1
|
Kong SG, Yamazaki Y, Shimada A, Kijima ST, Hirose K, Katoh K, Ahn J, Song HG, Han JW, Higa T, Takano A, Nakamura Y, Suetsugu N, Kohda D, Uyeda TQP, Wada M. CHLOROPLAST UNUSUAL POSITIONING 1 is a plant-specific actin polymerization factor regulating chloroplast movement. THE PLANT CELL 2024; 36:1159-1181. [PMID: 38134410 PMCID: PMC10980345 DOI: 10.1093/plcell/koad320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 11/09/2023] [Accepted: 12/18/2023] [Indexed: 12/24/2023]
Abstract
Plants have unique responses to fluctuating light conditions. One such response involves chloroplast photorelocation movement, which optimizes photosynthesis under weak light by the accumulation of chloroplasts along the periclinal side of the cell, which prevents photodamage under strong light by avoiding chloroplast positioning toward the anticlinal side of the cell. This light-responsive chloroplast movement relies on the reorganization of chloroplast actin (cp-actin) filaments. Previous studies have suggested that CHLOROPLAST UNUSUAL POSITIONING 1 (CHUP1) is essential for chloroplast photorelocation movement as a regulator of cp-actin filaments. In this study, we conducted comprehensive analyses to understand CHUP1 function. Functional, fluorescently tagged CHUP1 colocalized with and was coordinately reorganized with cp-actin filaments on the chloroplast outer envelope during chloroplast movement in Arabidopsis thaliana. CHUP1 distribution was reversibly regulated in a blue light- and phototropin-dependent manner. X-ray crystallography revealed that the CHUP1-C-terminal domain shares structural homology with the formin homology 2 (FH2) domain, despite lacking sequence similarity. Furthermore, the CHUP1-C-terminal domain promoted actin polymerization in the presence of profilin in vitro. Taken together, our findings indicate that CHUP1 is a plant-specific actin polymerization factor that has convergently evolved to assemble cp-actin filaments and enables chloroplast photorelocation movement.
Collapse
Affiliation(s)
- Sam-Geun Kong
- Department of Biological Sciences, College of Natural Sciences, Kongju National University, Chungnam 32588, Korea
- Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan
| | - Yosuke Yamazaki
- Department of Physics, Faculty of Science and Engineering, Waseda University, Tokyo 169-8555, Japan
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Atsushi Shimada
- Division of Structural Biology, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan
| | - Saku T Kijima
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology, Ibaraki 305-8562, Japan
| | - Keiko Hirose
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology, Ibaraki 305-8562, Japan
| | - Kaoru Katoh
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology, Ibaraki 305-8562, Japan
| | - Jeongsu Ahn
- Department of Biological Sciences, College of Natural Sciences, Kongju National University, Chungnam 32588, Korea
| | - Hyun-Geun Song
- Department of Biological Sciences, College of Natural Sciences, Kongju National University, Chungnam 32588, Korea
| | - Jae-Woo Han
- Department of Biological Sciences, College of Natural Sciences, Kongju National University, Chungnam 32588, Korea
| | - Takeshi Higa
- Institute for Protein Research, Osaka University, Osaka 565-0871, Japan
| | - Akira Takano
- Division of Structural Biology, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan
| | - Yuki Nakamura
- Division of Structural Biology, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan
| | - Noriyuki Suetsugu
- Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan
| | - Daisuke Kohda
- Division of Structural Biology, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan
| | - Taro Q P Uyeda
- Department of Physics, Faculty of Science and Engineering, Waseda University, Tokyo 169-8555, Japan
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology, Ibaraki 305-8562, Japan
| | - Masamitsu Wada
- Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan
- Graduate School of Science, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| |
Collapse
|
2
|
Zygnematophycean algae: Possible models for cellular and evolutionary biology. Semin Cell Dev Biol 2023; 134:59-68. [PMID: 35430142 DOI: 10.1016/j.semcdb.2022.03.042] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 03/29/2022] [Accepted: 03/31/2022] [Indexed: 11/20/2022]
Abstract
Plant terrestrialization was a critical event for our planet. For the study of plant evolution, charophytes have received a great deal of attention because of their phylogenetic position. Among charophytes, the class Zygnematophyceae is the closest lineage to land plants. During sexual reproduction, they show isogamous conjugation by immotile gametes, which is characteristic of zygnematophycean algae. Here, we introduce the genera Mougeotia, Penium, and Closterium, which are representative model organisms of Zygnematophyceae in terms of chloroplast photorelocation movement, the cell wall, and sexual reproduction, respectively.
Collapse
|
3
|
Kumar S, Jeevaraj T, Yunus MH, Chakraborty S, Chakraborty N. The plant cytoskeleton takes center stage in abiotic stress responses and resilience. PLANT, CELL & ENVIRONMENT 2023; 46:5-22. [PMID: 36151598 DOI: 10.1111/pce.14450] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 09/16/2022] [Accepted: 09/20/2022] [Indexed: 06/16/2023]
Abstract
Stress resilience behaviours in plants are defensive mechanisms that develop under adverse environmental conditions to promote growth, development and yield. Over the past decades, improving stress resilience, especially in crop species, has been a focus of intense research for global food security and economic growth. Plants have evolved specific mechanisms to sense external stress and transmit information to the cell interior and generate appropriate responses. Plant cytoskeleton, comprising microtubules and actin filaments, takes a center stage in stress-induced signalling pathways, either as a direct target or as a signal transducer. In the past few years, it has become apparent that the function of the plant cytoskeleton and other associated proteins are not merely limited to elementary processes of cell growth and proliferation, but they also function in stress response and resilience. This review summarizes recent advances in the role of plant cytoskeleton and associated proteins in abiotic stress management. We provide a thorough overview of the mechanisms that plant cells employ to withstand different abiotic stimuli such as hypersalinity, dehydration, high temperature and cold, among others. We also discuss the crucial role of the plant cytoskeleton in organellar positioning under the influence of high light intensity.
Collapse
Affiliation(s)
- Sunil Kumar
- Stress Biology, National Institute of Plant Genome Research, New Delhi, India
| | - Theboral Jeevaraj
- Stress Biology, National Institute of Plant Genome Research, New Delhi, India
| | - Mohd H Yunus
- Stress Biology, National Institute of Plant Genome Research, New Delhi, India
| | - Subhra Chakraborty
- Stress Biology, National Institute of Plant Genome Research, New Delhi, India
| | | |
Collapse
|
4
|
Christensen JR, Reck-Peterson SL. Hitchhiking Across Kingdoms: Cotransport of Cargos in Fungal, Animal, and Plant Cells. Annu Rev Cell Dev Biol 2022; 38:155-178. [PMID: 35905769 PMCID: PMC10967659 DOI: 10.1146/annurev-cellbio-120420-104341] [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] [Indexed: 11/09/2022]
Abstract
Eukaryotic cells across the tree of life organize their subcellular components via intracellular transport mechanisms. In canonical transport, myosin, kinesin, and dynein motor proteins interact with cargos via adaptor proteins and move along filamentous actin or microtubule tracks. In contrast to this canonical mode, hitchhiking is a newly discovered mode of intracellular transport in which a cargo attaches itself to an already-motile cargo rather than directly associating with a motor protein itself. Many cargos including messenger RNAs, protein complexes, and organelles hitchhike on membrane-bound cargos. Hitchhiking-like behaviors have been shown to impact cellular processes including local protein translation, long-distance signaling, and organelle network reorganization. Here, we review instances of cargo hitchhiking in fungal, animal, and plant cells and discuss the potential cellular and evolutionary importance of hitchhiking in these different contexts.
Collapse
Affiliation(s)
- Jenna R Christensen
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California, USA; ,
| | - Samara L Reck-Peterson
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California, USA; ,
- Department of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, California, USA
- Howard Hughes Medical Institute, Chevy Chase, Maryland, USA
| |
Collapse
|
5
|
Dwyer ME, Hangarter RP. Light-dependent phosphorylation of THRUMIN1 regulates its association with actin filaments and 14-3-3 proteins. PLANT PHYSIOLOGY 2021; 187:1445-1461. [PMID: 34618069 PMCID: PMC8566215 DOI: 10.1093/plphys/kiab374] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 07/12/2021] [Indexed: 06/13/2023]
Abstract
Light-dependent chloroplast movements in leaf cells contribute to the optimization of photosynthesis. Low-light conditions induce chloroplast accumulation along periclinal cell surfaces, providing greater access to available light, whereas high light induces movement of chloroplasts to anticlinal cell surfaces, providing photodamage protection and allowing more light to reach underlying cell layers. The THRUMIN1 protein is required for normal chloroplast movements in Arabidopsis (Arabidopsis thaliana) and has been shown to localize at the plasma membrane and to undergo rapid light-dependent interactions with actin filaments through the N-terminal intrinsically disordered region (IDR). A predicted WASP-Homology 2 domain was found in the IDR but mutations in this domain did not disrupt localization of THRUMIN1:YFP to actin filaments. A series of other protein truncations and site-directed mutations of known and putative phosphorylation sites indicated that a phosphomimetic mutation (serine to aspartic acid) at position 170 disrupted localization of THRUMIN1 to actin filaments. However, the phosphomimetic mutant rescued the thrumin1-2 mutant phenotype for chloroplast movement and raises questions about the role of THRUMIN1's interaction with actin. Mutation of serine 146 to aspartic acid also resulted in cytoplasmic localization of THRUMIN1:YFP in Nicotiana benthamiana. Mutations to a group of putative zinc-binding cysteine clusters implicate the C-terminus of THRUMIN1 in chloroplast movement. Phosphorylation-dependent association of THRUMIN1 with 14-3-3 KAPPA and OMEGA were also identified. Together, these studies provide insights into the mechanistic role of THRUMIN1 in light-dependent chloroplast movements.
Collapse
Affiliation(s)
- Matthew E Dwyer
- Department of Biology, Indiana University, Bloomington, Indiana 47405, USA
| | - Roger P Hangarter
- Department of Biology, Indiana University, Bloomington, Indiana 47405, USA
| |
Collapse
|
6
|
Abstract
Kinesins constitute a superfamily of ATP-driven microtubule motor enzymes that convert the chemical energy of ATP hydrolysis into mechanical work along microtubule tracks. Kinesins are found in all eukaryotic organisms and are essential to all eukaryotic cells, involved in diverse cellular functions such as microtubule dynamics and morphogenesis, chromosome segregation, spindle formation and elongation and transport of organelles. In this review, we explore recently reported functions of kinesins in eukaryotes and compare their specific cargoes in both plant and animal kingdoms to understand the possible roles of uncharacterized motors in a kingdom based on their reported functions in other kingdoms.
Collapse
Affiliation(s)
- Iftikhar Ali
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences , Beijing, China
| | - Wei-Cai Yang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences , Beijing, China.,The College of Advanced Agricultural Science, The University of Chinese Academy of Sciences , Beijing, China
| |
Collapse
|
7
|
Krzeszowiec W, Novokreshchenova M, Gabryś H. Chloroplasts in C3 grasses move in response to blue-light. PLANT CELL REPORTS 2020; 39:1331-1343. [PMID: 32661816 PMCID: PMC7497455 DOI: 10.1007/s00299-020-02567-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 07/08/2020] [Indexed: 05/13/2023]
Abstract
KEY MESSAGE Brachypodium distachyon is a good model for studying chloropla st movements in the crop plants, wheat, rye and barley. The movements are activated only by blue light, similar to Arabidopsis. Chloroplast translocations are ubiquitous in photosynthetic organisms. On the one hand, they serve to optimize energy capture under limiting light, on the other hand, they minimize potential photodamage to the photosynthetic apparatus in excess light. In higher plants chloroplast movements are mediated by phototropins (phots), blue light receptors that also control other light acclimation responses. So far, Arabidopsis thaliana has been the main model for studying the mechanism of blue light signaling to chloroplast translocations in terrestrial plants. Here, we propose Brachypodium distachyon as a model in research into chloroplast movements in C3 cereals. Brachypodium chloroplasts respond to light in a similar way to those in Arabidopsis. The amino acid sequence of Brachypodium PHOT1 is 79.3% identical, and that of PHOT2 is 73.6% identical to the sequence of the corresponding phototropin in Arabidopsis. Both phototropin1 and 2 are expressed in Brachypodium, as shown using quantitative real-time PCR. Intriguingly, the light-expression pattern of BradiPHOT1 and BradiPHOT2 is the opposite of that for Arabidopsis phototropins, suggesting potential unique light signaling in C3 grasses. To investigate if Brachypodium is a good model for studying grass chloroplast movements we analyzed these movements in the leaves of three C3 crop grasses, namely wheat, rye and barley. Similarly to Brachypodium, chloroplasts only respond to blue light in all these species.
Collapse
Affiliation(s)
- Weronika Krzeszowiec
- Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Maria Novokreshchenova
- Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Halina Gabryś
- Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| |
Collapse
|
8
|
Islam MS, Van Nguyen T, Sakamoto W, Takagi S. Phototropin- and photosynthesis-dependent mitochondrial positioning in Arabidopsis thaliana mesophyll cells. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2020; 62:1352-1371. [PMID: 31961050 DOI: 10.1111/jipb.12910] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 01/07/2020] [Indexed: 06/10/2023]
Abstract
Mitochondria are frequently observed in the vicinity of chloroplasts in photosynthesizing cells, and this association is considered necessary for their metabolic interactions. We previously reported that, in leaf palisade cells of Arabidopsis thaliana, mitochondria exhibit blue-light-dependent redistribution together with chloroplasts, which conduct accumulation and avoidance responses under the control of blue-light receptor phototropins. In this study, precise motility analyses by fluorescent microscopy revealed that the individual mitochondria in palisade cells, labeled with green fluorescent protein, exhibit typical stop-and-go movement. When exposed to blue light, the velocity of moving mitochondria increased in 30 min, whereas after 4 h, the frequency of stoppage of mitochondrial movement markedly increased. Using different mutant plants, we concluded that the presence of both phototropin1 and phototropin2 is necessary for the early acceleration of mitochondrial movement. On the contrary, the late enhancement of stoppage of mitochondrial movement occurs only in the presence of phototropin2 and only when intact photosynthesis takes place. A plasma-membrane ghost assay suggested that the stopped mitochondria are firmly adhered to chloroplasts. These results indicate that the physical interaction between mitochondria and chloroplasts is cooperatively mediated by phototropin2- and photosynthesis-dependent signals. The present study might add novel regulatory mechanism for light-dependent plant organelle interactions.
Collapse
Affiliation(s)
- Md Sayeedul Islam
- Department of Biological Sciences, Graduate School of Science, Osaka University, Machikaneyama-cho 1-1, Toyonaka, Osaka, 560-0043, Japan
| | - Toan Van Nguyen
- Department of Biological Sciences, Graduate School of Science, Osaka University, Machikaneyama-cho 1-1, Toyonaka, Osaka, 560-0043, Japan
- Agricultural Genetics Institute, National Key Laboratory for Plant Cell Biotechnology, Pham Van Dong road, Bac Tu Liem district, Ha Noi, Vietnam
| | - Wataru Sakamoto
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama, 710-0046, Japan
| | - Shingo Takagi
- Department of Biological Sciences, Graduate School of Science, Osaka University, Machikaneyama-cho 1-1, Toyonaka, Osaka, 560-0043, Japan
| |
Collapse
|
9
|
Wilson S, Ruban AV. Rethinking the Influence of Chloroplast Movements on Non-photochemical Quenching and Photoprotection. PLANT PHYSIOLOGY 2020; 183:1213-1223. [PMID: 32404415 PMCID: PMC7333707 DOI: 10.1104/pp.20.00549] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 05/04/2020] [Indexed: 05/25/2023]
Abstract
Under blue light, plant chloroplasts relocate to different areas of the cell. The photoreceptor phototropin2 (phot2) mediates the chloroplast movement mechanism under excess blue light alongside the chloroplast unusual positioning1 (chup1) protein. Recently, it has been proposed that leaf transmittance changes associated with chloroplast relocation affect measurements of nonphotochemical quenching (NPQ), resulting in kinetic differences due to these movements (termed "qM"). We evaluated these claims using Arabidopsis (Arabidopsis thaliana) knock-out mutants lacking either phot2 or chup1 and analyzed the kinetics of both the onset and recovery of NPQ under equivalent intensities of both red and blue light. We also evaluated the photoprotective ability of chloroplast movements both during the early onset of photoinhibition and under sustained excess light. We monitored photoinhibition using the chlorophyll fluorescence parameter of photochemical quenching in the dark, which measures the redox state of QA within PSII without any of the complications of traditional F v /F m measurements. While there were noticeable differences between the responses under red and blue light, the chloroplast movement mechanism had no effect on the rate or amplitude of NPQ onset or recovery. Therefore, we were unable to replicate the "qM" component and its corresponding influence on the kinetics of NPQ in Arabidopsis grown under "shade" conditions. Furthermore, chloroplast relocation had no effect on the high-light tolerance of these plants. These data cast doubt upon the existence of a chloroplast movement-dependent component of NPQ Therefore, the influence of chloroplast movements on photoprotection should be thoroughly reevaluated.
Collapse
Affiliation(s)
- Sam Wilson
- School of Biological and Chemical Sciences, Queen Mary University of London, London, E1 4NS, United Kingdom
| | - Alexander V Ruban
- School of Biological and Chemical Sciences, Queen Mary University of London, London, E1 4NS, United Kingdom
| |
Collapse
|
10
|
Czarnocka W, Rusaczonek A, Willems P, Sujkowska-Rybkowska M, Van Breusegem F, Karpiński S. Novel Role of JAC1 in Influencing Photosynthesis, Stomatal Conductance, and Photooxidative Stress Signalling Pathway in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2020; 11:1124. [PMID: 32849690 PMCID: PMC7403226 DOI: 10.3389/fpls.2020.01124] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Accepted: 07/08/2020] [Indexed: 05/03/2023]
Abstract
Regulation of light absorption under variable light conditions is essential to optimize photosynthetic and acclimatory processes in plants. Light energy absorbed in excess has a damaging effect on chloroplasts and can lead to cell death. Therefore, plants have evolved protective mechanisms against excess excitation energy that include chloroplast accumulation and avoidance responses. One of the proteins involved in facilitating chloroplast movements in Arabidopsis thaliana is the J domain-containing protein required for chloroplast accumulation response 1 (JAC1). The function of JAC1 relates to the chloroplast actin filaments appearance and disappearance. So far, the role of JAC1 was studied mainly in terms of chloroplasts photorelocation. Here, we demonstrate that the function of JAC1 is more complex, since it influences the composition of photosynthetic pigments, the efficiency of photosynthesis, and the CO2 uptake rate. JAC1 has positive effect on water use efficiency (WUE) by reducing stomatal aperture and water vapor conductance. Importantly, we show that the stomatal aperture regulation is genetically coupled with JAC1 activity. In addition, our data demonstrate that JAC1 is involved in the fine-tuning of H2O2 foliar levels, antioxidant enzymes activities and cell death after UV-C photooxidative stress. This work uncovers a novel function for JAC1 in affecting photosynthesis, CO2 uptake, and photooxidative stress responses.
Collapse
Affiliation(s)
- Weronika Czarnocka
- Department of Botany, Institute of Biology, Warsaw University of Life Sciences, Warsaw, Poland
- Department of Plant Genetics, Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences, Warsaw, Poland
- *Correspondence: Weronika Czarnocka,
| | - Anna Rusaczonek
- Department of Botany, Institute of Biology, Warsaw University of Life Sciences, Warsaw, Poland
- Department of Plant Genetics, Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences, Warsaw, Poland
| | - Patrick Willems
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center of Plant Systems Biology, VIB, Ghent, Belgium
| | | | - Frank Van Breusegem
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center of Plant Systems Biology, VIB, Ghent, Belgium
| | - Stanisław Karpiński
- Department of Plant Genetics, Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences, Warsaw, Poland
| |
Collapse
|
11
|
Pfündel EE, Latouche G, Meister A, Cerovic ZG. Linking chloroplast relocation to different responses of photosynthesis to blue and red radiation in low and high light-acclimated leaves of Arabidopsis thaliana (L.). PHOTOSYNTHESIS RESEARCH 2018; 137:105-128. [PMID: 29374806 DOI: 10.1007/s11120-018-0482-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Accepted: 01/09/2018] [Indexed: 05/16/2023]
Abstract
Low light (LL) and high light (HL)-acclimated plants of A. thaliana were exposed to blue (BB) or red (RR) light or to a mixture of blue and red light (BR) of incrementally increasing intensities. The light response of photosystem II was measured by pulse amplitude-modulated chlorophyll fluorescence and that of photosystem I by near infrared difference spectroscopy. The LL but not HL leaves exhibited blue light-specific responses which were assigned to relocation of chloroplasts from the dark to the light-avoidance arrangement. Blue light (BB and BR) decreased the minimum fluorescence ([Formula: see text]) more than RR light. This extra reduction of the [Formula: see text] was stronger than theoretically predicted for [Formula: see text] quenching by energy dissipation but actual measurement and theory agreed in RR treatments. The extra [Formula: see text] reduction was assigned to decreased light absorption of chloroplasts in the avoidance position. A maximum reduction of 30% was calculated. Increasing intensities of blue light affected the fluorescence parameters NPQ and qP to a lesser degree than red light. After correcting for the optical effects of chloroplast relocation, the NPQ responded similarly to blue and red light. The same correction method diminished the color-specific variations in qP but did not abolish it; thus strongly indicating the presence of another blue light effect which also moderates excitation pressure in PSII but cannot be ascribed to absorption variations. Only after RR exposure, a post-illumination overshoot of [Formula: see text] and fast oxidation of PSI electron acceptors occurred, thus, suggesting an electron flow from stromal reductants to the plastoquinone pool.
Collapse
Affiliation(s)
- Erhard E Pfündel
- Lehrstuhl für Botanik II der Universität Würzburg, Julius-von-Sachs Institut für Biowissenschaften, 97082, Würzburg, Germany.
- Heinz Walz GmbH, Eichenring 6, 91090, Effeltrich, Germany.
| | - Gwendal Latouche
- Université Paris-Saclay, Université Paris-Sud, Laboratoire Écologie Systématique et Évolution, UMR8079, Bât. 362, 91405, Orsay, France
- CNRS, 91405, Orsay, France
- AgroParisTech, 75231, Paris, France
| | - Armin Meister
- Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung (IPK), Corrensstraße 3, 06466, Gatersleben, Germany
| | - Zoran G Cerovic
- Université Paris-Saclay, Université Paris-Sud, Laboratoire Écologie Systématique et Évolution, UMR8079, Bât. 362, 91405, Orsay, France
- CNRS, 91405, Orsay, France
- AgroParisTech, 75231, Paris, France
| |
Collapse
|
12
|
Nebenführ A, Dixit R. Kinesins and Myosins: Molecular Motors that Coordinate Cellular Functions in Plants. ANNUAL REVIEW OF PLANT BIOLOGY 2018; 69:329-361. [PMID: 29489391 PMCID: PMC6653565 DOI: 10.1146/annurev-arplant-042817-040024] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Kinesins and myosins are motor proteins that can move actively along microtubules and actin filaments, respectively. Plants have evolved a unique set of motors that function as regulators and organizers of the cytoskeleton and as drivers of long-distance transport of various cellular components. Recent progress has established the full complement of motors encoded in plant genomes and has revealed valuable insights into the cellular functions of many kinesin and myosin isoforms. Interestingly, several of the motors were found to functionally connect the two cytoskeletal systems and thereby to coordinate their activities. In this review, we discuss the available genetic, cell biological, and biochemical data for each of the plant kinesin and myosin families from the context of their subcellular mechanism of action as well as their physiological function in the whole plant. We particularly emphasize work that illustrates mechanisms by which kinesins and myosins coordinate the activities of the cytoskeletal system.
Collapse
Affiliation(s)
- Andreas Nebenführ
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996-0840, USA;
| | - Ram Dixit
- Department of Biology and Center for Engineering Mechanobiology, Washington University, St. Louis, Missouri 63130-4899, USA;
| |
Collapse
|
13
|
Abstract
ABSTRACT
Plants are sessile and require diverse strategies to adapt to fluctuations in the surrounding light conditions. Consequently, the photorelocation movement of chloroplasts is essential to prevent damages that are induced by intense light (avoidance response) and to ensure efficient photosynthetic activities under weak light conditions (accumulation response). The mechanisms that underlie chloroplast movements have been revealed through analysis of the behavior of individual chloroplasts and it has been found that these organelles can move in any direction without turning. This implies that any part of the chloroplast periphery can function as the leading or trailing edge during movement. This ability is mediated by a special structure, which consists of short actin filaments that are polymerized at the leading edge of moving chloroplasts and are specifically localized in the space between the chloroplast and the plasma membrane, and is called chloroplast-actin. In addition, several of the genes that encode proteins that are involved in chloroplast-actin polymerization or maintenance have been identified. In this Review, we discuss the mechanisms that regulate chloroplast movements through polymerization of the chloroplast-actin and propose a model for actin-driven chloroplast photorelocation movement.
Collapse
Affiliation(s)
- Masamitsu Wada
- Department of Biological Sciences, Graduate School of Science and Engineering, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| | - Sam-Geun Kong
- Department of Biological Sciences, College of Natural Sciences, Kongju National University, 56 Gongjudaehak-ro Gongju-si, Chungcheongnam-do 32588, Republic of Korea
| |
Collapse
|
14
|
Suetsugu N, Higa T, Wada M. Ferns, mosses and liverworts as model systems for light-mediated chloroplast movements. PLANT, CELL & ENVIRONMENT 2017; 40:2447-2456. [PMID: 27859339 DOI: 10.1111/pce.12867] [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: 09/29/2016] [Revised: 11/03/2016] [Accepted: 11/07/2016] [Indexed: 05/05/2023]
Abstract
Light-induced chloroplast movement is found in most plant species, including algae and land plants. In land plants with multiple small chloroplasts, under weak light conditions, the chloroplasts move towards the light and accumulate on the periclinal cell walls to efficiently perceive light for photosynthesis (the accumulation response). Under strong light conditions, chloroplasts escape from light to avoid photodamage (the avoidance response). In most plant species, blue light induces chloroplast movement, and phototropin receptor kinases are the blue light receptors. Molecular mechanisms for photoreceptors, signal transduction and chloroplast motility systems are being studied using the model plant Arabidopsis thaliana. However, to further understand the molecular mechanisms and evolutionary history of chloroplast movement in green plants, analyses using other plant systems are required. Here, we review recent works on chloroplast movement in green algae, liverwort, mosses and ferns that provide new insights on chloroplast movement.
Collapse
Affiliation(s)
- Noriyuki Suetsugu
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan
| | - Takeshi Higa
- Department of Biological Sciences, Graduate School of Science and Engineering, Tokyo Metropolitan University, Tokyo, 192-0397, Japan
| | - Masamitsu Wada
- Department of Biological Sciences, Graduate School of Science and Engineering, Tokyo Metropolitan University, Tokyo, 192-0397, Japan
| |
Collapse
|
15
|
Suetsugu N, Higa T, Gotoh E, Wada M. Light-Induced Movements of Chloroplasts and Nuclei Are Regulated in Both Cp-Actin-Filament-Dependent and -Independent Manners in Arabidopsis thaliana. PLoS One 2016; 11:e0157429. [PMID: 27310016 PMCID: PMC4911103 DOI: 10.1371/journal.pone.0157429] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 05/31/2016] [Indexed: 11/19/2022] Open
Abstract
Light-induced chloroplast movement and attachment to the plasma membrane are dependent on actin filaments. In Arabidopsis thaliana, the short actin filaments on the chloroplast envelope, cp-actin filaments, are essential for chloroplast movement and positioning. Furthermore, cp-actin-filament-mediated chloroplast movement is necessary for the strong-light-induced nuclear avoidance response. The proteins CHLOROPLAST UNUSUAL POSITIONING 1 (CHUP1), KINESIN-LIKE PROTEIN FOR ACTIN-BASED CHLOROPLAST MOVEMENT 1 (KAC1) and KAC2 are required for the generation and/or maintenance of cp-actin filaments in Arabidopsis. In land plants, CHUP1 and KAC family proteins play pivotal roles in the proper movement of chloroplasts and their attachment to the plasma membrane. Here, we report similar but distinct phenotypes in chloroplast and nuclear photorelocation movements between chup1 and kac1kac2 mutants. Measurement of chloroplast photorelocation movement indicated that kac1kac2, but not chup1, exhibited a clear strong-light-induced increase in leaf transmittance changes. The chloroplast movement in kac1kac2 depended on phototropin 2, CHUP1 and two other regulators for cp-actin filaments, PLASTID MOVEMENT IMPAIRED 1 and THRUMIN 1. Furthermore, kac1kac2 retained a weak but significant nuclear avoidance response although chup1 displayed a severe defect in the nuclear avoidance response. The kac1kac2chup1 triple mutant was completely defective in both chloroplast and nuclear avoidance responses. These results indicate that CHUP1 and the KACs function somewhat independently, but interdependently mediate both chloroplast and nuclear photorelocation movements.
Collapse
Affiliation(s)
- Noriyuki Suetsugu
- Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka, Japan
| | - Takeshi Higa
- Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka, Japan
| | - Eiji Gotoh
- Department of Agriculture, Kyushu University, Fukuoka, Japan
| | - Masamitsu Wada
- Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka, Japan
- * E-mail:
| |
Collapse
|
16
|
WADA M. Chloroplast and nuclear photorelocation movements. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2016; 92:387-411. [PMID: 27840388 PMCID: PMC5328789 DOI: 10.2183/pjab.92.387] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 08/24/2016] [Indexed: 05/18/2023]
Abstract
Chloroplasts move toward weak light to increase photosynthetic efficiency, and migrate away from strong light to protect chloroplasts from photodamage and eventual cell death. These chloroplast behaviors were first observed more than 100 years ago, but the underlying mechanism has only recently been identified. Ideal plant materials, such as fern gametophytes for photobiological and cell biological approaches, and Arabidopsis thaliana for genetic analyses, have been used along with sophisticated methods, such as partial cell irradiation and time-lapse video recording under infrared light to study chloroplast movement. These studies have revealed precise chloroplast behavior, and identified photoreceptors, other relevant protein components, and novel actin filament structures required for chloroplast movement. In this review, our findings regarding chloroplast and nuclear movements are described.
Collapse
Affiliation(s)
- Masamitsu WADA
- Department Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa, Tokyo, Japan
| |
Collapse
|
17
|
Ueda H, Tamura K, Hara-Nishimura I. Functions of plant-specific myosin XI: from intracellular motility to plant postures. CURRENT OPINION IN PLANT BIOLOGY 2015; 28:30-8. [PMID: 26432645 DOI: 10.1016/j.pbi.2015.08.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2015] [Revised: 08/11/2015] [Accepted: 08/14/2015] [Indexed: 05/02/2023]
Abstract
The plant-specific protein motor class myosin XI is known to function in rapid bulk flow of the cytoplasm (cytoplasmic streaming) and in organellar movements. Recent studies unveiled a wide range of physiological functions of myosin XI motors, from intracellular motility to organ movements. Arabidopsis thaliana has 13 members of myosin XI class. In vegetative organs, myosins XIk, XI1, and XI2 primarily contribute to dynamics and spatial configurations of endoplasmic reticulum that develops a tubular network in the cell periphery and thick strand-like structures in the inner cell regions. Myosin XI-i forms a nucleocytoplasmic linker and is responsible for nuclear movement and shape. In addition to these intracellular functions, myosin XIf together with myosin XIk is involved in the fundamental nature of plants; the actin-myosin XI cytoskeleton regulates organ straightening to adjust plant posture.
Collapse
Affiliation(s)
- Haruko Ueda
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Kentaro Tamura
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Ikuko Hara-Nishimura
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
| |
Collapse
|
18
|
Suetsugu N, Higa T, Kong SG, Wada M. PLASTID MOVEMENT IMPAIRED1 and PLASTID MOVEMENT IMPAIRED1-RELATED1 Mediate Photorelocation Movements of Both Chloroplasts and Nuclei. PLANT PHYSIOLOGY 2015; 169:1155-67. [PMID: 26324877 PMCID: PMC4587439 DOI: 10.1104/pp.15.00214] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 08/27/2015] [Indexed: 05/05/2023]
Abstract
Organelle movement and positioning play important roles in fundamental cellular activities and adaptive responses to environmental stress in plants. To optimize photosynthetic light utilization, chloroplasts move toward weak blue light (the accumulation response) and escape from strong blue light (the avoidance response). Nuclei also move in response to strong blue light by utilizing the light-induced movement of attached plastids in leaf cells. Blue light receptor phototropins and several factors for chloroplast photorelocation movement have been identified through molecular genetic analysis of Arabidopsis (Arabidopsis thaliana). PLASTID MOVEMENT IMPAIRED1 (PMI1) is a plant-specific C2-domain protein that is required for efficient chloroplast photorelocation movement. There are two PLASTID MOVEMENT IMPAIRED1-RELATED (PMIR) genes, PMIR1 and PMIR2, in the Arabidopsis genome. However, the mechanism in which PMI1 regulates chloroplast and nuclear photorelocation movements and the involvement of PMIR1 and PMIR2 in these organelle movements remained unknown. Here, we analyzed chloroplast and nuclear photorelocation movements in mutant lines of PMI1, PMIR1, and PMIR2. In mesophyll cells, the pmi1 single mutant showed severe defects in both chloroplast and nuclear photorelocation movements resulting from the impaired regulation of chloroplast-actin filaments. In pavement cells, pmi1 mutant plants were partially defective in both plastid and nuclear photorelocation movements, but pmi1pmir1 and pmi1pmir1pmir2 mutant lines lacked the blue light-induced movement responses of plastids and nuclei completely. These results indicated that PMI1 is essential for chloroplast and nuclear photorelocation movements in mesophyll cells and that both PMI1 and PMIR1 are indispensable for photorelocation movements of plastids and thus, nuclei in pavement cells.
Collapse
Affiliation(s)
- Noriyuki Suetsugu
- Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan
| | - Takeshi Higa
- Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan
| | - Sam-Geun Kong
- Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan
| | - Masamitsu Wada
- Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan
| |
Collapse
|
19
|
Buchnik L, Abu-Abied M, Sadot E. Role of plant myosins in motile organelles: is a direct interaction required? JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2015; 57:23-30. [PMID: 25196231 DOI: 10.1111/jipb.12282] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 08/31/2014] [Indexed: 06/03/2023]
Abstract
Plant organelles are highly motile, with speed values of 3-7 µm/s in cells of land plants and about 20-60 µm/s in characean algal cells. This movement is believed to be important for rapid distribution of materials around the cell, for the plant's ability to respond to environmental biotic and abiotic signals and for proper growth. The main machinery that propels motility of organelles within plant cells is based on the actin cytoskeleton and its motor proteins the myosins. Most plants express multiple members of two main classes: myosin VIII and myosin XI. While myosin VIII has been characterized as a slow motor protein, myosins from class XI were found to be the fastest motor proteins known in all kingdoms. Paradoxically, while it was found that myosins from class XI regulate most organelle movement, it is not quite clear how or even if these motor proteins attach to the organelles whose movement they regulate.
Collapse
Affiliation(s)
- Limor Buchnik
- The Institute of Plant Sciences, The Volcani Center, ARO, PO Box 6, Bet-Dagan, 50250, Israel
| | | | | |
Collapse
|
20
|
Higa T, Suetsugu N, Wada M. Plant nuclear photorelocation movement. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:2873-2881. [PMID: 24336444 DOI: 10.1093/jxb/ert414] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Organelle movement and positioning are essential for proper cellular function. A nucleus moves dynamically during cell division and differentiation and in response to environmental changes in animal, fungal, and plant cells. Nuclear movement is well-studied and the mechanisms have been mostly elucidated in animal and fungal cells, but not in plant cells. In prothallial cells of the fern Adiantum capillus-veneris and leaf cells of the flowering plant Arabidopsis thaliana, light induces nuclear movement and nuclei change their position according to wavelength, intensity, and direction of light. This nuclear photorelocation movement shows some common features with the photorelocation movement of chloroplasts, which is one of the best-characterized plant organelle movements. This review summarizes nuclear movement and positioning in plant cells, especially plant-specific nuclear photorelocation movement and discusses the relationship between nuclear photorelocation movement and chloroplast photorelocation movement.
Collapse
Affiliation(s)
- Takeshi Higa
- Department of Biology, Faculty of Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
| | - Noriyuki Suetsugu
- Department of Biology, Faculty of Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
| | - Masamitsu Wada
- Department of Biology, Faculty of Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
| |
Collapse
|
21
|
Wang H, Liu R, Wang J, Wang P, Shen Y, Liu G. The Arabidopsis kinesin gene AtKin-1 plays a role in the nuclear division process during megagametogenesis. PLANT CELL REPORTS 2014; 33:819-828. [PMID: 24667993 DOI: 10.1007/s00299-014-1594-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 01/15/2014] [Accepted: 02/26/2014] [Indexed: 06/03/2023]
Abstract
Atkin - 1 , the only Kinesin-1 member of Arabidopsis thaliana , plays a role during female gametogenesis through regulation of nuclear division cycles. Kinesins are microtubule-dependent motor proteins found in eukaryotic organisms. They constitute a superfamily that can be further classified into at least 14 families. In the Kinesin-1 family, members from animal and fungi play roles in long-distance transport of organelles and vesicles. Although Kinesin-1-like sequences have been identified in higher plants, little is known about their function in plant cells, other than in a recently identified Kinesin-1-like protein in a rice pollen semi-sterile mutant. In this study, the gene encoding the only Kinesin-1 member in Arabidopsis, AtKin-1 was found to be specifically expressed in ovules and anthers. AtKin-1 loss-of-function mutants showed substantially aborted ovules in siliques, and this finding was supported by complementation testing. Reciprocal crossing between mutant and wild-type plants indicated that a defect in AtKin-1 results in partially aborted megagametophytes, with no observable effects on pollen fertility. Further observation of ovule development in the mutant pistils indicated that the enlargement of the megaspore was blocked and nuclear division arrested at the one-nucleate stage during embryo sac formation. Our data suggest that AtKin-1 plays a role in the nuclear division cycles during megagametogenesis.
Collapse
Affiliation(s)
- Haiqing Wang
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Plateau Institute of Biology, Chinese Academy of Sciences, 23 Xinning Road, Xining, 810001, China,
| | | | | | | | | | | |
Collapse
|
22
|
Recent advances in understanding the molecular mechanism of chloroplast photorelocation movement. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1837:522-30. [PMID: 24333784 DOI: 10.1016/j.bbabio.2013.12.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 11/25/2013] [Accepted: 12/04/2013] [Indexed: 11/21/2022]
Abstract
Plants are photosynthetic organisms that have evolved unique systems to adapt fluctuating environmental light conditions. In addition to well-known movement responses such as phototropism, stomatal opening, and nastic leaf movements, chloroplast photorelocation movement is one of the essential cellular responses to optimize photosynthetic ability and avoid photodamage. For these adaptations, chloroplasts accumulate at the areas of cells illuminated with low light (called accumulation response), while they scatter from the area illuminated with strong light (called avoidance response). Plant-specific photoreceptors (phototropin, phytochrome, and/or neochrome) mediate these dynamic directional movements in response to incident light position and intensity. Several factors involved in the mechanisms underlying the processes from light perception to actin-based movements have also been identified through molecular genetic approach. This review aims to discuss recent findings in the field relating to how chloroplasts move at molecular levels. This article is part of a Special Issue entitled: Dynamic and ultrastructure of bioenergetic membranes and their components.
Collapse
|
23
|
Wada M. Chloroplast movement. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2013; 210:177-82. [PMID: 23849124 DOI: 10.1016/j.plantsci.2013.05.016] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 05/26/2013] [Accepted: 05/27/2013] [Indexed: 05/18/2023]
Abstract
Chloroplast movement is important for plant survival under high light and for efficient photosynthesis under low light. This review introduces recent knowledge on chloroplast movement and shows how to analyze the responses and the moving mechanisms, potentially inspiring research in this field. Avoidance from the strong light is mediated by blue light receptor phototropin 2 (phot2) plausibly localized on the chloroplast envelop and accumulation at the week light-irradiated area is mediated by phot1 and phot2 localized on the plasma membrane. Chloroplasts move by chloroplast actin (cp-actin) filaments that must be polymerized by Chloroplast Unusual Positioning1 (CHUP1) at the front side of moving chloroplast. To understand the signal transduction pathways and the mechanism of chloroplast movement, that is, from light capture to motive force-generating mechanism, various methods should be employed based on the various aspects. Observation of chloroplast distribution pattern under different light condition by fixed cell sectioning is somewhat an old-fashioned technique but the most basic and important way. However, most importantly, precise chloroplast behavior during and just after the induction of chloroplast movement by partial cell irradiation using an irradiator with either low light or strong light microbeam should be recorded by time lapse photographs under infrared light and analyzed. Recently various factors involved in chloroplast movement, such as cp-actin filaments and CHUP1, could be traced in Arabidopsis transgenic lines with fluorescent protein tags under a confocal laser scanning microscope (CLSM) and/or a total internal reflection fluorescence microscope (TIRFM). These methods are listed and their advantages and disadvantages are evaluated.
Collapse
Affiliation(s)
- Masamitsu Wada
- Biology Department, Faculty of Science, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
| |
Collapse
|
24
|
Kong SG, Arai Y, Suetsugu N, Yanagida T, Wada M. Rapid severing and motility of chloroplast-actin filaments are required for the chloroplast avoidance response in Arabidopsis. THE PLANT CELL 2013; 25:572-90. [PMID: 23404888 PMCID: PMC3608779 DOI: 10.1105/tpc.113.109694] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 01/16/2013] [Accepted: 01/20/2013] [Indexed: 05/20/2023]
Abstract
Phototropins (phot1 and phot2 in Arabidopsis thaliana) relay blue light intensity information to the chloroplasts, which move toward weak light (the accumulation response) and away from strong light (the avoidance response). Chloroplast-actin (cp-actin) filaments are vital for mediating these chloroplast photorelocation movements. In this report, we examine in detail the cp-actin filament dynamics by which the chloroplast avoidance response is regulated. Although stochastic dynamics of cortical actin fragments are observed on the chloroplasts, the basic mechanisms underlying the disappearance (including severing and turnover) of the cp-actin filaments are regulated differently from those of cortical actin filaments. phot2 plays a pivotal role in the strong blue light-induced severing and random motility of cp-actin filaments, processes that are therefore essential for asymmetric cp-actin formation for the avoidance response. In addition, phot2 functions in the bundling of cp-actin filaments that is induced by dark incubation. By contrast, the function of phot1 is dispensable for these responses. Our findings suggest that phot2 is the primary photoreceptor involved in the rapid reorganization of cp-actin filaments that allows chloroplasts to change direction rapidly and control the velocity of the avoidance movement according to the light's intensity and position.
Collapse
Affiliation(s)
- Sam-Geun Kong
- Department of Biology, Graduate School of Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8581, Japan
| | - Yoshiyuki Arai
- Laboratories for Nanobiology, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan
| | - Noriyuki Suetsugu
- Department of Biology, Graduate School of Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8581, Japan
| | - Toshio Yanagida
- Laboratories for Nanobiology, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan
| | - Masamitsu Wada
- Department of Biology, Graduate School of Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8581, Japan
- Address correspondence to
| |
Collapse
|
25
|
Meyer Y, Belin C, Delorme-Hinoux V, Reichheld JP, Riondet C. Thioredoxin and glutaredoxin systems in plants: molecular mechanisms, crosstalks, and functional significance. Antioxid Redox Signal 2012; 17:1124-60. [PMID: 22531002 DOI: 10.1089/ars.2011.4327] [Citation(s) in RCA: 216] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Thioredoxins (Trx) and glutaredoxins (Grx) constitute families of thiol oxidoreductases. Our knowledge of Trx and Grx in plants has dramatically increased during the last decade. The release of the Arabidopsis genome sequence revealed an unexpectedly high number of Trx and Grx genes. The availability of several genomes of vascular and nonvascular plants allowed the establishment of a clear classification of the genes and the chronology of their appearance during plant evolution. Proteomic approaches have been developed that identified the putative Trx and Grx target proteins which are implicated in all aspects of plant growth, including basal metabolism, iron/sulfur cluster formation, development, adaptation to the environment, and stress responses. Analyses of the biochemical characteristics of specific Trx and Grx point to a strong specificity toward some target enzymes, particularly within plastidial Trx and Grx. In apparent contradiction with this specificity, genetic approaches show an absence of phenotype for most available Trx and Grx mutants, suggesting that redundancies also exist between Trx and Grx members. Despite this, the isolation of mutants inactivated in multiple genes and several genetic screens allowed the demonstration of the involvement of Trx and Grx in pathogen response, phytohormone pathways, and at several control points of plant development. Cytosolic Trxs are reduced by NADPH-thioredoxin reductase (NTR), while the reduction of Grx depends on reduced glutathione (GSH). Interestingly, recent development integrating biochemical analysis, proteomic data, and genetics have revealed an extensive crosstalk between the cytosolic NTR/Trx and GSH/Grx systems. This crosstalk, which occurs at multiple levels, reveals the high plasticity of the redox systems in plants.
Collapse
Affiliation(s)
- Yves Meyer
- Laboratoire Génome et Développement des Plantes, Université de Perpignan, Perpignan, France
| | | | | | | | | |
Collapse
|
26
|
Peled E, Pick U, Zarka A, Shimoni E, Leu S, Boussiba S. LIGHT-INDUCED OIL GLOBULE MIGRATION IN HAEMATOCOCCUS PLUVIALIS (CHLOROPHYCEAE). JOURNAL OF PHYCOLOGY 2012; 48:1209-19. [PMID: 27011280 DOI: 10.1111/j.1529-8817.2012.01210.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Accepted: 06/27/2012] [Indexed: 05/16/2023]
Abstract
Astaxanthin-rich oil globules in Haematococcus pluvialis display rapid light-induced peripheral migration that is unique to this organism and serves to protect the photosynthetic system from excessive light. We observed rapid light-induced peripheral migration that is associated with chlorophyll fluorescence quenching, whereas the recovery was slow. A simple assay to follow globule migration, based on chlorophyll fluorescence level has been developed. Globule migration was induced by high intensity blue light, but not by high intensity red light. The electron transport inhibitor dichlorophenyl-dimethylurea did not inhibit globule migration, whereas the quinone analog (dibromo-methyl-isopropylbenzoquinone), induced globule migration even at low light. Actin microfilament-directed toxins, such as cytochalasin B and latrunculin A, inhibited the light-induced globule migration, whereas toxins against microtubules were ineffective. Electron microscopic (EM) imaging confirmed the cytoplasmic localization and peripheral migration of globules upon exposure to very high light (VHL). Scanning EM of freeze-fractured cells also revealed globules within cytoplasmic bridges traversing the chloroplast, presumably representing the pathway of migration. Close alignments of globules with endoplasmic reticulum (ER) membranes were also observed following VHL illumination. We propose that light-induced globule migration is regulated by the redox state of the photosynthetic electron transport system. Possible mechanisms of actin-based globule migration are discussed.
Collapse
Affiliation(s)
- Ehud Peled
- Microalgal Biotechnology Laboratory, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus, Sede-Boqer, 84990, Israel
| | - Uri Pick
- Biological Chemistry, The Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Aliza Zarka
- Microalgal Biotechnology Laboratory, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus, Sede-Boqer, 84990, Israel
| | - Eyal Shimoni
- Biological Chemistry, The Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Stefan Leu
- Microalgal Biotechnology Laboratory, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus, Sede-Boqer, 84990, Israel
| | - Sammy Boussiba
- Microalgal Biotechnology Laboratory, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus, Sede-Boqer, 84990, Israel
| |
Collapse
|
27
|
Thomas C. Bundling actin filaments from membranes: some novel players. FRONTIERS IN PLANT SCIENCE 2012; 3:188. [PMID: 22936939 PMCID: PMC3426786 DOI: 10.3389/fpls.2012.00188] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 08/01/2012] [Indexed: 05/04/2023]
Abstract
Progress in live-cell imaging of the cytoskeleton has significantly extended our knowledge about the organization and dynamics of actin filaments near the plasma membrane of plant cells. Noticeably, two populations of filamentous structures can be distinguished. On the one hand, fine actin filaments which exhibit an extremely dynamic behavior basically characterized by fast polymerization and prolific severing events, a process referred to as actin stochastic dynamics. On the other hand, thick actin bundles which are composed of several filaments and which are comparatively more stable although they constantly remodel as well. There is evidence that the actin cytoskeleton plays critical roles in trafficking and signaling at both the cell cortex and organelle periphery but the exact contribution of actin bundles remains unclear. A common view is that actin bundles provide the long-distance tracks used by myosin motors to deliver their cargo to growing regions and accordingly play a particularly important role in cell polarization. However, several studies support that actin bundles are more than simple passive highways and display multiple and dynamic roles in the regulation of many processes, such as cell elongation, polar auxin transport, stomatal and chloroplast movement, and defense against pathogens. The list of identified plant actin-bundling proteins is ever expanding, supporting that plant cells shape structurally and functionally different actin bundles. Here I review the most recently characterized actin-bundling proteins, with a particular focus on those potentially relevant to membrane trafficking and/or signaling.
Collapse
Affiliation(s)
- Clément Thomas
- Laboratory of Molecular and Cellular Oncology, Department of Oncology, Public Research Centre for Health (CRP-Santé)Luxembourg, Luxembourg
| |
Collapse
|
28
|
Banaś AK, Aggarwal C, Łabuz J, Sztatelman O, Gabryś H. Blue light signalling in chloroplast movements. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:1559-74. [PMID: 22312115 DOI: 10.1093/jxb/err429] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Chloroplast movements are among the mechanisms allowing plants to cope with changes in their environment. Chloroplasts accumulate at illuminated cell areas under weak light while they avoid areas exposed to strong light. These directional responses may be controlled by blue and/or red light, depending on the plant group. In terrestrial angiosperms only the blue light perceived by phototropins is active. The last decade has seen a rapid development of studies on the mechanism of directional chloroplast movements, which started with an identification of the photoreceptors. A forward genetic approach has been used to identify the components which control chloroplast movements. This review summarizes the current state of research into the signalling pathways which lead to chloroplast responses. First, the molecular properties of phototropins are presented, followed by a characterization both of proteins which are active downstream of phototropins and of secondary messengers. Finally, cross-talk between light signalling involved in chloroplast movements and other signalling pathways is discussed.
Collapse
Affiliation(s)
- Agnieszka Katarzyna Banaś
- Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Krakow, Poland
| | | | | | | | | |
Collapse
|
29
|
Cai G, Cresti M. Are kinesins required for organelle trafficking in plant cells? FRONTIERS IN PLANT SCIENCE 2012; 3:170. [PMID: 22837763 PMCID: PMC3402901 DOI: 10.3389/fpls.2012.00170] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2012] [Accepted: 07/09/2012] [Indexed: 05/02/2023]
Abstract
Plant cells exhibit active movement of membrane-bounded materials, which is more pronounced in large cells but is also appreciable in medium-sized cells and in tip-growing cells (such as pollen tubes and root hairs). Trafficking of organelles (such as Golgi bodies, endoplasmic reticulum, peroxisomes, and mitochondria) and vesicles is essential for plant cell physiology and allows a more or less homogeneous distribution of the cell content. It is well established that the long-range trafficking of organelles is dependent essentially on the network of actin filaments and is powered by the enzyme activity of myosins. However, some lines of evidence suggest that microtubules and members of the kinesin microtubule-based motor superfamily might have a role in the positioning and/or short-range movement of cell organelles and vesicles. Data collected in different cells (such as trichomes and pollen tubes), in specific stages of the plant cell life cycle (for example, during phragmoplast development) and for different organelle classes (mitochondria, Golgi bodies, and chloroplasts) encourage the hypothesis that microtubule-based motors might play subtle yet unclarified roles in organelle trafficking. In some cases, this function could be carried out in cooperation with actin filaments according to the model of "functional cooperation" by which motors of different families are associated with the organelle surface. Since available data did not provide an unambiguous conclusion with regard to the role of kinesins in organelle transport, here we want to debate such hypothesis.
Collapse
Affiliation(s)
- Giampiero Cai
- *Correspondence: Giampiero Cai, Dipartimento Scienze Ambientali, University of Siena, Via Mattioli 4, Siena 53100, Italy. e-mail:
| | | |
Collapse
|
30
|
Shapiguzov A, Vainonen JP, Wrzaczek M, Kangasjärvi J. ROS-talk - how the apoplast, the chloroplast, and the nucleus get the message through. FRONTIERS IN PLANT SCIENCE 2012; 3:292. [PMID: 23293644 PMCID: PMC3530830 DOI: 10.3389/fpls.2012.00292] [Citation(s) in RCA: 145] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Accepted: 12/07/2012] [Indexed: 05/18/2023]
Abstract
The production of reactive oxygen species (ROS) in different plant subcellular compartments is the hallmark of the response to many stress stimuli and developmental cues. The past two decades have seen a transition from regarding ROS as exclusively cytotoxic agents to being considered as reactive compounds which participate in elaborate signaling networks connecting various aspects of plant life. We have now arrived at a stage where it has become increasingly difficult to disregard the communication between different types and pools of ROS. Production of ROS in the extracellular space, the apoplast, can influence their generation in the chloroplast and both can regulate nuclear gene expression. In spite of existing information on these signaling events, we can still barely grasp the mechanisms of ROS signaling and communication between the organelles. In this review, we summarize evidence that supports the mutual influence of extracellular and chloroplastic ROS production on nuclear gene regulation and how this interaction might occur. We also reflect on how, and via which routes signals might reach the nucleus where they are ultimately integrated for transcriptional reprogramming. New ideas and approaches will be needed in the future to address the pressing questions of how ROS as signaling molecules can participate in the coordination of stress adaptation and development and how they are involved in the chatter of the organelles.
Collapse
Affiliation(s)
| | | | | | - Jaakko Kangasjärvi
- *Correspondence: Jaakko Kangasjärvi, Division of Plant Biology, Department of Biosciences, University of Helsinki, Viikinkaari 1, P.O. Box 65, FIN-00014 Helsinki, Finland. e-mail:
| |
Collapse
|
31
|
Yamada N, Suetsugu N, Wada M, Kadota A. Phototropin-dependent biased relocalization of cp-actin filaments can be induced even when chloroplast movement is inhibited. PLANT SIGNALING & BEHAVIOR 2011; 6:1651-1653. [PMID: 22057335 PMCID: PMC3329327 DOI: 10.4161/psb.6.11.17767] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
In a recent publication using an actin-visualized line of Arabidopsis (Ichikawa et al. 2011, ref. 11), we reported a detailed analysis with higher time resolution on the dynamics of chloroplast actin filaments (cp-actin filaments) during chloroplast avoidance movement and demonstrated a good correlation between the biased configuration of cp-actin filaments and chloroplast movement. However, we could not conclusively determine whether the reorganization of cp-actin filaments into a biased configuration preceded actual chloroplast movement (and, thus, whether it could be a cause of the movement). In this report, we present clear evidence that the reorganization of cp-actin filaments into a biased distribution is induced even in the absence of the actual movement of chloroplasts. When the cells were treated with 2,3-butanedione monoxime (BDM), a potent inhibitor of myosin ATPase, chloroplast motility was completely suppressed. Nevertheless, the disappearance and biased relocalization of cp-actin filaments toward the side of the prospective movement direction were induced by irradiation with a strong blue light microbeam. The results definitively indicate that the reorganization of cp-actin filaments is not an effect of chloroplast movement; however, it is feasible that the biased localization of cp-actin filaments is an event leading to chloroplast movement.
Collapse
Affiliation(s)
- Noboru Yamada
- Department of Biological Sciences, Graduate School of Science and Engineering, Tokyo Metropolitan University; Tokyo, Japan
| | - Noriyuki Suetsugu
- Department of Biology, Faculty of Science, Kyushu University; Fukuoka, Japan
| | - Masamitsu Wada
- Department of Biology, Faculty of Science, Kyushu University; Fukuoka, Japan
| | - Akeo Kadota
- Department of Biological Sciences, Graduate School of Science and Engineering, Tokyo Metropolitan University; Tokyo, Japan
| |
Collapse
|
32
|
Ichikawa S, Yamada N, Suetsugu N, Wada M, Kadota A. Red light, Phot1 and JAC1 modulate Phot2-dependent reorganization of chloroplast actin filaments and chloroplast avoidance movement. PLANT & CELL PHYSIOLOGY 2011; 52:1422-32. [PMID: 21737483 DOI: 10.1093/pcp/pcr087] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The phototropin (phot)-dependent intracellular relocation of chloroplasts is a ubiquitous phenomenon in plants. We have previously revealed the involvement of a short cp-actin (chloroplast actin) filament-based mechanism in this movement. Here, the reorganization of cp-actin filaments during the avoidance movement of chloroplasts was analyzed in higher time resolution under blue GFP (green fluorescent protein) excitation light in an actin filament-visualized line of Arabidopsis thaliana. Under standard background red light of 89 μmol m(-2) s(-1), cp-actin filaments transiently disappeared at approximately 30 s and reappeared in a biased configuration on chloroplasts approximately 70 s after blue excitation light irradiation. The timing of biased cp-actin reappearance was delayed under the background of strong red light or in the absence of red light. Consistently, chloroplast movement was delayed under these conditions. In phot1 mutants, acceleration of both the disappearance and reappearance of cp-actin filaments occurred, indicating an inhibitory action of phot1 on reorganization of cp-actin filaments. Avoidance movements began sooner in phot1 than in wild-type plants. No reorganization of cp-actin filaments was seen in phot2 or phot1phot2 mutants lacking phot2, which is responsible for avoidance movements. Surprisingly, jac1 (j-domain protein required for chloroplast accumulation response 1) mutants, lacking the accumulation response, showed no avoidance movements under the whole-cell irradiation condition for GFP observation. Cp-actin filaments in jac1 did not show a biased distribution, with a small or almost no transient decrease in the number. These results indicate a close association between the biased distribution of cp-actin filaments and chloroplast movement. Further, JAC1 is suggested to function in the biased cp-actin filament distribution by regulating their appearance and disappearance.
Collapse
Affiliation(s)
- Satoshi Ichikawa
- Department of Biological Sciences, Graduate School of Science and Engineering, Tokyo Metropolitan University, Tokyo, 192-0397 Japan
| | | | | | | | | |
Collapse
|
33
|
Kodama Y, Suetsugu N, Wada M. Novel protein-protein interaction family proteins involved in chloroplast movement response. PLANT SIGNALING & BEHAVIOR 2011; 6:483-90. [PMID: 21389774 PMCID: PMC3142374 DOI: 10.4161/psb.6.4.14784] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
To optimize photosynthetic activity, chloroplasts change their intracellular location in response to ambient light conditions; chloroplasts move toward low intensity light to maximize light capture, and away from high intensity light to avoid photodamage. Although several proteins have been reported to be involved in the chloroplast photorelocation movement response, any physical interaction among them was not found so far. We recently found a physical interaction between two plant-specific coiled-coil proteins, WEB1 (Weak Chloroplast Movement under Blue Light 1) and PMI2 (Plastid Movement Impaired 2), that were identified to regulate chloroplast movement velocity. Since the both coiled-coil regions of WEB1 and PMI2 were classified into an uncharacterized protein family having DUF827 (DUF: Domain of Unknown Function) domain, it was the first report that DUF827 proteins could mediate protein-protein interaction. In this mini-review article, we discuss regarding molecular function of WEB1 and PMI2, and also define a novel protein family composed of WEB1, PMI2 and WEB1/PMI2-like proteins for protein-protein interaction in land plants.
Collapse
Affiliation(s)
- Yutaka Kodama
- Plant Functional Genomics Research Group; RIKEN Plant Science; Yokohama
| | - Noriyuki Suetsugu
- Department of Biology; Faculty of Sciences; Kyushu University; Fukuoka, Japan
| | - Masamitsu Wada
- Department of Biology; Faculty of Sciences; Kyushu University; Fukuoka, Japan
| |
Collapse
|
34
|
Peremyslov VV, Mockler TC, Filichkin SA, Fox SE, Jaiswal P, Makarova KS, Koonin EV, Dolja VV. Expression, splicing, and evolution of the myosin gene family in plants. PLANT PHYSIOLOGY 2011; 155:1191-204. [PMID: 21233331 PMCID: PMC3046578 DOI: 10.1104/pp.110.170720] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Plants possess two myosin classes, VIII and XI. The myosins XI are implicated in organelle transport, filamentous actin organization, and cell and plant growth. Due to the large size of myosin gene families, knowledge of these molecular motors remains patchy. Using deep transcriptome sequencing and bioinformatics, we systematically investigated myosin genes in two model plants, Arabidopsis (Arabidopsis thaliana) and Brachypodium (Brachypodium distachyon). We improved myosin gene models and found that myosin genes undergo alternative splicing. We experimentally validated the gene models for Arabidopsis myosin XI-K, which plays the principal role in cell interior dynamics, as well as for its Brachypodium ortholog. We showed that the Arabidopsis gene dubbed HDK (for headless derivative of myosin XI-K), which emerged through a partial duplication of the XI-K gene, is developmentally regulated. A gene with similar architecture was also found in Brachypodium. Our analyses revealed two predominant patterns of myosin gene expression, namely pollen/stamen-specific and ubiquitous expression throughout the plant. We also found that several myosins XI can be rhythmically expressed. Phylogenetic reconstructions indicate that the last common ancestor of the angiosperms possessed two myosins VIII and five myosins XI, many of which underwent additional lineage-specific duplications.
Collapse
|
35
|
Suetsugu N, Takano A, Kohda D, Wada M. Structure and activity of JAC1 J-domain implicate the involvement of the cochaperone activity with HSC70 in chloroplast photorelocation movement. PLANT SIGNALING & BEHAVIOR 2010; 5:1602-6. [PMID: 21139434 PMCID: PMC3115112 DOI: 10.4161/psb.5.12.13915] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Accepted: 10/11/2010] [Indexed: 05/20/2023]
Abstract
Chloroplast photorelocation movement towards weak light and away from strong light is essential for plants to adapt to the fluctuation of ambient light conditions. In the previous study, we showed that blue light receptor phototropins mediated blue light-induced chloroplast movement in Arabidopsis by regulating short actin filaments localized at the chloroplast periphery (cp-actin filaments) rather than actin cables in the cytoplasm. However, the signaling pathway for the chloroplast photorelocation movement is still unclear. We also identified JAC1 (J-domain protein required for chloroplast accumulation response 1) as an essential component for the accumulation response and dark positioning in Arabidopsis. We recently determined the crystal structure of the J-domain of JAC1. The JAC1 J-domain has a positively charged surface, which forms a putative interface with the Hsc70 chaperone by analogy to that of bovine auxilin. Furthermore, the mutation of the highly conserved HPD motif in the JAC1 J-domain impaired the in vivo activity of JAC1. These data suggest that JAC1 cochaperone activity with HSC70 is essential for chloroplast photorelocation movement.
Collapse
Affiliation(s)
- Noriyuki Suetsugu
- Department of Biology; Faculty of Sciences; Kyushu University; Fukuoka, Japan
| | - Akira Takano
- Division of Structural Biology; Medical Institute of Bioregulation; Kyushu University; Fukuoka, Japan
| | - Daisuke Kohda
- Division of Structural Biology; Medical Institute of Bioregulation; Kyushu University; Fukuoka, Japan
| | - Masamitsu Wada
- Department of Biology; Faculty of Sciences; Kyushu University; Fukuoka, Japan
| |
Collapse
|