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Wexler Y, Schroeder JI, Shkolnik D. Hydrotropism mechanisms and their interplay with gravitropism. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024; 118:1732-1746. [PMID: 38394056 DOI: 10.1111/tpj.16683] [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: 11/28/2023] [Revised: 01/29/2024] [Accepted: 02/02/2024] [Indexed: 02/25/2024]
Abstract
Plants partly optimize their water recruitment from the growth medium by directing root growth toward a moisture source, a phenomenon termed hydrotropism. The default mechanism of downward growth, termed gravitropism, often functions to counteract hydrotropism when the water-potential gradient deviates from the gravity vector. This review addresses the identity of the root sites in which hydrotropism-regulating factors function to attenuate gravitropism and the interplay between these various factors. In this context, the function of hormones, including auxin, abscisic acid, and cytokinins, as well as secondary messengers, calcium ions, and reactive oxygen species in the conflict between these two opposing tropisms is discussed. We have assembled the available data on the effects of various chemicals and genetic backgrounds on both gravitropism and hydrotropism, to provide an up-to-date perspective on the interactions that dictate the orientation of root tip growth. We specify the relevant open questions for future research. Broadening our understanding of root mechanisms of water recruitment holds great potential for providing advanced approaches and technologies that can improve crop plant performance under less-than-optimal conditions, in light of predicted frequent and prolonged drought periods due to global climate change.
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Affiliation(s)
- Yonatan Wexler
- Faculty of Life Sciences, School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Julian I Schroeder
- Cell and Developmental Biology Department, School of Biological Sciences, University of California San Diego, La Jolla, California, 92093-0116, USA
| | - Doron Shkolnik
- Faculty of Agriculture, Food and Environment, Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, Rehovot, 7610001, Israel
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2
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Yamazaki C, Yamazaki T, Kojima M, Takebayashi Y, Sakakibara H, Uheda E, Oka M, Kamada M, Shimazu T, Kasahara H, Sano H, Suzuki T, Higashibata A, Miyamoto K, Ueda J. Comprehensive analyses of plant hormones in etiolated pea and maize seedlings grown under microgravity conditions in space: Relevance to the International Space Station experiment "Auxin Transport". LIFE SCIENCES IN SPACE RESEARCH 2023; 36:138-146. [PMID: 36682823 DOI: 10.1016/j.lssr.2022.10.005] [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: 05/20/2022] [Revised: 09/29/2022] [Accepted: 10/11/2022] [Indexed: 06/17/2023]
Abstract
Functional relationships between endogenous levels of plant hormones in the growth and development of shoots in etiolated Alaska pea and etiolated Golden Cross Bantam maize seedlings under different gravities were investigated in the "Auxin Transport" experiment aboard the International Space Station (ISS). Comprehensive analyses of 31 species of plant hormones of pea and maize seedlings grown under microgravity (μg) in space and 1 g conditions were conducted. Principal component analysis (PCA) and a multiple regression analysis with the dataset from the plant hormone analysis of the etiolated pea seedlings grown under μg and 1 g conditions in the presence and absence of 2,3,5-triiodobenzoic acid (TIBA) revealed endogenous levels of auxin correlated positively with bending and length of epicotyls. Endogenous cytokinins correlated negatively with them. These results suggest an interaction of auxin and cytokinins in automorphogenesis and growth inhibition of etiolated Alaska pea epicotyls grown under μg conditions in space. Less polar auxin transport with reduced endogenous levels of auxin increased endogenous levels of cytokinins, resulting in changing the growth direction of epicotyls and inhibiting growth. On the other hand, almost no close relationship between endogenous plant hormone levels and growth and development in etiolated maize seedlings grown was observed under μg conditions in space, as per Schulze et al. (1992). However, endogenous levels of IAA in the seedlings grown under μg conditions in space were significantly higher than those grown on Earth, similar to the cases of polar auxin transport already reported.
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Affiliation(s)
- Chiaki Yamazaki
- Japan Aerospace Exploration Agency, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505, Japan.
| | - Tomokazu Yamazaki
- Japan Aerospace Exploration Agency, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505, Japan.
| | - Mikiko Kojima
- Mass Spectrometry and Microscopy Unit, RIKEN Center for Sustainable Resource Science (CSRS), Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan.
| | - Yumiko Takebayashi
- Mass Spectrometry and Microscopy Unit, RIKEN Center for Sustainable Resource Science (CSRS), Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan.
| | - Hitoshi Sakakibara
- Mass Spectrometry and Microscopy Unit, RIKEN Center for Sustainable Resource Science (CSRS), Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan; Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
| | - Eiji Uheda
- Graduate School of Science, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
| | - Mariko Oka
- Faculty of Agriculture, Tottori University, 4-101 Koyamacho-minami, Tottori 680-8553, Japan.
| | - Motoshi Kamada
- Future Development Division, Advanced Engineering Services Co., Ltd., 1-6-1 Takezono, Tsukuba, Ibaraki 305-0032, Japan.
| | - Toru Shimazu
- Technology and Research Promotion Department, Japan Space Forum, Shin-Otemachi Bldg. 7F, 2-2-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan.
| | - Haruo Kasahara
- Utilization Engineering Department, Japan Manned Space System Corporation, Space Station Test Building, Tsukuba Space Center, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505, Japan.
| | - Hiromi Sano
- Utilization Engineering Department, Japan Manned Space System Corporation, Space Station Test Building, Tsukuba Space Center, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505, Japan.
| | - Tomomi Suzuki
- Japan Aerospace Exploration Agency, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505, Japan.
| | - Akira Higashibata
- Japan Aerospace Exploration Agency, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505, Japan.
| | - Kensuke Miyamoto
- Faculty of Liberal Arts and Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
| | - Junichi Ueda
- Graduate School of Science, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
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3
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Abstract
Auxin has always been at the forefront of research in plant physiology and development. Since the earliest contemplations by Julius von Sachs and Charles Darwin, more than a century-long struggle has been waged to understand its function. This largely reflects the failures, successes, and inevitable progress in the entire field of plant signaling and development. Here I present 14 stations on our long and sometimes mystical journey to understand auxin. These highlights were selected to give a flavor of the field and to show the scope and limits of our current knowledge. A special focus is put on features that make auxin unique among phytohormones, such as its dynamic, directional transport network, which integrates external and internal signals, including self-organizing feedback. Accented are persistent mysteries and controversies. The unexpected discoveries related to rapid auxin responses and growth regulation recently disturbed our contentment regarding understanding of the auxin signaling mechanism. These new revelations, along with advances in technology, usher us into a new, exciting era in auxin research.
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Affiliation(s)
- Jiří Friml
- Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria
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4
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Transcription Profile of Auxin Related Genes during Positively Gravitropic Hypocotyl Curvature of Brassica rapa. PLANTS 2022; 11:plants11091191. [PMID: 35567192 PMCID: PMC9105288 DOI: 10.3390/plants11091191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/19/2022] [Accepted: 04/25/2022] [Indexed: 11/20/2022]
Abstract
Unlike typical negative gravitropic curvature, young hypocotyls of Brassica rapa and other dicots exhibit positive gravitropism. This positive curvature occurs at the base of the hypocotyl and is followed by the typical negative gravity-induced curvature. We investigated the role of auxin in both positive and negative hypocotyl curvature by examining the transcription of PIN1, PIN3, IAA5 and ARG1 in curving tissue. We compared tissue extraction of the convex and concave flank with Solid Phase Gene Extraction (SPGE). Based on Ubiquitin1 (UBQ1) as a reference gene, the log (2) fold change of all examined genes was determined. Transcription of the examined genes varied during the graviresponse suggesting that these genes affect differential elongation. The transcription of all genes was upregulated in the lower flank and downregulated in the upper flank during the initial downward curving period. After 48 h, the transcription profile reversed, suggesting that the ensuing negative gravicurvature is controlled by the same genes as the positive gravicurvature. High-spatial resolution profiling using SPGE revealed that the transcription profile of the examined genes was spatially distinct within the curving tissue. The comparison of the hypocotyl transcription profile with the root tip indicated that the tip tissue is a suitable reference for curving hypocotyls and that root and hypocotyl curvature are controlled by the same physiological processes.
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5
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Frank M, Cortleven A, Pěnčík A, Novak O, Schmülling T. The Photoperiod Stress Response in Arabidopsis thaliana Depends on Auxin Acting as an Antagonist to the Protectant Cytokinin. Int J Mol Sci 2022; 23:ijms23062936. [PMID: 35328357 PMCID: PMC8955046 DOI: 10.3390/ijms23062936] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/02/2022] [Accepted: 03/03/2022] [Indexed: 02/05/2023] Open
Abstract
Fluctuating environmental conditions trigger adaptive responses in plants, which are regulated by phytohormones. During photoperiod stress caused by a prolongation of the light period, cytokinin (CK) has a protective function. Auxin often acts as an antagonist of CK in developmental processes and stress responses. Here, we investigated the regulation of the photoperiod stress response in Arabidopsis thaliana by auxin and its interaction with CK. Transcriptome analysis revealed an altered transcript abundance of numerous auxin metabolism and signaling genes after photoperiod stress treatment. The changes appeared earlier and were stronger in the photoperiod-stress-sensitive CK receptor mutant arabidopsis histidine kinase 2 (ahk2),3 compared to wild-type plants. The concentrations of indole-3-acetic acid (IAA), IAA-Glc and IAA-Asp increased in both genotypes, but the increases were more pronounced in ahk2,3. Genetic analysis revealed that the gain-of-function YUCCA 1 (YUC1) mutant, yuc1D, displayed an increased photoperiod stress sensitivity. In contrast, a loss of the auxin receptors TRANSPORT-INHIBITOR-RESISTANT 1 (TIR1), AUXIN SIGNALING F-BOX 2 (AFB2) and AFB3 in wild-type and ahk2,3 background caused a reduced photoperiod stress response. Overall, this study revealed that auxin promotes response to photoperiod stress antagonizing the protective CK.
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Affiliation(s)
- Manuel Frank
- Institute of Biology/Applied Genetics, Dahlem Centre of Plant Sciences (DCPS), Freie Universität Berlin, D-14195 Berlin, Germany; (M.F.); (A.C.)
| | - Anne Cortleven
- Institute of Biology/Applied Genetics, Dahlem Centre of Plant Sciences (DCPS), Freie Universität Berlin, D-14195 Berlin, Germany; (M.F.); (A.C.)
| | - Aleš Pěnčík
- Laboratory of Growth Regulators, Faculty of Science, Palacký University & Institute of Experimental Botany, The Czech Academy of Sciences, Šlechtitelů 27, CZ-783 71 Olomouc, Czech Republic; (A.P.); (O.N.)
| | - Ondrej Novak
- Laboratory of Growth Regulators, Faculty of Science, Palacký University & Institute of Experimental Botany, The Czech Academy of Sciences, Šlechtitelů 27, CZ-783 71 Olomouc, Czech Republic; (A.P.); (O.N.)
| | - Thomas Schmülling
- Institute of Biology/Applied Genetics, Dahlem Centre of Plant Sciences (DCPS), Freie Universität Berlin, D-14195 Berlin, Germany; (M.F.); (A.C.)
- Correspondence:
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6
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Zimmermann MJ, Bose J, Kramer EM, Atkin OK, Tyerman SD, Baskin TI. Oxygen uptake rates have contrasting responses to temperature in the root meristem and elongation zone. PHYSIOLOGIA PLANTARUM 2022; 174:e13682. [PMID: 35373370 DOI: 10.1111/ppl.13682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 03/27/2022] [Accepted: 03/31/2022] [Indexed: 06/14/2023]
Abstract
Growing at either 15 or 25°C, roots of Arabidopsis thaliana, Columbia accession, produce cells at the same rate and have growth zones of the same length. To determine whether this constancy is related to energetics, we measured oxygen uptake by means of a vibrating oxygen-selective electrode. Concomitantly, the spatial distribution of elongation was measured kinematically, delineating meristem and elongation zone. All seedlings were germinated, grown, and measured at a given temperature (15 or 25°C). Columbia was compared to lines where cell production rate roughly doubles between 15 and 25°C: Landsberg and two Columbia mutants, er-105 and ahk3-3. For all genotypes and temperatures, oxygen uptake rate at any position was highest at the root cap, where mitochondrial density was maximal, based on the fluorescence of a reporter. Uptake rate declined through the meristem to plateau within the elongation zone. For oxygen uptake rate integrated over a zone, the meristem had steady-state Q10 values ranging from 0.7 to 2.1; by contrast, the elongation zone had values ranging from 2.6 to 3.3, implying that this zone exerts a greater respiratory demand. These results highlight a substantial energy consumption by the root cap, perhaps helpful for maintaining hypoxia in stem cells, and suggest that rapid elongation is metabolically more costly than is cell division.
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Affiliation(s)
- Maura J Zimmermann
- Plant Biology Program, University of Massachusetts, Amherst, Massachusetts, USA
- Biology Department, University of Massachusetts, Amherst, Massachusetts, USA
| | - Jayakumar Bose
- School of Agriculture, Food and Wine, Australian Research Council Centre of Excellence in Plant Energy Biology, University of Adelaide, Glen Osmond, South Australia, Australia
| | - Eric M Kramer
- Physics Department, Bard College at Simon's Rock, Great Barrington, Massachusetts, USA
| | - Owen K Atkin
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Stephen D Tyerman
- School of Agriculture, Food and Wine, Australian Research Council Centre of Excellence in Plant Energy Biology, University of Adelaide, Glen Osmond, South Australia, Australia
| | - Tobias I Baskin
- Biology Department, University of Massachusetts, Amherst, Massachusetts, USA
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7
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Hernández-Herrera P, Ugartechea-Chirino Y, Torres-Martínez HH, Arzola AV, Chairez-Veloz JE, García-Ponce B, Sánchez MDLP, Garay-Arroyo A, Álvarez-Buylla ER, Dubrovsky JG, Corkidi G. Live Plant Cell Tracking: Fiji plugin to analyze cell proliferation dynamics and understand morphogenesis. PLANT PHYSIOLOGY 2022; 188:846-860. [PMID: 34791452 PMCID: PMC8825436 DOI: 10.1093/plphys/kiab530] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 10/19/2021] [Indexed: 05/13/2023]
Abstract
Arabidopsis (Arabidopsis thaliana) primary and lateral roots (LRs) are well suited for 3D and 4D microscopy, and their development provides an ideal system for studying morphogenesis and cell proliferation dynamics. With fast-advancing microscopy techniques used for live-imaging, whole tissue data are increasingly available, yet present the great challenge of analyzing complex interactions within cell populations. We developed a plugin "Live Plant Cell Tracking" (LiPlaCeT) coupled to the publicly available ImageJ image analysis program and generated a pipeline that allows, with the aid of LiPlaCeT, 4D cell tracking and lineage analysis of populations of dividing and growing cells. The LiPlaCeT plugin contains ad hoc ergonomic curating tools, making it very simple to use for manual cell tracking, especially when the signal-to-noise ratio of images is low or variable in time or 3D space and when automated methods may fail. Performing time-lapse experiments and using cell-tracking data extracted with the assistance of LiPlaCeT, we accomplished deep analyses of cell proliferation and clonal relations in the whole developing LR primordia and constructed genealogical trees. We also used cell-tracking data for endodermis cells of the root apical meristem (RAM) and performed automated analyses of cell population dynamics using ParaView software (also publicly available). Using the RAM as an example, we also showed how LiPlaCeT can be used to generate information at the whole-tissue level regarding cell length, cell position, cell growth rate, cell displacement rate, and proliferation activity. The pipeline will be useful in live-imaging studies of roots and other plant organs to understand complex interactions within proliferating and growing cell populations. The plugin includes a step-by-step user manual and a dataset example that are available at https://www.ibt.unam.mx/documentos/diversos/LiPlaCeT.zip.
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Affiliation(s)
- Paul Hernández-Herrera
- Laboratorio de Imágenes y Visión por Computadora, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cd. de México, C.P. 04510, Mexico
| | - Yamel Ugartechea-Chirino
- Departamento de Ecología Funcional, Instituto de Ecología, Laboratorio de Genética Molecular, Epigenética, Desarrollo y Evolución de Plantas, Universidad Nacional Autónoma de México, Cd. de México, C.P. 04510, Mexico
| | - Héctor H Torres-Martínez
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cd. de México, C.P. 04510, Mexico
| | - Alejandro V Arzola
- Instituto de Física, Universidad Nacional Autónoma de México, Cd. de México, C.P. 04510, Mexico
| | - José Eduardo Chairez-Veloz
- Departamento de Control Automático, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Cd. de México, C.P. 07350, Mexico
| | - Berenice García-Ponce
- Departamento de Ecología Funcional, Instituto de Ecología, Laboratorio de Genética Molecular, Epigenética, Desarrollo y Evolución de Plantas, Universidad Nacional Autónoma de México, Cd. de México, C.P. 04510, Mexico
| | - María de la Paz Sánchez
- Departamento de Ecología Funcional, Instituto de Ecología, Laboratorio de Genética Molecular, Epigenética, Desarrollo y Evolución de Plantas, Universidad Nacional Autónoma de México, Cd. de México, C.P. 04510, Mexico
| | - Adriana Garay-Arroyo
- Departamento de Ecología Funcional, Instituto de Ecología, Laboratorio de Genética Molecular, Epigenética, Desarrollo y Evolución de Plantas, Universidad Nacional Autónoma de México, Cd. de México, C.P. 04510, Mexico
| | - Elena R Álvarez-Buylla
- Departamento de Ecología Funcional, Instituto de Ecología, Laboratorio de Genética Molecular, Epigenética, Desarrollo y Evolución de Plantas, Universidad Nacional Autónoma de México, Cd. de México, C.P. 04510, Mexico
- Centro de Ciencias de la Complejidad, Universidad Nacional Autónoma de México, Cd. de México, C.P. 04510, Mexico
| | - Joseph G Dubrovsky
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cd. de México, C.P. 04510, Mexico
| | - Gabriel Corkidi
- Laboratorio de Imágenes y Visión por Computadora, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cd. de México, C.P. 04510, Mexico
- Author for communication:
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8
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Genome-Wide Association Study of Root System Architecture in Maize. Genes (Basel) 2022; 13:genes13020181. [PMID: 35205226 PMCID: PMC8872597 DOI: 10.3390/genes13020181] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 01/16/2022] [Accepted: 01/18/2022] [Indexed: 01/05/2023] Open
Abstract
Roots are important plant organs for the absorption of water and nutrients. To date, there have been few genome-wide association studies of maize root system architecture (RSA) in the field. The genetic basis of maize RSA is poorly understood, and the maize RSA-related genes that have been cloned are very limited. Here, 421 maize inbred lines of an association panel were planted to measure the root systems at the maturity stage, and a genome-wide association study was performed. There was a strong correlation among eight RSA traits, and the RSA traits were highly correlated with the aboveground plant architecture traits (e.g., plant height and ear leaf length, r = 0.13–0.25, p < 0.05). The RSA traits of the stiff stalk subgroup (SS) showed lower values than those of the non-stiff stalk subgroup (NSS) and tropical/subtropical subgroup (TST). Using the RSA traits, the genome-wide association study identified 63 SNPs and 189 candidate genes. Among them, nine candidate genes co-localized between RSA and aboveground architecture traits. A further co-expression analysis identified 88 candidate genes having high confidence levels. Furthermore, we identified four highly reliable RSA candidate genes, GRMZM2G099797, GRMZM2G354338, GRMZM2G085042, and GRMZM5G812926. This research provides theoretical support for the genetic improvement of maize root systems, and it identified candidate genes that may act as genetic resources for breeding.
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9
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Chin S, Blancaflor EB. Plant Gravitropism: From Mechanistic Insights into Plant Function on Earth to Plants Colonizing Other Worlds. Methods Mol Biol 2022; 2368:1-41. [PMID: 34647245 DOI: 10.1007/978-1-0716-1677-2_1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Gravitropism, the growth of roots and shoots toward or away from the direction of gravity, has been studied for centuries. Such studies have not only led to a better understanding of the gravitropic process itself, but also paved new paths leading to deeper mechanistic insights into a wide range of research areas. These include hormone biology, cell signal transduction, regulation of gene expression, plant evolution, and plant interactions with a variety of environmental stimuli. In addition to contributions to basic knowledge about how plants function, there is accumulating evidence that gravitropism confers adaptive advantages to crops, particularly under marginal agricultural soils. Therefore, gravitropism is emerging as a breeding target for enhancing agricultural productivity. Moreover, research on gravitropism has spawned several studies on plant growth in microgravity that have enabled researchers to uncouple the effects of gravity from other tropisms. Although rapid progress on understanding gravitropism witnessed during the past decade continues to be driven by traditional molecular, physiological, and cell biological tools, these tools have been enriched by technological innovations in next-generation omics platforms and microgravity analog facilities. In this chapter, we review the field of gravitropism by highlighting recent landmark studies that have provided unique insights into this classic research topic while also discussing potential contributions to agriculture on Earth and beyond.
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Affiliation(s)
- Sabrina Chin
- Department of Botany, University of Wisconsin, Madison, WI, USA.
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10
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Kashkan I, Hrtyan M, Retzer K, Humpolíčková J, Jayasree A, Filepová R, Vondráková Z, Simon S, Rombaut D, Jacobs TB, Frilander MJ, Hejátko J, Friml J, Petrášek J, Růžička K. Mutually opposing activity of PIN7 splicing isoforms is required for auxin-mediated tropic responses in Arabidopsis thaliana. THE NEW PHYTOLOGIST 2022; 233:329-343. [PMID: 34637542 DOI: 10.1111/nph.17792] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Accepted: 10/03/2021] [Indexed: 06/13/2023]
Abstract
Advanced transcriptome sequencing has revealed that the majority of eukaryotic genes undergo alternative splicing (AS). Nonetheless, little effort has been dedicated to investigating the functional relevance of particular splicing events, even those in the key developmental and hormonal regulators. Combining approaches of genetics, biochemistry and advanced confocal microscopy, we describe the impact of alternative splicing on the PIN7 gene in the model plant Arabidopsis thaliana. PIN7 encodes a polarly localized transporter for the phytohormone auxin and produces two evolutionarily conserved transcripts, PIN7a and PIN7b. PIN7a and PIN7b, differing in a four amino acid stretch, exhibit almost identical expression patterns and subcellular localization. We reveal that they are closely associated and mutually influence each other's mobility within the plasma membrane. Phenotypic complementation tests indicate that the functional contribution of PIN7b per se is minor, but it markedly reduces the prominent PIN7a activity, which is required for correct seedling apical hook formation and auxin-mediated tropic responses. Our results establish alternative splicing of the PIN family as a conserved, functionally relevant mechanism, revealing an additional regulatory level of auxin-mediated plant development.
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Affiliation(s)
- Ivan Kashkan
- Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany, Czech Academy of Sciences, Prague, 16502, Czech Republic
- Functional Genomics and Proteomics of Plants, Central European Institute of Technology and National Centre for Biomolecular Research, Masaryk University, Brno, 62500, Czech Republic
| | - Mónika Hrtyan
- Functional Genomics and Proteomics of Plants, Central European Institute of Technology and National Centre for Biomolecular Research, Masaryk University, Brno, 62500, Czech Republic
| | - Katarzyna Retzer
- Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany, Czech Academy of Sciences, Prague, 16502, Czech Republic
| | - Jana Humpolíčková
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague 6, 166 10, Czech Republic
| | - Aswathy Jayasree
- Functional Genomics and Proteomics of Plants, Central European Institute of Technology and National Centre for Biomolecular Research, Masaryk University, Brno, 62500, Czech Republic
| | - Roberta Filepová
- Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany, Czech Academy of Sciences, Prague, 16502, Czech Republic
| | - Zuzana Vondráková
- Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany, Czech Academy of Sciences, Prague, 16502, Czech Republic
| | - Sibu Simon
- Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany, Czech Academy of Sciences, Prague, 16502, Czech Republic
| | - Debbie Rombaut
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, 9052, Belgium
- VIB Center for Plant Systems Biology, Ghent, 9052, Belgium
| | - Thomas B Jacobs
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, 9052, Belgium
- VIB Center for Plant Systems Biology, Ghent, 9052, Belgium
| | - Mikko J Frilander
- Institute of Biotechnology, University of Helsinki, Helsinki, 00014, Finland
| | - Jan Hejátko
- Functional Genomics and Proteomics of Plants, Central European Institute of Technology and National Centre for Biomolecular Research, Masaryk University, Brno, 62500, Czech Republic
| | - Jiří Friml
- Institute of Science and Technology (IST Austria), Klosterneuburg, 3400, Austria
| | - Jan Petrášek
- Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany, Czech Academy of Sciences, Prague, 16502, Czech Republic
| | - Kamil Růžička
- Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany, Czech Academy of Sciences, Prague, 16502, Czech Republic
- Functional Genomics and Proteomics of Plants, Central European Institute of Technology and National Centre for Biomolecular Research, Masaryk University, Brno, 62500, Czech Republic
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11
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Mazzoni-Putman SM, Brumos J, Zhao C, Alonso JM, Stepanova AN. Auxin Interactions with Other Hormones in Plant Development. Cold Spring Harb Perspect Biol 2021; 13:a039990. [PMID: 33903155 PMCID: PMC8485746 DOI: 10.1101/cshperspect.a039990] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Auxin is a crucial growth regulator that governs plant development and responses to environmental perturbations. It functions at the heart of many developmental processes, from embryogenesis to organ senescence, and is key to plant interactions with the environment, including responses to biotic and abiotic stimuli. As remarkable as auxin is, it does not act alone, but rather solicits the help of, or is solicited by, other endogenous signals, including the plant hormones abscisic acid, brassinosteroids, cytokinins, ethylene, gibberellic acid, jasmonates, salicylic acid, and strigolactones. The interactions between auxin and other hormones occur at multiple levels: hormones regulate one another's synthesis, transport, and/or response; hormone-specific transcriptional regulators for different pathways physically interact and/or converge on common target genes; etc. However, our understanding of this crosstalk is still fragmentary, with only a few pieces of the gigantic puzzle firmly established. In this review, we provide a glimpse into the complexity of hormone interactions that involve auxin, underscoring how patchy our current understanding is.
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Affiliation(s)
- Serina M Mazzoni-Putman
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Javier Brumos
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Chengsong Zhao
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Jose M Alonso
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Anna N Stepanova
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina 27695, USA
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12
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Jacobsen AGR, Jervis G, Xu J, Topping JF, Lindsey K. Root growth responses to mechanical impedance are regulated by a network of ROS, ethylene and auxin signalling in Arabidopsis. THE NEW PHYTOLOGIST 2021; 231:225-242. [PMID: 33428776 PMCID: PMC8651006 DOI: 10.1111/nph.17180] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 01/05/2021] [Indexed: 05/21/2023]
Abstract
The growth and development of root systems is influenced by mechanical properties of the substrate in which the plants grow. Mechanical impedance, such as by compacted soil, can reduce root elongation and limit crop productivity. To understand better the mechanisms involved in plant root responses to mechanical impedance stress, we investigated changes in the root transcriptome and hormone signalling responses of Arabidopsis to artificial root barrier systems in vitro. We demonstrate that upon encountering a barrier, reduced Arabidopsis root growth and a characteristic 'step-like' growth pattern is due to a reduction in cell elongation associated with changes in signalling gene expression. Data from RNA-sequencing combined with reporter line and mutant studies identified essential roles for reactive oxygen species, ethylene and auxin signalling during the barrier response. We propose a model in which early responses to mechanical impedance include reactive oxygen signalling integrated with ethylene and auxin responses to mediate root growth changes. Inhibition of ethylene responses allows improved growth in response to root impedance, an observation that may inform future crop breeding programmes.
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Affiliation(s)
| | - George Jervis
- Department of BiosciencesDurham UniversityDurhamDH1 3LEUK
| | - Jian Xu
- Department of Plant Systems PhysiologyInstitute for Water and Wetland ResearchRadboud UniversityHeyendaalseweg 135Nijmegen6525 AJthe Netherlands
- Department of Biological Sciences and Centre for BioImaging SciencesNational University of SingaporeSingapore117543Singapore
| | | | - Keith Lindsey
- Department of BiosciencesDurham UniversityDurhamDH1 3LEUK
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13
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Sharma M, Singh D, Saksena HB, Sharma M, Tiwari A, Awasthi P, Botta HK, Shukla BN, Laxmi A. Understanding the Intricate Web of Phytohormone Signalling in Modulating Root System Architecture. Int J Mol Sci 2021; 22:ijms22115508. [PMID: 34073675 PMCID: PMC8197090 DOI: 10.3390/ijms22115508] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 05/11/2021] [Accepted: 05/13/2021] [Indexed: 12/12/2022] Open
Abstract
Root system architecture (RSA) is an important developmental and agronomic trait that is regulated by various physical factors such as nutrients, water, microbes, gravity, and soil compaction as well as hormone-mediated pathways. Phytohormones act as internal mediators between soil and RSA to influence various events of root development, starting from organogenesis to the formation of higher order lateral roots (LRs) through diverse mechanisms. Apart from interaction with the external cues, root development also relies on the complex web of interaction among phytohormones to exhibit synergistic or antagonistic effects to improve crop performance. However, there are considerable gaps in understanding the interaction of these hormonal networks during various aspects of root development. In this review, we elucidate the role of different hormones to modulate a common phenotypic output, such as RSA in Arabidopsis and crop plants, and discuss future perspectives to channel vast information on root development to modulate RSA components.
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14
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Cytokinin-Controlled Gradient Distribution of Auxin in Arabidopsis Root Tip. Int J Mol Sci 2021; 22:ijms22083874. [PMID: 33918090 PMCID: PMC8069370 DOI: 10.3390/ijms22083874] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/04/2021] [Accepted: 04/06/2021] [Indexed: 01/21/2023] Open
Abstract
The plant root is a dynamic system, which is able to respond promptly to external environmental stimuli by constantly adjusting its growth and development. A key component regulating this growth and development is the finely tuned cross-talk between the auxin and cytokinin phytohormones. The gradient distribution of auxin is not only important for the growth and development of roots, but also for root growth in various response. Recent studies have shed light on the molecular mechanisms of cytokinin-mediated regulation of local auxin biosynthesis/metabolism and redistribution in establishing active auxin gradients, resulting in cell division and differentiation in primary root tips. In this review, we focus our attention on the molecular mechanisms underlying the cytokinin-controlled auxin gradient in root tips.
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15
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Konstantinova N, Korbei B, Luschnig C. Auxin and Root Gravitropism: Addressing Basic Cellular Processes by Exploiting a Defined Growth Response. Int J Mol Sci 2021; 22:ijms22052749. [PMID: 33803128 PMCID: PMC7963156 DOI: 10.3390/ijms22052749] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 03/04/2021] [Accepted: 03/06/2021] [Indexed: 12/14/2022] Open
Abstract
Root architecture and growth are decisive for crop performance and yield, and thus a highly topical research field in plant sciences. The root system of the model plant Arabidopsis thaliana is the ideal system to obtain insights into fundamental key parameters and molecular players involved in underlying regulatory circuits of root growth, particularly in responses to environmental stimuli. Root gravitropism, directional growth along the gravity, in particular represents a highly sensitive readout, suitable to study adjustments in polar auxin transport and to identify molecular determinants involved. This review strives to summarize and give an overview into the function of PIN-FORMED auxin transport proteins, emphasizing on their sorting and polarity control. As there already is an abundance of information, the focus lies in integrating this wealth of information on mechanisms and pathways. This overview of a highly dynamic and complex field highlights recent developments in understanding the role of auxin in higher plants. Specifically, it exemplifies, how analysis of a single, defined growth response contributes to our understanding of basic cellular processes in general.
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16
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Zhang Y, Rodriguez L, Li L, Zhang X, Friml J. Functional innovations of PIN auxin transporters mark crucial evolutionary transitions during rise of flowering plants. SCIENCE ADVANCES 2020; 6:6/50/eabc8895. [PMID: 33310852 PMCID: PMC7732203 DOI: 10.1126/sciadv.abc8895] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 10/26/2020] [Indexed: 05/31/2023]
Abstract
Flowering plants display the highest diversity among plant species and have notably shaped terrestrial landscapes. Nonetheless, the evolutionary origin of their unprecedented morphological complexity remains largely an enigma. Here, we show that the coevolution of cis-regulatory and coding regions of PIN-FORMED (PIN) auxin transporters confined their expression to certain cell types and directed their subcellular localization to particular cell sides, which together enabled dynamic auxin gradients across tissues critical to the complex architecture of flowering plants. Extensive intraspecies and interspecies genetic complementation experiments with PINs from green alga up to flowering plant lineages showed that PIN genes underwent three subsequent, critical evolutionary innovations and thus acquired a triple function to regulate the development of three essential components of the flowering plant Arabidopsis: shoot/root, inflorescence, and floral organ. Our work highlights the critical role of functional innovations within the PIN gene family as essential prerequisites for the origin of flowering plants.
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Affiliation(s)
- Yuzhou Zhang
- Institute of Science and Technology (IST) Austria, 3400 Klosterneuburg, Austria
| | - Lesia Rodriguez
- Institute of Science and Technology (IST) Austria, 3400 Klosterneuburg, Austria
| | - Lanxin Li
- Institute of Science and Technology (IST) Austria, 3400 Klosterneuburg, Austria
| | - Xixi Zhang
- Institute of Science and Technology (IST) Austria, 3400 Klosterneuburg, Austria
| | - Jiří Friml
- Institute of Science and Technology (IST) Austria, 3400 Klosterneuburg, Austria.
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17
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Shoaib M, Yang W, Shan Q, Sun L, Wang D, Sajjad M, Li X, Sun J, Liu D, Zhan K, Zhang A. TaCKX gene family, at large, is associated with thousand-grain weight and plant height in common wheat. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2020; 133:3151-3163. [PMID: 32852585 DOI: 10.1007/s00122-020-03661-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 08/03/2020] [Indexed: 10/23/2022]
Abstract
KEY MESSAGE We used SMRT sequencing and explored the haplotypes of TaCKX genes, linked with thousand-grain weight and plant height, and developed the functionally validated markers, which can be used in the marker-assisted breeding program. Cytokinin oxidase/dehydrogenase (CKX) enzymes catalyze the permanent degradation of cytokinins. Identification of the TaCKX alleles associated with yield traits and the development of functional markers is the first step in using these alleles in marker-assisted breeding program. To identify the alleles, we sequenced the genome fragments, containing TaCKX genes from 48 wheat genotypes, by PacBio® sequencing. Six out of 22 TaCKX genes were found polymorphic, forming 14 distinct haplotypes. Functional markers were developed and validated for all the polymorphic TaCKX genes. Four specific haplotypes, i.e., TaCKX2A_2, TaCKX4A_2, TaCKX5A_3, and TaCKX9A_2, were found significantly associated with high thousand-grain weight (TGW) and short plant height (PH) in Chinese wheat micro-core collection (MCC) and GWAS open population (GWAS-OP), whereas TaCKX1B_2 in GWAS-OP and TaCKX11A_3 in MCC were significantly associated with high TGW and short PH. The mean values of TGW and PH for cumulative favorable haplotypes from chromosome 3A, i.e., TaCKX2A_2, TaCKX4A_2, and TaCKX5A_3, were significantly higher as compared to the cumulative unfavored haplotypes, and the change was additive in manner. Frequency distribution analysis revealed that since the 1960s, the frequency of the favorable haplotypes and TGW has gradually increased in Chinese wheat cultivars. Expression profiling in the seed tissue excised at 2, 4, 6, and 8 days after anthesis depicted that the favorable haplotypes are significantly less expressive as compared to the unfavored haplotypes. We conclude that the functional markers developed in this study can be used to select the favorable haplotypes of TaCKX genes in wheat marker-assisted breeding programs.
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Affiliation(s)
- Muhammad Shoaib
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Wenlong Yang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China.
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
| | - Qiangqiang Shan
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
- The Collaborative Innovation Center for Grain Crops in Henan, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Linhe Sun
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Dongzhi Wang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Muhammad Sajjad
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
- Department of Biosciences, COMSATS University Islamabad, Park Road, Tarlaikalan, Islamabad, 45550, Pakistan
| | - Xin Li
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jiazhu Sun
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
| | - Dongcheng Liu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
| | - Kehui Zhan
- The Collaborative Innovation Center for Grain Crops in Henan, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Aimin Zhang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China.
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18
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Waidmann S, Kleine‐Vehn J. Asymmetric cytokinin signaling opposes gravitropism in roots. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2020; 62:882-886. [PMID: 32233010 PMCID: PMC7383806 DOI: 10.1111/jipb.12929] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 03/24/2020] [Indexed: 05/03/2023]
Abstract
Plants depend on gravity to provide the constant landmark for downward root growth and upward shoot growth. The phytohormone auxin and its cell-to-cell transport machinery are central determinants ensuring gravitropic growth. Statolith sedimentation toward gravity is sensed in specialized cells. This positional cue is translated into the polar distribution of PIN auxin efflux carriers at the plasma membrane, leading to asymmetric auxin distribution and consequently, differential growth and organ bending. While we have started to understand the general principles of how primary organs execute gravitropism, we currently lack basic understanding of how lateral plant organs can defy gravitropic responses. Here we briefly review the establishment of the oblique gravitropic set point angle in lateral roots and particularly discuss the emerging role of asymmetric cytokinin signaling as a central anti-gravitropic signal. Differential cytokinin signaling is co-opted in gravitropic lateral and hydrotropic primary roots to counterbalance gravitropic root growth.
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Affiliation(s)
- Sascha Waidmann
- Department of Applied Genetics and Cell BiologyUniversity of Natural Resources and Life Sciences (BOKU)Muthgasse 18Vienna1190Austria
| | - Jürgen Kleine‐Vehn
- Department of Applied Genetics and Cell BiologyUniversity of Natural Resources and Life Sciences (BOKU)Muthgasse 18Vienna1190Austria
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19
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Semeradova H, Montesinos JC, Benkova E. All Roads Lead to Auxin: Post-translational Regulation of Auxin Transport by Multiple Hormonal Pathways. PLANT COMMUNICATIONS 2020; 1:100048. [PMID: 33367243 PMCID: PMC7747973 DOI: 10.1016/j.xplc.2020.100048] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 03/26/2020] [Accepted: 04/18/2020] [Indexed: 05/03/2023]
Abstract
Auxin is a key hormonal regulator, that governs plant growth and development in concert with other hormonal pathways. The unique feature of auxin is its polar, cell-to-cell transport that leads to the formation of local auxin maxima and gradients, which coordinate initiation and patterning of plant organs. The molecular machinery mediating polar auxin transport is one of the important points of interaction with other hormones. Multiple hormonal pathways converge at the regulation of auxin transport and form a regulatory network that integrates various developmental and environmental inputs to steer plant development. In this review, we discuss recent advances in understanding the mechanisms that underlie regulation of polar auxin transport by multiple hormonal pathways. Specifically, we focus on the post-translational mechanisms that contribute to fine-tuning of the abundance and polarity of auxin transporters at the plasma membrane and thereby enable rapid modification of the auxin flow to coordinate plant growth and development.
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Affiliation(s)
- Hana Semeradova
- Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria
| | | | - Eva Benkova
- Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria
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20
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de Bang L, Paez-Garcia A, Cannon AE, Chin S, Kolape J, Liao F, Sparks JA, Jiang Q, Blancaflor EB. Brassinosteroids Inhibit Autotropic Root Straightening by Modifying Filamentous-Actin Organization and Dynamics. FRONTIERS IN PLANT SCIENCE 2020; 11:5. [PMID: 32117357 PMCID: PMC7010715 DOI: 10.3389/fpls.2020.00005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 01/06/2020] [Indexed: 05/12/2023]
Abstract
When positioned horizontally, roots grow down toward the direction of gravity. This phenomenon, called gravitropism, is influenced by most of the major plant hormones including brassinosteroids. Epi-brassinolide (eBL) was previously shown to enhance root gravitropism, a phenomenon similar to the response of roots exposed to the actin inhibitor, latrunculin B (LatB). This led us to hypothesize that eBL might enhance root gravitropism through its effects on filamentous-actin (F-actin). This hypothesis was tested by comparing gravitropic responses of maize (Zea mays) roots treated with eBL or LatB. LatB- and eBL-treated roots displayed similar enhanced downward growth compared with controls when vertical roots were oriented horizontally. Moreover, the effects of the two compounds on root growth directionality were more striking on a slowly-rotating two-dimensional clinostat. Both compounds inhibited autotropism, a process in which the root straightened after the initial gravistimulus was withdrawn by clinorotation. Although eBL reduced F-actin density in chemically-fixed Z. mays roots, the impact was not as strong as that of LatB. Modification of F-actin organization after treatment with both compounds was also observed in living roots of barrel medic (Medicago truncatula) seedlings expressing genetically encoded F-actin reporters. Like in fixed Z. mays roots, eBL effects on F-actin in living M. truncatula roots were modest compared with those of LatB. Furthermore, live cell imaging revealed a decrease in global F-actin dynamics in hypocotyls of etiolated M. truncatula seedlings treated with eBL compared to controls. Collectively, our data indicate that eBL-and LatB-induced enhancement of root gravitropism can be explained by inhibited autotropic root straightening, and that eBL affects this process, in part, by modifying F-actin organization and dynamics.
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Affiliation(s)
- Louise de Bang
- Noble Research Institute LLC, Ardmore, OK, United States
- Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Ashley E. Cannon
- Noble Research Institute LLC, Ardmore, OK, United States
- Department of Biological Sciences, University of North Texas, Denton, TX, United States
| | - Sabrina Chin
- Noble Research Institute LLC, Ardmore, OK, United States
| | - Jaydeep Kolape
- Noble Research Institute LLC, Ardmore, OK, United States
- Center for Biotechnology, University of Nebraska—Lincoln, Lincoln, NE, United States
| | - Fuqi Liao
- Noble Research Institute LLC, Ardmore, OK, United States
| | - J. Alan Sparks
- Noble Research Institute LLC, Ardmore, OK, United States
| | - Qingzhen Jiang
- Noble Research Institute LLC, Ardmore, OK, United States
| | - Elison B. Blancaflor
- Noble Research Institute LLC, Ardmore, OK, United States
- *Correspondence: Elison B. Blancaflor,
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21
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Deletion in the Promoter of PcPIN-L Affects the Polar Auxin Transport in Dwarf Pear (Pyrus communis L.). Sci Rep 2019; 9:18645. [PMID: 31819123 PMCID: PMC6901534 DOI: 10.1038/s41598-019-55195-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 11/25/2019] [Indexed: 12/31/2022] Open
Abstract
Dwarf cultivars or dwarfing rootstocks enable high-density planting and are therefore highly desirable in modern pear production. Previously, we found that the dwarf growth habit of pear is controlled by a single dominant gene PcDw. In this study, PcPIN-L (PCP021016) was cloned from dwarf-type and standard-type pears. PcPIN-L expression was significantly lower in the dwarf-type pears than in standard-type pears, which was caused by the CT repeat deletion in the promoter of dwarf-type pears. PcPIN-L overexpression in tobacco plants enhanced the growth of the stems and the roots. Notably, the indole acetic acid (IAA) content decreased in the shoot tips and increased in the stems of transgenic lines compared with wild type, which is consistent with the greater IAA content in the shoot tips and lower IAA content in the stems of dwarf-type pears than in standard-type pears. The CT repeat deletion in the promoter that causes a decrease in promoter activity is associated with lower PcPIN-L expression in the dwarf-type pears, which might limit the polar auxin transport and in turn result in the dwarf phenotype. Taken together, the results provide a novel dwarfing molecular mechanism in perennial woody plants.
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22
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Jin Y, Guo W, Hu X, Liu M, Xu X, Hu F, Lan Y, Lv C, Fang Y, Liu M, Shi T, Ma S, Fang Z, Huang J. Static magnetic field regulates Arabidopsis root growth via auxin signaling. Sci Rep 2019; 9:14384. [PMID: 31591431 PMCID: PMC6779896 DOI: 10.1038/s41598-019-50970-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 09/23/2019] [Indexed: 12/15/2022] Open
Abstract
Static magnetic field (SMF) plays important roles in biological processes of many living organisms. In plants, however, biological significance of SMF and molecular mechanisms underlying SMF action remain largely unknown. To address these questions, we treated Arabidopsis young seedlings with different SMF intensities and directions. Magnetic direction from the north to south pole was adjusted in parallel (N0) with, opposite (N180) and perpendicular to the gravity vector. We discovered that root growth is significantly inhanced by 600 mT treatments except for N180, but not by any 300 mT treatments. N0 treatments lead to more active cell division of the meristem, and higher auxin content that is regulated by coordinated expression of PIN3 and AUX1 in root tips. Consistently, N0-promoted root growth disappears in pin3 and aux1 mutants. Transcriptomic and gene ontology analyses revealed that in roots 85% of the total genes significantly down-regulated by N0 compared to untreatment are enriched in plastid biological processes, such as metabolism and chloroplast development. Lastly, no difference in root length is observed between N0-treated and untreated roots of the double cryptochrome mutant cry1 cry2. Taken together, our data suggest that SMF-regulated root growth is mediated by CRY and auxin signaling pathways in Arabidopsis.
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Affiliation(s)
- Yue Jin
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Wei Guo
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Xupeng Hu
- Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Mengmeng Liu
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Xiang Xu
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Fenhong Hu
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Yiheng Lan
- Shanghai Key Laboratory of Regulatory Biology, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Chenkai Lv
- Shanghai Key Laboratory of Regulatory Biology, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Yanwen Fang
- Heye Health Industrial Research Institute of Zhejiang Heye Health Technology, Anji, Zhejiang, 313300, China
| | - Mengyu Liu
- Heye Health Industrial Research Institute of Zhejiang Heye Health Technology, Anji, Zhejiang, 313300, China
| | - Tieliu Shi
- Shanghai Key Laboratory of Regulatory Biology, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Shisong Ma
- School of Life Sciences, University of Science and Technology of China, Hefei, 230026, China
| | - Zhicai Fang
- Heye Health Industrial Research Institute of Zhejiang Heye Health Technology, Anji, Zhejiang, 313300, China
| | - Jirong Huang
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China.
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23
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Zdarska M, Cuyacot AR, Tarr PT, Yamoune A, Szmitkowska A, Hrdinová V, Gelová Z, Meyerowitz EM, Hejátko J. ETR1 Integrates Response to Ethylene and Cytokinins into a Single Multistep Phosphorelay Pathway to Control Root Growth. MOLECULAR PLANT 2019; 12:1338-1352. [PMID: 31176773 PMCID: PMC8040967 DOI: 10.1016/j.molp.2019.05.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 04/17/2019] [Accepted: 05/28/2019] [Indexed: 05/18/2023]
Abstract
Cytokinins and ethylene control plant development via sensors from the histidine kinase (HK) family. However, downstream signaling pathways for the key phytohormones are distinct. Here we report that not only cytokinin but also ethylene is able to control root apical meristem (RAM) size through activation of the multistep phosphorelay (MSP) pathway. We found that both cytokinin and ethylene-dependent RAM shortening requires ethylene binding to ETR1 and the HK activity of ETR1. The receiver domain of ETR1 interacts with MSP signaling intermediates acting downstream of cytokinin receptors, further substantiating the role of ETR1 in MSP signaling. We revealed that both cytokinin and ethylene induce the MSP in similar and distinct cell types with ETR1-mediated ethylene signaling controlling MSP output specifically in the root transition zone. We identified members of the MSP pathway specific and common to both hormones and showed that ETR1-regulated ARR3 controls RAM size. ETR1-mediated MSP spatially differs from canonical CTR1/EIN2/EIN3 ethylene signaling and is independent of EIN2, indicating that both pathways can be spatially and functionally separated. Furthermore, we demonstrated that canonical ethylene signaling controls MSP responsiveness to cytokinin specifically in the root transition zone, presumably via regulation of ARR10, one of the positive regulators of MSP signaling in Arabidopsis.
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Affiliation(s)
- Marketa Zdarska
- Functional Genomics and Proteomics of Plants, Central European Institute of Technology and National Centre for Biomolecular Research, Masaryk University, CETEC-MU, Kamenice 5/A2, 625 00 Brno, Czech Republic; Division of Biology and Biological Engineering 156-29, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA.
| | - Abigail Rubiato Cuyacot
- Functional Genomics and Proteomics of Plants, Central European Institute of Technology and National Centre for Biomolecular Research, Masaryk University, CETEC-MU, Kamenice 5/A2, 625 00 Brno, Czech Republic
| | - Paul T Tarr
- Howard Hughes Medical Institute, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA; Division of Biology and Biological Engineering 156-29, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
| | - Amel Yamoune
- Functional Genomics and Proteomics of Plants, Central European Institute of Technology and National Centre for Biomolecular Research, Masaryk University, CETEC-MU, Kamenice 5/A2, 625 00 Brno, Czech Republic
| | - Agnieszka Szmitkowska
- Functional Genomics and Proteomics of Plants, Central European Institute of Technology and National Centre for Biomolecular Research, Masaryk University, CETEC-MU, Kamenice 5/A2, 625 00 Brno, Czech Republic
| | - Vendula Hrdinová
- Functional Genomics and Proteomics of Plants, Central European Institute of Technology and National Centre for Biomolecular Research, Masaryk University, CETEC-MU, Kamenice 5/A2, 625 00 Brno, Czech Republic
| | - Zuzana Gelová
- Functional Genomics and Proteomics of Plants, Central European Institute of Technology and National Centre for Biomolecular Research, Masaryk University, CETEC-MU, Kamenice 5/A2, 625 00 Brno, Czech Republic
| | - Elliot M Meyerowitz
- Howard Hughes Medical Institute, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA; Division of Biology and Biological Engineering 156-29, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
| | - Jan Hejátko
- Functional Genomics and Proteomics of Plants, Central European Institute of Technology and National Centre for Biomolecular Research, Masaryk University, CETEC-MU, Kamenice 5/A2, 625 00 Brno, Czech Republic.
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24
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CsBRC1 inhibits axillary bud outgrowth by directly repressing the auxin efflux carrier CsPIN3 in cucumber. Proc Natl Acad Sci U S A 2019; 116:17105-17114. [PMID: 31391306 DOI: 10.1073/pnas.1907968116] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Shoot branching is an important agronomic trait that directly determines plant architecture and affects crop productivity. To promote crop yield and quality, axillary branches need to be manually removed during cucumber production for fresh market and thus are undesirable. Auxin is well known as the primary signal imposing for apical dominance and acts as a repressor for lateral bud outgrowth indirectly. The TEOSINTE BRANCHED1/CYCLOIDEA/PCF (TCP) family gene BRANCHED1 (BRC1) has been shown to be the central integrator for multiple environmental and developmental factors that functions locally to inhibit shoot branching. However, the direct molecular link between auxin and BRC1 remains elusive. Here we find that cucumber BRANCHED1 (CsBRC1) is expressed in axillary buds and displays a higher expression level in cultivated cucumber than in its wild ancestor. Knockdown of CsBRC1 by RNAi leads to increased bud outgrowth and reduced auxin accumulation in buds. We further show that CsBRC1 directly binds to the auxin efflux carrier PIN-FORMED (CsPIN3) and negatively regulates its expression in vitro and in vivo. Elevated expression of CsPIN3 driven by the CsBRC1 promoter results in highly branched cucumber with decreased auxin levels in lateral buds. Therefore, our data suggest that CsBRC1 inhibits lateral bud outgrowth by direct suppression of CsPIN3 functioning and thus auxin accumulation in axillary buds in cucumber, providing a strategy to breed for cultivars with varying degrees of shoot branching grown in different cucumber production systems.
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25
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Waidmann S, Ruiz Rosquete M, Schöller M, Sarkel E, Lindner H, LaRue T, Petřík I, Dünser K, Martopawiro S, Sasidharan R, Novak O, Wabnik K, Dinneny JR, Kleine-Vehn J. Cytokinin functions as an asymmetric and anti-gravitropic signal in lateral roots. Nat Commun 2019; 10:3540. [PMID: 31387989 PMCID: PMC6684572 DOI: 10.1038/s41467-019-11483-4] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 07/16/2019] [Indexed: 11/09/2022] Open
Abstract
Directional organ growth allows the plant root system to strategically cover its surroundings. Intercellular auxin transport is aligned with the gravity vector in the primary root tips, facilitating downward organ bending at the lower root flank. Here we show that cytokinin signaling functions as a lateral root specific anti-gravitropic component, promoting the radial distribution of the root system. We performed a genome-wide association study and reveal that signal peptide processing of Cytokinin Oxidase 2 (CKX2) affects its enzymatic activity and, thereby, determines the degradation of cytokinins in natural Arabidopsis thaliana accessions. Cytokinin signaling interferes with growth at the upper lateral root flank and thereby prevents downward bending. Our interdisciplinary approach proposes that two phytohormonal cues at opposite organ flanks counterbalance each other's negative impact on growth, suppressing organ growth towards gravity and allow for radial expansion of the root system.
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Affiliation(s)
- Sascha Waidmann
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna (BOKU), Muthgasse 18, 1190, Vienna, Austria
| | - Michel Ruiz Rosquete
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna (BOKU), Muthgasse 18, 1190, Vienna, Austria
| | - Maria Schöller
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna (BOKU), Muthgasse 18, 1190, Vienna, Austria
| | - Elizabeth Sarkel
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna (BOKU), Muthgasse 18, 1190, Vienna, Austria
| | - Heike Lindner
- Department of Biology, Stanford University, 260 Panama Street, Stanford, CA, 94305, USA
| | - Therese LaRue
- Department of Biology, Stanford University, 260 Panama Street, Stanford, CA, 94305, USA.,Department of Plant Biology, Carnegie Institution for Science, 260 Panama Street, Stanford, CA, 94305, USA
| | - Ivan Petřík
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science of Palacký University and Institute of Experimental Botany of the Czech Academy of Sciences, Šlechtitelů 27, 78371, Olomouc, Czech Republic
| | - Kai Dünser
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna (BOKU), Muthgasse 18, 1190, Vienna, Austria
| | - Shanice Martopawiro
- Plant Ecophysiology, Institute of Environmental Biology, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands
| | - Rashmi Sasidharan
- Plant Ecophysiology, Institute of Environmental Biology, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands
| | - Ondrej Novak
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science of Palacký University and Institute of Experimental Botany of the Czech Academy of Sciences, Šlechtitelů 27, 78371, Olomouc, Czech Republic
| | - Krzysztof Wabnik
- Centro de Biotecnología y Genómica de Plantas (Universidad Politécnica de Madrid - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria), Autopista M-40, Km 38-Pozuelo de Alarcón, 28223, Madrid, Spain
| | - José R Dinneny
- Department of Biology, Stanford University, 260 Panama Street, Stanford, CA, 94305, USA.,Department of Plant Biology, Carnegie Institution for Science, 260 Panama Street, Stanford, CA, 94305, USA
| | - Jürgen Kleine-Vehn
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna (BOKU), Muthgasse 18, 1190, Vienna, Austria.
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26
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Mellor N, Vaughan-Hirsch J, Kümpers BMC, Help-Rinta-Rahko H, Miyashima S, Mähönen AP, Campilho A, King JR, Bishopp A. A core mechanism for specifying root vascular patterning can replicate the anatomical variation seen in diverse plant species. Development 2019; 146:dev.172411. [PMID: 30858228 PMCID: PMC6451317 DOI: 10.1242/dev.172411] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 02/18/2019] [Indexed: 01/06/2023]
Abstract
Pattern formation is typically controlled through the interaction between molecular signals within a given tissue. During early embryonic development, roots of the model plant Arabidopsis thaliana have a radially symmetric pattern, but a heterogeneous input of the hormone auxin from the two cotyledons forces the vascular cylinder to develop a diarch pattern with two xylem poles. Molecular analyses and mathematical approaches have uncovered the regulatory circuit that propagates this initial auxin signal into a stable cellular pattern. The diarch pattern seen in Arabidopsis is relatively uncommon among flowering plants, with most species having between three and eight xylem poles. Here, we have used multiscale mathematical modelling to demonstrate that this regulatory module does not require a heterogeneous auxin input to specify the vascular pattern. Instead, the pattern can emerge dynamically, with its final form dependent upon spatial constraints and growth. The predictions of our simulations compare to experimental observations of xylem pole number across a range of species, as well as in transgenic systems in Arabidopsis in which we manipulate the size of the vascular cylinder. By considering the spatial constraints, our model is able to explain much of the diversity seen in different flowering plant species.
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Affiliation(s)
- Nathan Mellor
- Centre for Plant Integrative Biology/School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
| | - John Vaughan-Hirsch
- Centre for Plant Integrative Biology/School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
| | - Britta M C Kümpers
- Centre for Plant Integrative Biology/School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
| | - Hanna Help-Rinta-Rahko
- Institute of Biotechnology, HiLIFE/Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki 00014, Finland
| | - Shunsuke Miyashima
- Graduate School of Science and Technology, Nara Institute of Science and Technology, Nara 630-0192, Japan
| | - Ari Pekka Mähönen
- Institute of Biotechnology, HiLIFE/Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki 00014, Finland
| | - Ana Campilho
- Research Center in Biodiversity and Genetic Resources, Department of Biology, Faculty of Sciences, University of Porto, 4485-661 Vairão, Portugal
| | - John R King
- School of Mathematical Sciences/Centre for Plant Integrative Biology, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Anthony Bishopp
- Centre for Plant Integrative Biology/School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
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27
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Salazar R, Pollmann S, Morales-Quintana L, Herrera R, Caparrós-Ruiz D, Ramos P. In seedlings of Pinus radiata, jasmonic acid and auxin are differentially distributed on opposite sides of tilted stems affecting lignin monomer biosynthesis and composition. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2019; 135:215-223. [PMID: 30576980 DOI: 10.1016/j.plaphy.2018.12.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 12/05/2018] [Accepted: 12/12/2018] [Indexed: 05/25/2023]
Abstract
Plants respond to the loss of vertical growth re-orientating their affected organs. In trees, this phenomenon has received the scientific attention due to its importance for the forestry industry. Nowadays it is accepted that auxin distribution is involved in the modulation of the tilting response, but how this distribution is controlled is not fully clear. Auxin transporters that determine the spatio-temporal auxin distribution in radiate pine seedlings exposed to 45° of tilting were identified. Additionally, based on indications for an intimate plant hormone crosstalk in this process, IAA and JA contents were evaluated. The experiments revealed that expression of the auxin transporters was down-regulated in the upper half of the tilted stem, while being induced in the lower half. Moreover, transporter-coding genes were first induced at the apical zone of the stem. IAA was consistently redistributed toward the lower half, which is in accordance with the expression profile of the auxin transporters. In contrast, JA was mainly accumulated in the upper half of tilted stems. Finally, lignin content and monomeric composition were analyzed in both sides of stem and along the time course of tilting. As expected, lignin accumulation was higher at the lower half of stem at longer times of tilting. However, the most marked difference was the accumulation of the H-lignin monomer in the lower half, while the G-lignin unit was more dominant in the upper half. Here, we provide detailed insight in the distribution of IAA and JA, affecting the lignin composition during the tilting response in Pinus radiata seedlings.
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Affiliation(s)
- Romina Salazar
- Instituto de Ciencias Biológicas, Campus Talca, Universidad de Talca, Avda. Lircay s/, Talca, Chile
| | - Stephan Pollmann
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Pozuelo de Alarcón, Spain
| | - Luis Morales-Quintana
- Multidisciplinary Agroindustry Research Laboratory, Universidad Autónoma de Chile, Chile
| | - Raul Herrera
- Instituto de Ciencias Biológicas, Campus Talca, Universidad de Talca, Avda. Lircay s/, Talca, Chile
| | - David Caparrós-Ruiz
- Centre for Research in Agricultural Genomics (CRAG) Consorci CSIC-IRTA-UAB-UB Edifici CRAG Campus de Bellaterra de la UAB, 08193, Cerdanyola del Valles, Barcelona, Spain
| | - Patricio Ramos
- Instituto de Ciencias Biológicas, Campus Talca, Universidad de Talca, Avda. Lircay s/, Talca, Chile.
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28
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Swarup R, Bhosale R. Developmental Roles of AUX1/LAX Auxin Influx Carriers in Plants. FRONTIERS IN PLANT SCIENCE 2019; 10:1306. [PMID: 31719828 PMCID: PMC6827439 DOI: 10.3389/fpls.2019.01306] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 09/19/2019] [Indexed: 05/06/2023]
Abstract
Plant hormone auxin regulates several aspects of plant growth and development. Auxin is predominantly synthesized in the shoot apex and developing leaf primordia and from there it is transported to the target tissues e.g. roots. Auxin transport is polar in nature and is carrier-mediated. AUXIN1/LIKE-AUX1 (AUX1/LAX) family members are the major auxin influx carriers whereas PIN-FORMED (PIN) family and some members of the P-GLYCOPROTEIN/ATP-BINDING CASSETTE B4 (PGP/ABCB) family are major auxin efflux carriers. AUX1/LAX auxin influx carriers are multi-membrane spanning transmembrane proteins sharing similarity to amino acid permeases. Mutations in AUX1/LAX genes result in auxin related developmental defects and have been implicated in regulating key plant processes including root and lateral root development, root gravitropism, root hair development, vascular patterning, seed germination, apical hook formation, leaf morphogenesis, phyllotactic patterning, female gametophyte development and embryo development. Recently AUX1 has also been implicated in regulating plant responses to abiotic stresses. This review summarizes our current understanding of the developmental roles of AUX1/LAX gene family and will also briefly discuss the modelling approaches that are providing new insight into the role of auxin transport in plant development.
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Affiliation(s)
- Ranjan Swarup
- Plant and Crop Sciences, School of Biosciences, University of Nottingham, Nottingham, United Kingdom
- Center for Plant Integrative Biology (CPIB), University of Nottingham, Nottingham, United Kingdom
- *Correspondence: Ranjan Swarup,
| | - Rahul Bhosale
- Plant and Crop Sciences, School of Biosciences, University of Nottingham, Nottingham, United Kingdom
- Center for Plant Integrative Biology (CPIB), University of Nottingham, Nottingham, United Kingdom
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29
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Grones P, Abas M, Hajný J, Jones A, Waidmann S, Kleine-Vehn J, Friml J. PID/WAG-mediated phosphorylation of the Arabidopsis PIN3 auxin transporter mediates polarity switches during gravitropism. Sci Rep 2018; 8:10279. [PMID: 29980705 PMCID: PMC6035267 DOI: 10.1038/s41598-018-28188-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 06/14/2018] [Indexed: 01/08/2023] Open
Abstract
Intercellular distribution of the plant hormone auxin largely depends on the polar subcellular distribution of the plasma membrane PIN-FORMED (PIN) auxin transporters. PIN polarity switches in response to different developmental and environmental signals have been shown to redirect auxin fluxes mediating certain developmental responses. PIN phosphorylation at different sites and by different kinases is crucial for PIN function. Here we investigate the role of PIN phosphorylation during gravitropic response. Loss- and gain-of-function mutants in PINOID and related kinases but not in D6PK kinase as well as mutations mimicking constitutive dephosphorylated or phosphorylated status of two clusters of predicted phosphorylation sites partially disrupted PIN3 phosphorylation and caused defects in gravitropic bending in roots and hypocotyls. In particular, they impacted PIN3 polarity rearrangements in response to gravity and during feed-back regulation by auxin itself. Thus PIN phosphorylation, besides regulating transport activity and apical-basal targeting, is also important for the rapid polarity switches in response to environmental and endogenous signals.
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Affiliation(s)
- Peter Grones
- Institute of Science and Technology Austria (IST Austria), Am Campus 1, 3400, Klosterneuburg, Austria
| | - Melinda Abas
- Institute of Science and Technology Austria (IST Austria), Am Campus 1, 3400, Klosterneuburg, Austria.,Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences (BOKU), Muthgasse 18, 1190, Vienna, Austria
| | - Jakub Hajný
- Institute of Science and Technology Austria (IST Austria), Am Campus 1, 3400, Klosterneuburg, Austria.,Laboratory of Growth Regulators, Palacký University, Křížkovského 511/8, 771 47, Olomouc, Czech Republic
| | - Angharad Jones
- Cardiff School of Biosciences, The Sir Martin Evans Building, Museum Avenue, Cardiff, CF10 3AX, United Kingdom
| | - Sascha Waidmann
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences (BOKU), Muthgasse 18, 1190, Vienna, Austria
| | - Jürgen Kleine-Vehn
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences (BOKU), Muthgasse 18, 1190, Vienna, Austria
| | - Jiří Friml
- Institute of Science and Technology Austria (IST Austria), Am Campus 1, 3400, Klosterneuburg, Austria.
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30
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Kimura T, Haga K, Shimizu-Mitao Y, Takebayashi Y, Kasahara H, Hayashi KI, Kakimoto T, Sakai T. Asymmetric Auxin Distribution is Not Required to Establish Root Phototropism in Arabidopsis. PLANT & CELL PHYSIOLOGY 2018; 59:823-835. [PMID: 29401292 DOI: 10.1093/pcp/pcy018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 01/25/2018] [Indexed: 05/11/2023]
Abstract
An asymmetric auxin distribution pattern is assumed to underlie the tropic responses of seed plants. It is unclear, however, whether this pattern is required for root negative phototropism. We here demonstrate that asymmetric auxin distribution is not required to establish root phototropism in Arabidopsis. Our detailed analyses of auxin reporter genes indicate that auxin accumulates on the irradiated side of roots in response to an incidental gravitropic stimulus caused by phototropic bending. Further, an agravitropic mutant showed a suppression of this accumulation with an enhancement of the phototropic response. In this context, our pharmacological and genetic analyses revealed that both polar auxin transport and auxin biosynthesis are critical for the establishment of root gravitropism, but not for root phototropism, and that defects in these processes actually enhance phototropic responses in roots. The auxin response factor double mutant arf7 arf19 and the auxin receptor mutant tir1 showed a slight reduction in phototropic curvatures in roots, suggesting that the transcriptional regulation by some specific ARF proteins and their regulators is at least partly involved in root phototropism. However, the auxin antagonist PEO-IAA [α-(phenylethyl-2-one)-indole-3-acetic acid] suppressed root gravitropism and enhanced root phototropism, suggesting that the TIR1/AFB auxin receptors and ARF transcriptional factors play minor roles in root phototropism. Taken together, we conclude from our current data that the phototropic response in Arabidopsis roots is induced by an unknown mechanism that does not require asymmetric auxin distribution and that the Cholodny-Went hypothesis probably does not apply to root phototropism.
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Affiliation(s)
- Taro Kimura
- Graduate School of Science and Technology, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata, 950-2181 Japan
- Research Fellow of Japan Society for the Promotion of Science, Kojimachi Business Center Building, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo, 102-0083 Japan
| | - Ken Haga
- Department of Human Science and Common Education, Nippon Institute of Technology, 4-1 Gakuendai, Miyashiro-cho, Minamisaitama-gun, Saitama, 345-8501 Japan
| | - Yasushi Shimizu-Mitao
- Department of Biological Science, Graduate School of Science, Osaka University, 1-4 Machikaneyama-cho, Toyonaka, Osaka, 560-0043 Japan
| | - Yumiko Takebayashi
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045 Japan
| | - Hiroyuki Kasahara
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045 Japan
- Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, 3-8-1 Harumi-cho, Fuchu-shi, Tokyo, 183-8538 Japan
| | - Ken-Ichiro Hayashi
- Department of Biochemistry, Okayama University of Science, 1-1 Ridaicho, Kita-ku, Okayama, 700-0005 Japan
| | - Tatsuo Kakimoto
- Department of Biological Science, Graduate School of Science, Osaka University, 1-4 Machikaneyama-cho, Toyonaka, Osaka, 560-0043 Japan
| | - Tatsuya Sakai
- Graduate School of Science and Technology, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata, 950-2181 Japan
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31
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Li J, Zhang J, Jia H, Liu B, Sun P, Hu J, Wang L, Lu M. The WUSCHEL-related homeobox 5a (PtoWOX5a) is involved in adventitious root development in poplar. TREE PHYSIOLOGY 2018; 38:139-153. [PMID: 29036435 DOI: 10.1093/treephys/tpx118] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 08/31/2017] [Indexed: 05/24/2023]
Abstract
Adventitious rooting is an essential step in vegetative propagation. Currently, the mechanism that regulates adventitious root (AR) development in woody plants is poorly understood. This work demonstrates that Populus tomentosa WUSCHEL-related homeobox 5a (PtoWOX5a) transcription factor is involved in AR development in poplar. PtoWOX5a was specifically expressed in the AR tip and lateral root tip during AR and lateral root regeneration from the stem segment. Phenotypic complementation experiments indicated that the PtoWOX5a can functionally complement AtWOX5 in quiescent center (QC) cells. Overexpression of PtoWOX5a introduces significant developmental phenotypes in roots and leaves, such as increased AR number, decreased AR length, swollen AR tip and lateral root tip, and decreased leaf number and area. The conserved mechanism of D-type cyclins (CYCD) repression mediated by WOX5 was confirmed in poplar. The co-expression network of PtWOX5a was constructed, which provided clues to reveal the molecular mechanism of PtoWOX5a in AR development in poplar. Taken together, our results suggest that the PtoWOX5a is involved in AR development though cooperating with a series of functional genes.
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Affiliation(s)
- Jianbo Li
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
- Experimental Center of Forestry in North China, Chinese Academy of Forestry, Beijing 100091, China
| | - Jin Zhang
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
| | - Huixia Jia
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
| | - Bobin Liu
- Basic Forestry and Proteomics Center, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350000, China
| | - Pei Sun
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
| | - Jianjun Hu
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
| | - Lijuan Wang
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
| | - Mengzhu Lu
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
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32
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Raboanatahiry N, Chao H, Dalin H, Pu S, Yan W, Yu L, Wang B, Li M. QTL Alignment for Seed Yield and Yield Related Traits in Brassica napus. FRONTIERS IN PLANT SCIENCE 2018; 9:1127. [PMID: 30116254 PMCID: PMC6083399 DOI: 10.3389/fpls.2018.01127] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 07/12/2018] [Indexed: 05/17/2023]
Abstract
Worldwide consumption of oil is increasing with the growing population in need for edible oil and the expansion of industry using biofuels. Then, demand for high yielding varieties of oil crops is always increasing. Brassica napus (rapeseed) is one of the most important oil crop in the world, therefore, increasing rapeseed yield through breeding is inevitable in order to cater for the high demand of vegetable oil and high-quality protein for live stocks. Quantitative trait loci (QTL) analysis is a powerful tool to identify important loci and which is also valuable for molecular marker assisted breeding. Seed-yield (SY) is a complex trait that is controlled by multiple loci and is affected directly by seed weight, seeds per silique and silique number. Some yield-related traits, such as plant height, biomass yield, flowering time, and so on, also affect the SY indirectly. This study reports the assembly of QTLs identified for seed-yield and yield-related traits in rapeseed, in one unique map. A total of 972 QTLs for seed-yield and yield-related were aligned into the physical map of B. napus Darmor-bzh and 92 regions where 198 QTLs overlapped, could be discovered on 16 chromosomes. Also, 147 potential candidate genes were discovered in 65 regions where 131 QTLs overlapped, and might affect nine different traits. At the end, interaction network of candidate genes was studied, and showed nine genes that could highly interact with the other genes, and might have more influence on them. The present results would be helpful to develop molecular markers for yield associated traits and could be used for breeding improvement in B. napus.
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Affiliation(s)
- Nadia Raboanatahiry
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
- Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resources Comprehensive Utilization, Hubei Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains, Huanggang Normal University, Huanggang, China
| | - Hongbo Chao
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
- Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resources Comprehensive Utilization, Hubei Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains, Huanggang Normal University, Huanggang, China
| | - Hou Dalin
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
- Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resources Comprehensive Utilization, Hubei Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains, Huanggang Normal University, Huanggang, China
| | - Shi Pu
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Wei Yan
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Longjiang Yu
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Baoshan Wang
- College of Life Sciences, Shandong Normal University, Jinan, China
| | - Maoteng Li
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
- Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resources Comprehensive Utilization, Hubei Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains, Huanggang Normal University, Huanggang, China
- *Correspondence: Maoteng Li,
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Pařízková B, Pernisová M, Novák O. What Has Been Seen Cannot Be Unseen-Detecting Auxin In Vivo. Int J Mol Sci 2017; 18:ijms18122736. [PMID: 29258197 PMCID: PMC5751337 DOI: 10.3390/ijms18122736] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 12/10/2017] [Accepted: 12/12/2017] [Indexed: 12/24/2022] Open
Abstract
Auxins mediate various processes that are involved in plant growth and development in response to specific environmental conditions. Its proper spatio-temporal distribution that is driven by polar auxin transport machinery plays a crucial role in the wide range of auxins physiological effects. Numbers of approaches have been developed to either directly or indirectly monitor auxin distribution in vivo in order to elucidate the basis of its precise regulation. Herein, we provide an updated list of valuable techniques used for monitoring auxins in plants, with their utilities and limitations. Because the spatial and temporal resolutions of the presented approaches are different, their combination may provide a comprehensive outcome of auxin distribution in diverse developmental processes.
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Affiliation(s)
- Barbora Pařízková
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science of Palacký University & Institute of Experimental Botany of the Czech Academy of Sciences, Šlechtitelů 27, CZ-783 71 Olomouc, Czech Republic.
- Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science of Palacký University, Šlechtitelů 27, CZ-783 71 Olomouc, Czech Republic.
| | - Markéta Pernisová
- Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science of Palacký University, Šlechtitelů 27, CZ-783 71 Olomouc, Czech Republic.
- Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, CZ-62500 Brno, Czech Republic.
| | - Ondřej Novák
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science of Palacký University & Institute of Experimental Botany of the Czech Academy of Sciences, Šlechtitelů 27, CZ-783 71 Olomouc, Czech Republic.
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Sun J, Wang L, Li S, Yin L, Huang J, Chen C. Toxicity of silver nanoparticles to Arabidopsis: Inhibition of root gravitropism by interfering with auxin pathway. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2017; 36:2773-2780. [PMID: 28440569 DOI: 10.1002/etc.3833] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 02/03/2017] [Accepted: 04/24/2017] [Indexed: 05/25/2023]
Abstract
Impacts of polyvinylpyrrolidine-coated silver nanoparticles (AgNPs) on root gravitropism in Arabidopsis thaliana were investigated at the physiological, cellular, and molecular levels. Our results showed that AgNPs were taken up by the root and primarily localized at the cell wall and intercellular spaces. Root gravitropism was inhibited by exposure to AgNPs, and the inhibition in root gravitropism caused by exposure to AgNPs exhibited a dose-response relationship. Auxin accumulation was reduced in the root tips because of exposure to AgNPs. However, increased indole-3-acetic acid level could not rescue the inhibition of root gravitropism. Real-time polymerase chain reaction showed significant downregulation of expression of auxin receptor-related genes, which is the TIR1/AFB family of F-box proteins including AFB1, AFB2, AFB3, AFB5, and TIR1. Therefore, the present study suggests that AgNPs have toxicity to the model plant A. thaliana as shown by inhibition of root gravitropism along with a reduction in auxin accumulation and expression of auxin receptors. Environ Toxicol Chem 2017;36:2773-2780. © 2017 SETAC.
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Affiliation(s)
- Juzhi Sun
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Likai Wang
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Shuang Li
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Liyan Yin
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, Agricultural College, Hainan University, Haikou, China
| | - Jin Huang
- School of Chemistry and Chemical Engineering, Southwest University, Chongqing, China
| | - Chunli Chen
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
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Singh M, Gupta A, Laxmi A. Striking the Right Chord: Signaling Enigma during Root Gravitropism. FRONTIERS IN PLANT SCIENCE 2017; 8:1304. [PMID: 28798760 PMCID: PMC5529344 DOI: 10.3389/fpls.2017.01304] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 07/11/2017] [Indexed: 05/29/2023]
Abstract
Plants being sessile can often be judged as passive acceptors of their environment. However, plants are actually even more active in responding to the factors from their surroundings. Plants do not have eyes, ears or vestibular system like animals, still they "know" which way is up and which way is down? This is facilitated by receptor molecules within plant which perceive changes in internal and external conditions such as light, touch, obstacles; and initiate signaling pathways that enable the plant to react. Plant responses that involve a definite and specific movement are called "tropic" responses. Perhaps the best known and studied tropisms are phototropism, i.e., response to light, and geotropism, i.e., response to gravity. A robust root system is vital for plant growth as it can provide physical anchorage to soil as well as absorb water, nutrients and essential minerals from soil efficiently. Gravitropic responses of both primary as well as lateral root thus become critical for plant growth and development. The molecular mechanisms of root gravitropism has been delved intensively, however, the mechanism behind how the potential energy of gravity stimulus converts into a biochemical signal in vascular plants is still unknown, due to which gravity sensing in plants still remains one of the most fascinating questions in molecular biology. Communications within plants occur through phytohormones and other chemical substances produced in plants which have a developmental or physiological effect on growth. Here, we review current knowledge of various intrinsic signaling mechanisms that modulate root gravitropism in order to point out the questions and emerging developments in plant directional growth responses. We are also discussing the roles of sugar signals and their interaction with phytohormone machinery, specifically in context of root directional responses.
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Affiliation(s)
- Manjul Singh
- National Institute of Plant Genome ResearchNew Delhi, India
- Interdisciplinary Centre for Plant Genomics, University of Delhi South CampusNew Delhi, India
| | - Aditi Gupta
- National Institute of Plant Genome ResearchNew Delhi, India
- Interdisciplinary Centre for Plant Genomics, University of Delhi South CampusNew Delhi, India
| | - Ashverya Laxmi
- National Institute of Plant Genome ResearchNew Delhi, India
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Mellor N, Adibi M, El-Showk S, De Rybel B, King J, Mähönen AP, Weijers D, Bishopp A. Theoretical approaches to understanding root vascular patterning: a consensus between recent models. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:5-16. [PMID: 27837006 DOI: 10.1093/jxb/erw410] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The root vascular tissues provide an excellent system for studying organ patterning, as the specification of these tissues signals a transition from radial symmetry to bisymmetric patterns. The patterning process is controlled by the combined action of hormonal signaling/transport pathways, transcription factors, and miRNA that operate through a series of non-linear pathways to drive pattern formation collectively. With the discovery of multiple components and feedback loops controlling patterning, it has become increasingly difficult to understand how these interactions act in unison to determine pattern formation in multicellular tissues. Three independent mathematical models of root vascular patterning have been formulated in the last few years, providing an excellent example of how theoretical approaches can complement experimental studies to provide new insights into complex systems. In many aspects these models support each other; however, each study also provides its own novel findings and unique viewpoints. Here we reconcile these models by identifying the commonalities and exploring the differences between them by testing how transferable findings are between models. New simulations herein support the hypothesis that an asymmetry in auxin input can direct the formation of vascular pattern. We show that the xylem axis can act as a sole source of cytokinin and specify the correct pattern, but also that broader patterns of cytokinin production are also able to pattern the root. By comparing the three modeling approaches, we gain further insight into vascular patterning and identify several key areas for experimental investigation.
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Affiliation(s)
- Nathan Mellor
- Centre for Plant Integrative Biology, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
| | - Milad Adibi
- Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
| | - Sedeer El-Showk
- Institute of Biotechnology, University of Helsinki, Helsinki FIN-00014, Finland
- Department of Biosciences, Viikki Plant Science Centre, University of Helsinki, Helsinki FIN-00014, Finland
| | - Bert De Rybel
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, 6708WE Wageningen, The Netherlands
- Department of Plant Systems Biology, VIB, Technologiepark 927, B-9052, Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, VIB, Technologiepark 927, B-9052, Ghent, Belgium
| | - John King
- Centre for Plant Integrative Biology, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
- School of Mathematical Sciences, University of Nottingham, Nottingham NG7 2RD, UK
- Synthetic Biology Research Centre, The University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Ari Pekka Mähönen
- Institute of Biotechnology, University of Helsinki, Helsinki FIN-00014, Finland
- Department of Biosciences, Viikki Plant Science Centre, University of Helsinki, Helsinki FIN-00014, Finland
| | - Dolf Weijers
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, 6708WE Wageningen, The Netherlands
| | - Anthony Bishopp
- Centre for Plant Integrative Biology, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
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