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Hu M, Zhao S, Zhao Y, Lu M, Song X. PagKNAT2/6b regulates tension wood formation and gravitropism by targeting cytokinin metabolism. TREE PHYSIOLOGY 2024; 44:tpae090. [PMID: 39030690 DOI: 10.1093/treephys/tpae090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 06/21/2024] [Accepted: 07/18/2024] [Indexed: 07/21/2024]
Abstract
Tension wood is a specialized xylem tissue associated with gravitropism in angiosperm trees. However, few regulators of tension wood formation have been identified. The molecular mechanisms underpinning tension wood formation remain elusive. Here, we report that a Populus KNOTTED-like homeobox gene, PagKNAT2/6b, is involved in tension wood formation and gravity response. Transgenic poplar plants overexpressing PagKNAT2/6b displayed more sensitive gravitropism than controls, as indicated by increased stem curvature. Microscopic examination revealed greater abundance of fibre cells with a gelatinous cell wall layer (G-layer) and asymmetric growth of secondary xylem in PagKNAT2/6b overexpression lines. Conversely, PagKNAT2/6b dominant repression plants exhibited decreased tension wood formation and reduced response to gravity stimulation. Moreover, sensitivity to gravity stimulation showed a negative relationship with development stage. Expression of genes related to growth and senescence was affected in PagKNAT2/6b transgenic plants. More importantly, transcription activation and electrophoretic mobility shift assays suggested that PagKNAT2/6b promotes the expression of cytokinin metabolism genes. Consistently, cytokinin content was increased in PagKNAT2/6b overexpression plants. Therefore, PagKNAT2/6b is involved in gravitropism and tension wood formation, likely via modulation of cytokinin metabolism.
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Affiliation(s)
- Mengxuan 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, Xiangshan Road, Haidian District, Beijing 100091, China
| | - Shutang Zhao
- 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, Xiangshan Road, Haidian District, Beijing 100091, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Longpan Road, Xuanwu District, Nanjing, Jiangsu 210037, China
| | - Yanqiu Zhao
- 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, Xiangshan Road, Haidian District, Beijing 100091, China
- School of Agriculture, Ludong University, Hongqizhong Road, Zhifu District, Yantai 264025, 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, Xiangshan Road, Haidian District, Beijing 100091, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Longpan Road, Xuanwu District, Nanjing, Jiangsu 210037, China
- State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang Agriculture & Forestry University, Wusu Street, Linan District, Hangzhou 311300, China
| | - Xueqin Song
- 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, Xiangshan Road, Haidian District, Beijing 100091, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Longpan Road, Xuanwu District, Nanjing, Jiangsu 210037, China
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Pozhvanov G, Suslov D. Sucrose and Mannans Affect Arabidopsis Shoot Gravitropism at the Cell Wall Level. PLANTS (BASEL, SWITZERLAND) 2024; 13:209. [PMID: 38256762 PMCID: PMC10819476 DOI: 10.3390/plants13020209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/08/2024] [Accepted: 01/08/2024] [Indexed: 01/24/2024]
Abstract
Gravitropism is the plant organ bending in response to gravity. Gravitropism, phototropism and sufficient mechanical strength define the optimal position of young shoots for photosynthesis. Etiolated wild-type Arabidopsis seedlings grown horizontally in the presence of sucrose had a lot more upright hypocotyls than seedlings grown without sucrose. We studied the mechanism of this effect at the level of cell wall biomechanics and biochemistry. Sucrose strengthened the bases of hypocotyls and decreased the content of mannans in their cell walls. As sucrose is known to increase the gravitropic bending of hypocotyls, and mannans have recently been shown to interfere with this process, we examined if the effect of sucrose on shoot gravitropism could be partially mediated by mannans. We compared cell wall biomechanics and metabolomics of hypocotyls at the early steps of gravitropic bending in Col-0 plants grown with sucrose and mannan-deficient mutant seedlings. Sucrose and mannans affected gravitropic bending via different mechanisms. Sucrose exerted its effect through cell wall-loosening proteins, while mannans changed the walls' viscoelasticity. Our data highlight the complexity of shoot gravitropism control at the cell wall level.
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Affiliation(s)
- Gregory Pozhvanov
- Department of Plant Physiology and Biochemistry, St. Petersburg State University, 199034 St. Petersburg, Russia;
- Laboratory of Analytical Phytochemistry, Komarov Botanical Institute of the Russian Academy of Sciences, 197376 St. Petersburg, Russia
- Department of Botany and Ecology, Herzen State Pedagogical University, 191186 St. Petersburg, Russia
| | - Dmitry Suslov
- Department of Plant Physiology and Biochemistry, St. Petersburg State University, 199034 St. Petersburg, Russia;
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Li J, Sheng Y, Xu H, Li Q, Lin X, Zhou Y, Zhao Y, Song X, Wang J. Transcriptome and hormone metabolome reveal the mechanism of stem bending in water lily ( Nymphaea tetragona) cut-flowers. FRONTIERS IN PLANT SCIENCE 2023; 14:1195389. [PMID: 37746018 PMCID: PMC10515221 DOI: 10.3389/fpls.2023.1195389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 08/24/2023] [Indexed: 09/26/2023]
Abstract
Water lilies are popular ornamental cut-flowers with significant economic and cultural value. However, stem bending affects the preservation of cut-flowers during their vase life. To gain further insights into the molecular mechanisms of stem bending, transcriptome profiling, hormone measurement, and morphological analysis were performed using the stems of the 'Blue Bird' water lily. Transcriptome analysis revealed that 607 differentially expressed genes (DEGs) were associated with the dorsal and ventral stems of the water lily, of which 247 were up-regulated and 360 were down-regulated. Significant differences in genes associated with plant hormones, calcium ions, glucose metabolism, and photosynthesis pathways genes involved in the dorsal and ventral areas of the curved stem. In particular, DEGs were associated with the hormone synthesis, gravity response, starch granules, Ca2+ ions, and photosynthesis. The results of qRT-PCR were consistent with that of the transcriptome sequence analysis. A total of 12 hormones were detected, of which abscisic acid, indole-3-carboxaldehyde, indole-3-carboxaldehyde and jasmonic acid were significantly differentially expressed in the dorsal and ventral stems, and were significantly higher in the dorsal stem than in the ventral stem. The cell morphology in the dorsal and ventral areas of the curved stem clearly changed during vase life. The direction of starch granule settlement was consistent with the bending direction of the water lily stem, as well as the direction of gravity. In conclusion, stem bending in water lily cut-flowers is regulated by multiple factors and genes. This study provides an important theoretical basis for understanding the complex regulatory mechanism of water lily stem bending.
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Affiliation(s)
- Jie Li
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Forest Trees and Ornamental Plants, Ministry of Education, College of Forestry, Hainan University, Haikou, Hainan, China
- Key Laboratory of Germplasm Resources Biology of Tropical Special Ornamental Plants of Hainan, Haikou, Hainan, China
| | - Yuhui Sheng
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Forest Trees and Ornamental Plants, Ministry of Education, College of Forestry, Hainan University, Haikou, Hainan, China
- Key Laboratory of Germplasm Resources Biology of Tropical Special Ornamental Plants of Hainan, Haikou, Hainan, China
- College of Agricultural, Hengxing University, Qingdao, Shandong, China
| | - Huixian Xu
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Forest Trees and Ornamental Plants, Ministry of Education, College of Forestry, Hainan University, Haikou, Hainan, China
- Key Laboratory of Germplasm Resources Biology of Tropical Special Ornamental Plants of Hainan, Haikou, Hainan, China
| | - Qinxue Li
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Forest Trees and Ornamental Plants, Ministry of Education, College of Forestry, Hainan University, Haikou, Hainan, China
- Key Laboratory of Germplasm Resources Biology of Tropical Special Ornamental Plants of Hainan, Haikou, Hainan, China
| | - Xiuya Lin
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Forest Trees and Ornamental Plants, Ministry of Education, College of Forestry, Hainan University, Haikou, Hainan, China
- Key Laboratory of Germplasm Resources Biology of Tropical Special Ornamental Plants of Hainan, Haikou, Hainan, China
| | - Yang Zhou
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Forest Trees and Ornamental Plants, Ministry of Education, College of Forestry, Hainan University, Haikou, Hainan, China
- Key Laboratory of Germplasm Resources Biology of Tropical Special Ornamental Plants of Hainan, Haikou, Hainan, China
| | - Ying Zhao
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Forest Trees and Ornamental Plants, Ministry of Education, College of Forestry, Hainan University, Haikou, Hainan, China
- Key Laboratory of Germplasm Resources Biology of Tropical Special Ornamental Plants of Hainan, Haikou, Hainan, China
| | - Xiqiang Song
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Forest Trees and Ornamental Plants, Ministry of Education, College of Forestry, Hainan University, Haikou, Hainan, China
- Key Laboratory of Germplasm Resources Biology of Tropical Special Ornamental Plants of Hainan, Haikou, Hainan, China
| | - Jian Wang
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Forest Trees and Ornamental Plants, Ministry of Education, College of Forestry, Hainan University, Haikou, Hainan, China
- Key Laboratory of Germplasm Resources Biology of Tropical Special Ornamental Plants of Hainan, Haikou, Hainan, China
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Transcriptomic Evidence Reveals Low Gelatinous Layer Biosynthesis in Neolamarckia cadamba after Gravistimulation. Int J Mol Sci 2022; 24:ijms24010268. [PMID: 36613711 PMCID: PMC9820806 DOI: 10.3390/ijms24010268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 11/26/2022] [Accepted: 11/28/2022] [Indexed: 12/28/2022] Open
Abstract
Trees can control their shape and resist gravity by producing tension wood (TW), which is a special wood that results from trees being put under stress. TW is characterized by the presence of a gelatinous layer (G layer) and the differential distribution of cell wall polymers. In this study, we investigated whether or not gravistimulation in N. cadamba resulted in TW with an obvious G layer. The results revealed an absence of an obvious G layer in samples of the upper side of a leaning stem (UW), as well as an accumulation of cellulose and a decrease in lignin content. A negligible change in the content of these polymers was recorded and compared to untreated plant (NW) samples, revealing the presence of a G layer either in much lower concentrations or in a lignified form. A transcriptomic investigation demonstrated a higher expression of cell wall esterase- and hydrolase-related genes in the UW, suggesting an accumulation of noncellulosic sugars in the UW, similar to the spectroscopy results. Furthermore, several G-layer-specific genes were also downregulated, including fasciclin-like arabinogalactan proteins (FLA), beta-galactosidase (BGAL) and chitinase-like proteins (CTL). The gene coexpression network revealed a strong correlation between cell-wall-synthesis-related genes and G-layer-synthesis-specific genes, suggesting their probable antagonistic role during G layer formation. In brief, the G layer in N. cadamba was either synthesized in a very low amount or was lignified during an early stage of growth; further experimental validation is required to understand the exact mechanism and stage of G layer formation in N. cadamba during gravistimulation.
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Yu J, Zhou C, Li D, Li S, Jimmy Lin YC, Wang JP, Chiang VL, Li W. A PtrLBD39-mediated transcriptional network regulates tension wood formation in Populus trichocarpa. PLANT COMMUNICATIONS 2022; 3:100250. [PMID: 35059630 PMCID: PMC8760142 DOI: 10.1016/j.xplc.2021.100250] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 09/10/2021] [Accepted: 10/19/2021] [Indexed: 05/29/2023]
Abstract
Tension wood (TW) is a specialized xylem tissue formed in angiosperm trees under gravitational stimulus or mechanical stresses (e.g., bending). The genetic regulation that underlies this important mechanism remains poorly understood. Here, we used laser capture microdissection of stem xylem cells coupled with full transcriptome RNA-sequencing to analyze TW formation in Populus trichocarpa. After tree bending, PtrLBD39 was the most significantly induced transcription factor gene; it has a phylogenetically paired homolog, PtrLBD22. CRISPR-based knockout of PtrLBD39/22 severely inhibited TW formation, reducing cellulose and increasing lignin content. Transcriptomic analyses of CRISPR-based PtrLBD39/22 double mutants showed that these two genes regulate a set of TW-related genes. Chromatin immunoprecipitation sequencing (ChIP-seq) was used to identify direct targets of PtrLBD39. We integrated transcriptomic analyses and ChIP-seq assays to construct a transcriptional regulatory network (TRN) mediated by PtrLBD39. In this TRN, PtrLBD39 directly regulates 26 novel TW-responsive transcription factor genes. Our work suggests that PtrLBD39 and PtrLBD22 specifically control TW formation by mediating a TW-specific TRN in Populus.
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Affiliation(s)
- Jing Yu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Chenguang Zhou
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Danning Li
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Shuang Li
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Ying-Chung Jimmy Lin
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
- Department of Life Sciences and Institute of Plant Biology, College of Life Science, National Taiwan University, Taipei, Taiwan 10617, China
| | - Jack P. Wang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
- Department of Forestry and Environmental Resources, Forest Biotechnology Group, North Carolina State University, Raleigh, NC 27695, USA
| | - Vincent L. Chiang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
- Department of Forestry and Environmental Resources, Forest Biotechnology Group, North Carolina State University, Raleigh, NC 27695, USA
| | - Wei Li
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
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6
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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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7
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Somssich M, Vandenbussche F, Ivakov A, Funke N, Ruprecht C, Vissenberg K, VanDer Straeten D, Persson S, Suslov D. Brassinosteroids Influence Arabidopsis Hypocotyl Graviresponses through Changes in Mannans and Cellulose. PLANT & CELL PHYSIOLOGY 2021; 62:678-692. [PMID: 33570567 DOI: 10.1093/pcp/pcab024] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 02/07/2021] [Indexed: 06/12/2023]
Abstract
The force of gravity is a constant environmental factor. Plant shoots respond to gravity through negative gravitropism and gravity resistance. These responses are essential for plants to direct the growth of aerial organs away from the soil surface after germination and to keep an upright posture above ground. We took advantage of the effect of brassinosteroids (BRs) on the two types of graviresponses in Arabidopsis thaliana hypocotyls to disentangle functions of cell wall polymers during etiolated shoot growth. The ability of etiolated Arabidopsis seedlings to grow upward was suppressed in the presence of 24-epibrassinolide (EBL) but enhanced in the presence of brassinazole (BRZ), an inhibitor of BR biosynthesis. These effects were accompanied by changes in cell wall mechanics and composition. Cell wall biochemical analyses, confocal microscopy of the cellulose-specific pontamine S4B dye and cellular growth analyses revealed that the EBL and BRZ treatments correlated with changes in cellulose fibre organization, cell expansion at the hypocotyl base and mannan content. Indeed, a longitudinal reorientation of cellulose fibres and growth inhibition at the base of hypocotyls supported their upright posture whereas the presence of mannans reduced gravitropic bending. The negative effect of mannans on gravitropism is a new function for this class of hemicelluloses. We also found that EBL interferes with upright growth of hypocotyls through their uneven thickening at the base.
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Affiliation(s)
- Marc Somssich
- School of Biosciences, University of Melbourne, Parkville, Melbourne, VIC, Australia
| | - Filip Vandenbussche
- Laboratory of Functional Plant Biology, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, Gent 9000, Belgium
| | - Alexander Ivakov
- Max-Planck Institute of Molecular Plant Physiology, Am Muehlenberg 1, Potsdam 14476, Germany
| | - Norma Funke
- Max-Planck Institute of Molecular Plant Physiology, Am Muehlenberg 1, Potsdam 14476, Germany
- Targenomix GmbH, Am Muehlenberg 11, Potsdam 14476, Germany
| | - Colin Ruprecht
- Max-Planck Institute of Molecular Plant Physiology, Am Muehlenberg 1, Potsdam 14476, Germany
- Max-Planck Institute of Colloids and Interfaces, Am Muehlenberg 1, Potsdam 14476, Germany
| | - Kris Vissenberg
- Biology Department, Integrated Molecular Plant Physiology Research, University of Antwerp, Groenenborgerlaan 171, Antwerpen 2020, Belgium
- Plant Biochemistry and Biotechnology Lab, Department of Agriculture, Hellenic Mediterranean University, Stavromenos, Heraklion, Crete 71410, Greece
| | - Dominique VanDer Straeten
- Laboratory of Functional Plant Biology, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, Gent 9000, Belgium
| | - Staffan Persson
- School of Biosciences, University of Melbourne, Parkville, Melbourne, VIC, Australia
- Joint International Research Laboratory of Metabolic & Developmental Sciences, State Key Laboratory of Hybrid Rice, SJTU-University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
- Department of Plant & Environmental Sciences, University of Copenhagen, Frederiksberg C 1871, Denmark
- Copenhagen Plant Science Center, University of Copenhagen, Frederiksberg C 1871, Denmark
| | - Dmitry Suslov
- Department of Plant Physiology and Biochemistry, Faculty of Biology, Saint Petersburg State University, Universitetskaya emb. 7/9, Saint Petersburg 199034, Russia
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Du J, Gerttula S, Li Z, Zhao ST, Liu YL, Liu Y, Lu MZ, Groover AT. Brassinosteroid regulation of wood formation in poplar. THE NEW PHYTOLOGIST 2020; 225:1516-1530. [PMID: 31120133 DOI: 10.1111/nph.15936] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 04/30/2019] [Indexed: 05/06/2023]
Abstract
Brassinosteroids have been implicated in the differentiation of vascular cell types in herbaceous plants, but their roles during secondary growth and wood formation are not well defined. Here we pharmacologically and genetically manipulated brassinosteroid levels in poplar trees and assayed the effects on secondary growth and wood formation, and on gene expression within stems. Elevated brassinosteroid levels resulted in increases in secondary growth and tension wood formation, while inhibition of brassinosteroid synthesis resulted in decreased growth and secondary vascular differentiation. Analysis of gene expression showed that brassinosteroid action is positively associated with genes involved in cell differentiation and cell-wall biosynthesis. The results presented here show that brassinosteroids play a foundational role in the regulation of secondary growth and wood formation, in part through the regulation of cell differentiation and secondary cell wall biosynthesis.
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Affiliation(s)
- Juan Du
- College of Life Sciences, Zhejiang University, 866 Yu Hang tang Road, Hangzhou, 310058, China
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
- Pacific Southwest Research Station, US Forest Service, Davis, CA, 95618, USA
| | - Suzanne Gerttula
- Pacific Southwest Research Station, US Forest Service, Davis, CA, 95618, USA
| | - Zehua Li
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Shu-Tang Zhao
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Ying-Li Liu
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Yu Liu
- College of Life Sciences, Zhejiang University, 866 Yu Hang tang Road, Hangzhou, 310058, China
| | - Meng-Zhu Lu
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
- State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang Agriculture and Forest University, Hangzhou, 311300, China
| | - Andrew T Groover
- Pacific Southwest Research Station, US Forest Service, Davis, CA, 95618, USA
- Department of Plant Biology, University of California Davis, Davis, CA, 95616, USA
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Yin W, Dong N, Niu M, Zhang X, Li L, Liu J, Liu B, Tong H. Brassinosteroid-regulated plant growth and development and gene expression in soybean. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/j.cj.2018.10.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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10
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Xue S, Zou J, Liu Y, Wang M, Zhang C, Le J. Involvement of BIG5 and BIG3 in BRI1 Trafficking Reveals Diverse Functions of BIG-subfamily ARF-GEFs in Plant Growth and Gravitropism. Int J Mol Sci 2019; 20:ijms20092339. [PMID: 31083521 PMCID: PMC6539719 DOI: 10.3390/ijms20092339] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2019] [Revised: 05/07/2019] [Accepted: 05/09/2019] [Indexed: 01/14/2023] Open
Abstract
ADP-ribosylation factor-guanine nucleotide exchange factors (ARF-GEFs) act as key regulators of vesicle trafficking in all eukaryotes. In Arabidopsis, there are eight ARF-GEFs, including three members of the GBF1 subfamily and five members of the BIG subfamily. These ARF-GEFs have different subcellular localizations and regulate different trafficking pathways. Until now, the roles of these BIG-subfamily ARF-GEFs have not been fully revealed. Here, analysis of the BIGs expression patterns showed that BIG3 and BIG5 have similar expression patterns. big5-1 displayed a dwarf growth and big3-1 big5-1 double mutant showed more severe defects, indicating functional redundancy between BIG3 and BIG5. Moreover, both big5-1 and big3-1 big5-1 exhibited a reduced sensitivity to Brassinosteroid (BR) treatment. Brefeldin A (BFA)-induced BR receptor Brassinosteroid insensitive 1 (BRI1) aggregation was reduced in big5-1 mutant, indicating that the action of BIG5 is required for BRI1 recycling. Furthermore, BR-induced dephosphorylation of transcription factor BZR1 was decreased in big3-1 big5-1 double mutants. The introduction of the gain-of-function of BZR1 mutant BZR1-1D in big3-1 big5-1 mutants can partially rescue the big3-1 big5-1 growth defects. Our findings revealed that BIG5 functions redundantly with BIG3 in plant growth and gravitropism, and BIG5 participates in BR signal transduction pathway through regulating BRI1 trafficking.
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Affiliation(s)
- Shan Xue
- Key Laboratory of Plant Molecular Physiology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
- University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Junjie Zou
- Key Laboratory of Plant Molecular Physiology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
| | - Yangfan Liu
- Key Laboratory of Plant Molecular Physiology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
- University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Ming Wang
- Key Laboratory of Plant Molecular Physiology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
- University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Chunxia Zhang
- Key Laboratory of Plant Molecular Physiology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
| | - Jie Le
- Key Laboratory of Plant Molecular Physiology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
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Gao J, Yu M, Zhu S, Zhou L, Liu S. Effects of exogenous 24-epibrassinolide and brassinazole on negative gravitropism and tension wood formation in hybrid poplar (Populus deltoids × Populus nigra). PLANTA 2019; 249:1449-1463. [PMID: 30689054 DOI: 10.1007/s00425-018-03074-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 12/19/2018] [Indexed: 06/09/2023]
Abstract
Exogenous 24-epibrassinolide (BL) and brassinazole (BRZ) have regulatory roles in G-fiber cell wall development and secondary xylem cell wall carbohydrate biosynthesis during tension wood formation in hybrid poplar. Brassinosteroids (BRs) play important roles in regulating gravitropism and vasculature development. Here, we report the effect of brassinosteroids on negative gravitropism and G-fiber cell wall development of the stem in woody angiosperms. We applied exogenous 24-epibrassinolide (BL) or its biosynthesis inhibitor brassinazole (BRZ) to slanted hybrid poplar trees (Populus deltoids × Populus nigra) and measured the morphology of gravitropic stems, anatomy and chemistry of secondary cell wall. We furthermore analyzed the expression levels of auxin transport and cellulose biosynthetic genes after 24-epibrassinolide (BL) or brassinazole (BRZ) application. The BL-treated seedlings showed no negative gravitropism bending, whereas application of BRZ dramatically enhanced negative gravitropic bending. BL treatment stimulated secondary xylem fiber elongation and G-fiber formation on the upper side of stems but delayed G-fiber maturation. BRZ inhibited xylem fiber elongation but induced the production of more mature G-fibers on the upper side of stems. Wood chemistry analyses and immunolocalization demonstrated that BL and BRZ treatments increased the cellulose content and modified the deposition of cell wall carbohydrates including arabinose, galactose and rhamnose in the secondary xylem. The expression of cellulose biosynthetic genes, especially those related to cellulose microfibril deposition (PtFLA12 and PtCOBL4) was significantly upregulated in BL- and BRZ-treated TW stems compared with control stems. The significant differences of G-fibers development and negative gravitropism bending between 24-epibrassinolide (BL) and brassinazole (BRZ) application suggest that brassinosteroids are important for secondary xylem development during tension wood formation. Our findings provide potential insights into the mechanism by which BRs regulate G-fiber cell wall development to accomplish negative gravitropism in TW formation.
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Affiliation(s)
- Junlan Gao
- School of Forestry and Landscape Architecture, Anhui Agricultural University, Hefei, 230036, Anhui, People's Republic of China
| | - Min Yu
- School of Forestry and Landscape Architecture, Anhui Agricultural University, Hefei, 230036, Anhui, People's Republic of China
| | - Shiliu Zhu
- School of Forestry and Landscape Architecture, Anhui Agricultural University, Hefei, 230036, Anhui, People's Republic of China
| | - Liang Zhou
- School of Forestry and Landscape Architecture, Anhui Agricultural University, Hefei, 230036, Anhui, People's Republic of China
| | - Shengquan Liu
- School of Forestry and Landscape Architecture, Anhui Agricultural University, Hefei, 230036, Anhui, People's Republic of China.
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12
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Hu Y, Depaepe T, Smet D, Hoyerova K, Klíma P, Cuypers A, Cutler S, Buyst D, Morreel K, Boerjan W, Martins J, Petrášek J, Vandenbussche F, Van Der Straeten D. ACCERBATIN, a small molecule at the intersection of auxin and reactive oxygen species homeostasis with herbicidal properties. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:4185-4203. [PMID: 28922768 PMCID: PMC5853866 DOI: 10.1093/jxb/erx242] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 06/22/2017] [Indexed: 05/30/2023]
Abstract
The volatile two-carbon hormone ethylene acts in concert with an array of signals to affect etiolated seedling development. From a chemical screen, we isolated a quinoline carboxamide designated ACCERBATIN (AEX) that exacerbates the 1-aminocyclopropane-1-carboxylic acid-induced triple response, typical for ethylene-treated seedlings in darkness. Phenotypic analyses revealed distinct AEX effects including inhibition of root hair development and shortening of the root meristem. Mutant analysis and reporter studies further suggested that AEX most probably acts in parallel to ethylene signaling. We demonstrated that AEX functions at the intersection of auxin metabolism and reactive oxygen species (ROS) homeostasis. AEX inhibited auxin efflux in BY-2 cells and promoted indole-3-acetic acid (IAA) oxidation in the shoot apical meristem and cotyledons of etiolated seedlings. Gene expression studies and superoxide/hydrogen peroxide staining further revealed that the disrupted auxin homeostasis was accompanied by oxidative stress. Interestingly, in light conditions, AEX exhibited properties reminiscent of the quinoline carboxylate-type auxin-like herbicides. We propose that AEX interferes with auxin transport from its major biosynthesis sites, either as a direct consequence of poor basipetal transport from the shoot meristematic region, or indirectly, through excessive IAA oxidation and ROS accumulation. Further investigation of AEX can provide new insights into the mechanisms connecting auxin and ROS homeostasis in plant development and provide useful tools to study auxin-type herbicides.
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Affiliation(s)
- Yuming Hu
- Laboratory of Functional Plant Biology, Department of Biology, Faculty of Sciences, Ghent University, K.L. Ledeganckstraat, Ghent, Belgium
| | - Thomas Depaepe
- Laboratory of Functional Plant Biology, Department of Biology, Faculty of Sciences, Ghent University, K.L. Ledeganckstraat, Ghent, Belgium
| | - Dajo Smet
- Laboratory of Functional Plant Biology, Department of Biology, Faculty of Sciences, Ghent University, K.L. Ledeganckstraat, Ghent, Belgium
| | - Klara Hoyerova
- Institute of Experimental Botany ASCR, Praha, Czech Republic
| | - Petr Klíma
- Institute of Experimental Botany ASCR, Praha, Czech Republic
| | - Ann Cuypers
- Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, Diepenbeek, Belgium
| | - Sean Cutler
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, CA, USA
| | - Dieter Buyst
- NMR and Structure Analysis, Department of Organic Chemistry, Krijgslaan, Ghent, Belgium
| | - Kris Morreel
- Department of Plant Systems Biology, VIB (Flanders Institute for Biotechnology), Technologiepark, Ghent, Belgium
| | - Wout Boerjan
- Department of Plant Systems Biology, VIB (Flanders Institute for Biotechnology), Technologiepark, Ghent, Belgium
| | - José Martins
- NMR and Structure Analysis, Department of Organic Chemistry, Krijgslaan, Ghent, Belgium
| | - Jan Petrášek
- Institute of Experimental Botany ASCR, Praha, Czech Republic
| | - Filip Vandenbussche
- Laboratory of Functional Plant Biology, Department of Biology, Faculty of Sciences, Ghent University, K.L. Ledeganckstraat, Ghent, Belgium
| | - Dominique Van Der Straeten
- Laboratory of Functional Plant Biology, Department of Biology, Faculty of Sciences, Ghent University, K.L. Ledeganckstraat, Ghent, Belgium
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Shen X, Li Y, Pan Y, Zhong S. Activation of HLS1 by Mechanical Stress via Ethylene-Stabilized EIN3 Is Crucial for Seedling Soil Emergence. FRONTIERS IN PLANT SCIENCE 2016; 7:1571. [PMID: 27822221 PMCID: PMC5075538 DOI: 10.3389/fpls.2016.01571] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 10/05/2016] [Indexed: 05/05/2023]
Abstract
The seeds of terrestrial flowering plants often start their life cycle in subterranean darkness. To protect the fragile apical meristematic tissues and cotyledons from mechanical injuries during soil penetration, dicotyledonous seedlings form an elegant apical hook at the top of the hypocotyl. The apical hook has been considered as an adaption structure to the subterranean environment. However, the role of the apical hook in seedling emergence and the molecular mechanism of apical hook formation under real-life conditions remain highly speculative. Here, we find that HOOKLESS 1 (HLS1), a critical gene in apical hook formation in Arabidopsis thaliana, is required for seedling emergence from the soil. When grown under soil, hls1 mutant exhibits severe emergence defects. By contrast, HLS1 overexpression in the hls1 background fully restores emergence defects and displays better emergence capacity than that of WT. Our results indicate that HLS1 transcription is stimulated in response to the mechanical stress of soil cover, which is dependent on the function of the transcription factors ETHYLENE INSENSITIVE 3 (EIN3) and EIN3-LIKE 1 (EIL1). Soil-conferred mechanical stress activates the ethylene signaling pathway to stabilize EIN3 by repressing the activity of the F-box proteins EBF1 and EBF2. These combined results reveal a signaling pathway in which plant seedlings transduce the mechanical pressure of soil cover to correctly modulate apical hook formation during soil emergence.
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Suslov D, Ivakov A, Boron AK, Vissenberg K. In vitro cell wall extensibility controls age-related changes in the growth rate of etiolated Arabidopsis hypocotyls. FUNCTIONAL PLANT BIOLOGY : FPB 2015; 42:1068-1079. [PMID: 32480746 DOI: 10.1071/fp15190] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Accepted: 09/05/2015] [Indexed: 06/11/2023]
Abstract
Plant cell growth is controlled by cell wall extensibility, which is currently estimated indirectly by various microtensile and nano/microindentation techniques. Their outputs differ in the accuracy of growth rate and in vivo extensibility prediction. Using the creep method we critically tested several metrics (creep rate, creep rate×stress-1, in vitro cell wall extensibility (ϕ) and in vitro cell wall yield threshold (y)) for their ability to predict growth rates of etiolated Arabidopsis thaliana (L. Heynh.) hypocotyls. We developed novel approaches for ϕ and y determination and statistical analysis based on creep measurements under single loads coupled with wall stress calculation. The best indicator of growth rate was ϕ because the 3-fold developmental decrease in the growth rate of 4- vs 3-day-old hypocotyls was accompanied by a 3-fold decrease in ϕ determined at pH 5. Although the acid-induced expansin-mediated creep of cell walls resulted exclusively from increasing ϕ values, the decrease in ϕ between 3- and 4-day-old hypocotyls was not mediated by a decrease in expansin abundance. We give practical recommendations on the most efficient use of creep rate, creep rate×stress-1, ϕ and y in different experimental situations and provide scripts for their automated calculations and statistical comparisons.
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Affiliation(s)
- Dmitry Suslov
- Biology Department, Plant Growth and Development, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium
| | - Alexander Ivakov
- Centre of Excellence in Plant Cell Walls, School of BioSciences, The University of Melbourne, Parkville, Vic. 3010, Australia
| | - Agnieszka K Boron
- Biology Department, Plant Growth and Development, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium
| | - Kris Vissenberg
- Biology Department, Plant Growth and Development, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium
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Gupta A, Singh M, Laxmi A. Interaction between glucose and brassinosteroid during the regulation of lateral root development in Arabidopsis. PLANT PHYSIOLOGY 2015; 168:307-20. [PMID: 25810094 PMCID: PMC4424020 DOI: 10.1104/pp.114.256313] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 03/19/2015] [Indexed: 05/04/2023]
Abstract
Glucose (Glc) plays a fundamental role in regulating lateral root (LR) development as well as LR emergence. In this study, we show that brassinosteroid (BR) signaling works downstream of Glc in controlling LR production/emergence in Arabidopsis (Arabidopsis thaliana) seedlings. Glc and BR can promote LR emergence at lower concentrations, while at higher concentrations, both have an inhibitory effect. The BR biosynthesis and perception mutants showed highly reduced numbers of emerged LRs at all the Glc concentrations tested. BR signaling works downstream of Glc signaling in regulating LR production, as in the glucose insensitive2-1brassinosteroid insensitive1 double mutant, Glc-induced LR production/emergence was severely reduced. Differential auxin distribution via the influx carriers AUXIN RESISTANT1/LIKE AUXIN RESISTANT1-3 and the efflux carrier PIN-FORMED2 plays a central role in controlling LR production in response to Glc and BR. Auxin signaling components AUXIN RESISTANT2,3 and SOLITARY ROOT act downstream of Glc and BR. AUXIN RESPONSE FACTOR7/19 work farther downstream and control LR production by regulating the expression of LATERAL ORGAN BOUNDARIES-DOMAIN29 and EXPANSIN17 genes. Increasing light flux could also mimic the Glc effect on LR production/emergence. However, increased light flux could not affect LR production in those BR and auxin signaling mutants that were defective for Glc-induced LR production. Altogether, our study suggests that, under natural environmental conditions, modulation of endogenous sugar levels can manipulate root architecture for optimized development by altering its nutrient/water uptake as well as its anchorage capacity.
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Affiliation(s)
- Aditi Gupta
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Manjul Singh
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Ashverya Laxmi
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India
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16
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Boron AK, Van Loock B, Suslov D, Markakis MN, Verbelen JP, Vissenberg K. Over-expression of AtEXLA2 alters etiolated arabidopsis hypocotyl growth. ANNALS OF BOTANY 2015; 115:67-80. [PMID: 25492062 PMCID: PMC4284114 DOI: 10.1093/aob/mcu221] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
BACKGROUND AND AIMS Plant stature and shape are largely determined by cell elongation, a process that is strongly controlled at the level of the cell wall. This is associated with the presence of many cell wall proteins implicated in the elongation process. Several proteins and enzyme families have been suggested to be involved in the controlled weakening of the cell wall, and these include xyloglucan endotransglucosylases/hydrolases (XTHs), yieldins, lipid transfer proteins and expansins. Although expansins have been the subject of much research, the role and involvement of expansin-like genes/proteins remain mostly unclear. This study investigates the expression and function of AtEXLA2 (At4g38400), a member of the expansin-like A (EXLA) family in arabidposis, and considers its possible role in cell wall metabolism and growth. METHODS Transgenic plants of Arabidopsis thaliana were grown, and lines over-expressing AtEXLA2 were identified. Plants were grown in the dark, on media containing growth hormones or precursors, or were gravistimulated. Hypocotyls were studied using transmission electron microscopy and extensiometry. Histochemical GUS (β-glucuronidase) stainings were performed. KEY RESULTS AtEXLA2 is one of the three EXLA members in arabidopsis. The protein lacks the typical domain responsible for expansin activity, but contains a presumed cellulose-interacting domain. Using promoter::GUS lines, the expression of AtEXLA2 was seen in germinating seedlings, hypocotyls, lateral root cap cells, columella cells and the central cylinder basally to the elongation zone of the root, and during different stages of lateral root development. Furthermore, promoter activity was detected in petioles, veins of leaves and filaments, and also in the peduncle of the flowers and in a zone just beneath the papillae. Over-expression of AtEXLA2 resulted in an increase of >10 % in the length of dark-grown hypocotyls and in slightly thicker walls in non-rapidly elongating etiolated hypocotyl cells. Biomechanical analysis by creep tests showed that AtEXLA2 over-expression may decrease the wall strength in arabidopsis hypocotyls. CONCLUSIONS It is concluded that AtEXLA2 may function as a positive regulator of cell elongation in the dark-grown hypocotyl of arabidopsis by possible interference with cellulose metabolism, deposition or its organization.
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MESH Headings
- Arabidopsis/genetics
- Arabidopsis/growth & development
- Arabidopsis/metabolism
- Arabidopsis/ultrastructure
- Arabidopsis Proteins/genetics
- Arabidopsis Proteins/metabolism
- Base Sequence
- Cell Wall/metabolism
- Cell Wall/ultrastructure
- Cloning, Molecular
- DNA, Complementary/genetics
- DNA, Complementary/metabolism
- Gene Expression Regulation, Plant
- Microscopy, Electron, Transmission
- Molecular Sequence Data
- Phylogeny
- Plants, Genetically Modified/genetics
- Plants, Genetically Modified/growth & development
- Plants, Genetically Modified/metabolism
- Plants, Genetically Modified/ultrastructure
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Affiliation(s)
- Agnieszka Karolina Boron
- Biology Department, Plant Growth and Development, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium and Saint-Petersburg State University, Faculty of Biology, Department of Plant Physiology and Biochemistry, Universitetskaya emb. 7/9, 199034 Saint-Petersburg, Russia
| | - Bram Van Loock
- Biology Department, Plant Growth and Development, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium and Saint-Petersburg State University, Faculty of Biology, Department of Plant Physiology and Biochemistry, Universitetskaya emb. 7/9, 199034 Saint-Petersburg, Russia
| | - Dmitry Suslov
- Biology Department, Plant Growth and Development, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium and Saint-Petersburg State University, Faculty of Biology, Department of Plant Physiology and Biochemistry, Universitetskaya emb. 7/9, 199034 Saint-Petersburg, Russia Biology Department, Plant Growth and Development, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium and Saint-Petersburg State University, Faculty of Biology, Department of Plant Physiology and Biochemistry, Universitetskaya emb. 7/9, 199034 Saint-Petersburg, Russia
| | - Marios Nektarios Markakis
- Biology Department, Plant Growth and Development, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium and Saint-Petersburg State University, Faculty of Biology, Department of Plant Physiology and Biochemistry, Universitetskaya emb. 7/9, 199034 Saint-Petersburg, Russia
| | - Jean-Pierre Verbelen
- Biology Department, Plant Growth and Development, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium and Saint-Petersburg State University, Faculty of Biology, Department of Plant Physiology and Biochemistry, Universitetskaya emb. 7/9, 199034 Saint-Petersburg, Russia
| | - Kris Vissenberg
- Biology Department, Plant Growth and Development, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium and Saint-Petersburg State University, Faculty of Biology, Department of Plant Physiology and Biochemistry, Universitetskaya emb. 7/9, 199034 Saint-Petersburg, Russia
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17
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Jaroensanti N, Yoon JM, Nakai Y, Shirai I, Otani M, Park SH, Hayashi KI, Nakajima M, Asami T. Does the brassinosteroid signal pathway in photomorphogenesis overlap with the gravitropic response caused by auxin? Biosci Biotechnol Biochem 2014; 78:1839-49. [PMID: 25351332 DOI: 10.1080/09168451.2014.925783] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Brassinosteroid (BR) and auxin co-regulate plant growth in a process termed cross-talking. Based on the assumption that their signal transductions are partially shared, inhibitory chemicals for both signal transductions were screened from a commercially available library. A chemical designated as NJ15 (ethyl 2-[5-(3,5-dichlorophenyl)-1,2,3,4-tetrazole-2-yl]acetate) diminished the growth promotion of both adzuki bean epicotyls and Arabidopsis seedlings, by the application of either BR or auxin. To understand its target site(s), bioassays with a high dependence on the signal transduction of either BR (BR-signaling) or auxin (AX-signaling) were performed. NJ15 inhibited the photomorphogenesis of Arabidopsis seedlings grown in the dark, which mainly depends on BR-signaling, while NJ15 also inhibited their gravitropic responses mainly depending on AX-signaling. On the study for the structure-activity relationships of NJ15 analogs, they showed strong correlations on the inhibitory profiles between BR- and AX-signalings. These correlations imply that NJ15 targets the downstream pathway after the integration of BR- and AX-signals.
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Affiliation(s)
- Naiyanate Jaroensanti
- a Department of Applied Biological Chemistry , The University of Tokyo , Tokyo , Japan
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18
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Boron AK, Vissenberg K. The Arabidopsis thaliana hypocotyl, a model to identify and study control mechanisms of cellular expansion. PLANT CELL REPORTS 2014; 33:697-706. [PMID: 24633990 DOI: 10.1007/s00299-014-1591-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 02/21/2014] [Accepted: 02/21/2014] [Indexed: 05/24/2023]
Abstract
Developmental biology studies in general benefit from model organisms that are well characterized. Arabidopsis thaliana fulfills this criterion and represents one of the best experimental systems to study developmental processes in higher plants. Light is a crucial factor that drives photosynthesis, but that also regulates plant morphogenesis. As the hypocotyl is completely embryonic of origin, its growth occurs solely by expansion of the cells and this process is strongly dependent on the light conditions. In this review, we provide evidence that the hypocotyl serves as ideal model object to study cell expansion mechanisms and its regulation. We focus on the regulation of hypocotyl development by light and highlight the key modulating proteins in this signaling cascade. Downstream of light-signaling, cellular expansion is greatly dependent on specific cell wall depositions, which is related to cortical microtubular (re)arrangements and on composition and/or extensibility of the cell wall. We discuss possible further experimental approaches to broaden our knowledge on hypocotyl development, which will give an outlook on the probable evolution of the field.
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Affiliation(s)
- Agnieszka Karolina Boron
- Plant Growth and Development, Biology Department, University of Antwerp, Groenenborgerlaan 122, 2020, Antwerp, Belgium
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19
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Hu L, Mei Z, Zang A, Chen H, Dou X, Jin J, Cai W. Microarray analyses and comparisons of upper or lower flanks of rice shoot base preceding gravitropic bending. PLoS One 2013; 8:e74646. [PMID: 24040303 PMCID: PMC3764065 DOI: 10.1371/journal.pone.0074646] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2011] [Accepted: 08/06/2013] [Indexed: 11/26/2022] Open
Abstract
Gravitropism is a complex process involving a series of physiological pathways. Despite ongoing research, gravitropism sensing and response mechanisms are not well understood. To identify the key transcripts and corresponding pathways in gravitropism, a whole-genome microarray approach was used to analyze transcript abundance in the shoot base of rice (Oryza sativa sp. japonica) at 0.5 h and 6 h after gravistimulation by horizontal reorientation. Between upper and lower flanks of the shoot base, 167 transcripts at 0.5 h and 1202 transcripts at 6 h were discovered to be significantly different in abundance by 2-fold. Among these transcripts, 48 were found to be changed both at 0.5 h and 6 h, while 119 transcripts were only changed at 0.5 h and 1154 transcripts were changed at 6 h in association with gravitropism. MapMan and PageMan analyses were used to identify transcripts significantly changed in abundance. The asymmetric regulation of transcripts related to phytohormones, signaling, RNA transcription, metabolism and cell wall-related categories between upper and lower flanks were demonstrated. Potential roles of the identified transcripts in gravitropism are discussed. Our results suggest that the induction of asymmetrical transcription, likely as a consequence of gravitropic reorientation, precedes gravitropic bending in the rice shoot base.
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Affiliation(s)
- Liwei Hu
- Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Graduate School of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Zhiling Mei
- Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Graduate School of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Aiping Zang
- Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Graduate School of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Haiying Chen
- Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Graduate School of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Xianying Dou
- Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Graduate School of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Jing Jin
- Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Graduate School of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Weiming Cai
- Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Graduate School of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
- * E-mail:
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20
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Zhou XY, Song L, Xue HW. Brassinosteroids regulate the differential growth of Arabidopsis hypocotyls through auxin signaling components IAA19 and ARF7. MOLECULAR PLANT 2013; 6:887-904. [PMID: 23125315 DOI: 10.1093/mp/sss123] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Brassinosteroids (BRs) are an important class of phytohormones which regulates a wide range of physiological processes. Genetic and physiological studies have revealed that BR responses usually depend on an intact auxin signaling pathway. Here, we demonstrate that high BR concentration or enhanced BR signaling induce the differential growth of etiolated hypocotyls and result in the morphological changes, while auxin-resistant mutants, msg2 (dominant mutant of IAA19) and arf7, are insensitive to the BR effect and can partially suppress the phenotype of bzr1-D (dominant mutant of BZR1 with enhanced BR signaling). Interestingly, BZR1 protein can directly bind to the promoter regions of both IAA19 and ARF7, indicating that IAA19 and ARF7 mediate the BR-induced differential growth by serving as direct targets of BZR1. Systemic microarray analysis revealed that a number of BR-responsive genes showed reduced BR response in msg2, confirming that BR employs auxin signaling components IAA19 and ARF7 to modulate the specific downstream processes. These results provide informative clues on the crosstalk of BR-auxin signaling and the mechanisms of BR-auxin effects in regulating differential growth.
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Affiliation(s)
- Xiao-Yi Zhou
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, 200032 Shanghai, China
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21
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Miedes E, Suslov D, Vandenbussche F, Kenobi K, Ivakov A, Van Der Straeten D, Lorences EP, Mellerowicz EJ, Verbelen JP, Vissenberg K. Xyloglucan endotransglucosylase/hydrolase (XTH) overexpression affects growth and cell wall mechanics in etiolated Arabidopsis hypocotyls. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:2481-97. [PMID: 23585673 DOI: 10.1093/jxb/ert107] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Growth and biomechanics of etiolated hypocotyls from Arabidopsis thaliana lines overexpressing xyloglucan endotransglucosylase/hydrolase AtXTH18, AtXTH19, AtXTH20, and PttXET16-34 were studied. Overexpression of AtXTH18, AtXTH19, and AtXTH20 stimulated growth of hypocotyls, while PttXET16-34 overexpression did not show this effect. In vitro extension of frozen/thawed hypocotyls measured by a constant-load extensiometer started from a high-amplitude initial deformation followed by a slow time-dependent creep. Creep of growing XTH-overexpressing (OE) hypocotyls was more linear in time compared with the wild type at pH 5.0, reflecting their higher potential for long-term extension. XTH-OE plants deposited 65-84% more cell wall material per hypocotyl cross-sectional area than wild-type plants. As a result, their wall stress under each external load was lower than in the wild-type. Growing XTH-OE hypocotyls had higher values of initial deformation·stress(-1) compared with the wild type. Plotting creep rates for each line under different loads against the respective wall stress values gave straight lines. Their slopes and intercepts with the abscissa correspond to ϕ (in vitro cell wall extensibility) and y (in vitro cell wall yield threshold) values characterizing cell wall material properties. The wall material in XTH-OE lines was more pliant than in the wild type due to lower y values. In contrast, the acid-induced wall extension in vitro resulted from increasing ϕ values. Thus, three factors contributed to the XTH-OE-stimulated growth in Arabidopsis hypocotyls: their more linear creep, higher values of initial deformation·stress(-1), and lower y values.
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Affiliation(s)
- Eva Miedes
- Department of Biology, Plant Growth and Development, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerpen, Belgium
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Vandenbussche F, Callebert P, Zadnikova P, Benkova E, Van Der Straeten D. Brassinosteroid control of shoot gravitropism interacts with ethylene and depends on auxin signaling components. AMERICAN JOURNAL OF BOTANY 2013; 100:215-25. [PMID: 23152331 DOI: 10.3732/ajb.1200264] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
PREMISE OF THE STUDY To reach favorable conditions for photosynthesis, seedlings grow upward when deprived of light upon underground germination. To direct their growth, they use their negative gravitropic capacity. Negative gravitropism is under tight control of multiple hormones. METHODS By counting the number of standing plants in a population or by real time monitoring of the reorientation of gravistimulated seedlings of Arabidopsis thaliana, we evaluated the negative gravitropism of ethylene or brassinosteroid (BR) treated plants. Meta-analysis of transcriptomic data on AUX/IAA genes was gathered, and subsequent mutant analysis was performed. KEY RESULTS Ethylene and BR have opposite effects in regulating shoot gravitropism. Lack of BR enhances gravitropic reorientation in 2-d-old seedlings, whereas ethylene does not. Lack of ethylene signaling results in enhanced BR sensitivity. Ethylene and BRs regulate overlapping sets of AUX/IAA genes. BRs regulate a wider range of auxin signaling components than ethylene. CONCLUSIONS Upward growth in seedlings depends strongly on the internal hormonal balance. Endogenous ethylene stimulates, whereas BRs reduce negative gravitropism in a manner that depends on the function of different, yet overlapping sets of auxin signaling components.
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Affiliation(s)
- Filip Vandenbussche
- Laboratory of Functional Plant Biology, Department of Physiology, Ghent University, Karel Lodewijk Ledeganckstraat 35, B-9000 Gent, Belgium
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Polko JK, Pierik R, van Zanten M, Tarkowská D, Strnad M, Voesenek LACJ, Peeters AJM. Ethylene promotes hyponastic growth through interaction with ROTUNDIFOLIA3/CYP90C1 in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:613-24. [PMID: 23264517 PMCID: PMC3542051 DOI: 10.1093/jxb/ers356] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Upward leaf movement, called hyponastic growth, is employed by plants to cope with adverse environmental conditions. Ethylene is a key regulator of this process and, in Arabidopsis thaliana, hyponasty is induced by this phytohormone via promotion of epidermal cell expansion in a proximal zone of the abaxial side of the petiole. ROTUNDIFOLIA3/CYP90C1 encodes an enzyme which was shown to catalyse C-23 hydroxylation of several brassinosteroids (BRs) - phytohormones involved in, for example, organ growth, cell expansion, cell division, and responses to abiotic and biotic stresses. This study tested the interaction between ethylene and BRs in regulating hyponastic growth. A mutant isolated in a forward genetic screen, with reduced hyponastic response to ethylene treatment, was allelic to rot3. The cause of the reduced hyponastic growth in this mutant was examined by studying ethylene-BR interaction during local cell expansion, pharmacological inhibition of BR synthesis and ethylene effects on transcription of BR-related genes. This work demonstrates that rot3 mutants are impaired in local cell expansion driving hyponasty. Moreover, the inhibition of BR biosynthesis reduces ethylene-induced hyponastic growth and ethylene increases sensitivity to BR in promoting cell elongation in Arabidopsis hypocotyls. Together, the results show that ROT3 modulates ethylene-induced petiole movement and that this function is likely BR related.
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Affiliation(s)
- Joanna K. Polko
- Plant Ecophysiology, Institute of Environmental Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Ronald Pierik
- Plant Ecophysiology, Institute of Environmental Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Martijn van Zanten
- Plant Ecophysiology, Institute of Environmental Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
- Molecular Plant Physiology, Institute of Environmental Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Danuše Tarkowská
- Laboratory of Growth Regulators, Faculty of Science, Palacký University and Institute of Experimental Botany AS CR, v.v.i., Šlechtitelů 11, CZ-783 71 Olomouc, Czech Republic
| | - Miroslav Strnad
- Laboratory of Growth Regulators, Faculty of Science, Palacký University and Institute of Experimental Botany AS CR, v.v.i., Šlechtitelů 11, CZ-783 71 Olomouc, Czech Republic
- Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 21, CZ-783 71 Olomouc, Czech Republic
| | - Laurentius A. C. J. Voesenek
- Plant Ecophysiology, Institute of Environmental Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Anton J. M. Peeters
- Plant Ecophysiology, Institute of Environmental Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
- Institute of Education, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
- * To whom correspondence should be addressed. E-mail:
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Gupta A, Singh M, Jones AM, Laxmi A. Hypocotyl directional growth in Arabidopsis: a complex trait. PLANT PHYSIOLOGY 2012; 159:1463-76. [PMID: 22689891 PMCID: PMC3425191 DOI: 10.1104/pp.112.195776] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The growth direction of the Arabidopsis (Arabidopsis thaliana) etiolated-seedling hypocotyl is a complex trait that is controlled by extrinsic signals such as gravity and touch as well as intrinsic signals such as hormones (brassinosteroid [BR], auxin, cytokinin, ethylene) and nutrient status (glucose [Glc], sucrose). We used a genetic approach to identify the signaling elements and their relationship underlying hypocotyl growth direction. BR randomizes etiolated-seedling growth by inhibiting negative gravitropism of the hypocotyls via modulating auxin homeostasis for which we designate as reset, not to be confused with the gravity set point angle. Cytokinin signaling antagonizes this BR reset of gravity sensing and/or tropism by affecting ethylene biosynthesis/signaling. Glc also antagonizes BR reset but acts independently of cytokinin and ethylene signaling pathways via inhibiting BR-regulated gene expression quantitatively and spatially, by altering protein degradation, and by antagonizing BR-induced changes in microtubule organization and cell patterning associated with hypocotyl agravitropism. This BR reset is reduced in the presence of the microtubule organization inhibitor oryzalin, suggesting a central role for cytoskeleton reorganization. A unifying and hierarchical model of Glc and hormone signaling interplay is proposed. The biological significance of BR-mediated changes in hypocotyl graviresponse lies in the fact that BR signaling sensitizes the dark-grown seedling hypocotyl to the presence of obstacles, overriding gravitropism, to enable efficient circumnavigation through soil.
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