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Chien YC, Reyes A, Park HL, Xu SL, Yoon GM. Uncovering the proximal proteome of CTR1 through TurboID-mediated proximity labeling. Proteomics 2024; 24:e2300212. [PMID: 37876141 DOI: 10.1002/pmic.202300212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 08/25/2023] [Accepted: 10/09/2023] [Indexed: 10/26/2023]
Abstract
Protein-protein interactions play a crucial role in driving cellular processes and enabling appropriate physiological responses in organisms. The plant hormone ethylene signaling pathway is complex and regulated by the spatiotemporal regulation of its signaling molecules. Constitutive Triple Response 1 (CTR1), a key negative regulator of the pathway, regulates the function of Ethylene-Insensitive 2 (EIN2), a positive regulator of ethylene signaling, at the endoplasmic reticulum (ER) through phosphorylation. Our recent study revealed that CTR1 can also translocate from the ER to the nucleus in response to ethylene and positively regulate ethylene responses by stabilizing EIN3. To gain further insights into the role of CTR1 in plants, we used TurboID-based proximity labeling and mass spectrometry to identify the proximal proteomes of CTR1 in Nicotiana benthamiana. The identified proximal proteins include known ethylene signaling components, as well as proteins involved in diverse cellular processes such as mitochondrial respiration, mRNA metabolism, and organelle biogenesis. Our study demonstrates the feasibility of proximity labeling using the N. benthamiana transient expression system and identifies the potential interactors of CTR1 in vivo, uncovering the potential roles of CTR1 in a wide range of cellular processes.
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Affiliation(s)
- Yuan-Chi Chien
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, USA
- The Center for Plant Biology, Purdue University, West Lafayette, Indiana, USA
| | - Andres Reyes
- Department of Plant Biology, Carnegie Institution for Science, Stanford University, Stanford, California, USA
- Carnegie Mass Spectrometry Facility, Carnegie Institution for Science, Stanford, California, USA
| | - Hye Lin Park
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, USA
- The Center for Plant Biology, Purdue University, West Lafayette, Indiana, USA
| | - Shou-Ling Xu
- Department of Plant Biology, Carnegie Institution for Science, Stanford University, Stanford, California, USA
- Carnegie Mass Spectrometry Facility, Carnegie Institution for Science, Stanford, California, USA
| | - Gyeong Mee Yoon
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, USA
- The Center for Plant Biology, Purdue University, West Lafayette, Indiana, USA
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2
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Zhang Y, Sun X, Aphalo PJ, Zhang Y, Cheng R, Li T. Ultraviolet-A1 radiation induced a more favorable light-intercepting leaf-area display than blue light and promoted plant growth. PLANT, CELL & ENVIRONMENT 2024; 47:197-212. [PMID: 37743709 DOI: 10.1111/pce.14727] [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: 01/17/2023] [Revised: 08/20/2023] [Accepted: 09/10/2023] [Indexed: 09/26/2023]
Abstract
Plants adjust their morphology in response to light environment by sensing an array of light cues. Though the wavelengths of ultraviolet-A1 radiation (UV-A1, 350-400 nm) are close to blue light (B, 400-500 nm) and share same flavoprotein photoreceptors, it remains poorly understood how plant responses to UV-A1 radiation could differ from those to B. We initially grown tomato plants under monochromatic red light (R, 660 nm) as control, subsequently transferred them to four dichromatic light treatments containing ~20 µmol m-2 s-1 of UV-A1 radiation, peaking at 370 nm (UV-A370 ) or 400 nm (V400 ), or B (450 nm, at ~20 or 1.5 µmol m-2 s-1 ), with same total photon irradiance (~200 μmol m-2 s-1 ). We show that UV-A370 radiation was the most effective in inducing light-intercepting leaf-area display formation, resulting in larger leaf area and more shoot biomass, while it triggered weaker and later transcriptome-wide responses than B. Mechanistically, UV-A370 -promoted leaf-area display response was apparent in less than 12 h and appeared as very weakly related to transcriptome level regulation, which likely depended on the auxin transportation and cell wall acidification. This study revealed wavelength-specific responses within UV-A/blue region challenging usual assumptions that the role of UV-A1 radiation function similarly as blue light in mediating plant processes.
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Affiliation(s)
- Yating Zhang
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
- Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
| | - Xuguang Sun
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Pedro J Aphalo
- Organismal and Evolutionary Biology, Viikki Plant Science Centre, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Yuqi Zhang
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Ruifeng Cheng
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Tao Li
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
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Lv QY, Zhao QP, Zhu C, Ding M, Chu FY, Li XK, Cheng K, Zhao X. Hydrogen peroxide mediates high-intensity blue light-induced hypocotyl phototropism of cotton seedlings. STRESS BIOLOGY 2023; 3:27. [PMID: 37676397 PMCID: PMC10442013 DOI: 10.1007/s44154-023-00111-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 07/16/2023] [Indexed: 09/08/2023]
Abstract
Phototropism is a classic adaptive growth response that helps plants to enhance light capture for photosynthesis. It was shown that hydrogen peroxide (H2O2) participates in the regulation of blue light-induced hypocotyl phototropism; however, the underlying mechanism is unclear. In this study, we demonstrate that the unilateral high-intensity blue light (HBL) could induce asymmetric distribution of H2O2 in cotton hypocotyls. Disruption of the HBL-induced asymmetric distribution of H2O2 by applying either H2O2 itself evenly on the hypocotyls or H2O2 scavengers on the lit side of hypocotyls could efficiently inhibit hypocotyl phototropic growth. Consistently, application of H2O2 on the shaded and lit sides of the hypocotyls led to reduced and enhanced hypocotyl phototropism, respectively. Further, we show that H2O2 inhibits hypocotyl elongation of cotton seedlings, thus supporting the repressive role of H2O2 in HBL-induced hypocotyl phototropism. Moreover, our results show that H2O2 interferes with HBL-induced asymmetric distribution of auxin in the cotton hypocotyls. Taken together, our study uncovers that H2O2 changes the asymmetric accumulation of auxin and inhibits hypocotyl cell elongation, thus mediating HBL-induced hypocotyl phototropism.
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Affiliation(s)
- Qian-Yi Lv
- National Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, School of Life Sciences, Henan University, Kaifeng, 475004, China
| | - Qing-Ping Zhao
- National Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, School of Life Sciences, Henan University, Kaifeng, 475004, China
- College of Life Science and Agricultural Engineering, Nanyang Normal University, 1638 Wolong Road, Nanyang, 473061, Henan, China
| | - Chen Zhu
- National Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, School of Life Sciences, Henan University, Kaifeng, 475004, China
| | - Meichen Ding
- National Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, School of Life Sciences, Henan University, Kaifeng, 475004, China
| | - Fang-Yuan Chu
- National Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, School of Life Sciences, Henan University, Kaifeng, 475004, China
| | - Xing-Kun Li
- National Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, School of Life Sciences, Henan University, Kaifeng, 475004, China
| | - Kai Cheng
- National Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, School of Life Sciences, Henan University, Kaifeng, 475004, China
| | - Xiang Zhao
- National Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, School of Life Sciences, Henan University, Kaifeng, 475004, China.
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Waksman T, Suetsugu N, Hermanowicz P, Ronald J, Sullivan S, Łabuz J, Christie JM. Phototropin phosphorylation of ROOT PHOTOTROPISM 2 and its role in mediating phototropism, leaf positioning, and chloroplast accumulation movement in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 114:390-402. [PMID: 36794876 PMCID: PMC10953443 DOI: 10.1111/tpj.16144] [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: 11/29/2022] [Accepted: 02/08/2023] [Indexed: 05/10/2023]
Abstract
Directional movements impact the ability of plants to respond and adjust their growth accordingly to the prevailing light environment. The plasma-membrane associated protein, ROOT PHOTOTROPISM 2 (RPT2) is a key signalling component involved in chloroplast accumulation movement, leaf positioning, and phototropism, all of which are regulated redundantly by the ultraviolet/blue light-activated AGC kinases phototropin 1 and 2 (phot1 and phot2). We recently demonstrated that members of the NON-PHOTOTROPIC HYPOCOTYL 3 (NPH3)/RPT2-like (NRL) family in Arabidopsis thaliana, including RPT2, are directly phosphorylated by phot1. However, whether RPT2 is a substrate for phot2, and the biological significance of phot phosphorylation of RPT2 remains to be determined. Here, we show that RPT2 is phosphorylated by both phot1 and phot2 at a conserved serine residue (S591) within the C-terminal region of the protein. Blue light triggered the association of 14-3-3 proteins with RPT2 consistent with S591 acting as a 14-3-3 binding site. Mutation of S591 had no effect on the plasma membrane localization of RPT2 but reduced its functionality for leaf positioning and phototropism. Moreover, our findings indicate that S591 phosphorylation within the C-terminus of RPT2 is required for chloroplast accumulation movement to low level blue light. Taken together, these findings further highlight the importance of the C-terminal region of NRL proteins and how its phosphorylation contributes to phot receptor signalling in plants.
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Affiliation(s)
- Thomas Waksman
- School of Molecular BiosciencesCollege of Medical, Veterinary and Life Sciences, University of GlasgowBower BuildingGlasgowG12 8QQUK
| | - Noriyuki Suetsugu
- School of Molecular BiosciencesCollege of Medical, Veterinary and Life Sciences, University of GlasgowBower BuildingGlasgowG12 8QQUK
- Graduate School of Arts and SciencesThe University of TokyoTokyo153‐8902Japan
| | - Pawel Hermanowicz
- Malopolska Centre of BiotechnologyJagiellonian UniversityGronostajowa 7A30‐387KrakówPoland
| | - James Ronald
- School of Molecular BiosciencesCollege of Medical, Veterinary and Life Sciences, University of GlasgowBower BuildingGlasgowG12 8QQUK
| | - Stuart Sullivan
- School of Molecular BiosciencesCollege of Medical, Veterinary and Life Sciences, University of GlasgowBower BuildingGlasgowG12 8QQUK
| | - Justyna Łabuz
- Malopolska Centre of BiotechnologyJagiellonian UniversityGronostajowa 7A30‐387KrakówPoland
| | - John M. Christie
- School of Molecular BiosciencesCollege of Medical, Veterinary and Life Sciences, University of GlasgowBower BuildingGlasgowG12 8QQUK
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5
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Xin GY, Li LP, Wang PT, Li XY, Han YJ, Zhao X. The action of enhancing weak light capture via phototropic growth and chloroplast movement in plants. STRESS BIOLOGY 2022; 2:50. [PMID: 37676522 PMCID: PMC10441985 DOI: 10.1007/s44154-022-00066-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 10/11/2022] [Indexed: 09/08/2023]
Abstract
To cope with fluctuating light conditions, terrestrial plants have evolved precise regulation mechanisms to help optimize light capture and increase photosynthetic efficiency. Upon blue light-triggered autophosphorylation, activated phototropin (PHOT1 and PHOT2) photoreceptors function solely or redundantly to regulate diverse responses, including phototropism, chloroplast movement, stomatal opening, and leaf positioning and flattening in plants. These responses enhance light capture under low-light conditions and avoid photodamage under high-light conditions. NON-PHOTOTROPIC HYPOCOTYL 3 (NPH3) and ROOT PHOTOTROPISM 2 (RPT2) are signal transducers that function in the PHOT1- and PHOT2-mediated response. NPH3 is required for phototropism, leaf expansion and positioning. RPT2 regulates chloroplast accumulation as well as NPH3-mediated responses. NRL PROTEIN FOR CHLOROPLAST MOVEMENT 1 (NCH1) was recently identified as a PHOT1-interacting protein that functions redundantly with RPT2 to mediate chloroplast accumulation. The PHYTOCHROME KINASE SUBSTRATE (PKS) proteins (PKS1, PKS2, and PKS4) interact with PHOT1 and NPH3 and mediate hypocotyl phototropic bending. This review summarizes advances in phototropic growth and chloroplast movement induced by light. We also focus on how crosstalk in signaling between phototropism and chloroplast movement enhances weak light capture, providing a basis for future studies aiming to delineate the mechanism of light-trapping plants to improve light-use efficiency.
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Affiliation(s)
- Guang-Yuan Xin
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China
| | - Lu-Ping Li
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China
| | - Peng-Tao Wang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China
| | - Xin-Yue Li
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China
| | - Yuan-Ji Han
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China
| | - Xiang Zhao
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China.
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Naqvi S, He Q, Trusch F, Qiu H, Pham J, Sun Q, Christie JM, Gilroy EM, Birch PRJ. Blue-light receptor phototropin 1 suppresses immunity to promote Phytophthora infestans infection. THE NEW PHYTOLOGIST 2022; 233:2282-2293. [PMID: 34923631 PMCID: PMC9255860 DOI: 10.1111/nph.17929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 11/04/2021] [Indexed: 06/14/2023]
Abstract
Blue-light (BL) phototropin receptors (phot1 and phot2) regulate plant growth by activating NPH3/RPT2-like (NRL) family members. Little is known about roles for BL and phots in regulating plant immunity. We showed previously that Phytophthora infestans RXLR effector Pi02860 targets potato (St)NRL1, promoting its ability to enhance susceptibility by facilitating proteasome-mediated degradation of the immune regulator StSWAP70. This raises the question: do BL and phots negatively regulate immunity? We employed coimmunoprecipitation, virus-induced gene silencing, transient overexpression and targeted mutation to investigate contributions of phots to regulating immunity. Whereas transient overexpression of Stphot1 and Stphot2 enhances P. infestans colonization of Nicotiana benthamiana, silencing endogenous Nbphot1 or Nbphot2 reduces infection. Stphot1, but not Stphot2, suppressed the INF1-triggered cell death (ICD) immune response in a BL- and NRL1-dependent manner. Stphot1, when coexpressed with StNRL1, promotes degradation of StSWAP70, whereas Stphot2 does not. Kinase-dead Stphot1 fails to suppress ICD, enhance P. infestans colonization or promote StSWAP70 degradation. Critically, BL enhances P. infestans infection, which probably involves phots but not other BL receptors such as cryptochromes and F-box proteins ZTL1 and FKF1. We demonstrate that Stphot1 and Stphot2 play different roles in promoting susceptibility, and Stphot1 kinase activity is required for BL- and StNRL1-mediated immune suppression.
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Affiliation(s)
- Shaista Naqvi
- Division of Plant SciencesJames Hutton InstituteUniversity of Dundee School of Life SciencesErrol RdInvergowrie, DundeeDD2 5DAUK
| | - Qin He
- Division of Plant SciencesJames Hutton InstituteUniversity of Dundee School of Life SciencesErrol RdInvergowrie, DundeeDD2 5DAUK
- Key Laboratory of Horticultural Plant Biology (HZAU)Ministry of EducationKey Laboratory of Potato Biology and Biotechnology (HZAU)Ministry of Agriculture and Rural AffairsHuazhong Agricultural UniversityWuhanHubei430070China
| | - Franziska Trusch
- Division of Plant SciencesJames Hutton InstituteUniversity of Dundee School of Life SciencesErrol RdInvergowrie, DundeeDD2 5DAUK
| | - Huishan Qiu
- Key Laboratory of Horticultural Plant Biology (HZAU)Ministry of EducationKey Laboratory of Potato Biology and Biotechnology (HZAU)Ministry of Agriculture and Rural AffairsHuazhong Agricultural UniversityWuhanHubei430070China
| | - Jasmine Pham
- Division of Plant SciencesJames Hutton InstituteUniversity of Dundee School of Life SciencesErrol RdInvergowrie, DundeeDD2 5DAUK
| | - Qingguo Sun
- Key Laboratory of Horticultural Plant Biology (HZAU)Ministry of EducationKey Laboratory of Potato Biology and Biotechnology (HZAU)Ministry of Agriculture and Rural AffairsHuazhong Agricultural UniversityWuhanHubei430070China
| | - John M. Christie
- Institute of Molecular, Cell and Systems BiologyCollege of Medical, Veterinary, and Life SciencesUniversity of GlasgowGlasgowG12 8QQUK
| | - Eleanor M. Gilroy
- Cell and Molecular ScienceJames Hutton InstituteInvergowrie, DundeeDD2 5DAUK
| | - Paul R. J. Birch
- Division of Plant SciencesJames Hutton InstituteUniversity of Dundee School of Life SciencesErrol RdInvergowrie, DundeeDD2 5DAUK
- Cell and Molecular ScienceJames Hutton InstituteInvergowrie, DundeeDD2 5DAUK
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7
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Wang X, Han L, Yin H, Zhao Z, Cao H, Shang Z, Kang E. AtANN1 and AtANN2 are involved in phototropism of etiolated hypocotyls of Arabidopsis by regulating auxin distribution. AOB PLANTS 2022; 14:plab075. [PMID: 35079328 PMCID: PMC8782606 DOI: 10.1093/aobpla/plab075] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 12/15/2021] [Indexed: 06/14/2023]
Abstract
Phototropism is an essential response in some plant organs and features several signalling molecules involved in either photo-sensing or post-sensing responses. Annexins are involved in regulating plant growth and its responses to various stimuli. Here, we provide novel data showing that two members of the Annexin family in Arabidopsis thaliana, AtANN1 and AtANN2, may be involved in the phototropism of etiolated hypocotyls. In wild type, unilateral blue light (BL) induced a strong phototropic response, while red light (RL) only induced a weak response. The responses of single- or double-null mutants of the two annexins, including atann1, atann2 and atann1/atann2, were significantly weaker than those observed in wild type, indicating the involvement of AtANN1 and AtANN2 in BL-induced phototropism. Unilateral BL induced asymmetric distribution of DR5-GFP and PIN3-GFP fluorescence in hypocotyls; notably, fluorescent intensity on the shaded side was markedly stronger than that on the illuminated side. In etiolated atann1, atann2 or atann1/atann2 hypocotyls, unilateral BL-induced asymmetric distributions of DR5-GFP and PIN3-GFP were weakened or impaired. Herein, we suggest that during hypocotyls phototropic response, AtANN1 and AtANN2 may be involved in BL-stimulated signalling by regulating PIN3-charged auxin transport.
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Affiliation(s)
- Xiaoxu Wang
- Key Laboratory of Molecular and Cellular Biology of the Ministry of Education, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China
- Department of Agricultural and Animal Engineering, Cangzhou Vocation College of Technology, Cangzhou 061001, China
| | - Lijuan Han
- Key Laboratory of Molecular and Cellular Biology of the Ministry of Education, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China
| | - Hongmin Yin
- Key Laboratory of Molecular and Cellular Biology of the Ministry of Education, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China
| | - Zhenping Zhao
- Key Laboratory of Molecular and Cellular Biology of the Ministry of Education, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China
| | - Huishu Cao
- Key Laboratory of Molecular and Cellular Biology of the Ministry of Education, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China
| | - Zhonglin Shang
- Key Laboratory of Molecular and Cellular Biology of the Ministry of Education, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China
| | - Erfang Kang
- Key Laboratory of Molecular and Cellular Biology of the Ministry of Education, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China
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8
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Zhai S, Cai W, Xiang ZX, Chen CY, Lu YT, Yuan TT. PIN3-mediated auxin transport contributes to blue light-induced adventitious root formation in Arabidopsis. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2021; 312:111044. [PMID: 34620442 DOI: 10.1016/j.plantsci.2021.111044] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 08/21/2021] [Accepted: 08/27/2021] [Indexed: 06/13/2023]
Abstract
Adventitious rooting is a heritable quantitative trait that is influenced by multiple endogenous and exogenous factors in plants, and one important environmental factor required for efficient adventitious root formation is light signaling. However, the physiological significance and molecular mechanism of light underlying adventitious root formation are still largely unexplored. Here, we report that blue light-induced adventitious root formation is regulated by PIN-FORMED3 (PIN3)-mediated auxin transport in Arabidopsis. Adventitious root formation is significantly impaired in the loss-of-function mutants of the blue light receptors, PHOTOROPIN1 (PHOT1) and PHOTOROPIN2 (PHOT2), as well as the phototropic transducer, NON-PHOTOTROPIC HYPOCOTYL3 (NPH3). In addition, blue light enhanced the auxin content in the adventitious root, and the pin3 loss-of-function mutant had a reduced adventitious rooting response under blue light compared to the wild type. The PIN3 protein level was higher in plants treated with blue light than in those in darkness, especially in the hypocotyl pericycle, while PIN3-GFP failed to accumulate in nph3 PIN3::PIN3-GFP. Furthermore, the results showed that PIN3 physically interacted with NPH3, a key transducer in phototropic signaling. Taken together, our study demonstrates that blue light induces adventitious root formation through the phototropic signal transducer, NPH3, which regulates adventitious root formation by affecting PIN3-mediated auxin transport.
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Affiliation(s)
- Shuang Zhai
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Wei Cai
- Institute of Crop Science of Wuhan Academy of Agriculture Science, Wuhan, 430345, China
| | - Zhi-Xin Xiang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Cai-Yan Chen
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Ying-Tang Lu
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Ting-Ting Yuan
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China.
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Light-triggered and phosphorylation-dependent 14-3-3 association with NON-PHOTOTROPIC HYPOCOTYL 3 is required for hypocotyl phototropism. Nat Commun 2021; 12:6128. [PMID: 34675219 PMCID: PMC8531446 DOI: 10.1038/s41467-021-26332-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 09/28/2021] [Indexed: 11/09/2022] Open
Abstract
NON-PHOTOTROPIC HYPOCOTYL 3 (NPH3) is a key component of the auxin-dependent plant phototropic growth response. We report that NPH3 directly binds polyacidic phospholipids, required for plasma membrane association in darkness. We further demonstrate that blue light induces an immediate phosphorylation of a C-terminal 14-3-3 binding motif in NPH3. Subsequent association of 14-3-3 proteins is causal for the light-induced release of NPH3 from the membrane and accompanied by NPH3 dephosphorylation. In the cytosol, NPH3 dynamically transitions into membraneless condensate-like structures. The dephosphorylated state of the 14-3-3 binding site and NPH3 membrane recruitment are recoverable in darkness. NPH3 variants that constitutively localize either to the membrane or to condensates are non-functional, revealing a fundamental role of the 14-3-3 mediated dynamic change in NPH3 localization for auxin-dependent phototropism. This regulatory mechanism might be of general nature, given that several members of the NPH3-like family interact with 14-3-3 via a C-terminal motif. NPH3 is required for auxin-dependent plant phototropism. Here Reuter et al. show that NPH3 is a plasma membrane-bound phospholipid-binding protein and that in response to blue light, NPH3 is phosphorylated and associates with 14-3-3 proteins which leads to dissociation from the plasma membrane.
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Sullivan S, Waksman T, Paliogianni D, Henderson L, Lütkemeyer M, Suetsugu N, Christie JM. Regulation of plant phototropic growth by NPH3/RPT2-like substrate phosphorylation and 14-3-3 binding. Nat Commun 2021; 12:6129. [PMID: 34675214 PMCID: PMC8531357 DOI: 10.1038/s41467-021-26333-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 09/28/2021] [Indexed: 11/09/2022] Open
Abstract
Polarity underlies all directional growth responses in plants including growth towards the light (phototropism). The plasma-membrane associated protein, NON-PHOTOTROPIC HYPOCOTYL 3 (NPH3) is a key determinant of phototropic growth which is regulated by phototropin (phot) AGC kinases. Here we demonstrate that NPH3 is directly phosphorylated by phot1 within a conserved C-terminal consensus sequence (RxS) that is necessary to promote phototropism and petiole positioning in Arabidopsis. RxS phosphorylation also triggers 14-3-3 binding combined with changes in NPH3 phosphorylation and localisation status. Mutants of NPH3 that are unable to bind or constitutively bind 14-3-3 s show compromised functionality consistent with a model where phototropic curvature is established by signalling outputs arising from a gradient of NPH3 RxS phosphorylation across the stem. Our findings therefore establish that NPH3/RPT2-Like (NRL) proteins are phosphorylation targets for plant AGC kinases. Moreover, RxS phosphorylation is conserved in other members of the NRL family, suggesting a common mechanism of regulating plant growth to the prevailing light environment.
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Affiliation(s)
- Stuart Sullivan
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, Bower Building, University of Glasgow, Glasgow, G12 8QQ, UK.
| | - Thomas Waksman
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, Bower Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Dimitra Paliogianni
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, Bower Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Louise Henderson
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, Bower Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Melanie Lütkemeyer
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, Bower Building, University of Glasgow, Glasgow, G12 8QQ, UK.,RNA Biology and Molecular Physiology, Faculty of Biology, Bielefeld University, 33615, Bielefeld, Germany
| | - Noriyuki Suetsugu
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, Bower Building, University of Glasgow, Glasgow, G12 8QQ, UK.,Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, 153-8902, Japan
| | - John M Christie
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, Bower Building, University of Glasgow, Glasgow, G12 8QQ, UK.
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Campos ML, Moreno JE. Moving around in a phototropic response: the phosphorylation of NPH3. PLANT PHYSIOLOGY 2021; 187:678-680. [PMID: 34608977 PMCID: PMC8491030 DOI: 10.1093/plphys/kiab358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 07/14/2021] [Indexed: 06/13/2023]
Affiliation(s)
- Marcelo Lattarulo Campos
- Integrative Plant Research Laboratory, Departamento de Botânica e Ecologia, Instituto de Biociências, Universidade Federal de Mato Grosso, Cuiabá, Mato Grosso, Brazil
| | - Javier Edgardo Moreno
- Instituto de Agrobiotecnología del Litoral (UNL-Conicet), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina
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12
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Kimura T, Haga K, Nomura Y, Higaki T, Nakagami H, Sakai T. Phosphorylation of NONPHOTOTROPIC HYPOCOTYL3 affects photosensory adaptation during the phototropic response. PLANT PHYSIOLOGY 2021; 187:981-995. [PMID: 34608954 PMCID: PMC8491083 DOI: 10.1093/plphys/kiab281] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 05/14/2021] [Indexed: 05/25/2023]
Abstract
Photosensory adaptation, which can be classified as sensor or effector adaptation, optimizes the light sensing of living organisms by tuning their sensitivity to changing light conditions. During the phototropic response in Arabidopsis (Arabidopsis thaliana), the light-dependent expression controls of blue-light (BL) photoreceptor phototropin 1 (phot1) and its modulator ROOT PHOTOTROPISM2 (RPT2) are known as the molecular mechanisms underlying sensor adaptation. However, little is known about effector adaption in plant phototropism. Here, we show that control of the phosphorylation status of NONPHOTOTROPIC HYPOCOTYL3 (NPH3) leads to effector adaptation in hypocotyl phototropism. We generated unphosphorable and phosphomimetic NPH3 proteins on seven phosphorylation sites in the etiolated seedlings of Arabidopsis. Unphosphorable NPH3 showed a shortening of its retention time in the cytosol and caused an inability to adapt to very low fluence rates of BL (∼10-5 µmol m-2 s-1) during the phototropic response. In contrast, the phosphomimetic NPH3 proteins had a lengthened retention time in the cytosol and could not enable the adaptation to BL at fluence rates of 10-3 µmol m-2 s-1 or more. Our results indicate that the activation level of phot1 and the corresponding phosphorylation level of NPH3 determine the dissociation rate and the reassociation rate of NPH3 on the plasma membrane, respectively. These mechanisms may moderately maintain the active state of phot1 signaling across a broad range of BL intensities and contribute to the photosensory adaptation of phot1 signaling during the phototropic response in hypocotyls.
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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
| | - Ken Haga
- Department of Applied Chemistry, Faculty of Fundamental Engineering, Nippon Institute of Technology, 4-1 Gakuendai, Miyashiro-cho, Minamisaitama-gun, Saitama 345-8501, Japan
| | - Yuko Nomura
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa 230-0045, Japan
| | - Takumi Higaki
- International Research Organization for Advanced Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto 860-8555, Japan
| | - Hirofumi Nakagami
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa 230-0045, Japan
- Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829 Cologne, Germany
| | - 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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13
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Han H, Adamowski M, Qi L, Alotaibi SS, Friml J. PIN-mediated polar auxin transport regulations in plant tropic responses. THE NEW PHYTOLOGIST 2021; 232:510-522. [PMID: 34254313 DOI: 10.1111/nph.17617] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Accepted: 07/03/2021] [Indexed: 05/27/2023]
Abstract
Tropisms, growth responses to environmental stimuli such as light or gravity, are spectacular examples of adaptive plant development. The plant hormone auxin serves as a major coordinative signal. The PIN auxin exporters, through their dynamic polar subcellular localizations, redirect auxin fluxes in response to environmental stimuli and the resulting auxin gradients across organs underlie differential cell elongation and bending. In this review, we discuss recent advances concerning regulations of PIN polarity during tropisms, focusing on PIN phosphorylation and trafficking. We also cover how environmental cues regulate PIN actions during tropisms, as well as the crucial role of auxin feedback on PIN polarity during bending termination. Finally, the interactions between different tropisms are reviewed to understand plant adaptive growth in the natural environment.
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Affiliation(s)
- Huibin Han
- Institute of Science and Technology Austria, Klosterneuburg, 3400, Austria
- Research Center for Plant Functional Genes and Tissue Culture Technology, College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Maciek Adamowski
- Institute of Science and Technology Austria, Klosterneuburg, 3400, Austria
| | - Linlin Qi
- Institute of Science and Technology Austria, Klosterneuburg, 3400, Austria
| | - Saqer S Alotaibi
- Department of Biotechnology, Taif University, PO Box 11099, Taif, 21944, Kingdom of Saudi Arabia
| | - Jiří Friml
- Institute of Science and Technology Austria, Klosterneuburg, 3400, Austria
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14
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Furuhashi K, Iwase K, Furuhashi T. Role of Light and Plant Hormones in Stem Parasitic Plant (Cuscuta and Cassytha) Twining and Haustoria Induction. Photochem Photobiol 2021; 97:1054-1062. [PMID: 33934364 DOI: 10.1111/php.13441] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 04/27/2021] [Accepted: 04/28/2021] [Indexed: 11/30/2022]
Abstract
Cuscuta and Cassytha are two distinct stem parasitic plant genera developing haustoria at their stem. The initial step to parasitization is twining onto the host plant. Although twining is the critical first step, less attention has been paid to this aspect in stem haustoria parasitic plant studies. As tendril coiling is also controlled by light and plant hormones, we investigated the role of light (blue, red and far-red) and hormones (auxin, brassinolide, cytokinin) in twining of stem parasitic plants (Cuscuta japonica and Cassytha filiformis). In general, both Cuscuta and Cassytha showed similar behavior to light cues. The data show that blue light is essential for twining, and a lower far-red/red light (FR/R) ratio is important for subsequent haustoria induction. Regarding plant hormones, seedlings with solely auxin or cytokinin (iP) under blue light showed not only twining but also haustoria induction, demonstrating that auxin and iP appear to be especially important for induction. Seedlings with solely brassinolide showed no positive influence, but brassinolide together with iP caused twining even under dark conditions. This points to the presence of cross-talk between brassinolide and cytokinin for twining.
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Affiliation(s)
- Katsuhisa Furuhashi
- Department of Parasitic Plant Physiology, Maeda-Institute of Plant Resources, Nagoya, Japan
| | - Koji Iwase
- Department of Natural and Environmental Science, Teikyo University of Science, Tokyo, Japan
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15
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Boccaccini A, Legris M, Krahmer J, Allenbach-Petrolati L, Goyal A, Galvan-Ampudia C, Vernoux T, Karayekov E, Casal JJ, Fankhauser C. Low Blue Light Enhances Phototropism by Releasing Cryptochrome1-Mediated Inhibition of PIF4 Expression. PLANT PHYSIOLOGY 2020; 183:1780-1793. [PMID: 32554507 PMCID: PMC7401145 DOI: 10.1104/pp.20.00243] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 06/08/2020] [Indexed: 05/23/2023]
Abstract
Shade-avoiding plants, including Arabidopsis (Arabidopsis thaliana), display a number of growth responses, such as elongation of stem-like structures and repositioning of leaves, elicited by shade cues, including a reduction in the blue and red portions of the solar spectrum and a low-red to far-red ratio. Shade also promotes phototropism of de-etiolated seedlings through repression of phytochrome B, presumably to enhance capture of unfiltered sunlight. Here we show that both low blue light and a low-red to far-red light ratio are required to rapidly enhance phototropism in Arabidopsis seedlings. However, prolonged low blue light treatments are sufficient to promote phototropism through reduced cryptochrome1 (cry1) activation. The enhanced phototropic response of cry1 mutants in the lab and in response to natural canopies depends on PHYTOCHROME INTERACTING FACTORs (PIFs). In favorable light conditions, cry1 limits the expression of PIF4, while in low blue light, PIF4 expression increases, which contributes to phototropic enhancement. The analysis of quantitative DII-Venus, an auxin signaling reporter, indicates that low blue light leads to enhanced auxin signaling in the hypocotyl and, upon phototropic stimulation, a steeper auxin signaling gradient across the hypocotyl. We conclude that phototropic enhancement by canopy shade results from the combined activities of phytochrome B and cry1 that converge on PIF regulation.
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Affiliation(s)
- Alessandra Boccaccini
- Centre for Integrative Genomics, Faculty of Biology and Medicine, Génopode Building, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Martina Legris
- Centre for Integrative Genomics, Faculty of Biology and Medicine, Génopode Building, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Johanna Krahmer
- Centre for Integrative Genomics, Faculty of Biology and Medicine, Génopode Building, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Laure Allenbach-Petrolati
- Centre for Integrative Genomics, Faculty of Biology and Medicine, Génopode Building, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Anupama Goyal
- Centre for Integrative Genomics, Faculty of Biology and Medicine, Génopode Building, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Carlos Galvan-Ampudia
- Laboratoire de Reproduction et Développement des Plantes, Université Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRAE, 69364 Lyon, France
| | - Teva Vernoux
- Laboratoire de Reproduction et Développement des Plantes, Université Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRAE, 69364 Lyon, France
| | - Elizabeth Karayekov
- IFEVA, Facultad de Agronomia, Universidad de Buenos Aires and CONICET, Av. San Martin 4453, 1417 Buenos Aires, Argentina
| | - Jorge J Casal
- IFEVA, Facultad de Agronomia, Universidad de Buenos Aires and CONICET, Av. San Martin 4453, 1417 Buenos Aires, Argentina
- Fundacion Instituto Leloir, Instituto de Investigaciones Bioquimicas de Buenos Aires-CONICET, 1405 Buenos Aires, Argentina
| | - Christian Fankhauser
- Centre for Integrative Genomics, Faculty of Biology and Medicine, Génopode Building, University of Lausanne, CH-1015 Lausanne, Switzerland
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16
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Küpers JJ, Oskam L, Pierik R. Photoreceptors Regulate Plant Developmental Plasticity through Auxin. PLANTS 2020; 9:plants9080940. [PMID: 32722230 PMCID: PMC7463442 DOI: 10.3390/plants9080940] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 07/17/2020] [Accepted: 07/22/2020] [Indexed: 12/13/2022]
Abstract
Light absorption by plants changes the composition of light inside vegetation. Blue (B) and red (R) light are used for photosynthesis whereas far-red (FR) and green light are reflected. A combination of UV-B, blue and R:FR-responsive photoreceptors collectively measures the light and temperature environment and adjusts plant development accordingly. This developmental plasticity to photoreceptor signals is largely regulated through the phytohormone auxin. The phytochrome, cryptochrome and UV Resistance Locus 8 (UVR8) photoreceptors are inactivated in shade and/or elevated temperature, which releases their repression of Phytochrome Interacting Factor (PIF) transcription factors. Active PIFs stimulate auxin synthesis and reinforce auxin signalling responses through direct interaction with Auxin Response Factors (ARFs). It was recently discovered that shade-induced hypocotyl elongation and petiole hyponasty depend on long-distance auxin transport towards target cells from the cotyledon and leaf tip, respectively. Other responses, such as phototropic bending, are regulated by auxin transport and signalling across only a few cell layers. In addition, photoreceptors can directly interact with components in the auxin signalling pathway, such as Auxin/Indole Acetic Acids (AUX/IAAs) and ARFs. Here we will discuss the complex interactions between photoreceptor and auxin signalling, addressing both mechanisms and consequences of these highly interconnected pathways.
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17
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Legris M, Boccaccini A. Stem phototropism toward blue and ultraviolet light. PHYSIOLOGIA PLANTARUM 2020; 169:357-368. [PMID: 32208516 DOI: 10.1111/ppl.13098] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 03/05/2020] [Accepted: 03/19/2020] [Indexed: 06/10/2023]
Abstract
Positive phototropism is the process through which plants orient their organs toward a directional light source. While the blue light receptors phototropins (phot) play a major role in phototropism toward blue (B) and ultraviolet (UV) radiation, recent research showed that the UVB light receptor UVR8 also triggers phototropism toward UVB. In addition, new details of the molecular mechanisms underlying the activity of these receptors and interaction with other environmental signals have emerged in the past years. In this review, we summarize the current knowledge about hypocotyledoneous and inflorescence stem growth reorientation toward B and UVB, with a focus on the molecular mechanisms.
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Affiliation(s)
- Martina Legris
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015, Lausanne, Switzerland
| | - Alessandra Boccaccini
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015, Lausanne, Switzerland
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18
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Kimura T, Tsuchida-Mayama T, Imai H, Okajima K, Ito K, Sakai T. Arabidopsis ROOT PHOTOTROPISM2 Is a Light-Dependent Dynamic Modulator of Phototropin1. THE PLANT CELL 2020; 32:2004-2019. [PMID: 32213636 PMCID: PMC7268816 DOI: 10.1105/tpc.19.00926] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 01/22/2020] [Accepted: 03/17/2020] [Indexed: 05/25/2023]
Abstract
The Arabidopsis (Arabidopsis thaliana) blue light photoreceptor phototropin1 (phot1) is a blue light-activated Ser/Thr protein kinase that mediates various light responses, including phototropism. The function of phot1 in hypocotyl phototropism is dependent on the light induction of ROOT PHOTOTROPISM2 (RPT2) proteins within a broad range of blue light intensities. It is not yet known however how RPT2 contributes to the photosensory adaptation of phot1 to high intensity blue light and the phototropic responses under bright light conditions. We show that RPT2 suppresses the activity of phot1 and demonstrate that RPT2 binds to the PHOT1 light, oxygen or voltage sensing1 (LOV1) domain that is required for its high photosensitivity. Our biochemical analyses revealed that RPT2 inhibits autophosphorylation of phot1, suggesting that it suppresses the photosensitivity and/or kinase activity of phot1 through the inhibition of LOV1 function. We found that RPT2 proteins are degraded via a ubiquitin-proteasome pathway when phot1 is inactive and are stabilized under blue light in a phot1-dependent manner. We propose that RPT2 is a molecular rheostat that maintains a moderate activation level of phot1 under any light intensity conditions.
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Affiliation(s)
- Taro Kimura
- Graduate School of Science and Technology, Niigata University, Niigata-shi, Niigata, 950-2181, Japan
| | | | - Hirotatsu Imai
- Graduate School of Science and Technology, Niigata University, Niigata-shi, Niigata, 950-2181, Japan
- Research Fellow of Japan Society for the Promotion of Science, Kojimachi Business Center Building, Chiyoda-ku, Tokyo 102-0083, Japan
| | - Koji Okajima
- Department of Physics, Keio University, 3-14-1, Hiyoshi, Kouhoku-ku, Yokohama, Kanagawa 223-8522, Japan
| | - Kosuke Ito
- Graduate School of Science and Technology, Niigata University, Niigata-shi, Niigata, 950-2181, Japan
| | - Tatsuya Sakai
- Graduate School of Science and Technology, Niigata University, Niigata-shi, Niigata, 950-2181, Japan
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19
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Liscum E, Nittler P, Koskie K. The continuing arc toward phototropic enlightenment. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:1652-1658. [PMID: 31907539 PMCID: PMC7242014 DOI: 10.1093/jxb/eraa005] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 01/05/2020] [Indexed: 05/20/2023]
Abstract
Phototropism represents a simple physiological mechanism-differential growth across the growing organ of a plant-to respond to gradients of light and maximize photosynthetic light capture (in aerial tissues) and water/nutrient acquisition (in roots). The phototropin blue light receptors, phot1 and phot2, have been identified as the essential sensors for phototropism. Additionally, several downstream signal/response components have been identified, including the phot-interacting proteins NON-PHOTOTROPIC HYPOCOTYL 3 (NPH3) and PHYTOCHROME SUBSTRATE 4 (PKS4). While the structural and photochemical properties of the phots are quite well understood, much less is known about how the phots signal through downstream regulators. Recent advances have, however, provided some intriguing clues. It appears that inactive receptor phot1 is found dispersed in a monomeric form at the plasma membrane in darkness. Upon light absorption dimerizes and clusters in sterol-rich microdomains where it is signal active. Additional studies showed that the phot-regulated phosphorylation status of both NPH3 and PKS4 is linked to phototropic responsiveness. While PKS4 can function as both a positive (in low light) and a negative (in high light) regulator of phototropism, NPH3 appears to function solely as a key positive regulator. Ultimately, it is the subcellular localization of NPH3 that appears crucial, an aspect regulated by its phosphorylation status. While phot1 activation promotes dephosphorylation of NPH3 and its movement from the plasma membrane to cytoplasmic foci, phot2 appears to modulate relocalization back to the plasma membrane. Together these findings are beginning to illuminate the complex biochemical and cellular events, involved in adaptively modifying phototropic responsiveness under a wide varying range of light conditions.
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Affiliation(s)
- Emmanuel Liscum
- C.S. Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
- Division of Biological Sciences, University of Missouri, Columbia, MO, USA
- Correspondence:
| | - Patrick Nittler
- C.S. Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
- Division of Biological Sciences, University of Missouri, Columbia, MO, USA
| | - Katelynn Koskie
- C.S. Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
- Division of Biological Sciences, University of Missouri, Columbia, MO, USA
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20
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Armarego-Marriott T, Sandoval-Ibañez O, Kowalewska Ł. Beyond the darkness: recent lessons from etiolation and de-etiolation studies. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:1215-1225. [PMID: 31854450 PMCID: PMC7031072 DOI: 10.1093/jxb/erz496] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 11/29/2019] [Indexed: 05/06/2023]
Abstract
The state of etiolation is generally defined by the presence of non-green plastids (etioplasts) in plant tissues that would normally contain chloroplasts. In the commonly used dark-grown seedling system, etiolation is coupled with a type of growth called skotomorphogenesis. Upon illumination, de-etiolation occurs, marked by the transition from etioplast to chloroplast, and, at the seedling level, a switch to photomorphogenic growth. Etiolation and de-etiolation systems are therefore important for understanding both the acquisition of photosynthetic capacity during chloroplast biogenesis and plant responses to light-the most relevant signal in the life and growth of the organism. In this review, we discuss recent discoveries (within the past 2-3 years) in the field of etiolation and de-etiolation, with a particular focus on post-transcriptional processes and ultrastructural changes. We further discuss ambiguities in definitions of the term 'etiolation', and benefits and biases of common etiolation/de-etiolation systems. Finally, we raise several open questions and future research possibilities.
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Affiliation(s)
| | | | - Łucja Kowalewska
- Faculty of Biology, Department of Plant Anatomy and Cytology, University of Warsaw, Warszawa, Poland
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21
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Gommers CMM. Light Triggers the Search for Light. PLANT PHYSIOLOGY 2019; 180:695-696. [PMID: 31160523 PMCID: PMC6548277 DOI: 10.1104/pp.19.00465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Affiliation(s)
- Charlotte M M Gommers
- Laboratory of Plant Physiology, Wageningen University and Research, 6700 HB Wageningen, The Netherlands
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