant Molecular Biology, Faculty of Agriculture, Tottori University, Tottori, Japan
| | - Naho Sakamoto
- Laboratory of Plant Molecular Biology, Faculty of Agriculture, Tottori University, Tottori, Japan
| | - Hironori Kaminaka
- Laboratory of Plant Molecular Biology, Faculty of Agriculture, Tottori University, Tottori, Japan
- * E-mail:
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44
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Hu Y, Yang L, Na X, You J, Hu W, Liang X, Liu J, Mao L, Wang X, Wang H, Bi Y. Narciclasine inhibits the responses of Arabidopsis roots to auxin. PLANTA 2012; 236:597-612. [PMID: 22476291 DOI: 10.1007/s00425-012-1632-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Accepted: 03/22/2012] [Indexed: 05/31/2023]
Abstract
The plant hormone auxin plays a central role in the regulation of plant growth and development, as well as in responses to environmental stimuli. Narciclasine (NCS, an Amaryllidaceae alkaloid) isolated from Narcissus tazetta bulbs has a broad range of inhibitory effects on plants. In this study, the role of NCS in responses to auxin in Arabidopsis thaliana roots was investigated. We demonstrated the inhibitory effects of NCS on auxin-inducible lateral root formation, root hair formation, primary root growth, and the expression of primary auxin-inducible genes in Arabidopsis roots using DR5::GUS reporter gene, native auxin promoters (IAA12::GUS, IAA13::GUS), and quantitative reverse transcription PCR analysis. Results also showed that NCS did not affect the expression of cytokinin-inducible ARR5::GUS reporter gene. NCS relieved the auxin-enhanced degradation of the Aux/IAA repressor modulated by the SCFTIR1 ubiquitin-proteasome pathway. In addition, NCS did not alter the auxin-stimulated interaction between IAA7/AXR2 (Aux/IAA proteins) and the F-box protein TIR1 activity of the proteasome. Taken together, these results suggest that NCS acts on the auxin signaling pathway upstream of TIR1, which modulates Aux/IAA protein degradation, and thereby affects the auxin-mediated responses in Arabidopsis roots.
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Affiliation(s)
- Yanfeng Hu
- School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
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45
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Rosquete MR, Barbez E, Kleine-Vehn J. Cellular auxin homeostasis: gatekeeping is housekeeping. MOLECULAR PLANT 2012; 5:772-86. [PMID: 22199236 DOI: 10.1093/mp/ssr109] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The phytohormone auxin is essential for plant development and contributes to nearly every aspect of the plant life cycle. The spatio-temporal distribution of auxin depends on a complex interplay between auxin metabolism and cell-to-cell auxin transport. Auxin metabolism and transport are both crucial for plant development; however, it largely remains to be seen how these processes are integrated to ensure defined cellular auxin levels or even gradients within tissues or organs. In this review, we provide a glance at very diverse topics of auxin biology, such as biosynthesis, conjugation, oxidation, and transport of auxin. This broad, but certainly superficial, overview highlights the mutual importance of auxin metabolism and transport. Moreover, it allows pinpointing how auxin metabolism and transport get integrated to jointly regulate cellular auxin homeostasis. Even though these processes have been so far only separately studied, we assume that the phytohormonal crosstalk integrates and coordinates auxin metabolism and transport. Besides the integrative power of the global hormone signaling, we additionally introduce the hypothetical concept considering auxin transport components as gatekeepers for auxin responses.
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Affiliation(s)
- Michel Ruiz Rosquete
- Department of Applied Genetics and Cell Biology, University of Applied Life Sciences and Natural Resources (BOKU), 1190 Vienna, Austria
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46
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Hayashi KI. The interaction and integration of auxin signaling components. PLANT & CELL PHYSIOLOGY 2012; 53:965-75. [PMID: 22433459 DOI: 10.1093/pcp/pcs035] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
IAA, a naturally occurring auxin, is a simple signaling molecule that regulates many diverse steps of plant development. Auxin essentially coordinates plant development through transcriptional regulation. Auxin binds to TIR1/AFB nuclear receptors, which are F-box subunits of the SCF ubiquitin ligase complex. The auxin signal is then modulated by the quantitative and qualitative responses of the Aux/IAA repressors and the auxin response factor (ARF) transcription factors. The specificity of the auxin-regulated gene expression profile is defined by several factors, such as the expression of these regulatory proteins, their post-transcriptional regulation, their stability and the affinity between these regulatory proteins. Auxin-binding protein 1 (ABP1) is a candidate protein for an auxin receptor that is implicated in non-transcriptional auxin signaling. ABP1 also affects TIR1/AFB-mediated auxin-responsive gene expression, implying that both the ABP1 and TIR1/AFB signaling machineries coordinately control auxin-mediated physiological events. Systematic approaches using the comprehensive mapping of the expression and interaction of signaling modules and computational modeling would be valuable for integrating our knowledge of auxin signals and responses.
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Affiliation(s)
- Ken-ichiro Hayashi
- Department of Biochemistry, Okayama University of Science, Okayama, 700-0005 Japan.
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47
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Chapman EJ, Greenham K, Castillejo C, Sartor R, Bialy A, Sun TP, Estelle M. Hypocotyl transcriptome reveals auxin regulation of growth-promoting genes through GA-dependent and -independent pathways. PLoS One 2012; 7:e36210. [PMID: 22590525 PMCID: PMC3348943 DOI: 10.1371/journal.pone.0036210] [Citation(s) in RCA: 114] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Accepted: 03/28/2012] [Indexed: 12/24/2022] Open
Abstract
Many processes critical to plant growth and development are regulated by the hormone auxin. Auxin responses are initiated through activation of a transcriptional response mediated by the TIR1/AFB family of F-box protein auxin receptors as well as the AUX/IAA and ARF families of transcriptional regulators. However, there is little information on how auxin regulates a specific cellular response. To begin to address this question, we have focused on auxin regulation of cell expansion in the Arabidopsis hypocotyl. We show that auxin-mediated hypocotyl elongation is dependent upon the TIR1/AFB family of auxin receptors and degradation of AUX/IAA repressors. We also use microarray studies of elongating hypocotyls to show that a number of growth-associated processes are activated by auxin including gibberellin biosynthesis, cell wall reorganization and biogenesis, and others. Our studies indicate that GA biosynthesis is required for normal response to auxin in the hypocotyl but that the overall transcriptional auxin output consists of PIF-dependent and -independent genes. We propose that auxin acts independently from and interdependently with PIF and GA pathways to regulate expression of growth-associated genes in cell expansion.
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Affiliation(s)
- Elisabeth J. Chapman
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Kathleen Greenham
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Cristina Castillejo
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Ryan Sartor
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Agniezska Bialy
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Tai-ping Sun
- Biology Department, Duke University, Durham, North Carolina, United States of America
| | - Mark Estelle
- Howard Hughes Medical Institute, University of California San Diego, La Jolla, California, United States of America
- * E-mail:
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Terrile MC, París R, Calderón-Villalobos LIA, Iglesias MJ, Lamattina L, Estelle M, Casalongué CA. Nitric oxide influences auxin signaling through S-nitrosylation of the Arabidopsis TRANSPORT INHIBITOR RESPONSE 1 auxin receptor. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2012; 70:492-500. [PMID: 22171938 PMCID: PMC3324642 DOI: 10.1111/j.1365-313x.2011.04885.x] [Citation(s) in RCA: 220] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Previous studies have demonstrated that auxin (indole-3-acetic acid) and nitric oxide (NO) are plant growth regulators that coordinate several plant physiological responses determining root architecture. Nonetheless, the way in which these factors interact to affect these growth and developmental processes is not well understood. The Arabidopsis thaliana F-box proteins TRANSPORT INHIBITOR RESPONSE 1/AUXIN SIGNALING F-BOX (TIR1/AFB) are auxin receptors that mediate degradation of AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) repressors to induce auxin-regulated responses. A broad spectrum of NO-mediated protein modifications are known in eukaryotic cells. Here, we provide evidence that NO donors increase auxin-dependent gene expression while NO depletion blocks Aux/IAA protein degradation. NO also enhances TIR1-Aux/IAA interaction as evidenced by pull-down and two-hybrid assays. In addition, we provide evidence for NO-mediated modulation of auxin signaling through S-nitrosylation of the TIR1 auxin receptor. S-nitrosylation of cysteine is a redox-based post-translational modification that contributes to the complexity of the cellular proteome. We show that TIR1 C140 is a critical residue for TIR1-Aux/IAA interaction and TIR1 function. These results suggest that TIR1 S-nitrosylation enhances TIR1-Aux/IAA interaction, facilitating Aux/IAA degradation and subsequently promoting activation of gene expression. Our findings underline the importance of NO in phytohormone signaling pathways.
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Affiliation(s)
- María C. Terrile
- Instituto de Investigaciones Biológicas, UE-CONICET-UNMDP, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3250, CC 1245, 7600, Mar del Plata, Argentina
| | - Ramiro París
- Instituto de Investigaciones Biológicas, UE-CONICET-UNMDP, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3250, CC 1245, 7600, Mar del Plata, Argentina
| | | | - María J. Iglesias
- Instituto de Investigaciones Biológicas, UE-CONICET-UNMDP, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3250, CC 1245, 7600, Mar del Plata, Argentina
| | - Lorenzo Lamattina
- Instituto de Investigaciones Biológicas, UE-CONICET-UNMDP, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3250, CC 1245, 7600, Mar del Plata, Argentina
| | - Mark Estelle
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA92093
| | - Claudia A. Casalongué
- Instituto de Investigaciones Biológicas, UE-CONICET-UNMDP, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3250, CC 1245, 7600, Mar del Plata, Argentina
- Corresponding author: Claudia Anahí Casalongué, Instituto de Investigaciones Biológicas, Universidad Nacional de Mar del Plata, Funes 3250, CC 1245, 7600 Mar del Plata, Argentina, Phone: 54 223 4753030, FAX: 54 223 4724143,
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Villalobos LIAC, Lee S, De Oliveira C, Ivetac A, Brandt W, Armitage L, Sheard LB, Tan X, Parry G, Mao H, Zheng N, Napier R, Kepinski S, Estelle M. A combinatorial TIR1/AFB-Aux/IAA co-receptor system for differential sensing of auxin. Nat Chem Biol 2012; 8:477-85. [PMID: 22466420 PMCID: PMC3331960 DOI: 10.1038/nchembio.926] [Citation(s) in RCA: 394] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Accepted: 02/02/2012] [Indexed: 12/31/2022]
Abstract
The plant hormone auxin regulates virtually every aspect of plant growth and development. Auxin acts by binding the F-box protein transport inhibitor response 1 (TIR1) and promotes the degradation of the AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) transcriptional repressors. Here we show that efficient auxin binding requires assembly of an auxin co-receptor complex consisting of TIR1 and an Aux/IAA protein. Heterologous experiments in yeast and quantitative IAA binding assays using purified proteins showed that different combinations of TIR1 and Aux/IAA proteins form co-receptor complexes with a wide range of auxin-binding affinities. Auxin affinity seems to be largely determined by the Aux/IAA. As there are 6 TIR1/AUXIN SIGNALING F-BOX proteins (AFBs) and 29 Aux/IAA proteins in Arabidopsis thaliana, combinatorial interactions may result in many co-receptors with distinct auxin-sensing properties. We also demonstrate that the AFB5-Aux/IAA co-receptor selectively binds the auxinic herbicide picloram. This co-receptor system broadens the effective concentration range of the hormone and may contribute to the complexity of auxin response.
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Affiliation(s)
- Luz Irina A. Calderón Villalobos
- Section of Cell and Developmental Biology and Howard Hughes Medical Institute, University of California San Diego, La Jolla, California, USA
| | - Sarah Lee
- School of Life sciences, University of Warwick, CV35 9EF, UK
| | - Cesar De Oliveira
- Department of Chemistry & Biochemistry and Howard Hughes Medical Institute, University of California San Diego, La Jolla, California, USA
| | - Anthony Ivetac
- Department of Chemistry & Biochemistry and Howard Hughes Medical Institute, University of California San Diego, La Jolla, California, USA
| | - Wolfgang Brandt
- Bioorganic Chemistry Department, IPB-Leibniz Institute of Plant Biochemistry, Halle (Saale), Germany
| | - Lynne Armitage
- Centre for Plant Sciences, University of Leeds, Leeds, United Kingdom
| | - Laura B. Sheard
- Department of Pharmacology and Howard Hughes Medical Institute, University of Washington, School of Medicine, Seattle, Washington, USA
| | - Xu Tan
- Department of Pharmacology and Howard Hughes Medical Institute, University of Washington, School of Medicine, Seattle, Washington, USA
| | - Geraint Parry
- Section of Cell and Developmental Biology and Howard Hughes Medical Institute, University of California San Diego, La Jolla, California, USA
- Department of Plant Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Haibin Mao
- Department of Pharmacology and Howard Hughes Medical Institute, University of Washington, School of Medicine, Seattle, Washington, USA
| | - Ning Zheng
- Department of Pharmacology and Howard Hughes Medical Institute, University of Washington, School of Medicine, Seattle, Washington, USA
| | - Richard Napier
- School of Life sciences, University of Warwick, CV35 9EF, UK
| | - Stefan Kepinski
- Centre for Plant Sciences, University of Leeds, Leeds, United Kingdom
| | - Mark Estelle
- Section of Cell and Developmental Biology and Howard Hughes Medical Institute, University of California San Diego, La Jolla, California, USA
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Mithila J, McLean MD, Chen S, Christopher Hall J. Development of near-isogenic lines and identification of markers linked to auxinic herbicide resistance in wild mustard (Sinapis arvensis L.). PEST MANAGEMENT SCIENCE 2012; 68:548-556. [PMID: 22307875 DOI: 10.1002/ps.2289] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Revised: 08/23/2011] [Accepted: 08/23/2011] [Indexed: 05/31/2023]
Abstract
BACKGROUND Auxinic herbicides are widely used for selective control of many broadleaf weeds, e.g. wild mustard. An auxinic-herbicide-resistant wild mustard biotype may offer an excellent model system to elucidate the mechanism of action of these herbicides. Classical genetic analyses demonstrate that the wild mustard auxinic herbicide resistance is determined by a single dominant gene. Availability of near-isogenic lines (NILs) of wild mustard with auxinic herbicide resistance (R) and herbicide susceptibility (S) will help to study the fitness penalty as well as the precise characterization of this gene. RESULTS Eight generations of backcrosses were performed, and homozygous auxinic-herbicide-resistant and auxinic-herbicide-susceptible NILs were identified from BC(8) F(3) families. S plants produced significantly more biomass and seed compared with R plants, suggesting that wild mustard auxinic herbicide resistance may result in fitness reduction. It was also found that the serrated margin of the first true leaf was closely linked to auxinic herbicide resistance. Using the introgressed progeny, molecular markers linked to auxinic herbicide resistance were identified, and a genetic map was constructed. CONCLUSION The fitness penalty associated with the auxinic herbicide resistance gene may explain the relatively slow occurrence and spread of auxinic-herbicide-resistant weeds. The detection of the closely linked markers should hasten the identification and characterization of this gene.
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Affiliation(s)
- Jugulam Mithila
- School of Environmental Sciences, University of Guelph, Guelph, Ontario, Canada
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