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Xu W, Cheng H, Cheng J, Zhu S, Cui Y, Wang C, Wu J, Lan X, Cheng Y. A COBRA family protein, PtrCOB3, contributes to gelatinous layer formation of tension wood fibers in poplar. PLANT PHYSIOLOGY 2024; 196:323-337. [PMID: 38850037 DOI: 10.1093/plphys/kiae328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 04/09/2024] [Accepted: 04/24/2024] [Indexed: 06/09/2024]
Abstract
Angiosperm trees usually develop tension wood (TW) in response to gravitational stimulation. TW comprises abundant gelatinous (G-) fibers with thick G-layers primarily composed of crystalline cellulose. Understanding the pivotal factors governing G-layer formation in TW fiber remains elusive. This study elucidates the role of a Populus trichocarpa COBRA family protein, PtrCOB3, in the G-layer formation of TW fibers. PtrCOB3 expression was upregulated, and its promoter activity was enhanced during TW formation. Comparative analysis with wild-type trees revealed that ptrcob3 mutants, mediated by Cas9/gRNA gene editing, were incapable of producing G-layers within TW fibers and showed severely impaired stem lift. Fluorescence immunolabeling data revealed a dearth of crystalline cellulose in the tertiary cell wall (TCW) of ptrcob3 TW fibers. The role of PtrCOB3 in G-layer formation is contingent upon its native promoter, as evidenced by the comparative phenotypic assessments of pCOB11::PtrCOB3, pCOB3::PtrCOB3, and pCOB3::PtrCOB11 transgenic lines in the ptrcob3 background. Overexpression of PtrCOB3 under the control of its native promoter expedited G-layer formation within TW fibers. We further identified 3 transcription factors that bind to the PtrCOB3 promoter and positively regulate its transcriptional levels. Alongside the primary TCW synthesis genes, these findings enable the construction of a 2-layer transcriptional regulatory network for the G-layer formation of TW fibers. Overall, this study uncovers mechanistic insight into TW formation, whereby a specific COB protein executes the deposition of cellulose, and consequently, G-layer formation within TW fibers.
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Affiliation(s)
- Wenjing Xu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
- College of Life Sciences, Northeast Forestry University, Harbin 150040, China
| | - Hao Cheng
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Jiyao Cheng
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Siran Zhu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Yongyao Cui
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Chong Wang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Jianzhen Wu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Xingguo Lan
- College of Life Sciences, Northeast Forestry University, Harbin 150040, China
| | - Yuxiang Cheng
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
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Cho Y, Kim Y, Lee H, Kim S, Kang J, Kadam US, Ju Park S, Sik Chung W, Chan Hong J. Cellular and physiological functions of SGR family in gravitropic response in higher plants. J Adv Res 2024:S2090-1232(24)00039-0. [PMID: 38295878 DOI: 10.1016/j.jare.2024.01.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 12/29/2023] [Accepted: 01/24/2024] [Indexed: 02/05/2024] Open
Abstract
BACKGROUND In plants, gravity directs bidirectional growth; it specifies upward growth of shoots and downward growth of roots. Due to gravity, roots establish robust anchorage and shoot, which enables to photosynthesize. It sets optimum posture and develops plant architecture to efficiently use resources like water, nutrients, CO2, and gaseous exchange. Hence, gravitropism is crucial for crop productivity as well as for the growth of plants in challenging climate. Some SGR members are known to affect tiller and shoot angle, organ size, and inflorescence stem in plants. AIM OF REVIEW Although the SHOOT GRAVITROPISM (SGR) family plays a key role in regulating the fate of shoot gravitropism, little is known about its function compared to other proteins involved in gravity response in plant cells and tissues. Moreover, less information on the SGR family's physiological activities and biochemical responses in shoot gravitropism is available. This review scrutinizes and highlights the recent developments in shoot gravitropism and provides an outlook for future crop development, multi-application scenarios, and translational research to improve agricultural productivity. KEY SCIENTIFIC CONCEPTS OF REVIEW Plants have evolved multiple gene families specialized in gravitropic responses, of which the SGR family is highly significant. The SGR family regulates the plant's gravity response by regulating specific physiological and biochemical processes such as transcription, cell division, amyloplast sedimentation, endodermis development, and vacuole formation. Here, we analyze the latest discoveries in shoot gravitropism with particular attention to SGR proteins in plant cell biology, cellular physiology, and homeostasis. Plant cells detect gravity signals by sedimentation of amyloplast (starch granules) in the direction of gravity, and the signaling cascade begins. Gravity sensing, signaling, and auxin redistribution (organ curvature) are the three components of plant gravitropism. Eventually, we focus on the role of multiple SGR genes in shoot and present a complete update on the participation of SGR family members in gravity.
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Affiliation(s)
- Yuhan Cho
- Division of Life Science and Division of Applied Life Science (BK21 Four), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Gyeongnam, 52828, Republic of Korea
| | - Yujeong Kim
- Division of Life Science and Division of Applied Life Science (BK21 Four), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Gyeongnam, 52828, Republic of Korea
| | - Hyebi Lee
- Division of Life Science and Division of Applied Life Science (BK21 Four), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Gyeongnam, 52828, Republic of Korea
| | - Sundong Kim
- Division of Life Science and Division of Applied Life Science (BK21 Four), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Gyeongnam, 52828, Republic of Korea
| | - Jaehee Kang
- Division of Life Science and Division of Applied Life Science (BK21 Four), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Gyeongnam, 52828, Republic of Korea
| | - Ulhas S Kadam
- Division of Life Science and Division of Applied Life Science (BK21 Four), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Gyeongnam, 52828, Republic of Korea.
| | - Soon Ju Park
- Division of Life Science and Division of Applied Life Science (BK21 Four), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Gyeongnam, 52828, Republic of Korea
| | - Woo Sik Chung
- Division of Life Science and Division of Applied Life Science (BK21 Four), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Gyeongnam, 52828, Republic of Korea
| | - Jong Chan Hong
- Division of Life Science and Division of Applied Life Science (BK21 Four), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Gyeongnam, 52828, Republic of Korea.
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The Course of Mechanical Stress: Types, Perception, and Plant Response. BIOLOGY 2023; 12:biology12020217. [PMID: 36829495 PMCID: PMC9953051 DOI: 10.3390/biology12020217] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 01/23/2023] [Accepted: 01/25/2023] [Indexed: 01/31/2023]
Abstract
Mechanical stimuli, together with the corresponding plant perception mechanisms and the finely tuned thigmomorphogenetic response, has been of scientific and practical interest since the mid-17th century. As an emerging field, there are many challenges in the research of mechanical stress. Indeed, studies on different plant species (annual/perennial) and plant organs (stem/root) using different approaches (field, wet lab, and in silico/computational) have delivered insufficient findings that frequently impede the practical application of the acquired knowledge. Accordingly, the current work distils existing mechanical stress knowledge by bringing in side-by-side the research conducted on both stem and roots. First, the various types of mechanical stress encountered by plants are defined. Second, plant perception mechanisms are outlined. Finally, the different strategies employed by the plant stem and roots to counteract the perceived mechanical stresses are summarized, depicting the corresponding morphological, phytohormonal, and molecular characteristics. The comprehensive literature on both perennial (woody) and annual plants was reviewed, considering the potential benefits and drawbacks of the two plant types, which allowed us to highlight current gaps in knowledge as areas of interest for future research.
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Hosamani R, Swamy BK, Dsouza A, Sathasivam M. Plant responses to hypergravity: a comprehensive review. PLANTA 2022; 257:17. [PMID: 36534189 DOI: 10.1007/s00425-022-04051-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Accepted: 12/10/2022] [Indexed: 06/17/2023]
Abstract
Hypergravity is an effective novel stimulus to elucidate plant gravitational and mechanobiological behaviour. Here, we review the current understanding of phenotypic, physio-biochemical, and molecular plant responses to simulated hypergravity. Plants readily respond to altered gravity conditions, such as microgravity or hypergravity. Hypergravity-a gravitational force higher than that on the Earth's surface (> 1g)-can be simulated using centrifuges. Exposing seeds, seedlings, or plant cell cultures to hypergravity elicits characteristic morphological, physio-biochemical, and molecular changes. While several studies have provided insights into plant responses and underlying mechanisms, much is still elusive, including the interplay of hypergravity with gravitropism. Moreover, hypergravity is of great significance for mechano- and space/gravitational biologists to elucidate fundamental plant behaviour. In this review, we provide an overview of the phenotypic, physiological, biochemical, and molecular responses of plants to hypergravity. We then discuss the involvement of hypergravity in plant gravitropism-the directional growth along the gravity vector. Finally, we highlight future research directions to expand our understanding of hypergravity in plant biology.
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Affiliation(s)
- Ravikumar Hosamani
- Institute of Agricultural Biotechnology (IABT), University of Agricultural Sciences, Dharwad, 580005, India.
| | - Basavalingayya K Swamy
- Institute of Agricultural Biotechnology (IABT), University of Agricultural Sciences, Dharwad, 580005, India
| | - Ajwal Dsouza
- Controlled Environment Systems Research Facility, School of Environmental Sciences, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada
| | - Malarvizhi Sathasivam
- Institute of Agricultural Biotechnology (IABT), University of Agricultural Sciences, Dharwad, 580005, India
- College of Agriculture, Forestry and Life Sciences, Clemson University, Clemson, South Carolina, USA
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Kawamoto N, Morita MT. Gravity sensing and responses in the coordination of the shoot gravitropic setpoint angle. THE NEW PHYTOLOGIST 2022; 236:1637-1654. [PMID: 36089891 PMCID: PMC9828789 DOI: 10.1111/nph.18474] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 08/13/2022] [Indexed: 06/15/2023]
Abstract
Gravity is one of the fundamental environmental cues that affect plant development. Indeed, the plant architecture in the shoots and roots is modulated by gravity. Stems grow vertically upward, whereas lateral organs, such as the lateral branches in shoots, tend to grow at a specific angle according to a gravity vector known as the gravitropic setpoint angle (GSA). During this process, gravity is sensed in specialised gravity-sensing cells named statocytes, which convert gravity information into biochemical signals, leading to asymmetric auxin distribution and driving asymmetric cell division/expansion in the organs to achieve gravitropism. As a hypothetical offset mechanism against gravitropism to determine the GSA, the anti-gravitropic offset (AGO) has been proposed. According to this concept, the GSA is a balance of two antagonistic growth components, that is gravitropism and the AGO. Although the nature of the AGO has not been clarified, studies have suggested that gravitropism and the AGO share a common gravity-sensing mechanism in statocytes. This review discusses the molecular mechanisms underlying gravitropism as well as the hypothetical AGO in the control of the GSA.
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Affiliation(s)
- Nozomi Kawamoto
- Division of Plant Environmental ResponsesNational Institute for Basic BiologyMyodaijiOkazaki444‐8556Japan
| | - Miyo Terao Morita
- Division of Plant Environmental ResponsesNational Institute for Basic BiologyMyodaijiOkazaki444‐8556Japan
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6
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Gravi-Sensitivity of Mosses and Their Gravity-Dependent Ontogenetic Adaptations. Life (Basel) 2022; 12:life12111782. [DOI: 10.3390/life12111782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 10/30/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022] Open
Abstract
Gravi-morphoses affect the variability of plants and are the morphogenetic adaptation to different environmental conditions. Gravity-dependent phenotypic plasticity of gametophytes as well as gravi-sensitivity of moss protonemata in microgravity and simulated microgravity conditions are discussed. The moss protonema, a filamentous multicellular system, representing a juvenile stage of moss development, develops as a result of the elongation and division of the apical cell. This apical cell of the protonema is a unique object for research on moss gravi-sensitivity, as graviperception and gravitropic growth occur within the same single cell. Attention is focused on the influence of gravity on bryophyte ontogenesis, including the gravitropic reactivity of moss protonemata, gravi-sensitivity at the stage of leafy shoot development and sporogonium formation, gravity-influenced morphogenesis of apical cell budding, and gravity-dependent spiral growth patterns. The role of gravireceptors in the growth processes of mosses at the cellular level under microgravity conditions are being discussed, as well as the involvement of auxin transport, Ca2+-induced gravitropism and the cytoskeleton in gravitropic reactions.
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Liang C, Wei C, Wang L, Guan Z, Shi T, Huang J, Li B, Lu Y, Liu H, Wang Y. Characterization of a Novel Creeping Tartary Buckwheat ( Fagopyrum tataricum) Mutant lazy1. FRONTIERS IN PLANT SCIENCE 2022; 13:815131. [PMID: 35574111 PMCID: PMC9094088 DOI: 10.3389/fpls.2022.815131] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 03/02/2022] [Indexed: 06/15/2023]
Abstract
Gravity is known as an important environmental factor involved in the regulation of plant architecture. To identify genes related to the gravitropism of Tartary buckwheat, a creeping line was obtained and designated as lazy1 from the mutant bank by 60Co-γ ray radiation. Genetic analysis indicated that the creeping phenotype of lazy1 was attributed to a single recessive locus. As revealed by the horizontal and inverted suspension tests, lazy1 was completely lacking in shoot negative gravitropism. The creeping growth of lazy1 occurred at the early seedling stage, which could not be recovered by exogenous heteroauxin, hormodin, α-rhodofix, or gibberellin. Different from the well-organized and equivalent cell elongation of wild type (WT), lazy1 exhibited dilated, distorted, and abnormally arranged cells in the bending stem. However, no statistical difference of indole-3-acetic acid (IAA) levels was found between the far- and near-ground bending sides in lazy1, which suggests that the asymmetric cell elongation of lazy1 was not induced by auxin gradient. Whereas, lazy1 showed up-expressed gibberellin-regulated genes by quantitative real-time PCR (qRT-PCR) as well as significantly higher levels of gibberellin, suggesting that gibberellin might be partly involved in the regulation of creeping growth in lazy1. RNA sequencing (RNA-seq) identified a number of differentially expressed genes (DEGs) related to gravitropism at stages I (before bending), II (bending), and III (after bending) between WT and lazy1. Venn diagram indicated that only Pectate lyase 5 was down-expressed at stages I [Log2 fold change (Log2FC): -3.20], II (Log2FC: -4.97), and III (Log2FC: -1.23) in lazy1, compared with WT. Gene sequencing revealed that a fragment deletion occurred in the coding region of Pectate lyase 5, which induced the destruction of a pbH domain in Pectate lyase 5 of lazy1. qRT-PCR indicated that Pectate lyase 5 was extremely down-expressed in lazy1 at stage II (0.02-fold of WT). Meanwhile, lazy1 showed the affected expression of lignin- and cellulose-related genes and cumulatively abnormal levels of pectin, lignin, and cellulose. These results demonstrate the possibility that Pectate lyase 5 functions as the key gene that could mediate primary cell wall metabolism and get involved in the asymmetric cell elongation regulation of lazy1.
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Affiliation(s)
- Chenggang Liang
- Research Center of Buckwheat Industry Technology, School of Life Sciences, Guizhou Normal University, Guiyang, China
| | - Chunyu Wei
- Research Center of Buckwheat Industry Technology, School of Life Sciences, Guizhou Normal University, Guiyang, China
| | - Li Wang
- Research Center of Buckwheat Industry Technology, School of Life Sciences, Guizhou Normal University, Guiyang, China
| | - Zhixiu Guan
- Research Center of Buckwheat Industry Technology, School of Life Sciences, Guizhou Normal University, Guiyang, China
| | - Taoxiong Shi
- Research Center of Buckwheat Industry Technology, School of Life Sciences, Guizhou Normal University, Guiyang, China
| | - Juan Huang
- Research Center of Buckwheat Industry Technology, School of Life Sciences, Guizhou Normal University, Guiyang, China
| | - Bin Li
- Research Center of Buckwheat Industry Technology, School of Life Sciences, Guizhou Normal University, Guiyang, China
| | - Yang Lu
- Guizhou Biotechnology Institute, Guizhou Academy of Agricultural Sciences, Guiyang, China
- Guizhou Key Laboratory of Agricultural Biotechnology, Guiyang, China
| | - Hui Liu
- Guizhou Biotechnology Institute, Guizhou Academy of Agricultural Sciences, Guiyang, China
- Guizhou Key Laboratory of Agricultural Biotechnology, Guiyang, China
| | - Yan Wang
- Research Center of Buckwheat Industry Technology, School of Life Sciences, Guizhou Normal University, Guiyang, China
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8
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Chin S, Blancaflor EB. Plant Gravitropism: From Mechanistic Insights into Plant Function on Earth to Plants Colonizing Other Worlds. Methods Mol Biol 2022; 2368:1-41. [PMID: 34647245 DOI: 10.1007/978-1-0716-1677-2_1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Gravitropism, the growth of roots and shoots toward or away from the direction of gravity, has been studied for centuries. Such studies have not only led to a better understanding of the gravitropic process itself, but also paved new paths leading to deeper mechanistic insights into a wide range of research areas. These include hormone biology, cell signal transduction, regulation of gene expression, plant evolution, and plant interactions with a variety of environmental stimuli. In addition to contributions to basic knowledge about how plants function, there is accumulating evidence that gravitropism confers adaptive advantages to crops, particularly under marginal agricultural soils. Therefore, gravitropism is emerging as a breeding target for enhancing agricultural productivity. Moreover, research on gravitropism has spawned several studies on plant growth in microgravity that have enabled researchers to uncouple the effects of gravity from other tropisms. Although rapid progress on understanding gravitropism witnessed during the past decade continues to be driven by traditional molecular, physiological, and cell biological tools, these tools have been enriched by technological innovations in next-generation omics platforms and microgravity analog facilities. In this chapter, we review the field of gravitropism by highlighting recent landmark studies that have provided unique insights into this classic research topic while also discussing potential contributions to agriculture on Earth and beyond.
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Affiliation(s)
- Sabrina Chin
- Department of Botany, University of Wisconsin, Madison, WI, USA.
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9
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Kume A, Kamachi H, Onoda Y, Hanba YT, Hiwatashi Y, Karahara I, Fujita T. How plants grow under gravity conditions besides 1 g: perspectives from hypergravity and space experiments that employ bryophytes as a model organism. PLANT MOLECULAR BIOLOGY 2021; 107:279-291. [PMID: 33852087 DOI: 10.1007/s11103-021-01146-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Accepted: 03/25/2021] [Indexed: 06/12/2023]
Abstract
Plants have evolved and grown under the selection pressure of gravitational force at 1 g on Earth. In response to this selection pressure, plants have acquired gravitropism to sense gravity and change their growth direction. In addition, plants also adjust their morphogenesis in response to different gravitational forces in a phenomenon known as gravity resistance. However, the gravity resistance phenomenon in plants is poorly understood due to the prevalence of 1 g gravitational force on Earth: not only it is difficult to culture plants at gravity > 1 g(hypergravity) for a long period of time but it is also impossible to create a < 1 genvironment (μg, micro g) on Earth without specialized facilities. Despite these technical challenges, it is important to understand how plants grow in different gravity conditions in order to understand land plant adaptation to the 1 g environment or for outer space exploration. To address this, we have developed a centrifugal device for a prolonged duration of plant culture in hypergravity conditions, and a project to grow plants under the μg environment in the International Space Station is also underway. Our plant material of choice is Physcomitrium (Physcomitrella) patens, one of the pioneer plants on land and a model bryophyte often used in plant biology. In this review, we summarize our latest findings regarding P. patens growth response to hypergravity, with reference to our on-going "Space moss" project. In our ground-based hypergravity experiments, we analyzed the morphological and physiological changes and found unexpected increments of chloroplast size and photosynthesis rate, which might underlie the enhancement of growth and increase in the number of gametophores and rhizoids. We further discussed our approaches at the cellular level and compare the gravity resistance in mosses and that in angiosperms. Finally, we highlight the advantages and perspectives from the space experiments and conclude that research with bryophytes is beneficial to comprehensively and precisely understand gravitational responses in plants.
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Affiliation(s)
- Atsushi Kume
- Faculty of Agriculture, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Hiroyuki Kamachi
- Faculty of Science, University of Toyama, 3190 Gofuku, Toyama, Toyama, 930-8555, Japan
| | - Yusuke Onoda
- Graduate School of Agriculture, Kyoto University, Oiwake, Kitashirakawa, Kyoto, 606-8502, Japan
| | - Yuko T Hanba
- Faculty of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan
| | - Yuji Hiwatashi
- School of Food Industrial Sciences, Miyagi University, 2-2-1 Hatatate, Taihaku-ku, Sendai, Miyagi, 982-0215, Japan
| | - Ichirou Karahara
- Faculty of Science, University of Toyama, 3190 Gofuku, Toyama, Toyama, 930-8555, Japan
| | - Tomomichi Fujita
- Faculty of Science, Hokkaido University, Kita 10 Nishi8 Kita-ku, Sapporo, Hokkaido, 060-0810, Japan.
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Song K, Lee DW, Kim J, Kim J, Guim H, Kim K, Jeon JS, Choi G. EARLY STARVATION 1 Is a Functionally Conserved Protein Promoting Gravitropic Responses in Plants by Forming Starch Granules. FRONTIERS IN PLANT SCIENCE 2021; 12:628948. [PMID: 34367195 PMCID: PMC8343138 DOI: 10.3389/fpls.2021.628948] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 06/29/2021] [Indexed: 05/29/2023]
Abstract
Starch granules in the endodermis of plant hypocotyls act as statoliths that promote hypocotyl negative gravitropism-the directional growth of hypocotyls against gravity-in the dark. To identify the molecular components that regulate hypocotyl negative gravitropism, we performed a mutagenesis screen and isolated reduced gravitropic 1 (rgv1) mutants that lack starch granules in their hypocotyl endodermis and show reduced hypocotyl negative gravitropism in the dark. Using whole genome sequencing, we identified three different rgv1 mutants that are allelic to the previously reported early starvation 1 mutant, which is rapidly depleted of starch just before the dawn. ESV1 orthologs are present in starch-producing green organisms, suggesting ESV1 is a functionally conserved protein necessary for the formation of starch granules. Consistent with this, we found that liverwort and rice ESV1 can complement the Arabidopsis ESV1 mutant phenotype for both starch granules and hypocotyl negative gravitropism. To further investigate the function of ESV1 in other plants, we isolated rice ESV1 mutants and found that they show reduced levels of starch in their leaves and loosely packed starch granules in their grains. Both Arabidopsis and rice ESV1 mutants also lack starch granules in root columella and show reduced root gravitropism. Together, these results indicate ESV1 is a functionally conserved protein that promotes gravitropic responses in plants via its role in starch granule formation.
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Affiliation(s)
- Kijong Song
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Dae-Woo Lee
- Graduate School of Biotechnology and Crop Biotech Institute, Kyung Hee University, Yongin-si, South Korea
| | - Jeongheon Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Jaewook Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Hwanuk Guim
- Research Center for Materials Analysis, Korea Basic Science Institute, Daejeon, South Korea
| | - Keunhwa Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Jong-Seong Jeon
- Graduate School of Biotechnology and Crop Biotech Institute, Kyung Hee University, Yongin-si, South Korea
| | - Giltsu Choi
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
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Abstract
Gravity determines shape of body tissue and affects the functions of life, both in plants and animals. The cellular response to gravity is an active process of mechanotransduction. Although plants and animals share some common mechanisms of gravity sensing in spite of their distant phylogenetic origin, each species has its own mechanism to sense and respond to gravity. In this review, we discuss current understanding regarding the mechanisms of cellular gravity sensing in plants and animals. Understanding gravisensing also contributes to life on Earth, e.g., understanding osteoporosis and muscle atrophy. Furthermore, in the current age of Mars exploration, understanding cellular responses to gravity will form the foundation of living in space.
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The gravistimulation-induced very slow Ca 2+ increase in Arabidopsis seedlings requires MCA1, a Ca 2+-permeable mechanosensitive channel. Sci Rep 2021; 11:227. [PMID: 33420331 PMCID: PMC7794229 DOI: 10.1038/s41598-020-80733-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 12/23/2020] [Indexed: 12/11/2022] Open
Abstract
Gravity is a critical environmental factor affecting the morphology and function of plants on Earth. Gravistimulation triggered by changes in the gravity vector induces an increase in the cytoplasmic free calcium ion concentration ([Ca2+]c) as an early process of gravity sensing; however, its role and molecular mechanism are still unclear. When seedlings of Arabidopsis thaliana expressing apoaequorin were rotated from the upright position to the upside-down position, a biphasic [Ca2+]c-increase composed of a fast-transient [Ca2+]c-increase followed by a slow [Ca2+]c-increase was observed. We find here a novel type [Ca2+]c-increase, designated a very slow [Ca2+]c-increase that is observed when the seedlings were rotated back to the upright position from the upside-down position. The very slow [Ca2+]c-increase was strongly attenuated in knockout seedlings defective in MCA1, a mechanosensitive Ca2+-permeable channel (MSCC), and was partially restored in MCA1-complemented seedlings. The mechanosensitive ion channel blocker, gadolinium, blocked the very slow [Ca2+]c-increase. This is the first report suggesting the possible involvement of MCA1 in an early event related to gravity sensing in Arabidopsis seedlings.
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Abe Y, Meguriya K, Matsuzaki T, Sugiyama T, Yoshikawa HY, Morita MT, Toyota M. Micromanipulation of amyloplasts with optical tweezers in Arabidopsis stems. PLANT BIOTECHNOLOGY (TOKYO, JAPAN) 2020; 37:405-415. [PMID: 33850427 PMCID: PMC8034693 DOI: 10.5511/plantbiotechnology.20.1201a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 12/01/2020] [Indexed: 05/25/2023]
Abstract
Intracellular sedimentation of highly dense, starch-filled amyloplasts toward the gravity vector is likely a key initial step for gravity sensing in plants. However, recent live-cell imaging technology revealed that most amyloplasts continuously exhibit dynamic, saltatory movements in the endodermal cells of Arabidopsis stems. These complicated movements led to questions about what type of amyloplast movement triggers gravity sensing. Here we show that a confocal microscope equipped with optical tweezers can be a powerful tool to trap and manipulate amyloplasts noninvasively, while simultaneously observing cellular responses such as vacuolar dynamics in living cells. A near-infrared (λ=1064 nm) laser that was focused into the endodermal cells at 1 mW of laser power attracted and captured amyloplasts at the laser focus. The optical force exerted on the amyloplasts was theoretically estimated to be up to 1 pN. Interestingly, endosomes and trans-Golgi network were trapped at 30 mW but not at 1 mW, which is probably due to lower refractive indices of these organelles than that of the amyloplasts. Because amyloplasts are in close proximity to vacuolar membranes in endodermal cells, their physical interaction could be visualized in real time. The vacuolar membranes drastically stretched and deformed in response to the manipulated movements of amyloplasts by optical tweezers. Our new method provides deep insights into the biophysical properties of plant organelles in vivo and opens a new avenue for studying gravity-sensing mechanisms in plants.
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Affiliation(s)
- Yoshinori Abe
- Department of Biochemistry and Molecular Biology, Saitama University, Saitama 338-8570, Japan
| | - Keisuke Meguriya
- Department of Chemistry, Saitama University, Saitama 338-8570, Japan
| | - Takahisa Matsuzaki
- Division of Strategic Research and Development, Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
| | - Teruki Sugiyama
- Department of Applied Chemistry, National Chiao Tung University, Hsinchu 30010, Taiwan
- Division of Materials Science, Nara Institute of Science and Technology, Nara 630-0192, Japan
- Center for Emergent Functional Matter Science, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Hiroshi Y. Yoshikawa
- Department of Chemistry, Saitama University, Saitama 338-8570, Japan
- Division of Strategic Research and Development, Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
| | - Miyo Terao Morita
- Division of Plant Environmental Responses, National Institute for Basic Biology, Aichi 444-8585, Japan
| | - Masatsugu Toyota
- Department of Biochemistry and Molecular Biology, Saitama University, Saitama 338-8570, Japan
- Department of Botany, University of Wisconsin, Madison, WI 53706, USA
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14
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Kimata Y, Ueda M. Intracellular dynamics and transcriptional regulations in plant zygotes: a case study of Arabidopsis. PLANT REPRODUCTION 2020; 33:89-96. [PMID: 32322957 DOI: 10.1007/s00497-020-00389-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 04/09/2020] [Indexed: 06/11/2023]
Abstract
Recent understandings ofArabidopsiszygote. Body axis formation is essential for the proper development of multicellular organisms. The apical-basal axis in Arabidopsis thaliana is determined by the asymmetric division of the zygote, following its cellular polarization. However, the regulatory mechanism of zygote polarization is unclear due to technical issues. The zygote is located deep in the seed (ovule) in flowers, which prevents the living dynamics of zygotes from being observed. In addition, elucidation of molecular pathways by conventional forward genetic screens was not enough because of high gene redundancy in early development. Here, we present a review introducing two new methods, which have been developed to overcome these problems. Method 1: the two-photon live-cell imaging method provides a new system to visualize the dynamics of intracellular structures in Arabidopsis zygotes, such as cytoskeletons and vacuoles. Microtubules form transverse rings and control zygote elongation, while vacuoles dynamically change their shapes along longitudinal actin filaments and support polar nuclear migration. Method 2: the transcriptome method uses isolated Arabidopsis zygotes and egg cells to reveal the gene expression profiles before and after fertilization. This approach revealed that de novo transcription occurs extensively and immediately after fertilization. Moreover, inhibition of the de novo transcription was shown to sufficiently block the zygotic division, thus indicating a strong possibility that yet unidentified zygote regulators can be found using this transcriptome approach. These new strategies in Arabidopsis will help to further our understanding of the fundamental principles regarding the proper formation of plant bodies from unicellular zygotes.
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Affiliation(s)
- Yusuke Kimata
- Institute of Transformative Bio-Molecules (ITbM), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8601, Japan
| | - Minako Ueda
- Institute of Transformative Bio-Molecules (ITbM), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8601, Japan.
- Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602, Japan.
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15
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Ditengou FA, Teale WD, Palme K. Settling for Less: Do Statoliths Modulate Gravity Perception? PLANTS (BASEL, SWITZERLAND) 2020; 9:E121. [PMID: 31963631 PMCID: PMC7020169 DOI: 10.3390/plants9010121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 01/13/2020] [Accepted: 01/16/2020] [Indexed: 01/20/2023]
Abstract
Plants orientate their growth either towards (in roots) or away from (in shoots) the Earth's gravitational field. While we are now starting to understand the molecular architecture of these gravity response pathways, the gravity receptor remains elusive. This perspective looks at the biology of statoliths and suggests it is conceivable that their immediate environment may be tuned to modulate the strength of the gravity response. It then suggests how mutant screens could use this hypothesis to identify the gravity receptor.
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Affiliation(s)
- Franck Anicet Ditengou
- Institute of Biology II, Faculty of Biology, Albert-Ludwigs-University of Freiburg, Schänzlestrasse 1, 79104 Freiburg, Germany
| | - William David Teale
- Institute of Biology II, Faculty of Biology, Albert-Ludwigs-University of Freiburg, Schänzlestrasse 1, 79104 Freiburg, Germany
| | - Klaus Palme
- Institute of Biology II, Faculty of Biology, Albert-Ludwigs-University of Freiburg, Schänzlestrasse 1, 79104 Freiburg, Germany
- BIOSS Center for Biological Signaling Studies, Albert-Ludwigs-University of Freiburg, Schänzlestrasse 18, 79104 Freiburg, Germany
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Daizong Street 61, Tai’an 271018, China
- Sino-German Joint Research Center on Agricultural Biology, College of Life Sciences, Shandong Agricultural University, Daizong Street 61, Tai’an 271018, China
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16
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Richter P, Strauch SM, Lebert M. Disproval of the Starch-Amyloplast Hypothesis? TRENDS IN PLANT SCIENCE 2019; 24:291-293. [PMID: 30827844 DOI: 10.1016/j.tplants.2019.02.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 02/13/2019] [Accepted: 02/13/2019] [Indexed: 05/14/2023]
Abstract
In a recent publication, Edelmann (Protoplasma 2018; 255,1877-1881) refuted the well-established starch-amyloplast hypothesis of gravitropism in plants. Gravitropic curvatures of shoots and roots were still present after amyloplast-containing tissues (in sheath of vascular bundles and root caps) were dissected. Here, we discuss Edelmann's data in the light of Popper's falsification principle.
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Affiliation(s)
- Peter Richter
- Department of Biology, Cell Biology Division, Gravitational Biology Group, Friedrich-Alexander-University Erlangen-Nuremberg, Staudtstrasse 5, 91058 Erlangen, Germany
| | - Sebastian M Strauch
- Department of Biology, Cell Biology Division, Gravitational Biology Group, Friedrich-Alexander-University Erlangen-Nuremberg, Staudtstrasse 5, 91058 Erlangen, Germany
| | - Michael Lebert
- Department of Biology, Cell Biology Division, Gravitational Biology Group, Friedrich-Alexander-University Erlangen-Nuremberg, Staudtstrasse 5, 91058 Erlangen, Germany.
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17
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Polar vacuolar distribution is essential for accurate asymmetric division of Arabidopsis zygotes. Proc Natl Acad Sci U S A 2019; 116:2338-2343. [PMID: 30651313 DOI: 10.1073/pnas.1814160116] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
In most flowering plants, the asymmetric cell division of the zygote is the initial step in establishing the apical-basal axis of the mature plant. The zygote is polarized, possessing the nucleus at the apical tip and large vacuoles at the basal end. Despite their known polar localization, whether the positioning of the vacuoles and the nucleus is coordinated and what the role of the vacuole is in the asymmetric zygotic division remain elusive. In the present study, we utilized a live-cell imaging system to visualize the dynamics of vacuoles during the entire process of zygote polarization in Arabidopsis Image analysis revealed that the vacuoles formed tubular strands around the apically migrating nucleus. They gradually accumulated at the basal region and filled the space, resulting in asymmetric distribution in the mature zygote. To assess the role of vacuoles in the zygote, we screened various vacuole mutants and identified that shoot gravitropism2 (sgr2), in which the vacuolar structural change was impaired, failed to form tubular vacuoles and to polarly distribute the vacuole. In sgr2, large vacuoles occupied the apical tip and thus nuclear migration was blocked, resulting in a more symmetric zygotic division. We further observed that tubular vacuole formation and asymmetric vacuolar distribution both depended on the longitudinal array of actin filaments. Overall, our results show that vacuolar dynamics is crucial not only for the polar distribution along actin filaments but also for adequate nuclear positioning, and consequently zygote-division asymmetry.
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18
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Zinkgraf M, Gerttula S, Zhao S, Filkov V, Groover A. Transcriptional and temporal response of Populus stems to gravi-stimulation. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2018; 60:578-590. [PMID: 29480544 DOI: 10.1111/jipb.12645] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 02/24/2018] [Indexed: 05/12/2023]
Abstract
Plants modify development in response to external stimuli, to produce new growth that is appropriate for environmental conditions. For example, gravi-stimulation of leaning branches in angiosperm trees results in modifications of wood development, to produce tension wood that pulls leaning stems upright. Here, we use gravi-stimulation and tension wood response to dissect the temporal changes in gene expression underlying wood formation in Populus stems. Using time-series analysis of seven time points over a 14-d experiment, we identified 8,919 genes that were differentially expressed between tension wood (upper) and opposite wood (lower) sides of leaning stems. Clustering of differentially expressed genes showed four major transcriptional responses, including gene clusters whose transcript levels were associated with two types of tissue-specific impulse responses that peaked at about 24-48 h, and gene clusters with sustained changes in transcript levels that persisted until the end of the 14-d experiment. Functional enrichment analysis of those clusters suggests they reflect temporal changes in pathways associated with hormone regulation, protein localization, cell wall biosynthesis and epigenetic processes. Time-series analysis of gene expression is an underutilized approach for dissecting complex developmental responses in plants, and can reveal gene clusters and mechanisms influencing development.
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Affiliation(s)
- Matthew Zinkgraf
- USDA Forest Service, Pacific Southwest Research Station, 1731 Research Park Drive, Davis, CA 95618, USA
- Department of Computer Science, University of California Davis, One Shields Avenue, Davis, CA 95618, USA
| | - Suzanne Gerttula
- USDA Forest Service, Pacific Southwest Research Station, 1731 Research Park Drive, Davis, CA 95618, USA
- Department of Computer Science, University of California Davis, One Shields Avenue, Davis, CA 95618, USA
| | - Shutang Zhao
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
| | - Vladimir Filkov
- Department of Computer Science, University of California Davis, One Shields Avenue, Davis, CA 95618, USA
| | - Andrew Groover
- USDA Forest Service, Pacific Southwest Research Station, 1731 Research Park Drive, Davis, CA 95618, USA
- Department of Plant Biology, University of California Davis, One Shields Avenue, Davis, CA 95618, USA
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19
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Bérut A, Chauvet H, Legué V, Moulia B, Pouliquen O, Forterre Y. Gravisensors in plant cells behave like an active granular liquid. Proc Natl Acad Sci U S A 2018; 115:5123-5128. [PMID: 29712863 PMCID: PMC5960325 DOI: 10.1073/pnas.1801895115] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Plants are able to sense and respond to minute tilt from the vertical direction of the gravity, which is key to maintain their upright posture during development. However, gravisensing in plants relies on a peculiar sensor made of microsize starch-filled grains (statoliths) that sediment and form tiny granular piles at the bottom of the cell. How such a sensor can detect inclination is unclear, as granular materials like sand are known to display flow threshold and finite avalanche angle due to friction and interparticle jamming. Here, we address this issue by combining direct visualization of statolith avalanches in plant cells and experiments in biomimetic cells made of microfluidic cavities filled with a suspension of heavy Brownian particles. We show that, despite their granular nature, statoliths move and respond to the weakest angle, as a liquid clinometer would do. Comparison between the biological and biomimetic systems reveals that this liquid-like behavior comes from the cell activity, which agitates statoliths with an apparent temperature one order of magnitude larger than actual temperature. Our results shed light on the key role of active fluctuations of statoliths for explaining the remarkable sensitivity of plants to inclination. Our study also provides support to a recent scenario of gravity perception in plants, by bridging the active granular rheology of statoliths at the microscopic level to the macroscopic gravitropic response of the plant.
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Affiliation(s)
- Antoine Bérut
- Aix-Marseille Univ, CNRS, IUSTI (Institut Universitaire des Systèmes Thermiques Industriels), 13013 Marseille, France
| | - Hugo Chauvet
- Aix-Marseille Univ, CNRS, IUSTI (Institut Universitaire des Systèmes Thermiques Industriels), 13013 Marseille, France
- Université Clermont Auvergne, INRA, PIAF, F-63000 Clermont-Ferrand, France
| | - Valérie Legué
- Université Clermont Auvergne, INRA, PIAF, F-63000 Clermont-Ferrand, France
| | - Bruno Moulia
- Université Clermont Auvergne, INRA, PIAF, F-63000 Clermont-Ferrand, France
| | - Olivier Pouliquen
- Aix-Marseille Univ, CNRS, IUSTI (Institut Universitaire des Systèmes Thermiques Industriels), 13013 Marseille, France
| | - Yoël Forterre
- Aix-Marseille Univ, CNRS, IUSTI (Institut Universitaire des Systèmes Thermiques Industriels), 13013 Marseille, France;
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20
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Wang T, Xu W, Li H, Deng C, Zhao H, Wu Y, Liu M, Wu L, Lu J, Bian P. Effect of modeled microgravity on UV-C-induced interplant communication of Arabidopsis thaliana. Mutat Res 2017; 806:1-8. [PMID: 28926746 DOI: 10.1016/j.mrfmmm.2017.09.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 08/14/2017] [Accepted: 09/01/2017] [Indexed: 06/07/2023]
Abstract
Controlled ecological life support systems (CELSS) will be an important feature of long-duration space missions of which higher plants are one of the indispensable components. Because of its pivotal role in enabling plants to cope with environmental stress, interplant communication might have important implications for the ecological stability of such CELSS. However, the manifestations of interplant communication in microgravity conditions have yet to be fully elucidated. To address this, a well-established Arabidopsis thaliana co-culture experimental system, in which UV-C-induced airborne interplant communication is evaluated by the alleviation of transcriptional gene silencing (TGS) in bystander plants, was placed in microgravity modeled by a two-dimensional rotating clinostat. Compared with plants under normal gravity, TGS alleviation in bystander plants was inhibited in microgravity. Moreover, TGS alleviation was also prevented when plants of the pgm-1 line, which are impaired in gravity sensing, were used in either the UV-C-irradiated or bystander group. In addition to the specific TGS-loci, interplant communication-shaped genome-wide DNA methylation in bystander plants was altered under microgravity conditions. These results indicate that interplant communications might be modified in microgravity. Time course analysis showed that microgravity interfered with both the production of communicative signals in UV-C-irradiated plants and the induction of epigenetic responses in bystander plants. This was further confirmed by the experimental finding that microgravity also prevented the response of bystander plants to exogenous methyl jasmonate (JA) and methyl salicylate (SA), two well-known airborne signaling molecules, and down-regulated JA and SA biosynthesis in UV-C-irradiated plants.
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Affiliation(s)
- Ting Wang
- Key Laboratory of Ion Beam Bio-Engineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, P.O. Box 1138, Hefei, Anhui, 230031, PR China
| | - Wei Xu
- Key Laboratory of Ion Beam Bio-Engineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, P.O. Box 1138, Hefei, Anhui, 230031, PR China
| | - Huasheng Li
- China Space Molecular Biological Lab, China Academy of Space Technology, Beijing 100086, PR China
| | - Chenguang Deng
- Key Laboratory of Ion Beam Bio-Engineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, P.O. Box 1138, Hefei, Anhui, 230031, PR China
| | - Hui Zhao
- China Space Molecular Biological Lab, China Academy of Space Technology, Beijing 100086, PR China
| | - Yuejin Wu
- Key Laboratory of Ion Beam Bio-Engineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, P.O. Box 1138, Hefei, Anhui, 230031, PR China
| | - Min Liu
- China Space Molecular Biological Lab, China Academy of Space Technology, Beijing 100086, PR China
| | - Lijun Wu
- Key Laboratory of Ion Beam Bio-Engineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, P.O. Box 1138, Hefei, Anhui, 230031, PR China
| | - Jinying Lu
- China Space Molecular Biological Lab, China Academy of Space Technology, Beijing 100086, PR China.
| | - Po Bian
- Key Laboratory of Ion Beam Bio-Engineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, P.O. Box 1138, Hefei, Anhui, 230031, PR China.
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21
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Basu P, Kruse CPS, Luesse DR, Wyatt SE. Growth in spaceflight hardware results in alterations to the transcriptome and proteome. LIFE SCIENCES IN SPACE RESEARCH 2017; 15:88-96. [PMID: 29198318 DOI: 10.1016/j.lssr.2017.09.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 09/18/2017] [Accepted: 09/19/2017] [Indexed: 05/21/2023]
Abstract
The Biological Research in Canisters (BRIC) hardware has been used to house many biology experiments on both the Space Transport System (STS, commonly known as the space shuttle) and the International Space Station (ISS). However, microscopic examination of Arabidopsis seedlings by Johnson et al. (2015) indicated the hardware itself may affect cell morphology. The experiment herein was designed to assess the effects of the BRIC-Petri Dish Fixation Units (BRIC-PDFU) hardware on the transcriptome and proteome of Arabidopsis seedlings. To our knowledge, this is the first transcriptomic and proteomic comparison of Arabidopsis seedlings grown with and without hardware. Arabidopsis thaliana wild-type Columbia (Col-0) seeds were sterilized and bulk plated on forty-four 60 mm Petri plates, of which 22 were integrated into the BRIC-PDFU hardware and 22 were maintained in closed containers at Ohio University. Seedlings were grown for approximately 3 days, fixed with RNAlater® and stored at -80 °C prior to RNA and protein extraction, with proteins separated into membrane and soluble fractions prior to analysis. The RNAseq analysis identified 1651 differentially expressed genes; MS/MS analysis identified 598 soluble and 589 membrane proteins differentially abundant both at p < .05. Fold enrichment analysis of gene ontology terms related to differentially expressed transcripts and proteins highlighted a variety of stress responses. Some of these genes and proteins have been previously identified in spaceflight experiments, indicating that these genes and proteins may be perturbed by both conditions.
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Affiliation(s)
- Proma Basu
- Department of Environmental and Plant Biology, Ohio University, Athens, OH 45701, United States; Interdisciplinary Molecular and Cellular Biology Program, Ohio University, Athens, OH 45701, United States
| | - Colin P S Kruse
- Department of Environmental and Plant Biology, Ohio University, Athens, OH 45701, United States; Interdisciplinary Molecular and Cellular Biology Program, Ohio University, Athens, OH 45701, United States
| | - Darron R Luesse
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL, United States
| | - Sarah E Wyatt
- Department of Environmental and Plant Biology, Ohio University, Athens, OH 45701, United States; Interdisciplinary Molecular and Cellular Biology Program, Ohio University, Athens, OH 45701, United States.
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22
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Pouliquen O, Forterre Y, Bérut A, Chauvet H, Bizet F, Legué V, Moulia B. A new scenario for gravity detection in plants: the position sensor hypothesis. Phys Biol 2017; 14:035005. [PMID: 28535150 DOI: 10.1088/1478-3975/aa6876] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The detection of gravity plays a fundamental role during the growth and evolution of plants. Although progress has been made in our understanding of the molecular, cellular and physical mechanisms involved in the gravity detection, a coherent scenario consistent with all the observations is still lacking. In this special issue article, we discuss recent experiments showing that the response to inclination of shoots is independent of the gravity intensity, meaning that the gravity sensor detects an inclination and not a force. This result questions some of the commonly accepted hypotheses and leads to propose a new 'position sensor hypothesis'. The implications of this new scenario are discussed in light of the different observations available in the literature.
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Affiliation(s)
- O Pouliquen
- Aix Marseille University, CNRS, IUSTI, Marseille, France
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23
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Häder DP, Braun M, Grimm D, Hemmersbach R. Gravireceptors in eukaryotes-a comparison of case studies on the cellular level. NPJ Microgravity 2017; 3:13. [PMID: 28649635 PMCID: PMC5460273 DOI: 10.1038/s41526-017-0018-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 01/27/2017] [Accepted: 03/09/2017] [Indexed: 01/03/2023] Open
Abstract
We have selected five evolutionary very different biological systems ranging from unicellular protists via algae and higher plants to human cells showing responses to the gravity vector of the Earth in order to compare their graviperception mechanisms. All these systems use a mass, which may either by a heavy statolith or the whole content of the cell heavier than the surrounding medium to operate on a gravireceptor either by exerting pressure or by pulling on a cytoskeletal element. In many cases the receptor seems to be a mechanosensitive ion channel activated by the gravitational force which allows a gated ion flux across the membrane when activated. This has been identified in many systems to be a calcium current, which in turn activates subsequent elements of the sensory transduction chain, such as calmodulin, which in turn results in the activation of ubiquitous enzymes, gene expression activation or silencing. Naturally, the subsequent responses to the gravity stimulus differ widely between the systems ranging from orientational movement and directed growth to physiological reactions and adaptation to the environmental conditions.
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Affiliation(s)
- Donat-P. Häder
- Erlangen-Nürnberg, Dept. Biol. Neue Str. 9, Emeritus from Friedrich-Alexander Universität, Möhrendorf, 91096 Germany
| | - Markus Braun
- Gravitational Biology, Universität Bonn, Kirschallee 1, Bonn, 53115 Germany
| | - Daniela Grimm
- Department of Biomedicine, Pharmacology, Aarhus University, Aarhus C, DK 8000 Denmark
| | - Ruth Hemmersbach
- Institute of Aerospace Medicine, Gravitational Biology, DLR (German Aerospace Center), Cologne, Linder Höhe 51147 Germany
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24
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Kamachi H, Tamaoki D, Karahara I. Plasma membrane-anchored chloroplasts are necessary for the gravisensing system of Ceratopteris richardii prothalli. JOURNAL OF PLANT RESEARCH 2017; 130:397-405. [PMID: 27988818 DOI: 10.1007/s10265-016-0889-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 11/15/2016] [Indexed: 06/06/2023]
Abstract
The prothalli of the fern Ceratopteris richardii exhibit negative gravitropism when grown in darkness. However, no sedimentable organelles or substances have been detected in the prothallial cells, suggesting that a non-sedimentable gravisensor exists. We investigated whether chloroplasts are involved in the gravisensing system of C. richardii prothalli. We used a clumped-chloroplast mutant, clumped chloroplast 1 (cp1), in which the chloroplasts are detached from the plasma membrane and clustered around the nucleus likely because of a partial deletion in the KINESIN-LIKE PROTEIN FOR ACTIN-BASED CHLOROPLAST MOVEMENT 1 gene. The cp1 mutation resulted in prothalli that had a significantly diminished gravitropic response, while the phototropic response occurred normally. These results suggest that plasma membrane-anchored chloroplasts in prothallial cells function as one of the gravisensors in C. richardii prothalli.
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Affiliation(s)
- Hiroyuki Kamachi
- Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama, 930-8555, Japan.
| | - Daisuke Tamaoki
- Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama, 930-8555, Japan
- Division of Functional Genomics, Advanced Science Research Center, Kanazawa University, Takara-machi 13-1, Kanazawa, Ishikawa, 920-0934, Japan
| | - Ichirou Karahara
- Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama, 930-8555, Japan
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25
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Alvarez AA, Han SW, Toyota M, Brillada C, Zheng J, Gilroy S, Rojas-Pierce M. Wortmannin-induced vacuole fusion enhances amyloplast dynamics in Arabidopsis zigzag1 hypocotyls. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:6459-6472. [PMID: 27816929 PMCID: PMC5181587 DOI: 10.1093/jxb/erw418] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Gravitropism in Arabidopsis shoots depends on the sedimentation of amyloplasts in the endodermis, and a complex interplay between the vacuole and F-actin. Gravity response is inhibited in zigzag-1 (zig-1), a mutant allele of VTI11, which encodes a SNARE protein involved in vacuole fusion. zig-1 seedlings have fragmented vacuoles that fuse after treatment with wortmannin, an inhibitor of phosphatidylinositol 3-kinase, and underscore a role of phosphoinositides in vacuole fusion. Using live-cell imaging with a vertical stage microscope, we determined that young endodermal cells below the apical hook that are smaller than 70 μm in length are the graviperceptive cells in dark-grown hypocotyls. This result was confirmed by local wortmannin application to the top of zig-1 hypocotyls, which enhanced shoot gravitropism in zig-1 mutants. Live-cell imaging of zig-1 hypocotyl endodermal cells indicated that amyloplasts are trapped between juxtaposed vacuoles and their movement is severely restricted. Wortmannin-induced fusion of vacuoles in zig-1 seedlings increased the formation of transvacuolar strands, enhanced amyloplast sedimentation and partially suppressed the agravitropic phenotype of zig-1 seedlings. Hypergravity conditions at 10 g were not sufficient to displace amyloplasts in zig-1, suggesting the existence of a physical tether between the vacuole and amyloplasts. Our results overall suggest that vacuole membrane remodeling may be involved in regulating the association of vacuoles and amyloplasts during graviperception.
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Affiliation(s)
- Ashley Ann Alvarez
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, USA
| | - Sang Won Han
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, USA
| | - Masatsugu Toyota
- Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Saitama, Japan
- Department of Botany, University of Wisconsin, Madison, WI, USA
- Department of Biochemistry and Molecular Biology, Saitama University, Saitama, Japan
| | - Carla Brillada
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, USA
| | - Jiameng Zheng
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, USA
| | - Simon Gilroy
- Department of Botany, University of Wisconsin, Madison, WI, USA
| | - Marcela Rojas-Pierce
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, USA
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26
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Chauvet H, Pouliquen O, Forterre Y, Legué V, Moulia B. Inclination not force is sensed by plants during shoot gravitropism. Sci Rep 2016; 6:35431. [PMID: 27739470 PMCID: PMC5064399 DOI: 10.1038/srep35431] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 09/27/2016] [Indexed: 12/03/2022] Open
Abstract
Gravity perception plays a key role in how plants develop and adapt to environmental changes. However, more than a century after the pioneering work of Darwin, little is known on the sensing mechanism. Using a centrifugal device combined with growth kinematics imaging, we show that shoot gravitropic responses to steady levels of gravity in four representative angiosperm species is independent of gravity intensity. All gravitropic responses tested are dependent only on the angle of inclination from the direction of gravity. We thus demonstrate that shoot gravitropism is stimulated by sensing inclination not gravitational force or acceleration as previously believed. This contrasts with the otolith system in the internal ear of vertebrates and explains the robustness of the control of growth direction by plants despite perturbations like wind shaking. Our results will help retarget the search for the molecular mechanism linking shifting statoliths to signal transduction.
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Affiliation(s)
- Hugo Chauvet
- Aix-Marseille Univ., CNRS, IUSTI UMR 7343, 13453 Marseille Cedex 13, France.,Integrative Physics and Physiology of Trees (PIAF), INRA, Univ. Clermont-Auvergne, 63000 Clermont-Ferrand, France
| | - Olivier Pouliquen
- Aix-Marseille Univ., CNRS, IUSTI UMR 7343, 13453 Marseille Cedex 13, France
| | - Yoël Forterre
- Aix-Marseille Univ., CNRS, IUSTI UMR 7343, 13453 Marseille Cedex 13, France
| | - Valérie Legué
- Integrative Physics and Physiology of Trees (PIAF), INRA, Univ. Clermont-Auvergne, 63000 Clermont-Ferrand, France
| | - Bruno Moulia
- Integrative Physics and Physiology of Trees (PIAF), INRA, Univ. Clermont-Auvergne, 63000 Clermont-Ferrand, France
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27
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Zou JJ, Zheng ZY, Xue S, Li HH, Wang YR, Le J. The role of Arabidopsis Actin-Related Protein 3 in amyloplast sedimentation and polar auxin transport in root gravitropism. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:5325-5337. [PMID: 27473572 PMCID: PMC5049384 DOI: 10.1093/jxb/erw294] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Gravitropism is vital for shaping directional plant growth in response to the forces of gravity. Signals perceived in the gravity-sensing cells can be converted into biochemical signals and transmitted. Sedimentation of amyloplasts in the columella cells triggers asymmetric auxin redistribution in root tips, leading to downward root growth. The actin cytoskeleton is thought to play an important role in root gravitropism, although the molecular mechanism has not been resolved. DISTORTED1 (DIS1) encodes the ARP3 subunit of the Arabidopsis Actin-Related Protein 2/3 (ARP2/3) complex, and the ARP3/DIS1 mutant dis1-1 showed delayed root curvature after gravity stimulation. Microrheological analysis revealed that the high apparent viscosity within dis1-1 central columella cells is closely associated with abnormal movement trajectories of amyloplasts. Analysis using a sensitive auxin input reporter DII-VENUS showed that asymmetric auxin redistribution was reduced in the root tips of dis1-1, and the actin-disrupting drug Latrunculin B increased the asymmetric auxin redistribution. An uptake assay using the membrane-selective dye FM4-64 indicated that endocytosis was decelerated in dis1-1 root epidermal cells. Treatment and wash-out with Brefeldin A, which inhibits protein transport from the endoplasmic reticulum to the Golgi apparatus, showed that cycling of the auxin-transporter PIN-FORMED (PIN) proteins to the plasma membrane was also suppressed in dis1-1 roots. The results reveal that ARP3/DIS1 acts in root gravitropism by affecting amyloplast sedimentation and PIN-mediated polar auxin transport through regulation of PIN protein trafficking.
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Affiliation(s)
- Jun-Jie Zou
- Key Laboratory of Plant Molecular Physiology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Zhong-Yu Zheng
- Key Laboratory of Microgravity, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China
| | - Shan Xue
- Key Laboratory of Plant Molecular Physiology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Han-Hai Li
- Key Laboratory of Microgravity, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yu-Ren Wang
- Key Laboratory of Microgravity, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jie Le
- Key Laboratory of Plant Molecular Physiology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
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28
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Mori A, Toyota M, Shimada M, Mekata M, Kurata T, Tasaka M, Morita MT. Isolation of New Gravitropic Mutants under Hypergravity Conditions. FRONTIERS IN PLANT SCIENCE 2016; 7:1443. [PMID: 27746791 PMCID: PMC5040707 DOI: 10.3389/fpls.2016.01443] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 09/09/2016] [Indexed: 05/31/2023]
Abstract
Forward genetics is a powerful approach used to link genotypes and phenotypes, and mutant screening/analysis has provided deep insights into many aspects of plant physiology. Gravitropism is a tropistic response in plants, in which hypocotyls and stems sense the direction of gravity and grow upward. Previous studies of gravitropic mutants have suggested that shoot endodermal cells in Arabidopsis stems and hypocotyls are capable of sensing gravity (i.e., statocytes). In the present study, we report a new screening system using hypergravity conditions to isolate enhancers of gravitropism mutants, and we also describe a rapid and efficient genome mapping method, using next-generation sequencing (NGS) and single nucleotide polymorphism (SNP)-based markers. Using the endodermal-amyloplast less 1 (eal1) mutant, which exhibits defective development of endodermal cells and gravitropism, we found that hypergravity (10 g) restored the reduced gravity responsiveness in eal1 hypocotyls and could, therefore, be used to obtain mutants with further reduction in gravitropism in the eal1 background. Using the new screening system, we successfully isolated six ene (enhancer of eal1) mutants that exhibited little or no gravitropism under hypergravity conditions, and using NGS and map-based cloning with SNP markers, we narrowed down the potential causative genes, which revealed a new genetic network for shoot gravitropism in Arabidopsis.
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Affiliation(s)
- Akiko Mori
- Graduate School of Bioagricultural Sciences, Nagoya UniversityNagoya, Japan
| | - Masatsugu Toyota
- Department of Botany, University of WisconsinMadison, MadisonWI, USA
- Japan Science and Technology Agency, Precursory Research for Embryonic Science and TechnologySaitama, Japan
| | - Masayoshi Shimada
- Graduate School of Biological Sciences, Nara Institute of Science and TechnologyIkoma, Japan
| | - Mika Mekata
- Graduate School of Biological Sciences, Nara Institute of Science and TechnologyIkoma, Japan
| | - Tetsuya Kurata
- Graduate School of Life Sciences, Tohoku UniversitySendai, Japan
| | - Masao Tasaka
- Graduate School of Biological Sciences, Nara Institute of Science and TechnologyIkoma, Japan
| | - Miyo T. Morita
- Graduate School of Bioagricultural Sciences, Nagoya UniversityNagoya, Japan
- CREST, Japan Science and Technology AgencyTokyo, Japan
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29
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Groover A. Gravitropisms and reaction woods of forest trees - evolution, functions and mechanisms. THE NEW PHYTOLOGIST 2016; 211:790-802. [PMID: 27111862 DOI: 10.1111/nph.13968] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 03/15/2016] [Indexed: 05/03/2023]
Abstract
Contents 790 I. 790 II. 792 III. 795 IV. 797 V. 798 VI. 800 VII. 800 800 References 800 SUMMARY: The woody stems of trees perceive gravity to determine their orientation, and can produce reaction woods to reinforce or change their position. Together, graviperception and reaction woods play fundamental roles in tree architecture, posture control, and reorientation of stems displaced by wind or other environmental forces. Angiosperms and gymnosperms have evolved strikingly different types of reaction wood. Tension wood of angiosperms creates strong tensile force to pull stems upward, while compression wood of gymnosperms creates compressive force to push stems upward. In this review, the general features and evolution of tension wood and compression wood are presented, along with descriptions of how gravitropisms and reaction woods contribute to the survival and morphology of trees. An overview is presented of the molecular and genetic mechanisms underlying graviperception, initial graviresponse and the regulation of tension wood development in the model angiosperm, Populus. Critical research questions and new approaches are discussed.
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Affiliation(s)
- Andrew Groover
- Pacific Southwest Research Station, US Forest Service, Davis, CA, 95618, USA
- Department of Plant Biology, University of California Davis, Davis, CA, 95616, USA
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30
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Kim JY, Ryu JY, Baek K, Park CM. High temperature attenuates the gravitropism of inflorescence stems by inducing SHOOT GRAVITROPISM 5 alternative splicing in Arabidopsis. THE NEW PHYTOLOGIST 2016; 209:265-279. [PMID: 26256266 DOI: 10.1111/nph.13602] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 07/09/2015] [Indexed: 06/04/2023]
Abstract
In higher plants, gravitropism proceeds through three sequential steps in the responding organs: perception of gravity signals, signal transduction and asymmetric cell elongation. Light and temperature also influence the gravitropic orientation of plant organs. A series of Arabidopsis shoot gravitropism (sgr) mutants has been shown to exhibit disturbed shoot gravitropism. SGR5 is functionally distinct from other SGR members in that it mediates the early events of gravitropic responses in inflorescence stems. Here, we demonstrated that SGR5 alternative splicing produces two protein variants (SGR5α and SGR5β) in modulating the gravitropic response of inflorescence stems at high temperatures. SGR5β inhibits SGR5α function by forming non-DNA-binding heterodimers. Transgenic plants overexpressing SGR5β (35S:SGR5β) exhibit reduced gravitropic growth of inflorescence stems, as observed in the SGR5-deficient sgr5-5 mutant. Interestingly, SGR5 alternative splicing is accelerated at high temperatures, resulting in the high-level accumulation of SGR5β transcripts. When plants were exposed to high temperatures, whereas gravitropic curvature was reduced in Col-0 inflorescence stems, it was uninfluenced in the inflorescence stems of 35S:SGR5β transgenic plants and sgr5-5 mutant. We propose that the thermoresponsive alternative splicing of SGR5 provides an adaptation strategy by which plants protect the shoots from hot air under high temperature stress in natural habitats.
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Affiliation(s)
- Joo-Young Kim
- Department of Chemistry, Seoul National University, Seoul, 151-742, Korea
| | - Jae Yong Ryu
- Department of Chemistry, Seoul National University, Seoul, 151-742, Korea
| | - Kon Baek
- Department of Chemistry, Seoul National University, Seoul, 151-742, Korea
| | - Chung-Mo Park
- Department of Chemistry, Seoul National University, Seoul, 151-742, Korea
- Plant Genomics and Breeding Institute, Seoul National University, Seoul, 151-742, Korea
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31
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Zheng Z, Zou J, Li H, Xue S, Wang Y, Le J. Microrheological insights into the dynamics of amyloplasts in root gravity-sensing cells. MOLECULAR PLANT 2015; 8:660-3. [PMID: 25704165 DOI: 10.1016/j.molp.2014.12.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 12/20/2014] [Accepted: 12/29/2014] [Indexed: 05/10/2023]
Affiliation(s)
- Zhongyu Zheng
- Key Laboratory of Microgravity, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China
| | - Junjie Zou
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Hanhai Li
- Key Laboratory of Microgravity, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China
| | - Shan Xue
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Yuren Wang
- Key Laboratory of Microgravity, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China.
| | - Jie Le
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
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32
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Nakamura M, Toyota M, Tasaka M, Morita MT. Live cell imaging of cytoskeletal and organelle dynamics in gravity-sensing cells in plant gravitropism. Methods Mol Biol 2015; 1309:57-69. [PMID: 25981768 DOI: 10.1007/978-1-4939-2697-8_6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Plants sense gravity and change their morphology/growth direction accordingly (gravitropism). The early process of gravitropism, gravity sensing, is supposed to be triggered by sedimentation of starch-filled plastids (amyloplasts) in statocytes such as root columella cells and shoot endodermal cells. For several decades, many scientists have focused on characterizing the role of the amyloplasts and observed their intracellular sedimentation in various plants. Recently, it has been discovered that the complex sedimentary movements of the amyloplasts are created not only by gravity but also by cytoskeletal/organelle dynamics, such as those of actin filaments and the vacuolar membrane. Thus, to understand how plants sense gravity, we need to analyze both amyloplast movements and their regulatory systems in statocytes. We have developed a vertical-stage confocal microscope that allows multicolor fluorescence imaging of amyloplasts, actin filaments and vacuolar membranes in vertically oriented plant tissues. We also developed a centrifuge microscope that allows bright-field imaging of amyloplasts during centrifugation. These microscope systems provide new insights into gravity-sensing mechanisms in Arabidopsis.
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Affiliation(s)
- Moritaka Nakamura
- Institute of Biochemistry and Biology, Plant Physiology, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, 14476, Potsdam-Golm, Germany
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33
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Toyota M, Ikeda N, Tasaka M, Morita M. Centrifuge Microscopy to Analyze the Sedimentary Movements of Amyloplasts. Bio Protoc 2014. [DOI: 10.21769/bioprotoc.1229] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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34
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Taniguchi M, Nakamura M, Tasaka M, Morita MT. Identification of gravitropic response indicator genes in Arabidopsis inflorescence stems. PLANT SIGNALING & BEHAVIOR 2014; 9:e29570. [PMID: 25763694 PMCID: PMC4203507 DOI: 10.4161/psb.29570] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Differential organ growth during gravitropic response is caused by differential accumulation of auxin, that is, relative higher auxin concentration in lower flanks than in upper flanks of responding organs. Auxin responsive reporter systems such as DR5::GUS and DR5::GFP have usually been used as indicators of gravitropic response in roots and hypocotyls of Arabidopsis. However, in the inflorescence stems, the reporter systems don't work well to monitor gravitropic response. Here, we aim to certify appropriate gravitropic response indicators (GRIs) in inflorescence stems. We performed microarray analysis comparing gene expression profiles between upper and lower flanks of Arabidopsis inflorescence stems after gravistimulation. Thirty genes showed > 2-fold differentially increased expression in lower flanks at 30 min, of which 19 were auxin response genes. We focused on IAA5 and IAA2 and verified whether they are appropriate GRIs by real-time qRT-PCR analyses. Transcript levels of IAA5 and IAA2 were remarkably higher in lower flanks than in upper flanks after gravistimulation. The biased IAA5 or IAA2 expression is disappeared in sgr2-1 mutant which is defective in gravity perception, indicating that gravity perception process is essential for formation of the biased gene expression during gravitropism. IAA5 expression was remarkably increased in lower flanks at 30 min after gravistimulation, whereas IAA2 expression was gradually decreased in upper flanks in a time-dependent manner. Therefore, we conclude that IAA5 is a sensitive GRI to monitor asymmetric auxin signaling caused by gravistimulation in Arabidopsis inflorescence stems.
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Affiliation(s)
- Masatoshi Taniguchi
- Graduate School of Bioagricultural Sciences; Nagoya University; Furo-cho, Chikusa-ku, Nagoya, Japan
| | - Moritaka Nakamura
- Institute of Biochemistry and Biology; Plant Physiology; University of Potsdam; Potsdam-Golm, Germany
| | - Masao Tasaka
- Graduate School of Biological Sciences; Nara Institute of Science and Technology; Takayama, Ikoma, Nara, Japan
| | - Miyo Terao Morita
- Graduate School of Bioagricultural Sciences; Nagoya University; Furo-cho, Chikusa-ku, Nagoya, Japan
- Correspondence to: Miyo Terao Morita,
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