1
|
Cho HT, Lee M, Choi HS, Maeng KH, Lee K, Lee HY, Ganguly A, Park H, Ho CH. A dose-dependent bimodal switch by homologous Aux/IAA transcriptional repressors. MOLECULAR PLANT 2024; 17:1407-1422. [PMID: 39095993 DOI: 10.1016/j.molp.2024.07.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Revised: 07/15/2024] [Accepted: 07/30/2024] [Indexed: 08/04/2024]
Abstract
Combinatorial interactions between different regulators diversify and enrich the chance of transcriptional regulation in eukaryotic cells. However, a dose-dependent functional switch of homologous transcriptional repressors has rarely been reported. Here, we show that SHY2, an auxin/indole-3-acetic acid (Aux/IAA) repressor, exhibits a dose-dependent bimodal role in auxin-sensitive root-hair growth and gene transcription in Arabidopsis, whereas other Aux/IAA homologs consistently repress the auxin responses. The co-repressor (TOPLESS [TPL])-binding affinity of a bimodal Aux/IAA was lower than that of a consistently repressing Aux/IAA. The switch of a single amino acid residue in the TPL-binding motif between the bimodal form and the consistently repressing form switched their TPL-binding affinity and transcriptional and biological roles in auxin responses. Based on these data, we propose a model whereby competition between homologous repressors with different co-repressor-binding affinities could generate a bimodal output at the transcriptional and developmental levels.
Collapse
Affiliation(s)
- Hyung-Taeg Cho
- Department of Biological Sciences, Seoul National University, Seoul, Korea.
| | - Minsu Lee
- Department of Biological Sciences, Seoul National University, Seoul, Korea
| | - Hee-Seung Choi
- Department of Biological Sciences, Seoul National University, Seoul, Korea
| | - Kwang-Ho Maeng
- Department of Biological Sciences, Seoul National University, Seoul, Korea
| | - Kyeonghoon Lee
- Department of Biological Sciences, Seoul National University, Seoul, Korea
| | - Ha-Yeon Lee
- Department of Biological Sciences, Seoul National University, Seoul, Korea
| | - Anindya Ganguly
- Department of Biological Sciences, Seoul National University, Seoul, Korea
| | - Hoonyoung Park
- School of Earth and Environmental Sciences, Seoul National University, Seoul, Korea
| | - Chang-Hoi Ho
- School of Earth and Environmental Sciences, Seoul National University, Seoul, Korea; Department of Climate and Energy Systems Engineering, Ewha Womans University, Seoul, Korea
| |
Collapse
|
2
|
Liu L, Yahaya BS, Li J, Wu F. Enigmatic role of auxin response factors in plant growth and stress tolerance. FRONTIERS IN PLANT SCIENCE 2024; 15:1398818. [PMID: 38903418 PMCID: PMC11188990 DOI: 10.3389/fpls.2024.1398818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Accepted: 05/23/2024] [Indexed: 06/22/2024]
Abstract
Abiotic and biotic stresses globally constrain plant growth and impede the optimization of crop productivity. The phytohormone auxin is involved in nearly every aspect of plant development. Auxin acts as a chemical messenger that influences gene expression through a short nuclear pathway, mediated by a family of specific DNA-binding transcription factors known as Auxin Response Factors (ARFs). ARFs thus act as effectors of auxin response and translate chemical signals into the regulation of auxin responsive genes. Since the initial discovery of the first ARF in Arabidopsis, advancements in genetics, biochemistry, genomics, and structural biology have facilitated the development of models elucidating ARF action and their contributions to generating specific auxin responses. Yet, significant gaps persist in our understanding of ARF transcription factors despite these endeavors. Unraveling the functional roles of ARFs in regulating stress response, alongside elucidating their genetic and molecular mechanisms, is still in its nascent phase. Here, we review recent research outcomes on ARFs, detailing their involvement in regulating leaf, flower, and root organogenesis and development, as well as stress responses and their corresponding regulatory mechanisms: including gene expression patterns, functional characterization, transcriptional, post-transcriptional and post- translational regulation across diverse stress conditions. Furthermore, we delineate unresolved questions and forthcoming challenges in ARF research.
Collapse
Affiliation(s)
- Ling Liu
- Faculty of Agriculture, Forestry and Food Engineering, Yibin University, Yibin, Sichuan, China
| | - Baba Salifu Yahaya
- Maize Research Institute, Sichuan Agricultural University, Wenjiang, Sichuan, China
- Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Ministry of Agriculture, Wenjiang, Sichuan, China
| | - Jing Li
- Maize Research Institute, Sichuan Agricultural University, Wenjiang, Sichuan, China
- Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Ministry of Agriculture, Wenjiang, Sichuan, China
| | - Fengkai Wu
- Maize Research Institute, Sichuan Agricultural University, Wenjiang, Sichuan, China
- Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Ministry of Agriculture, Wenjiang, Sichuan, China
| |
Collapse
|
3
|
Blanc-Mathieu R, Dumas R, Turchi L, Lucas J, Parcy F. Plant-TFClass: a structural classification for plant transcription factors. TRENDS IN PLANT SCIENCE 2024; 29:40-51. [PMID: 37482504 DOI: 10.1016/j.tplants.2023.06.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 06/26/2023] [Accepted: 06/27/2023] [Indexed: 07/25/2023]
Abstract
Transcription factors (TFs) bind DNA at specific sequences to regulate gene expression. This universal process is achieved via their DNA-binding domain (DBD). In mammals, the vast diversity of DBD structural conformations and the way in which they contact DNA has been used to organize TFs in the TFClass hierarchical classification. However, the numerous DBD types present in plants but absent from mammalian genomes were missing from this classification. We reviewed DBD 3D structures and models available for plant TFs to classify most of the 56 recognized plant TF types within the TFClass framework. This extended classification adds eight new classes and 37 new families corresponding to DBD structures absent in mammals. Plant-TFClass provides a unique resource for TF comparison across families and organisms.
Collapse
Affiliation(s)
- Romain Blanc-Mathieu
- Laboratoire Physiologie Cellulaire et Végétale, Université Grenoble Alpes, CNRS, CEA, INRAE, IRIG-DBSCI-LPCV, 17 Avenue des Martyrs, F-38054, Grenoble, France
| | - Renaud Dumas
- Laboratoire Physiologie Cellulaire et Végétale, Université Grenoble Alpes, CNRS, CEA, INRAE, IRIG-DBSCI-LPCV, 17 Avenue des Martyrs, F-38054, Grenoble, France
| | - Laura Turchi
- Laboratoire Physiologie Cellulaire et Végétale, Université Grenoble Alpes, CNRS, CEA, INRAE, IRIG-DBSCI-LPCV, 17 Avenue des Martyrs, F-38054, Grenoble, France
| | - Jérémy Lucas
- Laboratoire Physiologie Cellulaire et Végétale, Université Grenoble Alpes, CNRS, CEA, INRAE, IRIG-DBSCI-LPCV, 17 Avenue des Martyrs, F-38054, Grenoble, France
| | - François Parcy
- Laboratoire Physiologie Cellulaire et Végétale, Université Grenoble Alpes, CNRS, CEA, INRAE, IRIG-DBSCI-LPCV, 17 Avenue des Martyrs, F-38054, Grenoble, France.
| |
Collapse
|
4
|
Song Q, He F, Kong L, Yang J, Wang X, Zhao Z, Zhang Y, Xu C, Fan C, Luo K. The IAA17.1/HSFA5a module enhances salt tolerance in Populus tomentosa by regulating flavonol biosynthesis and ROS levels in lateral roots. THE NEW PHYTOLOGIST 2024; 241:592-606. [PMID: 37974487 DOI: 10.1111/nph.19382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 10/09/2023] [Indexed: 11/19/2023]
Abstract
Auxin signaling provides a promising approach to controlling root system architecture and improving stress tolerance in plants. However, how the auxin signaling is transducted in this process remains unclear. The Aux indole-3-acetic acid (IAA) repressor IAA17.1 is stabilized by salinity, and primarily expressed in the lateral root (LR) primordia and tips in poplar. Overexpression of the auxin-resistant form of IAA17.1 (IAA17.1m) led to growth inhibition of LRs, markedly reduced salt tolerance, increased reactive oxygen species (ROS) levels, and decreased flavonol content. We further identified that IAA17.1 can interact with the heat shock protein HSFA5a, which was highly expressed in roots and induced by salt stress. Overexpression of HSFA5a significantly increased flavonol content, reduced ROS accumulation, enhanced LR growth and salt tolerance in transgenic poplar. Moreover, HSFA5a could rescue the defective phenotypes caused by IAA17.1m. Expression analysis showed that genes associated with flavonol biosynthesis were altered in IAA17.1m- and HAFA5a-overexpressing plants. Furthermore, we identified that HSFA5a directly activated the expression of key enzyme genes in the flavonol biosynthesis pathway, while IAA17.1 suppressed HSFA5a-mediated activation of these genes. Collectively, the IAA17.1/HSFA5a module regulates flavonol biosynthesis, controls ROS accumulation, thereby modulating the root system of poplar to adapt to salt stress.
Collapse
Affiliation(s)
- Qin Song
- Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences, Southwest University, Chongqing, 400715, China
- Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Fu He
- Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences, Southwest University, Chongqing, 400715, China
- Key Laboratory of Three Gorges Regional Plant Genetics & Germplasm Enhancement (CTGU), Biotechnology Research Center, China Three Gorges University, Yichang, 443000, China
| | - Lingfei Kong
- Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences, Southwest University, Chongqing, 400715, China
- Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Jiarui Yang
- Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences, Southwest University, Chongqing, 400715, China
- Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Xiaojing Wang
- Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences, Southwest University, Chongqing, 400715, China
- Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Zhengjie Zhao
- Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences, Southwest University, Chongqing, 400715, China
- Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Yuqian Zhang
- Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences, Southwest University, Chongqing, 400715, China
- Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Changzheng Xu
- Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Chunfen Fan
- Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences, Southwest University, Chongqing, 400715, China
- Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Keming Luo
- Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences, Southwest University, Chongqing, 400715, China
- Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, 400715, China
| |
Collapse
|
5
|
Rienstra J, Hernández-García J, Weijers D. To bind or not to bind: how AUXIN RESPONSE FACTORs select their target genes. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:6922-6932. [PMID: 37431145 PMCID: PMC10690724 DOI: 10.1093/jxb/erad259] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 07/05/2023] [Indexed: 07/12/2023]
Abstract
Most plant growth and development processes are regulated in one way or another by auxin. The best-studied mechanism by which auxin exerts its regulatory effects is through the nuclear auxin pathway (NAP). In this pathway, Auxin Response Factors (ARFs) are the transcription factors that ultimately determine which genes become auxin regulated by binding to specific DNA sequences. ARFs have primarily been studied in Arabidopsis thaliana, but recent studies in other species have revealed family-wide DNA binding specificities for different ARFs and the minimal functional system of the NAP system, consisting of a duo of competing ARFs of the A and B classes. In this review, we provide an overview of key aspects of ARF DNA binding such as auxin response elements (TGTCNN) and tandem repeat motifs, and consider how structural biology and in vitro studies help us understand ARF DNA preferences. We also highlight some recent aspects related to the regulation of ARF levels inside a cell, which may alter the DNA binding profile of ARFs in different tissues. We finally emphasize the need to study minimal NAP systems to understand fundamental aspects of ARF function, the need to characterize algal ARFs to understand how ARFs evolved, how cutting-edge techniques can increase our understanding of ARFs, and which remaining questions can only be answered by structural biology.
Collapse
Affiliation(s)
- Juriaan Rienstra
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, 6708WE Wageningen, The Netherlands
| | - Jorge Hernández-García
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, 6708WE Wageningen, The Netherlands
| | - Dolf Weijers
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, 6708WE Wageningen, The Netherlands
| |
Collapse
|
6
|
Jing H, Strader LC. AUXIN RESPONSE FACTOR protein accumulation and function. Bioessays 2023; 45:e2300018. [PMID: 37584215 PMCID: PMC10592145 DOI: 10.1002/bies.202300018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 08/02/2023] [Accepted: 08/07/2023] [Indexed: 08/17/2023]
Abstract
Auxin is a key regulator of plant developmental processes. Its effects on transcription are mediated by the AUXIN RESPONSE FACTOR (ARF) family of transcription factors. ARFs tightly control specific auxin responses necessary for proper plant growth and development. Recent research has revealed that regulated ARF protein accumulation and ARF nucleo-cytoplasmic partitioning can determine auxin transcriptional outputs. In this review, we explore these recent findings and consider the potential for regulated ARF accumulation in driving auxin responses in plants.
Collapse
Affiliation(s)
- Hongwei Jing
- Department of Biology, Duke University, Durham, NC 27008, USA
| | | |
Collapse
|
7
|
Ramans-Harborough S, Kalverda AP, Manfield IW, Thompson GS, Kieffer M, Uzunova V, Quareshy M, Prusinska JM, Roychoudhry S, Hayashi KI, Napier R, del Genio C, Kepinski S. Intrinsic disorder and conformational coexistence in auxin coreceptors. Proc Natl Acad Sci U S A 2023; 120:e2221286120. [PMID: 37756337 PMCID: PMC10556615 DOI: 10.1073/pnas.2221286120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 07/17/2023] [Indexed: 09/29/2023] Open
Abstract
AUXIN/INDOLE 3-ACETIC ACID (Aux/IAA) transcriptional repressor proteins and the TRANSPORT INHIBITOR RESISTANT 1/AUXIN SIGNALING F-BOX (TIR1/AFB) proteins to which they bind act as auxin coreceptors. While the structure of TIR1 has been solved, structural characterization of the regions of the Aux/IAA protein responsible for auxin perception has been complicated by their predicted disorder. Here, we use NMR, CD and molecular dynamics simulation to investigate the N-terminal domains of the Aux/IAA protein IAA17/AXR3. We show that despite the conformational flexibility of the region, a critical W-P bond in the core of the Aux/IAA degron motif occurs at a strikingly high (1:1) ratio of cis to trans isomers, consistent with the requirement of the cis conformer for the formation of the fully-docked receptor complex. We show that the N-terminal half of AXR3 is a mixture of multiple transiently structured conformations with a propensity for two predominant and distinct conformational subpopulations within the overall ensemble. These two states were modeled together with the C-terminal PB1 domain to provide the first complete simulation of an Aux/IAA. Using MD to recreate the assembly of each complex in the presence of auxin, both structural arrangements were shown to engage with the TIR1 receptor, and contact maps from the simulations match closely observations of NMR signal-decreases. Together, our results and approach provide a platform for exploring the functional significance of variation in the Aux/IAA coreceptor family and for understanding the role of intrinsic disorder in auxin signal transduction and other signaling systems.
Collapse
Affiliation(s)
- Sigurd Ramans-Harborough
- School of Biology, Faculty of Biological Sciences, University of Leeds, LeedsLS2 9JT, United Kingdom
| | - Arnout P. Kalverda
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, LeedsLS2 9JT, United Kingdom
| | - Iain W. Manfield
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, LeedsLS2 9JT, United Kingdom
| | - Gary S. Thompson
- Wellcome Biological Nuclear Magnetic Resonance Facility, Division of Natural Sciences, University of Kent, CanterburyCT2 7NJ, United Kingdom
| | - Martin Kieffer
- School of Biology, Faculty of Biological Sciences, University of Leeds, LeedsLS2 9JT, United Kingdom
| | - Veselina Uzunova
- School of Life Sciences, University of Warwick, CoventryCV4 7AL, United Kingdom
| | - Mussa Quareshy
- School of Life Sciences, University of Warwick, CoventryCV4 7AL, United Kingdom
| | | | - Suruchi Roychoudhry
- School of Biology, Faculty of Biological Sciences, University of Leeds, LeedsLS2 9JT, United Kingdom
| | - Ken-ichiro Hayashi
- Department of Bioscience, Okayama University of Science, Okayama700-0005, Japan
| | - Richard Napier
- School of Life Sciences, University of Warwick, CoventryCV4 7AL, United Kingdom
| | - Charo del Genio
- Centre for Fluid and Complex Systems, Coventry University, CoventryCV1 5FB, United Kingdom
| | - Stefan Kepinski
- School of Biology, Faculty of Biological Sciences, University of Leeds, LeedsLS2 9JT, United Kingdom
| |
Collapse
|
8
|
Sun N, Hu J, Li C, Wang X, Gai Y, Jiang X. Fusion gene 4CL-CCR promotes lignification in tobacco suspension cells. PLANT CELL REPORTS 2023; 42:939-952. [PMID: 36964306 DOI: 10.1007/s00299-023-03002-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 03/03/2023] [Indexed: 05/06/2023]
Abstract
KEY MESSAGE The fusion gene 4CL-CCR promotes lignification and activates lignin-related MYB expression in tobacco but inhibits auxin-related gene expression and hinders the auxin absorption of cells. Given the importance of lignin polymers in plant growth and their industrial value, it is necessary to investigate how plants synthesize monolignols and regulate the level of lignin in cell walls. In our previous study, expression of the Populus tomentosa fusion gene 4CL-CCR significantly promoted the production of 4-hydroxycinnamyl alcohols. However, the function of 4CL-CCR in organisms remains poorly understood. In this study, the fusion gene 4CL-CCR was heterologously expressed in tobacco suspension cells. We found that the transgenic suspension cells exhibited lignification earlier. Furthermore, 4CL-CCR significantly reduced the content of phenolic acids and increased the content of aldehydes in the medium, which led to an increase in lignin deposition. Moreover, transcriptome results showed that the genes related to lignin synthesis, such as PAL, 4CL, CCoAOMT and CAD, were significantly upregulated in the 4CL-CCR group. The expression of genes related to auxin, such as ARF3, ARF5 and ARF6, was significantly downregulated. The downregulation of auxin affected the expression of transcription factor MYBs. We hypothesize that the upregulated genes MYB306 and MYB315 are involved in the regulation of cell morphogenesis and lignin biosynthesis and eventually enhance lignification in tobacco suspension cells. Our findings provide insight into the function of 4CL-CCR in lignification and how secondary cell walls are formed in plants.
Collapse
Affiliation(s)
- Nan Sun
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology , Beijing Forestry University, Beijing, 100083, China
- The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, Beijing, 100083, China
| | - Jiaqi Hu
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology , Beijing Forestry University, Beijing, 100083, China
- The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, Beijing, 100083, China
| | - Can Li
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology , Beijing Forestry University, Beijing, 100083, China
- The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, Beijing, 100083, China
| | - Xuechun Wang
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology , Beijing Forestry University, Beijing, 100083, China
- The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, Beijing, 100083, China
| | - Ying Gai
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology , Beijing Forestry University, Beijing, 100083, China.
- The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, Beijing, 100083, China.
| | - Xiangning Jiang
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology , Beijing Forestry University, Beijing, 100083, China.
- The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, Beijing, 100083, China.
| |
Collapse
|
9
|
Caumon H, Vernoux T. A matter of time: auxin signaling dynamics and the regulation of auxin responses during plant development. JOURNAL OF EXPERIMENTAL BOTANY 2023:erad132. [PMID: 37042516 DOI: 10.1093/jxb/erad132] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Indexed: 06/19/2023]
Abstract
As auxin is a major regulator of plant development, studying the signaling mechanisms by which auxin influences cellular activities is of primary importance. In this review, we describe the current knowledge on the different modalities of signaling, from the well-characterized canonical nuclear auxin pathway, to the more recently discovered or re-discovered non-canonical modes of auxin signaling. In particular, we discuss how both the modularity of the nuclear auxin pathway and the dynamic regulation of its core components allow to trigger specific transcriptomic responses. We highlight the fact that the diversity of modes of auxin signaling allows for a wide range of timescales of auxin responses, from second-scale cytoplasmic responses to minute/hour-scale modifications of gene expression. Finally, we question the extent to which the temporality of auxin signaling and responses contributes to development in both the shoot and the root meristems. We conclude by stressing the fact that future investigations should allow to build an integrative view not only of the spatial control, but also of the temporality of auxin-mediated regulation of plant development, from the cell to the whole organism.
Collapse
Affiliation(s)
- Hugo Caumon
- Laboratoire Reproduction et Développement des Plantes, Univ Lyon, ENS de Lyon, CNRS, INRAE, F-69342, Lyon, France
| | - Teva Vernoux
- Laboratoire Reproduction et Développement des Plantes, Univ Lyon, ENS de Lyon, CNRS, INRAE, F-69342, Lyon, France
| |
Collapse
|
10
|
Cancé C, Martin-Arevalillo R, Boubekeur K, Dumas R. Auxin response factors are keys to the many auxin doors. THE NEW PHYTOLOGIST 2022; 235:402-419. [PMID: 35434800 DOI: 10.1111/nph.18159] [Citation(s) in RCA: 51] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 03/22/2022] [Indexed: 06/14/2023]
Abstract
In plants, most developmental programs depend on the action of auxin. The best described model of the auxin signaling pathway, which explains most, but not all, of the auxin transcriptional responses, relies on a de-repression mechanism. The auxin/indole-3-acetic acid repressors (Aux/IAAs) interact with the auxin response factors (ARFs), the transcription factors of the auxin signaling pathway, leading to repression of the ARF-controlled genes. Auxin induces Aux/IAA degradation, releases ARFs and activates transcription. However, this elegant model is not suitable for all ARFs. Indeed, in Arabidopsis, which has 22 ARFs, only five of them fit into the model since they are the ones able to interact with Aux/IAAs. The remaining 17 have a limited capacity to interact with the repressors, and their mechanisms of action are still unclear. The differential interactions between ARF and Aux/IAA proteins constitute one of many examples of the biochemical and structural diversification of ARFs that affect their action and therefore affect auxin transcriptional responses. A deeper understanding of the structural properties of ARFs is fundamental to obtaining a better explanation of the action of auxin in plants.
Collapse
Affiliation(s)
- Coralie Cancé
- Univ. Grenoble Alpes, CNRS, CEA, INRAE, IRIG-DBSCI-LPCV, 38000, Grenoble, France
| | - Raquel Martin-Arevalillo
- Laboratoire de Reproduction et Développement des Plantes, ENS de Lyon, UCB Lyon 1, CNRS, INRA, Univ. Lyon, Lyon, France
| | - Kenza Boubekeur
- Univ. Grenoble Alpes, CNRS, CEA, INRAE, IRIG-DBSCI-LPCV, 38000, Grenoble, France
| | - Renaud Dumas
- Univ. Grenoble Alpes, CNRS, CEA, INRAE, IRIG-DBSCI-LPCV, 38000, Grenoble, France
| |
Collapse
|
11
|
Al-Saharin R, Hellmann H, Mooney S. Plant E3 Ligases and Their Role in Abiotic Stress Response. Cells 2022; 11:cells11050890. [PMID: 35269512 PMCID: PMC8909703 DOI: 10.3390/cells11050890] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 02/24/2022] [Accepted: 03/02/2022] [Indexed: 11/16/2022] Open
Abstract
Plants, as sessile organisms, have limited means to cope with environmental changes. Consequently, they have developed complex regulatory systems to ameliorate abiotic stresses im-posed by environmental changes. One such system is the ubiquitin proteasome pathway, which utilizes E3 ligases to target proteins for proteolytic degradation via the 26S proteasome. Plants ex-press a plethora of E3 ligases that are categorized into four major groups depending on their structure. They are involved in many biological and developmental processes in plants, such as DNA repair, photomorphogenesis, phytohormones signaling, and biotic stress. Moreover, many E3 ligase targets are proteins involved in abiotic stress responses, such as salt, drought, heat, and cold. In this review, we will provide a comprehensive overview of E3 ligases and their substrates that have been connected with abiotic stress in order to illustrate the diversity and complexity of how this pathway enables plant survival under stress conditions.
Collapse
Affiliation(s)
- Raed Al-Saharin
- Department of Applied Biology, Tafila Technical University, At-Tafilah 66110, Jordan
- Correspondence:
| | - Hanjo Hellmann
- School of Biological Sciences, Washington State University, Pullman, WA 99163, USA; (H.H.); (S.M.)
| | - Sutton Mooney
- School of Biological Sciences, Washington State University, Pullman, WA 99163, USA; (H.H.); (S.M.)
| |
Collapse
|
12
|
Abstract
Auxin signaling regulates growth and developmental processes in plants. The core of nuclear auxin signaling relies on just three components: TIR1/AFBs, Aux/IAAs, and ARFs. Each component is itself made up of several domains, all of which contribute to the regulation of auxin signaling. Studies of the structural aspects of these three core signaling components have deepened our understanding of auxin signaling dynamics and regulation. In addition to the structured domains of these components, intrinsically disordered regions within the proteins also impact auxin signaling outcomes. New research is beginning to uncover the role intrinsic disorder plays in auxin-regulated degradation and subcellular localization. Structured and intrinsically disordered domains affect auxin perception, protein degradation dynamics, and DNA binding. Taken together, subtle differences within the domains and motifs of each class of auxin signaling component affect signaling outcomes and specificity.
Collapse
Affiliation(s)
- Nicholas Morffy
- Department of Biology, Duke University, Durham, North Carolina 27708, USA
- Center for Science and Engineering Living Systems (CSELS), Washington University, St. Louis, Missouri 63130, USA
| | - Lucia C Strader
- Department of Biology, Duke University, Durham, North Carolina 27708, USA
- Center for Science and Engineering Living Systems (CSELS), Washington University, St. Louis, Missouri 63130, USA
- Center for Engineering Mechanobiology, Washington University, St. Louis, Missouri 63130, USA
| |
Collapse
|
13
|
Jia M, Li Y, Wang Z, Tao S, Sun G, Kong X, Wang K, Ye X, Liu S, Geng S, Mao L, Li A. TaIAA21 represses TaARF25-mediated expression of TaERFs required for grain size and weight development in wheat. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 108:1754-1767. [PMID: 34643010 DOI: 10.1111/tpj.15541] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 09/28/2021] [Accepted: 10/05/2021] [Indexed: 05/02/2023]
Abstract
Auxin signaling is essential for the development of grain size and grain weight, two important components for crop yield. However, no auxin/indole acetic acid repressor (Aux/IAA) has been functionally characterized to be involved in the development of wheat (Triticum aestivum L.) grains to date. Here, we identified a wheat Aux/IAA gene, TaIAA21, and studied its regulatory pathway. We found that TaIAA21 mutation significantly increased grain length, grain width, and grain weight. Cross-sections of mutant grains revealed elongated outer pericarp cells compared to those of the wild type, where the expression of TaIAA21 was detected by in situ hybridization. Screening of auxin response factor (ARF) genes highly expressed in early developing grains revealed that TaARF25 interacts with TaIAA21. In contrast, mutation of the tetraploid wheat (Triticum turgidum) ARF25 gene significantly reduced grain size and weight. RNA sequencing analysis revealed upregulation of several ethylene response factor genes (ERFs) in taiaa21 mutants which carried auxin response cis-elements in their promoter. One of them, ERF3, was upregulated in the taiaa21 mutant and downregulated in the ttarf25 mutant. Transactivation assays showed that ARF25 promotes ERF3 transcription, while mutation of TtERF3 resulted in reduced grain size and weight. Analysis of natural variations identified three TaIAA21-A haplotypes with increased allele frequencies in cultivars relative to landraces, a signature of breeding selection. Our work demonstrates that TaIAA21 works as a negative regulator of grain size and weight development via the ARF25-ERFs module and is useful for yield improvement in wheat.
Collapse
Affiliation(s)
- Meiling Jia
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Yanan Li
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Zhenyu Wang
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Shu Tao
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Guoliang Sun
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Xingchen Kong
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Ke Wang
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Xingguo Ye
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Shaoshuai Liu
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Shuaifeng Geng
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Long Mao
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Aili Li
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| |
Collapse
|
14
|
Abstract
Auxin regulates the transcription of auxin-responsive genes by the TIR1/AFBs-Aux/IAA-ARF signaling pathway, and in this way facilitates plant growth and development. However, rapid, nontranscriptional responses to auxin that cannot be explained by this pathway have been reported. In this review, we focus on several examples of rapid auxin responses: (1) the triggering of changes in plasma membrane potential in various plant species and tissues, (2) inhibition of root growth, which also correlates with membrane potential changes, cytosolic Ca2+ spikes, and a rise of apoplastic pH, (3) the influence on endomembrane trafficking of PIN proteins and other membrane cargoes, and (4) activation of ROPs (Rho of plants) and their downstream effectors such as the cytoskeleton or vesicle trafficking. In most cases, the signaling pathway triggering the response is poorly understood. A role for the TIR1/AFBs in rapid root growth regulation is emerging, as well as the involvement of transmembrane kinases (TMKs) in the activation of ROPs. We discuss similarities and differences among these rapid responses and focus on their physiological significance, which remains an enigma in most cases.
Collapse
|
15
|
Jaeger R, Moody LA. A fundamental developmental transition in Physcomitrium patens is regulated by evolutionarily conserved mechanisms. Evol Dev 2021; 23:123-136. [PMID: 33822471 DOI: 10.1111/ede.12376] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 03/09/2021] [Accepted: 03/11/2021] [Indexed: 01/15/2023]
Abstract
One of the most defining moments in history was the colonization of land by plants approximately 470 million years ago. The transition from water to land was accompanied by significant changes in the plant body plan, from those than resembled filamentous representatives of the charophytes, the sister group to land plants, to those that were morphologically complex and capable of colonizing harsher habitats. The moss Physcomitrium patens (also known as Physcomitrella patens) is an extant representative of the bryophytes, the earliest land plant lineage. The protonema of P. patens emerges from spores from a chloronemal initial cell, which can divide to self-renew to produce filaments of chloronemal cells. A chloronemal initial cell can differentiate into a caulonemal initial cell, which can divide and self-renew to produce filaments of caulonemal cells, which branch extensively and give rise to three-dimensional shoots. The process by which a chloronemal initial cell differentiates into a caulonemal initial cell is tightly regulated by auxin-induced remodeling of the actin cytoskeleton. Studies have revealed that the genetic mechanisms underpinning this transition also regulate tip growth and differentiation in diverse plant taxa. This review summarizes the known cellular and molecular mechanisms underpinning the chloronema to caulonema transition in P. patens.
Collapse
Affiliation(s)
- Richard Jaeger
- Department of Plant Sciences, University of Oxford, Oxford, UK
| | - Laura A Moody
- Department of Plant Sciences, University of Oxford, Oxford, UK
| |
Collapse
|
16
|
IAA3-mediated repression of PIF proteins coordinates light and auxin signaling in Arabidopsis. PLoS Genet 2021; 17:e1009384. [PMID: 33600444 PMCID: PMC7924758 DOI: 10.1371/journal.pgen.1009384] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 03/02/2021] [Accepted: 01/29/2021] [Indexed: 11/20/2022] Open
Abstract
The exogenous light signal and endogenous auxin are two critical factors that antagonistically regulate hypocotyl growth. However, the regulatory mechanisms integrating light and auxin signaling pathways need further investigation. In this study, we identified a direct link between the light and auxin signaling pathways mediated by the auxin transcriptional repressor IAA3 and light-controlled PIF transcription factors in Arabidopsis. The gain-of-function mutation in IAA3 caused hyposensitivity to light, whereas disruption of IAA3 led to an elongated hypocotyl under different light intensity conditions, indicating that IAA3 is required in light regulated hypocotyl growth. Genetic studies showed that the function of IAA3 in hypocotyl elongation is dependent on PIFs. Our data further demonstrated that IAA3 interacts with PIFs in vitro and in vivo, and it attenuates the DNA binding activities of PIFs to the target genes. Moreover, IAA3 negatively regulates the expression of PIFs-dependent genes. Collectively, our study reveals an interplay mechanism of light and auxin on the regulation of hypocotyl growth, coordinated by the IAA3 and PIFs transcriptional regulatory module. Sessile plants integrate environmental and endogenous signals to optimize their growth and development. Hypocotyl growth is a crucial developmental process tightly affected by light and auxin, but the underlying mechanism is still not well understood. Here, we demonstrate that the IAA3, a suppressor in auxin signaling, negatively regulates the light signaling regulator PIF protein activities. The IAA3 gain-of-function mutant displays reduced responses to light, while disruption of IAA3 results in elongated hypocotyl under various light intensity conditions. Genetic studies showed that IAA3 functions through PIFs to regulate hypocotyl growth. IAA3 physically interacts with PIFs through its C-terminal region and inhibits PIFs binding to target genes. Furthermore, IAA3 and PIFs coregulated a subset of downstream genes. The IAA3-PIFs interaction represents a novel layer of the regulatory mechanism by which light and auxin signals are integrated to affect hypocotyl growth.
Collapse
|
17
|
Favero DS, Lambolez A, Sugimoto K. Molecular pathways regulating elongation of aerial plant organs: a focus on light, the circadian clock, and temperature. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 105:392-420. [PMID: 32986276 DOI: 10.1111/tpj.14996] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 09/11/2020] [Accepted: 09/15/2020] [Indexed: 06/11/2023]
Abstract
Organs such as hypocotyls and petioles rapidly elongate in response to shade and temperature cues, contributing to adaptive responses that improve plant fitness. Growth plasticity in these organs is achieved through a complex network of molecular signals. Besides conveying information from the environment, this signaling network also transduces internal signals, such as those associated with the circadian clock. A number of studies performed in Arabidopsis hypocotyls, and to a lesser degree in petioles, have been informative for understanding the signaling networks that regulate elongation of aerial plant organs. In particular, substantial progress has been made towards understanding the molecular mechanisms that regulate responses to light, the circadian clock, and temperature. Signals derived from these three stimuli converge on the BAP module, a set of three different types of transcription factors that interdependently promote gene transcription and growth. Additional key positive regulators of growth that are also affected by environmental cues include the CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) and SUPPRESSOR OF PHYA-105 (SPA) E3 ubiquitin ligase proteins. In this review we summarize the key signaling pathways that regulate the growth of hypocotyls and petioles, focusing specifically on molecular mechanisms important for transducing signals derived from light, the circadian clock, and temperature. While it is clear that similarities abound between the signaling networks at play in these two organs, there are also important differences between the mechanisms regulating growth in hypocotyls and petioles.
Collapse
Affiliation(s)
- David S Favero
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan
| | - Alice Lambolez
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan
- Department of Biological Sciences, The University of Tokyo, Tokyo, 119-0033, Japan
| | - Keiko Sugimoto
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan
- Department of Biological Sciences, The University of Tokyo, Tokyo, 119-0033, Japan
| |
Collapse
|
18
|
Todd OE, Figueiredo MRA, Morran S, Soni N, Preston C, Kubeš MF, Napier R, Gaines TA. Synthetic auxin herbicides: finding the lock and key to weed resistance. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2020; 300:110631. [PMID: 33180710 DOI: 10.1016/j.plantsci.2020.110631] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/17/2020] [Accepted: 08/03/2020] [Indexed: 06/11/2023]
Abstract
Synthetic auxin herbicides are designed to mimic indole-3-acetic acid (IAA), an integral plant hormone affecting cell growth, development, and tropism. In this review, we explore target site genes in the auxin signaling pathway including SCFTIR1/AFB, Aux/IAA, and ARFs that are confirmed or proposed mechanisms for weed resistance to synthetic auxin herbicides. Resistance to auxin herbicides by metabolism, either by enhanced cytochrome P450 detoxification or by loss of pro-herbicide activation, is a major non-target-site resistance pathway. We speculate about potential fitness costs of resistance due to effects of resistance-conferring mutations, provide insight into the role of polyploidy in synthetic auxin resistance evolution, and address the genetic resources available for weeds. This knowledge will be the key to unlock the long-standing questions as to which components of the auxin signaling pathway are most likely to have a role in resistance evolution. We propose that an ambitious research effort into synthetic auxin herbicide/target site interactions is needed to 1) explain why some synthetic auxin chemical families have activity on certain dicot plant families but not others and 2) fully elucidate target-site cross-resistance patterns among synthetic auxin chemical families to guide best practices for resistance management.
Collapse
Affiliation(s)
- Olivia E Todd
- Department of Agricultural Biology, 1177 Campus Delivery, Colorado State University, Fort Collins, CO 80525, USA.
| | - Marcelo R A Figueiredo
- Department of Agricultural Biology, 1177 Campus Delivery, Colorado State University, Fort Collins, CO 80525, USA.
| | - Sarah Morran
- Department of Agricultural Biology, 1177 Campus Delivery, Colorado State University, Fort Collins, CO 80525, USA.
| | - Neeta Soni
- Department of Agricultural Biology, 1177 Campus Delivery, Colorado State University, Fort Collins, CO 80525, USA.
| | - Christopher Preston
- School of Agriculture, Food and Wine, University of Adelaide, Glen Osmond, SA, 5005, Australia.
| | - Martin F Kubeš
- School of Life Sciences, The University of Warwick, Coventry, CV4 7AL, UK.
| | - Richard Napier
- School of Life Sciences, The University of Warwick, Coventry, CV4 7AL, UK.
| | - Todd A Gaines
- Department of Agricultural Biology, 1177 Campus Delivery, Colorado State University, Fort Collins, CO 80525, USA.
| |
Collapse
|
19
|
Determinants of PB1 Domain Interactions in Auxin Response Factor ARF5 and Repressor IAA17. J Mol Biol 2020; 432:4010-4022. [PMID: 32305460 DOI: 10.1016/j.jmb.2020.04.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 04/08/2020] [Accepted: 04/08/2020] [Indexed: 02/06/2023]
Abstract
Auxin is a plant hormone that is central to plant growth and development from embryogenesis to senescence. Auxin signaling is mediated by auxin response transcription factors (ARFs) and Aux/IAA repressors that regulate the expression of a multitude of auxin response genes. ARF and Aux/IAA proteins assemble into homomeric and heteromeric complexes via their conserved PB1 domains. Here we report the first crystal structure of the PB1 complex between ARF5 and IAA17 of Arabidopsis thaliana, which represents the transcriptionally repressed state at low auxin levels. The PB1 domains assemble in a head-to-tail manner with a backbone arrangement similar to that of the ARF5:ARF5 PB1 complex. The ARF5:IAA17 complex, however, reveals distinct points of contact that promote the ARF5:IAA17 interaction over the ARF5:ARF5 interaction. Specifically, surface charges at the interface form salt-bridges that distinguish the homomeric and heteromeric complexes, revealing common and specific interfaces between transcriptionally repressed and derepressed states. Further, the salt-bridges can be reconfigured to switch the affinity between homomeric and heteromeric complexes in an incremental manner. The complex structure combined with quantitative binding analyses would be essential for deciphering the PB1 interaction code underlying the transcriptional regulation of auxin signaling.
Collapse
|
20
|
Niemeyer M, Moreno Castillo E, Ihling CH, Iacobucci C, Wilde V, Hellmuth A, Hoehenwarter W, Samodelov SL, Zurbriggen MD, Kastritis PL, Sinz A, Calderón Villalobos LIA. Flexibility of intrinsically disordered degrons in AUX/IAA proteins reinforces auxin co-receptor assemblies. Nat Commun 2020; 11:2277. [PMID: 32385295 PMCID: PMC7210949 DOI: 10.1038/s41467-020-16147-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 04/17/2020] [Indexed: 12/31/2022] Open
Abstract
Cullin RING-type E3 ubiquitin ligases SCFTIR1/AFB1-5 and their AUX/IAA targets perceive the phytohormone auxin. The F-box protein TIR1 binds a surface-exposed degron in AUX/IAAs promoting their ubiquitylation and rapid auxin-regulated proteasomal degradation. Here, by adopting biochemical, structural proteomics and in vivo approaches we unveil how flexibility in AUX/IAAs and regions in TIR1 affect their conformational ensemble allowing surface accessibility of degrons. We resolve TIR1·auxin·IAA7 and TIR1·auxin·IAA12 complex topology, and show that flexible intrinsically disordered regions (IDRs) in the degron’s vicinity, cooperatively position AUX/IAAs on TIR1. We identify essential residues at the TIR1 N- and C-termini, which provide non-native interaction interfaces with IDRs and the folded PB1 domain of AUX/IAAs. We thereby establish a role for IDRs in modulating auxin receptor assemblies. By securing AUX/IAAs on two opposite surfaces of TIR1, IDR diversity supports locally tailored positioning for targeted ubiquitylation, and might provide conformational flexibility for a multiplicity of functional states. Auxin-mediated recruitment of AUX/IAAs by the F-box protein TIR1 prompts rapid AUX/IAA ubiquitylation and degradation. By resolving auxin receptor topology, the authors show that intrinsically disordered regions near the degrons of two Aux/IAA proteins reinforce complex assembly and position Aux/IAAs for ubiquitylation.
Collapse
Affiliation(s)
- Michael Niemeyer
- Molecular Signal Processing Department, Leibniz Institute of Plant Biochemistry (IPB), Weinberg 3, 06120, Halle (Saale), Germany
| | - Elena Moreno Castillo
- Molecular Signal Processing Department, Leibniz Institute of Plant Biochemistry (IPB), Weinberg 3, 06120, Halle (Saale), Germany
| | - Christian H Ihling
- Department of Pharmaceutical Chemistry & Bioanalytics, Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Charles Tanford Protein Center, Kurt-Mothes-Straße 3a, 06120, Halle (Saale), Germany
| | - Claudio Iacobucci
- Department of Pharmaceutical Chemistry & Bioanalytics, Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Charles Tanford Protein Center, Kurt-Mothes-Straße 3a, 06120, Halle (Saale), Germany
| | - Verona Wilde
- Molecular Signal Processing Department, Leibniz Institute of Plant Biochemistry (IPB), Weinberg 3, 06120, Halle (Saale), Germany
| | - Antje Hellmuth
- Molecular Signal Processing Department, Leibniz Institute of Plant Biochemistry (IPB), Weinberg 3, 06120, Halle (Saale), Germany
| | - Wolfgang Hoehenwarter
- Proteome Analytics, Leibniz Institute of Plant Biochemistry (IPB), Weinberg 3, 06120, Halle (Saale), Germany
| | - Sophia L Samodelov
- Institute of Synthetic Biology & Cluster of Excellence on Plant Science (CEPLAS), Heinrich-Heine University of Düsseldorf, Universitätsstrasse 1, 40225, Düsseldorf, Germany
| | - Matias D Zurbriggen
- Institute of Synthetic Biology & Cluster of Excellence on Plant Science (CEPLAS), Heinrich-Heine University of Düsseldorf, Universitätsstrasse 1, 40225, Düsseldorf, Germany
| | - Panagiotis L Kastritis
- ZIK HALOMEM & Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Biozentrum, Weinbergweg 22, 06120, Halle (Saale), Germany
| | - Andrea Sinz
- Department of Pharmaceutical Chemistry & Bioanalytics, Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Charles Tanford Protein Center, Kurt-Mothes-Straße 3a, 06120, Halle (Saale), Germany
| | - Luz Irina A Calderón Villalobos
- Molecular Signal Processing Department, Leibniz Institute of Plant Biochemistry (IPB), Weinberg 3, 06120, Halle (Saale), Germany.
| |
Collapse
|
21
|
Wang Z, Wang X, Zhang H, Ma L, Zhao H, Jones CS, Chen J, Liu G. A genome-wide association study approach to the identification of candidate genes underlying agronomic traits in alfalfa (Medicago sativa L.). PLANT BIOTECHNOLOGY JOURNAL 2020; 18:611-613. [PMID: 31487419 PMCID: PMC7004897 DOI: 10.1111/pbi.13251] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 08/26/2019] [Accepted: 08/29/2019] [Indexed: 05/04/2023]
Affiliation(s)
- Zan Wang
- Institute of Animal SciencesChinese Academy of Agricultural SciencesBeijingChina
| | - Xuemin Wang
- Institute of Animal SciencesChinese Academy of Agricultural SciencesBeijingChina
| | - Han Zhang
- Institute of Animal SciencesChinese Academy of Agricultural SciencesBeijingChina
| | - Lin Ma
- Institute of Animal SciencesChinese Academy of Agricultural SciencesBeijingChina
| | - Haiming Zhao
- Institute of Dry FarmingHebei Academy of Agriculture and Forestry SciencesHengshuiChina
| | | | - Jin Chen
- Institute of Animal SciencesChinese Academy of Agricultural SciencesBeijingChina
| | - Guibo Liu
- Institute of Dry FarmingHebei Academy of Agriculture and Forestry SciencesHengshuiChina
| |
Collapse
|
22
|
Powers SK, Strader LC. Regulation of auxin transcriptional responses. Dev Dyn 2019; 249:483-495. [PMID: 31774605 PMCID: PMC7187202 DOI: 10.1002/dvdy.139] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 11/17/2019] [Accepted: 11/22/2019] [Indexed: 01/27/2023] Open
Abstract
The plant hormone auxin acts as a signaling molecule to regulate a vast number of developmental responses throughout all stages of plant growth. Tight control and coordination of auxin signaling is required for the generation of specific auxin‐response outputs. The nuclear auxin signaling pathway controls auxin‐responsive gene transcription through the TRANSPORT INHIBITOR RESPONSE1/AUXIN SIGNALING F‐BOX pathway. Recent work has uncovered important details into how regulation of auxin signaling components can generate unique and specific responses to determine auxin outputs. In this review, we discuss what is known about the core auxin signaling components and explore mechanisms important for regulating auxin response specificity. A review of recent updates to our understanding of auxin signaling.
Collapse
Affiliation(s)
- Samantha K Powers
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri
| | - Lucia C Strader
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri.,Center for Science and Engineering of Living Systems (CSELS), Washington University in St. Louis, St. Louis, Missouri.,Center for Engineering MechanoBiology, Washington University in St. Louis, St. Louis, Missouri
| |
Collapse
|
23
|
Schreier S, Petla BP, Lin T, Chakravarty S, Subramanian S. A simple and sensitive SYBR Gold-based assay to quantify DNA-protein interactions. PLANT MOLECULAR BIOLOGY 2019; 101:499-506. [PMID: 31621004 DOI: 10.1007/s11103-019-00922-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 10/09/2019] [Indexed: 06/10/2023]
Abstract
A simple, accessible, and inexpensive assay to quantify the strength of DNA-protein interactions was developed. The assay relies on capturing DNA-protein complexes using an affinity resin that binds tagged, recombinant proteins. Sequential washes with filtration spin cups and centrifugation remove non-specific interactions in a gentle, uniform manner and a final elution isolates specific DNA-protein complexes. SYBR Gold nucleic acid stain is added to the eluted product and the fluorescence intensity accurately quantifies the amount of captured DNA, ultimately illustrating the relative strength of the DNA-protein interaction. The major utility of the assay resides in the versatility and quantitative nature of the SYBR Gold:nucleic acid interaction, eliminating the need for customized or labeled oligos and permitting relatively inexpensive quantification of binding capacity. The assay also employs DNA-protein complex capture by the very common purification tag, 6xHis, but other tags could likely be utilized. Further, SYBR Gold fluorescence is compatible with a wide variety of instruments, including UV transilluminators, a staple to any molecular biology laboratory. This assay was used to compare the binding capacities of different auxin response factor (ARF) transcription factors to various dsDNA targets, including the classical AuxRE motif and several divergent sequences. Results from dose-response assays suggest that different ARF proteins might show distinct comparative affinities for AuxRE variants, emphasizing that specific ARF-AuxRE binding strengths likely contribute to the complex and fine-tuned cellular auxin response.
Collapse
Affiliation(s)
- Spencer Schreier
- Department of Agronomy, Horticulture, and Plant Science, South Dakota State University, Brookings, SD, 57007, USA
- Center for Molecular Medicine, University of Nevada, Reno, 1664 N Virginia St, Reno, NV, 89557, USA
| | - Bhanu Prakash Petla
- Department of Agronomy, Horticulture, and Plant Science, South Dakota State University, Brookings, SD, 57007, USA
| | - Tao Lin
- Department of Chemistry and Biochemistry, South Dakota State University, Brookings, SD, 57007, USA
| | - Suvobrata Chakravarty
- Department of Chemistry and Biochemistry, South Dakota State University, Brookings, SD, 57007, USA
| | - Senthil Subramanian
- Department of Agronomy, Horticulture, and Plant Science, South Dakota State University, Brookings, SD, 57007, USA.
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD, 57007, USA.
| |
Collapse
|
24
|
Powers SK, Holehouse AS, Korasick DA, Schreiber KH, Clark NM, Jing H, Emenecker R, Han S, Tycksen E, Hwang I, Sozzani R, Jez JM, Pappu RV, Strader LC. Nucleo-cytoplasmic Partitioning of ARF Proteins Controls Auxin Responses in Arabidopsis thaliana. Mol Cell 2019; 76:177-190.e5. [PMID: 31421981 DOI: 10.1016/j.molcel.2019.06.044] [Citation(s) in RCA: 139] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 06/06/2019] [Accepted: 06/26/2019] [Indexed: 12/14/2022]
Abstract
The phytohormone auxin plays crucial roles in nearly every aspect of plant growth and development. The auxin response factor (ARF) transcription factor family regulates auxin-responsive gene expression and exhibits nuclear localization in regions of high auxin responsiveness. Here we show that the ARF7 and ARF19 proteins accumulate in micron-sized assemblies within the cytoplasm of tissues with attenuated auxin responsiveness. We found that the intrinsically disordered middle region and the folded PB1 interaction domain of ARFs drive protein assembly formation. Mutation of a single lysine within the PB1 domain abrogates cytoplasmic assemblies, promotes ARF nuclear localization, and results in an altered transcriptome and morphological defects. Our data suggest a model in which ARF nucleo-cytoplasmic partitioning regulates auxin responsiveness, providing a mechanism for cellular competence for auxin signaling.
Collapse
Affiliation(s)
- Samantha K Powers
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Alex S Holehouse
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - David A Korasick
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Katherine H Schreiber
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA; Center for Engineering MechanoBiology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Natalie M Clark
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, USA
| | - Hongwei Jing
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA; Center for Engineering MechanoBiology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Ryan Emenecker
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Soeun Han
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Eric Tycksen
- Genome Technology Access Center, Department of Genetics, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Ildoo Hwang
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Rosangela Sozzani
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, USA
| | - Joseph M Jez
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Rohit V Pappu
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA; Center for Science and Engineering of Living Systems (CSELS), Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Lucia C Strader
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA; Center for Engineering MechanoBiology, Washington University in St. Louis, St. Louis, MO 63130, USA; Center for Science and Engineering of Living Systems (CSELS), Washington University in St. Louis, St. Louis, MO 63130, USA.
| |
Collapse
|
25
|
Stigliani A, Martin-Arevalillo R, Lucas J, Bessy A, Vinos-Poyo T, Mironova V, Vernoux T, Dumas R, Parcy F. Capturing Auxin Response Factors Syntax Using DNA Binding Models. MOLECULAR PLANT 2019; 12:822-832. [PMID: 30336329 DOI: 10.1016/j.molp.2018.09.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 08/31/2018] [Accepted: 09/28/2018] [Indexed: 05/03/2023]
Abstract
Auxin is a key hormone performing a wealth of functions throughout the life cycle of plants. It acts largely by regulating genes at the transcriptional level through a family of transcription factors called auxin response factors (ARFs). Even though all ARF monomers analyzed so far bind a similar DNA sequence, there is evidence that ARFs differ in their target genomic regions and regulated genes. Here, we report the use of position weight matrices (PWMs) to model ARF DNA binding specificity based on published DNA affinity purification sequencing (DAP-seq) data. We found that the genome binding of two ARFs (ARF2 and ARF5/Monopteros [MP]) differ largely because these two factors have different preferred ARF binding site (ARFbs) arrangements (orientation and spacing). We illustrated why PWMs are more versatile to reliably identify ARFbs than the widely used consensus sequences and demonstrated their power with biochemical experiments in the identification of the regulatory regions of IAA19, an well-characterized auxin-responsive gene. Finally, we combined gene regulation by auxin with ARF-bound regions and identified specific ARFbs configurations that are over-represented in auxin-upregulated genes, thus deciphering the ARFbs syntax functional for regulation. Our study provides a general method to exploit the potential of genome-wide DNA binding assays and to decode gene regulation.
Collapse
Affiliation(s)
- Arnaud Stigliani
- Univ. Grenoble Alpes, CNRS, CEA, INRA, BIG-LPCV, 38000 Grenoble, France
| | - Raquel Martin-Arevalillo
- Univ. Grenoble Alpes, CNRS, CEA, INRA, BIG-LPCV, 38000 Grenoble, France; Laboratoire de Reproduction et Développement des Plantes, Univ. Lyon, ENS de Lyon, UCB Lyon1, CNRS, INRA, 46 allée d'Italie, 69364, Lyon, France
| | - Jérémy Lucas
- Univ. Grenoble Alpes, CNRS, CEA, INRA, BIG-LPCV, 38000 Grenoble, France
| | - Adrien Bessy
- Univ. Grenoble Alpes, CNRS, CEA, INRA, BIG-LPCV, 38000 Grenoble, France
| | - Thomas Vinos-Poyo
- Univ. Grenoble Alpes, CNRS, CEA, INRA, BIG-LPCV, 38000 Grenoble, France
| | - Victoria Mironova
- Novosibirsk State University, Pirogova Street 2, Novosibirsk, Russia; Institute of Cytology and Genetics SB RAS, Lavrentyeva Avenue 10, Novosibirsk, Russia
| | - Teva Vernoux
- Laboratoire de Reproduction et Développement des Plantes, Univ. Lyon, ENS de Lyon, UCB Lyon1, CNRS, INRA, 46 allée d'Italie, 69364, Lyon, France
| | - Renaud Dumas
- Univ. Grenoble Alpes, CNRS, CEA, INRA, BIG-LPCV, 38000 Grenoble, France
| | - François Parcy
- Univ. Grenoble Alpes, CNRS, CEA, INRA, BIG-LPCV, 38000 Grenoble, France.
| |
Collapse
|
26
|
The auxin response factor gene family in allopolyploid Brassica napus. PLoS One 2019; 14:e0214885. [PMID: 30958842 PMCID: PMC6453480 DOI: 10.1371/journal.pone.0214885] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Accepted: 03/21/2019] [Indexed: 12/20/2022] Open
Abstract
Auxin response factor (ARF) is a member of the plant-specific B3 DNA binding superfamily. Here, we report the results of a comprehensive analysis of ARF genes in allotetraploid Brassica napus (2n = 38, AACC). Sixty-seven ARF genes were identified in B. napus (BnARFs) and divided into four subfamilies (I–IV). Sixty-one BnARFs were distributed on all chromosomes except C02; the remaining were on Ann and Cnn. The full length of the BnARF proteins was highly conserved especially within each subfamily with all members sharing the N-terminal DNA binding domain (DBD) and the middle region (MR), and most contained the C-terminal dimerization domain (PBI). Twenty-one members had a glutamine-rich MR that may be an activator and the remaining were repressors. Accordingly, the intron patterns are highly conserved in each subfamily or clade, especially in DBD and PBI domains. Several members in subfamily III are potential targets for miR167. Many putative cis-elements involved in phytohormones, light signaling responses, and biotic and abiotic stress were identified in BnARF promoters, implying their possible roles. Most ARF proteins are likely to interact with auxin/indole-3-acetic acid (Aux/IAA) -related proteins, and members from different subfamilies generally shared many common interaction proteins. Whole genome-wide duplication (WGD) by hybridization between Brassica rapa and Brassica oleracea and segmental duplication led to gene expansion. Gene loss following WGD is biased with the An-subgenome retaining more ancestral genes than the Cn-subgenome. BnARFs have wide expression profiles across vegetative and reproductive organs during different developmental stages. No obvious expression bias was observed between An- and Cn-subgenomes. Most synteny-pair genes had similar expression patterns, indicating their functional redundancy. BnARFs were sensitive to exogenous IAA and 6-BA treatments especially subfamily III. The present study provides insights into the distribution, phylogeny, and evolution of ARF gene family.
Collapse
|
27
|
Reed JW, Wu MF, Reeves PH, Hodgens C, Yadav V, Hayes S, Pierik R. Three Auxin Response Factors Promote Hypocotyl Elongation. PLANT PHYSIOLOGY 2018; 178:864-875. [PMID: 30139794 PMCID: PMC6181040 DOI: 10.1104/pp.18.00718] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 08/09/2018] [Indexed: 05/18/2023]
Abstract
The hormone auxin regulates growth largely by affecting gene expression. By studying Arabidopsis (Arabidopsis thaliana) mutants deficient in AUXIN RESPONSE FACTORS (ARFs), we have identified three ARF proteins that are required for auxin-responsive hypocotyl elongation. Plants deficient in these factors have reduced responses to environmental conditions that increase auxin levels, including far-red-enriched light and high temperature. Despite having decreased auxin responses, the ARF-deficient plants responded to brassinosteroid and gibberellin, indicating that different hormones can act partially independently. Aux/IAA proteins, encoded by IAA genes, interact with ARF proteins to repress auxin response. Silencing expression of multiple IAA genes increased hypocotyl elongation, suggesting that Aux/IAA proteins modulate ARF activity in hypocotyls in a potential negative feedback loop.
Collapse
Affiliation(s)
- Jason W Reed
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599-3280
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, North Carolina 27599-3280
| | - Miin-Feng Wu
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599-3280
| | - Paul H Reeves
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599-3280
| | - Charles Hodgens
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599-3280
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, North Carolina 27599-3280
| | - Vandana Yadav
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599-3280
| | - Scott Hayes
- Department of Biology, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Ronald Pierik
- Department of Biology, Utrecht University, 3584 CH Utrecht, The Netherlands
| |
Collapse
|
28
|
Pandey SK, Lee HW, Kim MJ, Cho C, Oh E, Kim J. LBD18 uses a dual mode of a positive feedback loop to regulate ARF expression and transcriptional activity in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 95:233-251. [PMID: 29681137 DOI: 10.1111/tpj.13945] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 04/02/2018] [Accepted: 04/05/2018] [Indexed: 05/10/2023]
Abstract
A hierarchy of transcriptional regulators controlling lateral root formation in Arabidopsis thaliana has been identified, including the AUXIN RESPONSE FACTOR 7 (ARF7)/ARF19-LATERAL ORGAN BOUNDARIES DOMAIN 16 (LBD16)/LBD18 transcriptional network; however, their feedback regulation mechanisms are not known. Here we show that LBD18 controls ARF activity using the dual mode of a positive feedback loop. We showed that ARF7 and ARF19 directly bind AuxRE in the LBD18 promoter. A variety of molecular and biochemical experiments demonstrated that LBD18 binds a specific DNA motif in the ARF19 promoter to regulate its expression in vivo as well as in vitro. LBD18 interacts with ARFs including ARF7 and ARF19 via the Phox and Bem1 domain of ARF to enhance the transcriptional activity of ARF7 on AuxRE, and competes with auxin/indole-3-acetic acid (IAA) repressors for ARF binding, overriding the negative feedback loop exerted by Aux/IAA repressors. Taken together, these results show that LBD18 and ARFs form a double positive feedback loop, and that LBD18 uses the dual mode of a positive feedback loop by binding directly to the ARF19 promoter and through the protein-protein interactions with ARF7 and ARF19. This novel mechanism of feedback loops may constitute a robust feedback mechanism that ensures continued lateral root growth in response to auxin in Arabidopsis.
Collapse
Affiliation(s)
- Shashank K Pandey
- Department of Bioenergy Science and Technology, Chonnam National University, Buk-Gu, Gwangju, 500-757, Korea
| | - Han Woo Lee
- Department of Bioenergy Science and Technology, Chonnam National University, Buk-Gu, Gwangju, 500-757, Korea
| | - Min-Jung Kim
- Department of Bioenergy Science and Technology, Chonnam National University, Buk-Gu, Gwangju, 500-757, Korea
| | - Chuloh Cho
- Department of Bioenergy Science and Technology, Chonnam National University, Buk-Gu, Gwangju, 500-757, Korea
| | - Eunkyoo Oh
- Department of Bioenergy Science and Technology, Chonnam National University, Buk-Gu, Gwangju, 500-757, Korea
| | - Jungmook Kim
- Department of Bioenergy Science and Technology, Chonnam National University, Buk-Gu, Gwangju, 500-757, Korea
- Kumho Life Science Laboratory, Chonnam National University, Buk-Gu, Gwangju, 500-757, Korea
| |
Collapse
|
29
|
Nemhauser JL. Back to basics: what is the function of an Aux/IAA in auxin response? THE NEW PHYTOLOGIST 2018; 218:1295-1297. [PMID: 29738089 DOI: 10.1111/nph.15172] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
|
30
|
Xu F, He S, Zhang J, Mao Z, Wang W, Li T, Hua J, Du S, Xu P, Li L, Lian H, Yang HQ. Photoactivated CRY1 and phyB Interact Directly with AUX/IAA Proteins to Inhibit Auxin Signaling in Arabidopsis. MOLECULAR PLANT 2018; 11:523-541. [PMID: 29269022 DOI: 10.1016/j.molp.2017.12.003] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 12/11/2017] [Accepted: 12/11/2017] [Indexed: 05/04/2023]
Abstract
Light is a key environmental cue that inhibits hypocotyl cell elongation through the blue and red/far-red light photoreceptors cryptochrome- and phytochrome-mediated pathways in Arabidopsis. In contrast, as a pivotal endogenous phytohormone auxin promotes hypocotyl elongation through the auxin receptors TIR1/AFBs-mediated degradation of AUX/IAA proteins (AUX/IAAs). However, the molecular mechanisms underlying the antagonistic interaction of light and auxin signaling remain unclear. Here, we report that light inhibits auxin signaling through stabilization of AUX/IAAs by blue and red light-dependent interactions of cryptochrome 1 (CRY1) and phytochrome B with AUX/IAAs, respectively. Blue light-triggered interactions of CRY1 with AUX/IAAs inhibit the associations of TIR1 with AUX/IAAs, leading to the repression of auxin-induced degradation of these proteins. Our results indicate that photoreceptors share AUX/IAAs with auxin receptors as the same direct downstream signaling components. We propose that antagonistic regulation of AUX/IAA protein stability by photoreceptors and auxin receptors allows plants to balance light and auxin signals to optimize their growth.
Collapse
Affiliation(s)
- Feng Xu
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Shengbo He
- School of Agriculture and Biology/School of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200240, China
| | - Jingyi Zhang
- School of Agriculture and Biology/School of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200240, China
| | - Zhilei Mao
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Wenxiu Wang
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Ting Li
- School of Agriculture and Biology/School of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200240, China
| | - Jie Hua
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Shasha Du
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Pengbo Xu
- School of Agriculture and Biology/School of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200240, China
| | - Ling Li
- School of Agriculture and Biology/School of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200240, China
| | - Hongli Lian
- School of Agriculture and Biology/School of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200240, China
| | - Hong-Quan Yang
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200438, China.
| |
Collapse
|
31
|
Luo J, Zhou JJ, Zhang JZ. Aux/IAA Gene Family in Plants: Molecular Structure, Regulation, and Function. Int J Mol Sci 2018; 19:ijms19010259. [PMID: 29337875 PMCID: PMC5796205 DOI: 10.3390/ijms19010259] [Citation(s) in RCA: 219] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 01/10/2018] [Accepted: 01/13/2018] [Indexed: 12/31/2022] Open
Abstract
Auxin plays a crucial role in the diverse cellular and developmental responses of plants across their lifespan. Plants can quickly sense and respond to changes in auxin levels, and these responses involve several major classes of auxin-responsive genes, including the Auxin/Indole-3-Acetic Acid (Aux/IAA) family, the auxin response factor (ARF) family, small auxin upregulated RNA (SAUR), and the auxin-responsive Gretchen Hagen3 (GH3) family. Aux/IAA proteins are short-lived nuclear proteins comprising several highly conserved domains that are encoded by the auxin early response gene family. These proteins have specific domains that interact with ARFs and inhibit the transcription of genes activated by ARFs. Molecular studies have revealed that Aux/IAA family members can form diverse dimers with ARFs to regulate genes in various ways. Functional analyses of Aux/IAA family members have indicated that they have various roles in plant development, such as root development, shoot growth, and fruit ripening. In this review, recently discovered details regarding the molecular characteristics, regulation, and protein-protein interactions of the Aux/IAA proteins are discussed. These details provide new insights into the molecular basis of the Aux/IAA protein functions in plant developmental processes.
Collapse
Affiliation(s)
- Jie Luo
- College of Horticulture and Forestry Science, Hubei Engineering Technology Research Center for Forestry Information, Huazhong Agricultural University, Wuhan 430070, China.
| | - Jing-Jing Zhou
- College of Horticulture and Forestry Science, Hubei Engineering Technology Research Center for Forestry Information, Huazhong Agricultural University, Wuhan 430070, China.
| | - Jin-Zhi Zhang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan 430070, China.
| |
Collapse
|
32
|
Roosjen M, Paque S, Weijers D. Auxin Response Factors: output control in auxin biology. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:179-188. [PMID: 28992135 DOI: 10.1093/jxb/erx237] [Citation(s) in RCA: 120] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The phytohormone auxin is involved in almost all developmental processes in land plants. Most, if not all, of these processes are mediated by changes in gene expression. Auxin acts on gene expression through a short nuclear pathway that converges upon the activation of a family of DNA-binding transcription factors. These AUXIN RESPONSE FACTORS (ARFs) are thus the effector of auxin response and translate the chemical signal into the regulation of a defined set of genes. Given the limited number of dedicated components in auxin signaling, distinct properties among the ARF family probably contribute to the establishment of multiple unique auxin responses in plant development. In the two decades following the identification of the first ARF in Arabidopsis, much has been learnt about how these transcription factors act, and how they generate unique auxin responses. Progress in genetics, biochemistry, genomics, and structural biology has helped to develop mechanistic models for ARF action. However, despite intensive efforts, many central questions are yet to be addressed. In this review, we highlight what has been learnt about ARF transcription factors, and identify outstanding questions and challenges for the near future.
Collapse
Affiliation(s)
- Mark Roosjen
- Laboratory of Biochemistry, Wageningen University, The Netherlands
| | - Sébastien Paque
- Laboratory of Biochemistry, Wageningen University, The Netherlands
| | - Dolf Weijers
- Laboratory of Biochemistry, Wageningen University, The Netherlands
| |
Collapse
|
33
|
Ma Q, Grones P, Robert S. Auxin signaling: a big question to be addressed by small molecules. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:313-328. [PMID: 29237069 PMCID: PMC5853230 DOI: 10.1093/jxb/erx375] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 10/16/2017] [Indexed: 05/20/2023]
Abstract
Providing a mechanistic understanding of the crucial roles of the phytohormone auxin has been an important and coherent aspect of plant biology research. Since its discovery more than a century ago, prominent advances have been made in the understanding of auxin action, ranging from metabolism and transport to cellular and transcriptional responses. However, there is a long road ahead before a thorough understanding of its complex effects is achieved, because a lot of key information is still missing. The availability of an increasing number of technically advanced scientific tools has boosted the basic discoveries in auxin biology. A plethora of bioactive small molecules, consisting of the synthetic auxin-like herbicides and the more specific auxin-related compounds, developed as a result of the exploration of chemical space by chemical biology, have made the tool box for auxin research more comprehensive. This review mainly focuses on the compounds targeting the auxin co-receptor complex, demonstrates the various ways to use them, and shows clear examples of important basic knowledge obtained by their usage. Application of these precise chemical tools, together with an increasing amount of structural information for the major components in auxin action, will certainly aid in strengthening our insights into the complexity and diversity of auxin response.
Collapse
Affiliation(s)
- Qian Ma
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Sweden
| | - Peter Grones
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Sweden
| | | |
Collapse
|
34
|
Choi HJ, Kim I, Lee HJ, Park YH, Suh J, Han JY. Chicken NANOG self‐associates
via
a novel folding‐upon‐binding mechanism. FASEB J 2018; 32:2563-2573. [PMID: 29295863 DOI: 10.1096/fj.201700924rr] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Hee Jung Choi
- Department of Agricultural Biotechnology Research Institute of Agriculture and Life Sciences College of Agriculture and Life Sciences Seoul National University Seoul South Korea
| | - Iktae Kim
- Department of Agricultural Biotechnology Research Institute of Agriculture and Life Sciences College of Agriculture and Life Sciences Seoul National University Seoul South Korea
| | - Hong Jo Lee
- Department of Agricultural Biotechnology Research Institute of Agriculture and Life Sciences College of Agriculture and Life Sciences Seoul National University Seoul South Korea
| | - Young Hyun Park
- Department of Agricultural Biotechnology Research Institute of Agriculture and Life Sciences College of Agriculture and Life Sciences Seoul National University Seoul South Korea
| | - Jeong‐Yong Suh
- Department of Agricultural Biotechnology Research Institute of Agriculture and Life Sciences College of Agriculture and Life Sciences Seoul National University Seoul South Korea
- Institute for Biomedical Sciences Shinshu University Minamiminowa Japan
| | - Jae Yong Han
- Department of Agricultural Biotechnology Research Institute of Agriculture and Life Sciences College of Agriculture and Life Sciences Seoul National University Seoul South Korea
- Institute for Biomedical Sciences Shinshu University Minamiminowa Japan
| |
Collapse
|
35
|
Shen Y, Yang Y, Xu E, Ge X, Xiang Y, Li Z. Novel and major QTL for branch angle detected by using DH population from an exotic introgression in rapeseed (Brassica napus L.). TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2018; 131:67-78. [PMID: 28942459 DOI: 10.1007/s00122-017-2986-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 09/01/2017] [Indexed: 05/28/2023]
Abstract
A high-density SNP map was constructed and several novel QTL for branch angle across six environments in Brassica napus were identified. Branch angle is a major determinant for the ideotype of a plant, while the mechanisms underlying this trait in Brassica napus remain elusive. Herein, we developed one doubled haploid population from a cross involving one Capsella bursa-pastoris derived B. napus intertribal introgression line with the compressed branches and wooden stems, and constructed a high-density SNP map covering the genetic distance of 2242.14 cM, with an average marker interval of 0.73 cM. After phenotypic measurements across six environments, the inclusive composite interval mapping algorithm was conducted to analyze the QTL associated with branch angle. In single-environment analysis, a total of 17 QTL were detected and mainly distributed on chromosomes A01, A03, A09 and C03. Of these, three major QTL, qBA.A03-2, qBA.C03-3 and qBA.C03-4 were steadily expressed, each explaining more than 10% of the phenotypic variation in at least two environments. Compared with other results on rapeseed branch angle, these major QTL were newly detected. In QTL by environment interactions (QEI) mapping, 10 QTL were identified, and the QTL average effect and QEI effect were estimated. Of these, 7 QTL were detected in both single-environment analysis and QEI mapping. Based on the physical positions of SNPs and the functional annotation of the Arabidopsis thaliana genome, 27 genes within the QTL regions were selected as candidate genes, including early auxin-responsive genes, small auxin-up RNA, auxin/indoleacetic acid and gretchenhagen-3. These results may pave the way for deciphering the genetic control of branch angle in B. napus.
Collapse
Affiliation(s)
- Yusen Shen
- National Key Lab of Crop Genetic Improvement, National Center of Oil Crop Improvement (Wuhan), College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Yi Yang
- National Key Lab of Crop Genetic Improvement, National Center of Oil Crop Improvement (Wuhan), College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Ensheng Xu
- National Key Lab of Crop Genetic Improvement, National Center of Oil Crop Improvement (Wuhan), College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Xianhong Ge
- National Key Lab of Crop Genetic Improvement, National Center of Oil Crop Improvement (Wuhan), College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Yang Xiang
- Guizhou Rapeseed Institute, Guizhou Academy of Agricultural Sciences, Guiyang, 550008, People's Republic of China.
| | - Zaiyun Li
- National Key Lab of Crop Genetic Improvement, National Center of Oil Crop Improvement (Wuhan), College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China.
| |
Collapse
|
36
|
Grigolon S, Bravi B, Martin OC. Responses to auxin signals: an operating principle for dynamical sensitivity yet high resilience. ROYAL SOCIETY OPEN SCIENCE 2018; 5:172098. [PMID: 29410878 PMCID: PMC5792956 DOI: 10.1098/rsos.172098] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 12/08/2017] [Indexed: 05/29/2023]
Abstract
Plants depend on the signalling of the phytohormone auxin for their development and for responding to environmental perturbations. The associated biomolecular signalling network involves a negative feedback on Aux/IAA proteins which mediate the influence of auxin (the signal) on the auxin response factor (ARF) transcription factors (the drivers of the response). To probe the role of this feedback, we consider alternative in silico signalling networks implementing different operating principles. By a comparative analysis, we find that the presence of a negative feedback allows the system to have a far larger sensitivity in its dynamical response to auxin and that this sensitivity does not prevent the system from being highly resilient. Given this insight, we build a new biomolecular signalling model for quantitatively describing such Aux/IAA and ARF responses.
Collapse
Affiliation(s)
- S. Grigolon
- LPTMS, Université Paris-Sud XI-Université Paris-Saclay, 15, Rue Georges Clémenceau, 91405 Orsay, France
| | - B. Bravi
- Department of Mathematics, King’s College London, The Strand, London WC2R 2LS, UK
| | - O. C. Martin
- GQE-Le Moulon, INRA, Université Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, 91190 Gif-sur-Yvette, France
| |
Collapse
|
37
|
Abstract
The plant hormone auxin triggers complex growth and developmental processes. Its underlying molecular mechanism of action facilitates rapid switching between transcriptional repression and gene activation through the auxin-dependent degradation of transcriptional repressors. The nuclear auxin signaling pathway consists of a small number of core components. However, in most plants each component is represented by a large gene family. The modular construction of the pathway can thus produce diverse transcriptional outputs depending on the cellular and environmental context. Here, and in the accompanying poster, we outline the current model for TIR1/AFB-dependent auxin signaling with an emphasis on recent studies.
Collapse
Affiliation(s)
- Meirav Lavy
- Section of Cell and Developmental Biology and Howard Hughes Medical Institute, University of California San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA
| | - Mark Estelle
- Section of Cell and Developmental Biology and Howard Hughes Medical Institute, University of California San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA
| |
Collapse
|
38
|
Winkler M, Niemeyer M, Hellmuth A, Janitza P, Christ G, Samodelov SL, Wilde V, Majovsky P, Trujillo M, Zurbriggen MD, Hoehenwarter W, Quint M, Calderón Villalobos LIA. Variation in auxin sensing guides AUX/IAA transcriptional repressor ubiquitylation and destruction. Nat Commun 2017; 8:15706. [PMID: 28589936 PMCID: PMC5467235 DOI: 10.1038/ncomms15706] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 04/21/2017] [Indexed: 12/24/2022] Open
Abstract
Auxin is a small molecule morphogen that bridges SCFTIR1/AFB-AUX/IAA co-receptor interactions leading to ubiquitylation and proteasome-dependent degradation of AUX/IAA transcriptional repressors. Here, we systematically dissect auxin sensing by SCFTIR1-IAA6 and SCFTIR1-IAA19 co-receptor complexes, and assess IAA6/IAA19 ubiquitylation in vitro and IAA6/IAA19 degradation in vivo. We show that TIR1-IAA19 and TIR1-IAA6 have distinct auxin affinities that correlate with ubiquitylation and turnover dynamics of the AUX/IAA. We establish a system to track AUX/IAA ubiquitylation in IAA6 and IAA19 in vitro and show that it occurs in flexible hotspots in degron-flanking regions adorned with specific Lys residues. We propose that this signature is exploited during auxin-mediated SCFTIR1-AUX/IAA interactions. We present evidence for an evolving AUX/IAA repertoire, typified by the IAA6/IAA19 ohnologues, that discriminates the range of auxin concentrations found in plants. We postulate that the intrinsic flexibility of AUX/IAAs might bias their ubiquitylation and destruction kinetics enabling specific auxin responses.
Collapse
Affiliation(s)
- Martin Winkler
- Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry (IPB), Halle (Saale) D-06120, Germany
| | - Michael Niemeyer
- Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry (IPB), Halle (Saale) D-06120, Germany
| | - Antje Hellmuth
- Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry (IPB), Halle (Saale) D-06120, Germany
| | - Philipp Janitza
- Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Halle (Saale) D-06120, Germany
| | - Gideon Christ
- Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry (IPB), Halle (Saale) D-06120, Germany
| | - Sophia L. Samodelov
- Institute of Synthetic Biology, University of Düsseldorf, Düsseldorf D-40225, Germany
- Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, Freiburg D-79104, Germany
| | - Verona Wilde
- Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry (IPB), Halle (Saale) D-06120, Germany
| | - Petra Majovsky
- Proteome Analytics Research Group, Leibniz Institute of Plant Biochemistry (IPB), Halle (Saale) D-06120, Germany
| | - Marco Trujillo
- Independent Junior Research Group Ubiquitination in Immunity, Leibniz Institute of Plant Biochemistry (IPB), Halle (Saale) D-06120, Germany
| | - Matias D. Zurbriggen
- Institute of Synthetic Biology, University of Düsseldorf, Düsseldorf D-40225, Germany
- Cluster of Excellence on Plant Science (CEPLAS), University of Düsseldorf, Düsseldorf D-40225, Germany
| | - Wolfgang Hoehenwarter
- Proteome Analytics Research Group, Leibniz Institute of Plant Biochemistry (IPB), Halle (Saale) D-06120, Germany
| | - Marcel Quint
- Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Halle (Saale) D-06120, Germany
| | | |
Collapse
|
39
|
Mironova V, Teale W, Shahriari M, Dawson J, Palme K. The Systems Biology of Auxin in Developing Embryos. TRENDS IN PLANT SCIENCE 2017; 22:225-235. [PMID: 28131745 DOI: 10.1016/j.tplants.2016.11.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 11/08/2016] [Accepted: 11/11/2016] [Indexed: 05/13/2023]
Abstract
Systems biology orientates signaling pathways in their biological context. This aim invariably requires models that ignore extraneous factors and focus on the most crucial pathways of any given process. The developing embryo encapsulates many important processes in plant development; understanding their interaction will be key to designing crops able to maximize yield in an ever-more challenging world. Here, we briefly summarize the role of auxin during embryo development. We highlight recent advances in our understanding of auxin signaling and discuss implications for a systems understanding of development.
Collapse
Affiliation(s)
- Victoria Mironova
- Institute of Cytology and Genetics, Novosibirsk, 630090, Russia; Novosibirsk State University, Novosibirsk, 630090, Russia
| | - William Teale
- Institute of Biology II, University of Freiburg, Schänzlestrasse 1, 79104 Freiburg, Germany
| | - Mojgan Shahriari
- Institute of Biology II, University of Freiburg, Schänzlestrasse 1, 79104 Freiburg, Germany
| | - Jonathan Dawson
- Department of Physics, Syracuse University, Syracuse, NY 13210, USA
| | - Klaus Palme
- Institute of Biology II, University of Freiburg, Schänzlestrasse 1, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, Albert-Ludwigs-University of Freiburg, Freiburg 79104, Germany; Freiburg Institute of Advanced Sciences (FRIAS), Albert-Ludwigs-University of Freiburg, Freiburg79104, Germany.
| |
Collapse
|
40
|
Functional analysis of molecular interactions in synthetic auxin response circuits. Proc Natl Acad Sci U S A 2016; 113:11354-11359. [PMID: 27647902 DOI: 10.1073/pnas.1604379113] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Auxin-regulated transcription pivots on the interaction between the AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) repressor proteins and the AUXIN RESPONSE FACTOR (ARF) transcription factors. Recent structural analyses of ARFs and Aux/IAAs have raised questions about the functional complexes driving auxin transcriptional responses. To parse the nature and significance of ARF-DNA and ARF-Aux/IAA interactions, we analyzed structure-guided variants of synthetic auxin response circuits in the budding yeast Saccharomyces cerevisiae Our analysis revealed that promoter architecture could specify ARF activity and that ARF19 required dimerization at two distinct domains for full transcriptional activation. In addition, monomeric Aux/IAAs were able to repress ARF activity in both yeast and plants. This systematic, quantitative structure-function analysis identified a minimal complex-comprising a single Aux/IAA repressing a pair of dimerized ARFs-sufficient for auxin-induced transcription.
Collapse
|
41
|
Palovaara J, de Zeeuw T, Weijers D. Tissue and Organ Initiation in the Plant Embryo: A First Time for Everything. Annu Rev Cell Dev Biol 2016; 32:47-75. [PMID: 27576120 DOI: 10.1146/annurev-cellbio-111315-124929] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Land plants can grow to tremendous body sizes, yet even the most complex architectures are the result of iterations of the same developmental processes: organ initiation, growth, and pattern formation. A central question in plant biology is how these processes are regulated and coordinated to allow for the formation of ordered, 3D structures. All these elementary processes first occur in early embryogenesis, during which, from a fertilized egg cell, precursors for all major tissues and stem cells are initiated, followed by tissue growth and patterning. Here we discuss recent progress in our understanding of this phase of plant life. We consider the cellular basis for multicellular development in 3D and focus on the genetic regulatory mechanisms that direct specific steps during early embryogenesis.
Collapse
Affiliation(s)
- Joakim Palovaara
- Laboratory of Biochemistry, Wageningen University, 6703 HA Wageningen, The Netherlands;
| | - Thijs de Zeeuw
- Laboratory of Biochemistry, Wageningen University, 6703 HA Wageningen, The Netherlands;
| | - Dolf Weijers
- Laboratory of Biochemistry, Wageningen University, 6703 HA Wageningen, The Netherlands;
| |
Collapse
|
42
|
Parcy F, Vernoux T, Dumas R. A Glimpse beyond Structures in Auxin-Dependent Transcription. TRENDS IN PLANT SCIENCE 2016; 21:574-583. [PMID: 26994657 DOI: 10.1016/j.tplants.2016.02.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 02/09/2016] [Accepted: 02/16/2016] [Indexed: 05/28/2023]
Abstract
Auxin response factors (ARFs), transcription factors (TFs), and their Aux/IAA (IAA) repressors are central components of the auxin signalling pathway. They interact as homo- and heteromultimers. The structure of their interacting domains revealed a PB1 fold mediating electrostatic interactions through positive and negative faces. Detailed structural analysis revealed additional hydrophobic and polar determinants and started unveiling an ARF/IAA interaction code. Structural progress also shed new light on the DNA binding mode of ARFs showing how they dimerize to bind repeated DNA elements. Here, we discuss the in vitro and in vivo significance of these structural properties for the ARF family of TFs and identify some critical missing information on how specificity might be achieved in the auxin signalling pathway.
Collapse
Affiliation(s)
- François Parcy
- Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble Alpes, CNRS UMR5168, CEA/DRF/BIG, INRA UMR 1417, Grenoble, France.
| | - Teva Vernoux
- Laboratoire de Reproduction et Développement des Plantes, CNRS, INRA, ENS de Lyon, UCBL, Université de Lyon, 46 Allée d'Italie, F-69342 Lyon, France.
| | - Renaud Dumas
- Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble Alpes, CNRS UMR5168, CEA/DRF/BIG, INRA UMR 1417, Grenoble, France
| |
Collapse
|
43
|
Lavy M, Prigge MJ, Tao S, Shain S, Kuo A, Kirchsteiger K, Estelle M. Constitutive auxin response in Physcomitrella reveals complex interactions between Aux/IAA and ARF proteins. eLife 2016; 5. [PMID: 27247276 PMCID: PMC4889330 DOI: 10.7554/elife.13325] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 04/02/2016] [Indexed: 01/03/2023] Open
Abstract
The coordinated action of the auxin-sensitive Aux/IAA transcriptional repressors and ARF transcription factors produces complex gene-regulatory networks in plants. Despite their importance, our knowledge of these two protein families is largely based on analysis of stabilized forms of the Aux/IAAs, and studies of a subgroup of ARFs that function as transcriptional activators. To understand how auxin regulates gene expression we generated a Physcomitrella patens line that completely lacks Aux/IAAs. Loss of the repressors causes massive changes in transcription with misregulation of over a third of the annotated genes. Further, we find that the aux/iaa mutant is blind to auxin indicating that auxin regulation of transcription occurs exclusively through Aux/IAA function. We used the aux/iaa mutant as a simplified platform for studies of ARF function and demonstrate that repressing ARFs regulate auxin-induced genes and fine-tune their expression. Further the repressing ARFs coordinate gene induction jointly with activating ARFs and the Aux/IAAs.
Collapse
Affiliation(s)
- Meirav Lavy
- Section of Cell and Developmental Biology, Howard Hughes Medical Institute, University of California, San Diego, San Diego, United States
| | - Michael J Prigge
- Section of Cell and Developmental Biology, Howard Hughes Medical Institute, University of California, San Diego, San Diego, United States
| | - Sibo Tao
- Section of Cell and Developmental Biology, Howard Hughes Medical Institute, University of California, San Diego, San Diego, United States
| | - Stephanie Shain
- Section of Cell and Developmental Biology, Howard Hughes Medical Institute, University of California, San Diego, San Diego, United States
| | - April Kuo
- Section of Cell and Developmental Biology, Howard Hughes Medical Institute, University of California, San Diego, San Diego, United States
| | - Kerstin Kirchsteiger
- Section of Cell and Developmental Biology, Howard Hughes Medical Institute, University of California, San Diego, San Diego, United States
| | - Mark Estelle
- Section of Cell and Developmental Biology, Howard Hughes Medical Institute, University of California, San Diego, San Diego, United States
| |
Collapse
|
44
|
Dinesh DC, Villalobos LIAC, Abel S. Structural Biology of Nuclear Auxin Action. TRENDS IN PLANT SCIENCE 2016; 21:302-316. [PMID: 26651917 DOI: 10.1016/j.tplants.2015.10.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 09/29/2015] [Accepted: 10/23/2015] [Indexed: 05/23/2023]
Abstract
Auxin coordinates plant development largely via hierarchical control of gene expression. During the past decades, the study of early auxin genes paired with the power of Arabidopsis genetics have unraveled key nuclear components and molecular interactions that perceive the hormone and activate primary response genes. Recent research in the realm of structural biology allowed unprecedented insight into: (i) the recognition of auxin-responsive DNA elements by auxin transcription factors; (ii) the inactivation of those auxin response factors by early auxin-inducible repressors; and (iii) the activation of target genes by auxin-triggered repressor degradation. The biophysical studies reviewed here provide an impetus for elucidating the molecular determinants of the intricate interactions between core components of the nuclear auxin response module.
Collapse
Affiliation(s)
- Dhurvas Chandrasekaran Dinesh
- Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry, Weinberg 3, D-06120 Halle (Saale), Germany
| | - Luz Irina A Calderón Villalobos
- Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry, Weinberg 3, D-06120 Halle (Saale), Germany
| | - Steffen Abel
- Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry, Weinberg 3, D-06120 Halle (Saale), Germany; Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Strasse 3, D-06120 Halle (Saale), Germany; Department of Plant Sciences, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA.
| |
Collapse
|
45
|
Modelling the influence of dimerisation sequence dissimilarities on the auxin signalling network. BMC SYSTEMS BIOLOGY 2016; 10:22. [PMID: 26932351 PMCID: PMC4774195 DOI: 10.1186/s12918-016-0254-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 01/05/2016] [Indexed: 11/10/2022]
Abstract
BACKGROUND Auxin is a major phytohormone involved in many developmental processes by controlling gene expression through a network of transcriptional regulators. In Arabidopsis thaliana, the auxin signalling network is made of 52 potentially interacting transcriptional regulators, activating or repressing gene expression. All the possible interactions were tested in two-way yeast-2-hybrid experiments. Our objective was to characterise this auxin signalling network and to quantify the influence of the dimerisation sequence dissimilarities on the interaction between transcriptional regulators. RESULTS We applied model-based graph clustering methods relying on connectivity profiles between transcriptional regulators. Incorporating dimerisation sequence dissimilarities as explanatory variables, we modelled their influence on the auxin network topology using mixture of linear models for random graphs. Our results provide evidence that the network can be simplified into four groups, three of them being closely related to biological groups. We found that these groups behave differently, depending on their dimerisation sequence dissimilarities, and that the two dimerisation sub-domains might play different roles. CONCLUSIONS We propose here the first pipeline of statistical methods combining yeast-2-hybrid data and protein sequence dissimilarities for analysing protein-protein interactions. We unveil using this pipeline of analysis the transcriptional regulator interaction modes.
Collapse
|
46
|
Smit ME, Weijers D. The role of auxin signaling in early embryo pattern formation. CURRENT OPINION IN PLANT BIOLOGY 2015; 28:99-105. [PMID: 26495766 DOI: 10.1016/j.pbi.2015.10.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 09/28/2015] [Accepted: 10/02/2015] [Indexed: 05/09/2023]
Abstract
Pattern formation of the early Arabidopsis embryo generates precursors to all major cell types, and is profoundly controlled by the signaling molecule auxin. Here we discuss recent milestones in our understanding of auxin-dependent embryo patterning. Auxin biosynthesis, transport and response mechanisms interact to generate local auxin accumulation in the early embryo. New auxin-dependent reporters help identifying these sites, while atomic structures of transcriptional response mediators help explain the diverse outputs of auxin signaling. Key auxin outputs are control of cell identity and cell division orientation, and progress has been made towards understanding the cellular basis of each. Importantly, a number of studies have combined computational modeling and experiments to analyze the developmental role, genetic circuitry and molecular mechanisms of auxin-dependent cell division control.
Collapse
Affiliation(s)
- Margot E Smit
- Laboratory of Biochemistry, Wageningen University, Wageningen, The Netherlands
| | - Dolf Weijers
- Laboratory of Biochemistry, Wageningen University, Wageningen, The Netherlands.
| |
Collapse
|
47
|
A coherent transcriptional feed-forward motif model for mediating auxin-sensitive PIN3 expression during lateral root development. Nat Commun 2015; 6:8821. [PMID: 26578065 PMCID: PMC4673502 DOI: 10.1038/ncomms9821] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2015] [Accepted: 10/07/2015] [Indexed: 11/24/2022] Open
Abstract
Multiple plant developmental processes, such as lateral root development, depend on auxin distribution patterns that are in part generated by the PIN-formed family of auxin-efflux transporters. Here we propose that AUXIN RESPONSE FACTOR7 (ARF7) and the ARF7-regulated FOUR LIPS/MYB124 (FLP) transcription factors jointly form a coherent feed-forward motif that mediates the auxin-responsive PIN3 transcription in planta to steer the early steps of lateral root formation. This regulatory mechanism might endow the PIN3 circuitry with a temporal ‘memory' of auxin stimuli, potentially maintaining and enhancing the robustness of the auxin flux directionality during lateral root development. The cooperative action between canonical auxin signalling and other transcription factors might constitute a general mechanism by which transcriptional auxin-sensitivity can be regulated at a tissue-specific level. Lateral root development is dependent on precise control of the distribution of the plant hormone auxin. Here Chen et al. propose the transcription factors ARF7 and FLP participate in a feed forward motif to mediate expression of the auxin transporter PIN3 and consequently regulate lateral root development.
Collapse
|
48
|
Han M, Suh JY. Dynamics of the mobile insert helix in the domain III-IV of Aux/IAA17 probed by site-directed spin labeling and paramagnetic NMR spectroscopy. JOURNAL OF THE KOREAN MAGNETIC RESONANCE SOCIETY 2015. [DOI: 10.6564/jkmrs.2015.19.2.061] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
49
|
Korasick DA, Jez JM, Strader LC. Refining the nuclear auxin response pathway through structural biology. CURRENT OPINION IN PLANT BIOLOGY 2015; 27:22-8. [PMID: 26048079 PMCID: PMC4618177 DOI: 10.1016/j.pbi.2015.05.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 05/12/2015] [Indexed: 05/03/2023]
Abstract
Auxin is a key regulator of plant growth and development. Classical molecular and genetic techniques employed over the past 20 years identified the major players in auxin-mediated gene expression and suggest a canonical auxin response pathway. In recent years, structural and biophysical studies clarified the molecular details of auxin perception, the recognition of DNA by auxin transcription factors, and the interaction of auxin transcription factors with repressor proteins. These studies refine the auxin signal transduction model and raise new questions that increase the complexity of auxin signaling.
Collapse
Affiliation(s)
- David A Korasick
- Department of Biology, Washington University, St. Louis, MO 63130, USA
| | - Joseph M Jez
- Department of Biology, Washington University, St. Louis, MO 63130, USA.
| | - Lucia C Strader
- Department of Biology, Washington University, St. Louis, MO 63130, USA.
| |
Collapse
|
50
|
Ke J, Ma H, Gu X, Thelen A, Brunzelle JS, Li J, Xu HE, Melcher K. Structural basis for recognition of diverse transcriptional repressors by the TOPLESS family of corepressors. SCIENCE ADVANCES 2015; 1:e1500107. [PMID: 26601214 PMCID: PMC4646777 DOI: 10.1126/sciadv.1500107] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 06/04/2015] [Indexed: 05/18/2023]
Abstract
TOPLESS (TPL) and TOPLESS-related (TPR) proteins comprise a conserved family of plant transcriptional corepressors that are related to Tup1, Groucho, and TLE (transducin-like enhancer of split) corepressors in yeast, insects, and mammals. In plants, TPL/TPR corepressors regulate development, stress responses, and hormone signaling through interaction with small ethylene response factor-associated amphiphilic repression (EAR) motifs found in diverse transcriptional repressors. How EAR motifs can interact with TPL/TPR proteins is unknown. We confirm the amino-terminal domain of the TPL family of corepressors, which we term TOPLESS domain (TPD), as the EAR motif-binding domain. To understand the structural basis of this interaction, we determined the crystal structures of the TPD of rice (Os) TPR2 in apo (apo protein) state and in complexes with the EAR motifs from Arabidopsis NINJA (novel interactor of JAZ), IAA1 (auxin-responsive protein 1), and IAA10, key transcriptional repressors involved in jasmonate and auxin signaling. The OsTPR2 TPD adopts a new fold of nine helices, followed by a zinc finger, which are arranged into a disc-like tetramer. The EAR motifs in the three different complexes adopt a similar extended conformation with the hydrophobic residues fitting into the same surface groove of each OsTPR2 monomer. Sequence alignments and structure-based mutagenesis indicate that this mode of corepressor binding is highly conserved in a large set of transcriptional repressors, thus providing a general mechanism for gene repression mediated by the TPL family of corepressors.
Collapse
Affiliation(s)
- Jiyuan Ke
- Key Laboratory of Receptor Research, VARI-SIMM Center, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 201203, People’s Republic of China
- Laboratory of Structural Sciences and Laboratory of Structural Biology and Biochemistry, Van Andel Research Institute, 333 Bostwick Avenue Northeast, Grand Rapids, MI 49503, USA
| | - Honglei Ma
- Key Laboratory of Receptor Research, VARI-SIMM Center, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 201203, People’s Republic of China
- Laboratory of Structural Sciences and Laboratory of Structural Biology and Biochemistry, Van Andel Research Institute, 333 Bostwick Avenue Northeast, Grand Rapids, MI 49503, USA
| | - Xin Gu
- Laboratory of Structural Sciences and Laboratory of Structural Biology and Biochemistry, Van Andel Research Institute, 333 Bostwick Avenue Northeast, Grand Rapids, MI 49503, USA
| | - Adam Thelen
- Laboratory of Structural Sciences and Laboratory of Structural Biology and Biochemistry, Van Andel Research Institute, 333 Bostwick Avenue Northeast, Grand Rapids, MI 49503, USA
| | - Joseph S. Brunzelle
- Department of Molecular Pharmacology and Biological Chemistry, Life Sciences Collaborative Access Team, Synchrotron Research Center, Northwestern University, Argonne, IL 60439, USA
| | - Jiayang Li
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, People’s Republic of China
| | - H. Eric Xu
- Key Laboratory of Receptor Research, VARI-SIMM Center, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 201203, People’s Republic of China
- Laboratory of Structural Sciences and Laboratory of Structural Biology and Biochemistry, Van Andel Research Institute, 333 Bostwick Avenue Northeast, Grand Rapids, MI 49503, USA
- Corresponding author. E-mail: (H.E.X.); (K.M.)
| | - Karsten Melcher
- Key Laboratory of Receptor Research, VARI-SIMM Center, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 201203, People’s Republic of China
- Laboratory of Structural Sciences and Laboratory of Structural Biology and Biochemistry, Van Andel Research Institute, 333 Bostwick Avenue Northeast, Grand Rapids, MI 49503, USA
- Corresponding author. E-mail: (H.E.X.); (K.M.)
| |
Collapse
|