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Zhong S, Zhao P, Peng X, Li HJ, Duan Q, Cheung AY. From gametes to zygote: Mechanistic advances and emerging possibilities in plant reproduction. PLANT PHYSIOLOGY 2024; 195:4-35. [PMID: 38431529 PMCID: PMC11060694 DOI: 10.1093/plphys/kiae125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 02/13/2024] [Accepted: 02/13/2024] [Indexed: 03/05/2024]
Affiliation(s)
- Sheng Zhong
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, New Cornerstone Science Laboratory, College of Life Sciences, Peking University, Beijing 100871, China
| | - Peng Zhao
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
- Hubei Hongshan Laboratory, Wuhan 430070, China
| | - Xiongbo Peng
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
- Hubei Hongshan Laboratory, Wuhan 430070, China
| | - Hong-Ju Li
- Key Laboratory of Seed Innovation, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Center for Molecular Agrobiology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Qiaohong Duan
- College of Horticulture Science and Engineering, Shandong Agricultural University, Tai’an, Shandong 271018, China
| | - Alice Y Cheung
- Department of Biochemistry and Molecular Biology, Molecular and Cellular Biology Program, Plant Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, USA
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2
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Yuan G, Gao H, Yang T. Exploring the Role of the Plant Actin Cytoskeleton: From Signaling to Cellular Functions. Int J Mol Sci 2023; 24:15480. [PMID: 37895158 PMCID: PMC10607326 DOI: 10.3390/ijms242015480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/06/2023] [Accepted: 10/21/2023] [Indexed: 10/29/2023] Open
Abstract
The plant actin cytoskeleton is characterized by the basic properties of dynamic array, which plays a central role in numerous conserved processes that are required for diverse cellular functions. Here, we focus on how actins and actin-related proteins (ARPs), which represent two classical branches of a greatly diverse superfamily of ATPases, are involved in fundamental functions underlying signal regulation of plant growth and development. Moreover, we review the structure, assembly dynamics, and biological functions of filamentous actin (F-actin) from a molecular perspective. The various accessory proteins known as actin-binding proteins (ABPs) partner with F-actin to finely tune actin dynamics, often in response to various cell signaling pathways. Our understanding of the significance of the actin cytoskeleton in vital cellular activities has been furthered by comparison of conserved functions of actin filaments across different species combined with advanced microscopic techniques and experimental methods. We discuss the current model of the plant actin cytoskeleton, followed by examples of the signaling mechanisms under the supervision of F-actin related to cell morphogenesis, polar growth, and cytoplasmic streaming. Determination of the theoretical basis of how the cytoskeleton works is important in itself and is beneficial to future applications aimed at improving crop biomass and production efficiency.
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Affiliation(s)
| | | | - Tao Yang
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China; (G.Y.); (H.G.)
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3
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Zhang R, Xu Y, Yi R, Shen J, Huang S. Actin cytoskeleton in the control of vesicle transport, cytoplasmic organization, and pollen tube tip growth. PLANT PHYSIOLOGY 2023; 193:9-25. [PMID: 37002825 DOI: 10.1093/plphys/kiad203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 03/08/2023] [Accepted: 03/17/2023] [Indexed: 06/19/2023]
Abstract
Pollen tubes extend rapidly via tip growth. This process depends on a dynamic actin cytoskeleton, which has been implicated in controlling organelle movements, cytoplasmic streaming, vesicle trafficking, and cytoplasm organization in pollen tubes. In this update review, we describe the progress in understanding the organization and regulation of the actin cytoskeleton and the function of the actin cytoskeleton in controlling vesicle traffic and cytoplasmic organization in pollen tubes. We also discuss the interplay between ion gradients and the actin cytoskeleton that regulates the spatial arrangement and dynamics of actin filaments and the organization of the cytoplasm in pollen tubes. Finally, we describe several signaling components that regulate actin dynamics in pollen tubes.
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Affiliation(s)
- Ruihui Zhang
- National Key Laboratory of Crop Genetic Improvement, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Yanan Xu
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Ran Yi
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Jiangfeng Shen
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Shanjin Huang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
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4
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Zakharova E, Khanina T, Knyazev A, Milyukova N, Kovaleva LV. Hormonal Signaling during dPCD: Cytokinin as the Determinant of RNase-Based Self-Incompatibility in Solanaceae. Biomolecules 2023; 13:1033. [PMID: 37509069 PMCID: PMC10377171 DOI: 10.3390/biom13071033] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 06/19/2023] [Accepted: 06/20/2023] [Indexed: 07/30/2023] Open
Abstract
Research into molecular mechanisms of self-incompatibility (SI) in plants can be observed in representatives of various families, including Solanaceae. Earlier studies of the mechanisms of S-RNase-based SI in petunia (Petunia hybrida E. Vilm.) demonstrate that programmed cell death (PCD) is an SI factor. These studies suggest that the phytohormon cytokinin (CK) is putative activator of caspase-like proteases (CLPs). In this work, data confirming this hypothesis were obtained in two model objects-petunia and tomato (six Solanaceae representatives). The exogenous zeatin treatment of tomato and petunia stigmas before a compatible pollination activates CLPs in the pollen tubes in vivo, as shown via the intravital imaging of CLP activities. CK at any concentration slows down the germination and growth of petunia and tomato male gametophytes both in vitro and in vivo; shifts the pH of the cytoplasm (PHc) to the acid region, thereby creating the optimal conditions for CLP to function and inhibiting the F-actin formation and/or destructing the cytoskeleton in pollen tubes to point foci during SI-induced PCD; and accumulates in style tissues during SI response. The activity of the ISOPENTENYLTRANSFERASE 5 (IPT5) gene at this moment exceeds its activity in a cross-compatible pollination, and the levels of expression of the CKX1 and CKX2 genes (CK OXIDASE/DEHYDROGENASE) are significantly lower in self-incompatible pollination. All this suggests that CK plays a decisive role in the mechanism underlying SI-induced PCD.
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Affiliation(s)
- Ekaterina Zakharova
- All-Russia Research Institute of Agricultural Biotechnology, 127550 Moscow, Russia
| | - Tatiana Khanina
- All-Russia Research Institute of Agricultural Biotechnology, 127550 Moscow, Russia
| | - Andrey Knyazev
- All-Russia Research Institute of Agricultural Biotechnology, 127550 Moscow, Russia
| | - Natalia Milyukova
- All-Russia Research Institute of Agricultural Biotechnology, 127550 Moscow, Russia
| | - Lidia V Kovaleva
- Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, 191186 Moscow, Russia
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Mi Q, Pang H, Luan F, Gao P, Liu S. Integrated analysis of biparental and natural populations reveals CRIB domain-containing protein underlying seed coat crack trait in watermelon. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2023; 136:95. [PMID: 37014431 DOI: 10.1007/s00122-023-04320-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 02/07/2023] [Indexed: 06/19/2023]
Abstract
The scc locus of the watermelon seed coat crack trait was fine mapped on chromosome 3. Cla97C03G056110 (annotated as CRIB domain-containing protein) was regarded as the most likely candidate gene Seed coat crack (scc) is a special characteristic of watermelon compared with other cucurbit crops. However, information regarding the genetic basis of this trait is limited. We conducted a genetic analysis of six generations derived from PI 192938 (scc) and Cream of Saskatchewan (COS) (non-scc) parental lines and found that the scc trait was regulated by a single recessive gene through two years. Bulk segregant analysis sequencing (BSA-seq) and initial mapping placed the scc locus into an 808.8 kb region on chromosome 3. Evaluation of another 1152 F2 plants narrowed the scc locus to a 277.11 kb region containing 37 candidate genes. Due to the lack of molecular markers in the fine-mapping interval, we extracted the genome sequence variations in this 277.11 kb region with in silico BSA among seventeen re-sequenced lines (6 scc and 11 non-scc) and finally delimited the scc locus to an 8.34 kb region with only one candidate gene Cla97C03G056110 (CRIB domain-containing protein). Three single nucleotide polymorphism loci in the promoter region of Cla97C03G056110 altered cis-acting elements that were highly correlated with the nature watermelon panel. The expression of Cla97C03G056110 in seed coat tissue was higher in non-scc than in scc lines and was specifically expressed in seed coat compared with fruit flesh.
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Affiliation(s)
- Qi Mi
- Key Laboratory of Biology and Genetic Improvement of Horticulture Crops (Northeast Region), Ministry of Agriculture and Rural Affairs, Northeast Agricultural University, Harbin, 150030, Heilongjiang Province, China
- College of Horticulture and Landscape Architecture, Northeast Agricultural University, Harbin, 150030, Heilongjiang Province, China
| | - Hongqian Pang
- Key Laboratory of Biology and Genetic Improvement of Horticulture Crops (Northeast Region), Ministry of Agriculture and Rural Affairs, Northeast Agricultural University, Harbin, 150030, Heilongjiang Province, China
- College of Horticulture and Landscape Architecture, Northeast Agricultural University, Harbin, 150030, Heilongjiang Province, China
| | - Feishi Luan
- Key Laboratory of Biology and Genetic Improvement of Horticulture Crops (Northeast Region), Ministry of Agriculture and Rural Affairs, Northeast Agricultural University, Harbin, 150030, Heilongjiang Province, China.
- College of Horticulture and Landscape Architecture, Northeast Agricultural University, Harbin, 150030, Heilongjiang Province, China.
| | - Peng Gao
- Key Laboratory of Biology and Genetic Improvement of Horticulture Crops (Northeast Region), Ministry of Agriculture and Rural Affairs, Northeast Agricultural University, Harbin, 150030, Heilongjiang Province, China.
- College of Horticulture and Landscape Architecture, Northeast Agricultural University, Harbin, 150030, Heilongjiang Province, China.
| | - Shi Liu
- Key Laboratory of Biology and Genetic Improvement of Horticulture Crops (Northeast Region), Ministry of Agriculture and Rural Affairs, Northeast Agricultural University, Harbin, 150030, Heilongjiang Province, China.
- College of Horticulture and Landscape Architecture, Northeast Agricultural University, Harbin, 150030, Heilongjiang Province, China.
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Wang Q, Xu Y, Zhao S, Jiang Y, Yi R, Guo Y, Huang S. Activation of actin-depolymerizing factor by CDPK16-mediated phosphorylation promotes actin turnover in Arabidopsis pollen tubes. PLoS Biol 2023; 21:e3002073. [PMID: 37011088 PMCID: PMC10101649 DOI: 10.1371/journal.pbio.3002073] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 04/13/2023] [Accepted: 03/11/2023] [Indexed: 04/05/2023] Open
Abstract
As the stimulus-responsive mediator of actin dynamics, actin-depolymerizing factor (ADF)/cofilin is subject to tight regulation. It is well known that kinase-mediated phosphorylation inactivates ADF/cofilin. Here, however, we found that the activity of Arabidopsis ADF7 is enhanced by CDPK16-mediated phosphorylation. We found that CDPK16 interacts with ADF7 both in vitro and in vivo, and it enhances ADF7-mediated actin depolymerization and severing in vitro in a calcium-dependent manner. Accordingly, the rate of actin turnover is reduced in cdpk16 pollen and the amount of actin filaments increases significantly at the tip of cdpk16 pollen tubes. CDPK16 phosphorylates ADF7 at Serine128 both in vitro and in vivo, and the phospho-mimetic mutant ADF7S128D has enhanced actin-depolymerizing activity compared to ADF7. Strikingly, we found that failure in the phosphorylation of ADF7 at Ser128 impairs its function in promoting actin turnover in vivo, which suggests that this phospho-regulation mechanism is biologically significant. Thus, we reveal that CDPK16-mediated phosphorylation up-regulates ADF7 to promote actin turnover in pollen.
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Affiliation(s)
- Qiannan Wang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yanan Xu
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Shuangshuang Zhao
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, China
- Key Laboratory of Plant Stress, Life Science College, Shandong Normal University, Jinan, China
| | - Yuxiang Jiang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Ran Yi
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yan Guo
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Shanjin Huang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China
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7
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Cai G. The legacy of kinesins in the pollen tube thirty years later. Cytoskeleton (Hoboken) 2022; 79:8-19. [PMID: 35766009 PMCID: PMC9542081 DOI: 10.1002/cm.21713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 06/06/2022] [Accepted: 06/27/2022] [Indexed: 11/10/2022]
Abstract
The pollen tube is fundamental in the reproduction of seed plants. Particularly in angiosperms, we now have much information about how it grows, how it senses extracellular signals, and how it converts them into a directional growth mechanism. The expansion of the pollen tube is also related to dynamic cytoplasmic processes based on the cytoskeleton (such as polymerization/depolymerization of microtubules and actin filaments) or motor activity along with the two cytoskeletal systems and is dependent on motor proteins. While a considerable amount of information is available for the actomyosin system in the pollen tube, the role of microtubules in the transport of organelles or macromolecular structures is still quite uncertain despite that 30 years ago the first work on the presence of kinesins in the pollen tube was published. Since then, progress has been made in elucidating the role of kinesins in plant cells. However, their role within the pollen tube is still enigmatic. In this review, I will postulate some roles of kinesins in the pollen tube 30 years after their initial discovery based on information obtained in other plant cells in the meantime. The most concrete hypotheses predict that kinesins in the pollen tube enable the short movement of specific organelles or contribute to generative cell or sperm cell transport, as well as mediate specific steps in the process of endocytosis.
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Affiliation(s)
- Giampiero Cai
- Dipartimento Scienze della Vita, Università di Siena, via Mattioli 4, Siena, Italy
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8
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Çetinbaş-Genç A, Conti V, Cai G. Let's shape again: the concerted molecular action that builds the pollen tube. PLANT REPRODUCTION 2022; 35:77-103. [PMID: 35041045 DOI: 10.1007/s00497-022-00437-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 01/06/2022] [Indexed: 06/14/2023]
Abstract
The pollen tube is being subjected to control by a complex network of communication that regulates its shape and the misfunction of a single component causes specific deformations. In flowering plants, the pollen tube is a tubular extension of the pollen grain required for successful sexual reproduction. Indeed, maintaining the unique shape of the pollen tube is essential for the pollen tube to approach the embryo sac. Many processes and molecules (such as GTPase activity, phosphoinositides, Ca2+ gradient, distribution of reactive oxygen species and nitric oxide, nonuniform pH values, organization of the cytoskeleton, balance between exocytosis and endocytosis, and cell wall structure) play key and coordinated roles in maintaining the cylindrical shape of pollen tubes. In addition, the above factors must also interact with each other so that the cell shape is maintained while the pollen tube follows chemical signals in the pistil that guide it to the embryo sac. Any intrinsic changes (such as erroneous signals) or extrinsic changes (such as environmental stresses) can affect the above factors and thus fertilization by altering the tube morphology. In this review, the processes and molecules that enable the development and maintenance of the unique shape of pollen tubes in angiosperms are presented emphasizing their interaction with specific tube shape. Thus, the purpose of the review is to investigate whether specific deformations in pollen tubes can help us to better understand the mechanism underlying pollen tube shape.
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Affiliation(s)
- Aslıhan Çetinbaş-Genç
- Department of Biology, Marmara University, Göztepe Campus, 34722, Kadıköy, Istanbul, Turkey.
| | - Veronica Conti
- Department of Life Sciences, University of Siena, via Mattioli 4, 53100, Siena, Italy
| | - Giampiero Cai
- Department of Life Sciences, University of Siena, via Mattioli 4, 53100, Siena, Italy
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9
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Cheung AY, Cosgrove DJ, Hara-Nishimura I, Jürgens G, Lloyd C, Robinson DG, Staehelin LA, Weijers D. A rich and bountiful harvest: Key discoveries in plant cell biology. THE PLANT CELL 2022; 34:53-71. [PMID: 34524464 PMCID: PMC8773953 DOI: 10.1093/plcell/koab234] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 09/01/2021] [Indexed: 05/13/2023]
Abstract
The field of plant cell biology has a rich history of discovery, going back to Robert Hooke's discovery of cells themselves. The development of microscopes and preparation techniques has allowed for the visualization of subcellular structures, and the use of protein biochemistry, genetics, and molecular biology has enabled the identification of proteins and mechanisms that regulate key cellular processes. In this review, seven senior plant cell biologists reflect on the development of this research field in the past decades, including the foundational contributions that their teams have made to our rich, current insights into cell biology. Topics covered include signaling and cell morphogenesis, membrane trafficking, cytokinesis, cytoskeletal regulation, and cell wall biology. In addition, these scientists illustrate the pathways to discovery in this exciting research field.
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Affiliation(s)
- Alice Y Cheung
- Author for correspondence: (A.Y.C.), (D.J.C.), (I.H.N.), (G.J.), (C.L.), (D.G.R.), (L.A.S.) (D.W.)
| | - Daniel J Cosgrove
- Author for correspondence: (A.Y.C.), (D.J.C.), (I.H.N.), (G.J.), (C.L.), (D.G.R.), (L.A.S.) (D.W.)
| | | | - Gerd Jürgens
- Author for correspondence: (A.Y.C.), (D.J.C.), (I.H.N.), (G.J.), (C.L.), (D.G.R.), (L.A.S.) (D.W.)
| | - Clive Lloyd
- Author for correspondence: (A.Y.C.), (D.J.C.), (I.H.N.), (G.J.), (C.L.), (D.G.R.), (L.A.S.) (D.W.)
| | - David G Robinson
- Author for correspondence: (A.Y.C.), (D.J.C.), (I.H.N.), (G.J.), (C.L.), (D.G.R.), (L.A.S.) (D.W.)
| | - L Andrew Staehelin
- Author for correspondence: (A.Y.C.), (D.J.C.), (I.H.N.), (G.J.), (C.L.), (D.G.R.), (L.A.S.) (D.W.)
| | - Dolf Weijers
- Author for correspondence: (A.Y.C.), (D.J.C.), (I.H.N.), (G.J.), (C.L.), (D.G.R.), (L.A.S.) (D.W.)
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10
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Jaeger R, Moody LA. A fundamental developmental transition in Physcomitrium patens is regulated by evolutionarily conserved mechanisms. Evol Dev 2021; 23:123-136. [PMID: 33822471 DOI: 10.1111/ede.12376] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 03/09/2021] [Accepted: 03/11/2021] [Indexed: 01/15/2023]
Abstract
One of the most defining moments in history was the colonization of land by plants approximately 470 million years ago. The transition from water to land was accompanied by significant changes in the plant body plan, from those than resembled filamentous representatives of the charophytes, the sister group to land plants, to those that were morphologically complex and capable of colonizing harsher habitats. The moss Physcomitrium patens (also known as Physcomitrella patens) is an extant representative of the bryophytes, the earliest land plant lineage. The protonema of P. patens emerges from spores from a chloronemal initial cell, which can divide to self-renew to produce filaments of chloronemal cells. A chloronemal initial cell can differentiate into a caulonemal initial cell, which can divide and self-renew to produce filaments of caulonemal cells, which branch extensively and give rise to three-dimensional shoots. The process by which a chloronemal initial cell differentiates into a caulonemal initial cell is tightly regulated by auxin-induced remodeling of the actin cytoskeleton. Studies have revealed that the genetic mechanisms underpinning this transition also regulate tip growth and differentiation in diverse plant taxa. This review summarizes the known cellular and molecular mechanisms underpinning the chloronema to caulonema transition in P. patens.
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Affiliation(s)
- Richard Jaeger
- Department of Plant Sciences, University of Oxford, Oxford, UK
| | - Laura A Moody
- Department of Plant Sciences, University of Oxford, Oxford, UK
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11
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Hayashi M, Palmgren M. The quest for the central players governing pollen tube growth and guidance. PLANT PHYSIOLOGY 2021; 185:682-693. [PMID: 33793904 PMCID: PMC8133568 DOI: 10.1093/plphys/kiaa092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 12/06/2020] [Indexed: 05/02/2023]
Abstract
Recent insights into the mechanism of pollen tube growth and guidance point to the importance of H+ dynamics, which are regulated by the plasma membrane H+-ATPase.
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Affiliation(s)
- Maki Hayashi
- Department for Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Copenhagen, Denmark
| | - Michael Palmgren
- Department for Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Copenhagen, Denmark
- International Research Centre for Environmental Membrane Biology, Foshan University, Foshan 528000,China
- Author for communication:
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12
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Zhang P, Qian D, Luo C, Niu Y, Li T, Li C, Xiang Y, Wang X, Niu Y. Arabidopsis ADF5 Acts as a Downstream Target Gene of CBFs in Response to Low-Temperature Stress. Front Cell Dev Biol 2021; 9:635533. [PMID: 33585491 PMCID: PMC7876393 DOI: 10.3389/fcell.2021.635533] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 01/08/2021] [Indexed: 12/13/2022] Open
Abstract
Low temperature is a major adverse environment that affects normal plant growth. Previous reports showed that the actin cytoskeleton plays an important role in the plant response to low-temperature stress, but the regulatory mechanism of the actin cytoskeleton in this process is not clear. C-repeat binding factors (CBFs) are the key molecular switches for plants to adapt to cold stress. However, whether CBFs are involved in the regulation of the actin cytoskeleton has not been reported. We found that Arabidopsis actin depolymerizing factor 5 (ADF5), an ADF that evolved F-actin bundling function, was up-regulated at low temperatures. We also demonstrated that CBFs bound to the ADF5 promoter directly in vivo and in vitro. The cold-induced expression of ADF5 was significantly inhibited in the cbfs triple mutant. The freezing resistance of the adf5 knockout mutant was weaker than that of wild type (WT) with or without cold acclimation. After low-temperature treatment, the actin cytoskeleton of WT was relatively stable, but the actin cytoskeletons of adf5, cbfs, and adf5 cbfs were disturbed to varying degrees. Compared to WT, the endocytosis rate of the amphiphilic styryl dye FM4-64 in adf5, cbfs, and adf5 cbfs at low temperature was significantly reduced. In conclusion, CBFs directly combine with the CRT/DRE DNA regulatory element of the ADF5 promoter after low-temperature stress to transcriptionally activate the expression of ADF5; ADF5 further regulates the actin cytoskeleton dynamics to participate in the regulation of plant adaptation to a low-temperature environment.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Yue Niu
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
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Wallner ES. The value of asymmetry: how polarity proteins determine plant growth and morphology. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:5733-5739. [PMID: 32687194 PMCID: PMC7888286 DOI: 10.1093/jxb/eraa329] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 07/14/2020] [Indexed: 06/11/2023]
Abstract
Cell polarity is indispensable for forming complex multicellular organisms. Proteins that polarize at specific plasma membrane domains can either serve as scaffolds for effectors or coordinate intercellular communication and transport. Here, I give an overview of polarity protein complexes and their fundamental importance for plant development, and summarize novel mechanistic insights into their molecular networks. Examples are presented for proteins that polarize at specific plasma membrane domains to orient cell division planes, alter cell fate progression, control transport, direct cell growth, read global polarity axes, or integrate external stimuli into plant growth. The recent advances in characterizing protein polarity during plant development enable a better understanding of coordinated plant growth and open up intriguing paths that could provide a means to modulate plant morphology and adaptability in the future.
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Scholz P, Anstatt J, Krawczyk HE, Ischebeck T. Signalling Pinpointed to the Tip: The Complex Regulatory Network That Allows Pollen Tube Growth. PLANTS (BASEL, SWITZERLAND) 2020; 9:E1098. [PMID: 32859043 PMCID: PMC7569787 DOI: 10.3390/plants9091098] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 08/18/2020] [Accepted: 08/23/2020] [Indexed: 12/13/2022]
Abstract
Plants display a complex life cycle, alternating between haploid and diploid generations. During fertilisation, the haploid sperm cells are delivered to the female gametophyte by pollen tubes, specialised structures elongating by tip growth, which is based on an equilibrium between cell wall-reinforcing processes and turgor-driven expansion. One important factor of this equilibrium is the rate of pectin secretion mediated and regulated by factors including the exocyst complex and small G proteins. Critically important are also non-proteinaceous molecules comprising protons, calcium ions, reactive oxygen species (ROS), and signalling lipids. Among the latter, phosphatidylinositol 4,5-bisphosphate and the kinases involved in its formation have been assigned important functions. The negatively charged headgroup of this lipid serves as an interaction point at the apical plasma membrane for partners such as the exocyst complex, thereby polarising the cell and its secretion processes. Another important signalling lipid is phosphatidic acid (PA), that can either be formed by the combination of phospholipases C and diacylglycerol kinases or by phospholipases D. It further fine-tunes pollen tube growth, for example by regulating ROS formation. How the individual signalling cues are intertwined or how external guidance cues are integrated to facilitate directional growth remain open questions.
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Affiliation(s)
- Patricia Scholz
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences and Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, Justus-von-Liebig Weg 11, D-37077 Goettingen, Germany; (J.A.); (H.E.K.)
| | | | | | - Till Ischebeck
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences and Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, Justus-von-Liebig Weg 11, D-37077 Goettingen, Germany; (J.A.); (H.E.K.)
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15
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Yu Y, Qiao L, Chen J, Rong Y, Zhao Y, Cui X, Xu J, Hou X, Dong CH. Arabidopsis REM16 acts as a B3 domain transcription factor to promote flowering time via directly binding to the promoters of SOC1 and FT. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:1386-1398. [PMID: 32391591 DOI: 10.1111/tpj.14807] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 04/22/2020] [Accepted: 05/01/2020] [Indexed: 05/25/2023]
Abstract
Actin depolymerizing factor (ADF) is a key modulator for dynamic organization of actin cytoskeleton. Interestingly, it was found that the ADF1 gene silencing delays flowering, but its mechanism remains unclear. In this study, ADF1 was used as a bait to screen its interacting proteins by the yeast two-hybrid (Y2H) system. One of them, the REM16 transcription factor was identified. As one of the AP2/B3-like transcriptional factor family members, the REM16 contains two B3 domains and its transcript levels kept increasing during the floral transition stage. Overexpression of REM16 accelerates flowering while silencing of REM16 delays flowering. Gene expression analysis indicated that the key flowering activation genes such as CONSTANS (CO), FLOWERING LOCUS T (FT), LEAFY (LFY) and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS (SOC1) were upregulated in the REM16 overexpression lines, while the transcription of the flowering suppression gene FLOWERING LOCUS C (FLC) was decreased. In contrast, the REM16 gene silencing lines contained lower transcript levels of the CO, FT, LFY and SOC1 but higher transcript levels of the FLC compared with the wild-type plants. It was proved that REM16 could directly bind to the promoter regions of SOC1 and FT by in vitro and in vivo assays. Genetic analysis supported that REM16 acts upstream of SOC1 and FT in flowering pathways. All these studies provided strong evidence demonstrating that REM16 promotes flowering by directly activating SOC1 and FT.
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Affiliation(s)
- Yanchong Yu
- College of Life Sciences, Qingdao Agricultural University, Qingdao, China
| | - Longfei Qiao
- College of Life Sciences, Qingdao Agricultural University, Qingdao, China
| | - Jiacai Chen
- College of Life Sciences, Qingdao Agricultural University, Qingdao, China
| | - Yongheng Rong
- College of Life Sciences, Qingdao Agricultural University, Qingdao, China
| | - Yuhang Zhao
- College of Life Sciences, Qingdao Agricultural University, Qingdao, China
| | - Xiankui Cui
- College of Life Sciences, Qingdao Agricultural University, Qingdao, China
| | - Jinpeng Xu
- College of Life Sciences, Qingdao Agricultural University, Qingdao, China
| | - Xiaomin Hou
- College of Life Sciences, Qingdao Agricultural University, Qingdao, China
| | - Chun-Hai Dong
- College of Life Sciences, Qingdao Agricultural University, Qingdao, China
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16
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Wong A, Donaldson L, Portes MT, Eppinger J, Feijó JA, Gehring C. Arabidopsis DIACYLGLYCEROL KINASE4 is involved in nitric oxide-dependent pollen tube guidance and fertilization. Development 2020; 147:dev.183715. [PMID: 32220864 DOI: 10.1242/dev.183715] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 02/26/2020] [Indexed: 12/16/2022]
Abstract
Nitric oxide (NO) is a key signaling molecule that regulates diverse biological processes in both animals and plants, including important roles in male gamete physiology. In plants, NO is generated in pollen tubes (PTs) and affects intracellular responses through the modulation of Ca2+ signaling, actin organization, vesicle trafficking and cell wall deposition, bearing consequences in pollen-stigma interactions and PT guidance. In contrast, the NO-responsive proteins that mediate these responses remain elusive. Here, we show that PTs of Arabidopsis thaliana mutants impaired in the pollen-specific DIACYLGLYCEROL KINASE4 (DGK4) grow slower and become partially insensitive to NO-dependent growth inhibition and re-orientation responses. Recombinant DGK4 protein yields NO-responsive spectral and catalytic changes in vitro that are compatible with a role in NO perception and signaling in PTs. In addition to the expected phosphatidic acid-producing kinase activity, DGK4 recombinant protein also revealed guanylyl cyclase activity, as inferred by sequence analysis. Our results are compatible with a role for the fast-diffusible NO gas in signaling and cell-cell communication via the modulation of DGK4 activity during the progamic phase of angiosperm reproduction.
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Affiliation(s)
- Aloysius Wong
- Department of Biology, College of Science and Technology, Wenzhou-Kean University, 88 Daxue Road, Ouhai, Wenzhou, Zhejiang Province 325060, China.,Division of Biological and Environmental Sciences and Engineering, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Lara Donaldson
- Division of Biological and Environmental Sciences and Engineering, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.,Department of Molecular and Cell Biology, University of Cape Town, Rondebosch 7701, South Africa
| | - Maria Teresa Portes
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742-5815, USA
| | - Jörg Eppinger
- Division of Physical Sciences and Engineering, Biological and Organometallic Catalysis Laboratory, KAUST Catalysis Center, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - José A Feijó
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742-5815, USA
| | - Christoph Gehring
- Division of Biological and Environmental Sciences and Engineering, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
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17
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Guo J, Yang Z. Exocytosis and endocytosis: coordinating and fine-tuning the polar tip growth domain in pollen tubes. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:2428-2438. [PMID: 32173729 PMCID: PMC7178420 DOI: 10.1093/jxb/eraa134] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Accepted: 03/11/2020] [Indexed: 05/06/2023]
Abstract
Pollen tubes rapidly elongate, penetrate, and navigate through multiple female tissues to reach ovules for sperm delivery by utilizing a specialized form of polar growth known as tip growth. This process requires a battery of cellular activities differentially occurring at the apical growing region of the plasma membrane (PM), such as the differential cellular signaling involving calcium (Ca2+), phospholipids, and ROP-type Rho GTPases, fluctuation of ions and pH, exocytosis and endocytosis, and cell wall construction and remodeling. There is an emerging understanding of how at least some of these activities are coordinated and/or interconnected. The apical active ROP modulates exocytosis to the cell apex for PM and cell wall expansion differentially occurring at the tip. The differentiation of the cell wall involves at least the preferential distribution of deformable pectin polymers to the apex and non-deformable pectin polymers to the shank of pollen tubes, facilitating the apical cell expansion driven by high internal turgor pressure. Recent studies have generated inroads into how the ROP GTPase-based intracellular signaling is coordinated spatiotemporally with the external wall mechanics to maintain the tubular cell shape and how the apical cell wall mechanics are regulated to allow rapid tip growth while maintaining the cell wall integrity under the turgor pressure. Evidence suggests that exocytosis and endocytosis play crucial but distinct roles in this spatiotemporal coordination. In this review, we summarize recent advances in the regulation and coordination of the differential pectin distribution and the apical domain of active ROP by exocytosis and endocytosis in pollen tubes.
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Affiliation(s)
- Jingzhe Guo
- FAFU-UCR Joint Center for Horticultural Biology and Metabolomics, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- Department of Botany and Plant Sciences and Institute for Integrative Genome Biology, University of California, Riverside, CA, USA
| | - Zhenbiao Yang
- Department of Botany and Plant Sciences and Institute for Integrative Genome Biology, University of California, Riverside, CA, USA
- Correspondence:
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18
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Podolyan A, Maksimov N, Breygina M. Redox-regulation of ion homeostasis in growing lily pollen tubes. JOURNAL OF PLANT PHYSIOLOGY 2019; 243:153050. [PMID: 31639533 DOI: 10.1016/j.jplph.2019.153050] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 07/24/2019] [Accepted: 07/31/2019] [Indexed: 05/13/2023]
Abstract
The pollen tube is characterized by cytoplasm compartmentalization typical for cells with polar growth. This concept includes "ion zoning", i.e. gradient distribution of ionic currents across the plasma membrane and free inorganic ions in the cytoplasm. One of the putative mechanisms for maintaining "ion zoning" is indicated by the sensitivity of the ion transport systems to reactive oxygen species (ROS). Here we test the possibility of redox regulation of ionic gradients and membrane potential (MP) gradient in growing pollen tubes using quantitative fluorescence microscopy. ROS quencher MnTMPP and exogenic H2O2 cause different alterations of intracellular Ca2+ gradient, pH gradient and MP gradient during short-term exposure. MnTMPP significantly shifts the gradients of Ca2+ and MP at low concentrations while high concentration cause growth alterations (ballooned tips) and cytoplasm acidification. H2O2 at 0,5 and 1 mM affects ion homeostasis as well (MP, Ca2+, pH) but doesn't decrease viability or alter shape of the tubes. Here we present original quantitative data on the interconnection between ROS and ion transport during tip growth.
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Affiliation(s)
- Alexandra Podolyan
- Lomonosov Moscow State University, School of Biology, Department of Plant Physiology, Leninskiye Gory 1-12, Moscow, 119991, Russia
| | - Nikita Maksimov
- Lomonosov Moscow State University, School of Biology, Department of Plant Physiology, Leninskiye Gory 1-12, Moscow, 119991, Russia
| | - Maria Breygina
- Lomonosov Moscow State University, School of Biology, Department of Plant Physiology, Leninskiye Gory 1-12, Moscow, 119991, Russia; Pirogov Russian National Research Medical University, Ostrovitjanova Street 1, Moscow, 117997, Russia.
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19
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Qian D, Xiang Y. Actin Cytoskeleton as Actor in Upstream and Downstream of Calcium Signaling in Plant Cells. Int J Mol Sci 2019; 20:ijms20061403. [PMID: 30897737 PMCID: PMC6471457 DOI: 10.3390/ijms20061403] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 03/14/2019] [Accepted: 03/15/2019] [Indexed: 01/04/2023] Open
Abstract
In plant cells, calcium (Ca2+) serves as a versatile intracellular messenger, participating in several fundamental and important biological processes. Recent studies have shown that the actin cytoskeleton is not only an upstream regulator of Ca2+ signaling, but also a downstream regulator. Ca2+ has been shown to regulates actin dynamics and rearrangements via different mechanisms in plants, and on this basis, the upstream signaling encoded within the Ca2+ transient can be decoded. Moreover, actin dynamics have also been proposed to act as an upstream of Ca2+, adjust Ca2+ oscillations, and establish cytosolic Ca2+ ([Ca2+]cyt) gradients in plant cells. In the current review, we focus on the advances in uncovering the relationship between the actin cytoskeleton and calcium in plant cells and summarize our current understanding of this relationship.
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Affiliation(s)
- Dong Qian
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
| | - Yun Xiang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
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20
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Dong Q, Zhang Z, Liu Y, Tao LZ, Liu H. FERONIA regulates auxin-mediated lateral root development and primary root gravitropism. FEBS Lett 2018; 593:97-106. [PMID: 30417333 DOI: 10.1002/1873-3468.13292] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Revised: 11/02/2018] [Accepted: 11/05/2018] [Indexed: 12/23/2022]
Abstract
The Arabidopsis FERONIA (FER) receptor kinase is a key hub of cell signaling networks mediating various hormone, stress, and immune responses. Previous studies have shown that FER functions correlate with auxin responses, but the underlying molecular mechanism is unknown. Here, we demonstrate that the primary root of the fer-4 mutant displays increased lateral root branching and a delayed gravitropic response, which are associated with polar auxin transport (PAT). Our data suggest that aberrant PIN2 polarity is responsible for the delayed gravitropic response in fer-4. Furthermore, the diminished F-actin cytoskeleton in fer-4 implies that FER modulates F-actin-mediated PIN2 polar localization. Our findings provide new insights into the function of FER in PAT.
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Affiliation(s)
- QingKun Dong
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, China
| | - ZhiWei Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, China
| | - YuTing Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, China
| | - Li-Zhen Tao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, China
| | - HuiLi Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, China
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21
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Zhang S, Wang C, Xie M, Liu J, Kong Z, Su H. Actin Bundles in The Pollen Tube. Int J Mol Sci 2018; 19:ijms19123710. [PMID: 30469514 PMCID: PMC6321563 DOI: 10.3390/ijms19123710] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Revised: 11/18/2018] [Accepted: 11/19/2018] [Indexed: 12/31/2022] Open
Abstract
The angiosperm pollen tube delivers two sperm cells into the embryo sac through a unique growth strategy, named tip growth, to accomplish fertilization. A great deal of experiments have demonstrated that actin bundles play a pivotal role in pollen tube tip growth. There are two distinct actin bundle populations in pollen tubes: the long, rather thick actin bundles in the shank and the short, highly dynamic bundles near the apex. With the development of imaging techniques over the last decade, great breakthroughs have been made in understanding the function of actin bundles in pollen tubes, especially short subapical actin bundles. Here, we tried to draw an overall picture of the architecture, functions and underlying regulation mechanism of actin bundles in plant pollen tubes.
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Affiliation(s)
- Shujuan Zhang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education College of Life Science, Northwest University, Xi'an 710069, China.
| | - Chunbo Wang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education College of Life Science, Northwest University, Xi'an 710069, China.
| | - Min Xie
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education College of Life Science, Northwest University, Xi'an 710069, China.
| | - Jinyu Liu
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education College of Life Science, Northwest University, Xi'an 710069, China.
| | - Zhe Kong
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education College of Life Science, Northwest University, Xi'an 710069, China.
| | - Hui Su
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education College of Life Science, Northwest University, Xi'an 710069, China.
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22
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Dai S, Kai W, Liang B, Wang J, Jiang L, Du Y, Sun Y, Leng P. The functional analysis of SlNCED1 in tomato pollen development. Cell Mol Life Sci 2018; 75:3457-3472. [PMID: 29632966 PMCID: PMC11105544 DOI: 10.1007/s00018-018-2809-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 03/29/2018] [Indexed: 12/31/2022]
Abstract
Abscisic acid (ABA) regulates plant growth and development, but the role of ABA in the development of reproductive organs in tomato has rarely been addressed. In the present study, the role of ABA in the regulation of male and female gametogenesis as well as pollen development and germination is tested in tomato. qRT-PCR and in situ hybridization analysis of 9-cis-epoxycarotenoid dioxygenase (SlNCED1), a key enzyme in the ABA biosynthetic pathway, showed high expression of SlNCED1 primarily in the meristem during gametogenesis and mainly in ovule, stigma, anther/pollen and vascular tissues during floral organ development. SlNCED1 expression and ABA accumulation in anther peak at stages 13-14, suggesting that ABA plays a role in the primary formation of pollen grains. Over expression and suppression of SlNCED1 led to the abnormal development of anther/pollen, especially in SlNCED1-OE lines, which have serious pollen deterioration. The percentage of pollen germination in wild type is 91.47%, whereas it is 6.85% in OE transgenic lines and 38.4% at anthesis in RNAi lines. RNA-Seq of anthers shows that SlNCED1-OE can significantly enhance the expression of SlPP2Cs and down-regulate the expression of SlMYB108 and SlMYB21, which are anther/flower-specific transcriptional factors in tomato. Finally, anther transcriptome data indicate that SlNCED1 is involved in ABA-mediated regulation in pollen/anther metabolism, cell wall modification, and transcription levels. These results support an important role for ABA in the development of reproductive organs in tomato and contribute to the elucidation of the underlying regulatory mechanisms.
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Affiliation(s)
- Shengjie Dai
- College of Horticulture, China Agricultural University, Beijing, 100193, China
- College of Agriculture and Forestry Science, Linyi University, Linyi, 276000, Shandong, China
| | - Wenbin Kai
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Bin Liang
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Juan Wang
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Li Jiang
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Yangwei Du
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Yufei Sun
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Ping Leng
- College of Horticulture, China Agricultural University, Beijing, 100193, China.
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23
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Feiguelman G, Fu Y, Yalovsky S. ROP GTPases Structure-Function and Signaling Pathways. PLANT PHYSIOLOGY 2018; 176:57-79. [PMID: 29150557 PMCID: PMC5761820 DOI: 10.1104/pp.17.01415] [Citation(s) in RCA: 116] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 11/13/2017] [Indexed: 05/19/2023]
Abstract
Interactions between receptor like kinases and guanyl nucleotide exchange factors together with identification of effector proteins reveal putative ROP GTPases signaling cascades.
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Affiliation(s)
- Gil Feiguelman
- School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Ying Fu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Shaul Yalovsky
- School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv 6997801, Israel
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24
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Jia H, Yang J, Liesche J, Liu X, Hu Y, Si W, Guo J, Li J. Ethylene promotes pollen tube growth by affecting actin filament organization via the cGMP-dependent pathway in Arabidopsis thaliana. PROTOPLASMA 2018; 255:273-284. [PMID: 28864968 DOI: 10.1007/s00709-017-1158-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 08/23/2017] [Indexed: 06/07/2023]
Abstract
Ethylene and cGMP are key regulators of plant developmental processes. In this study, we demonstrate that ethylene or cGMP promote pollen tube growth in a dose-dependent manner. The etr1-1 mutant was found to be insensitive to ethylene with regard to pollen tube growth, while the growth-promoting effect of ethylene in etr2-2, ein4-4, or ein4-7 did not change, suggesting that ethylene signaling was mainly perceived by ETR1. However, the function of cGMP was not inhibited in etr1-1 and pollen tubes became insensitive to ethylene when the endogenous cGMP level was artificially decreased. This shows that cGMP is necessary for the control of pollen tube growth and that it might be a downstream component of ETR1 in the ethylene signaling pathway. Our study also found that ethylene or cGMP increase the actin bundles and elevated the percentage of relative amount of F-actin, while removal of cGMP decreased actin bundles abundance and altered the ratio of F-actin in the tip and base regions of pollen tubes. In conclusion, our data suggests that ethylene functions as the upstream signal of cGMP, and that both signals promote pollen germination and tube growth by regulating F-actin, which is essential for vesicular transport and cytoplasmic streaming.
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Affiliation(s)
- Honglei Jia
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China
- School of Environmental Science and Engineering, Shaanxi University of Science & Technology, Xi'an, Shaanxi, 710021, China
| | - Jun Yang
- School of Environmental Science and Engineering, Shaanxi University of Science & Technology, Xi'an, Shaanxi, 710021, China
| | - Johannes Liesche
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Xin Liu
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Yanfeng Hu
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Nangang District, Harbin, 150000, China
| | - Wantong Si
- Inner Mongolia Key Laboratory of Biomass-Energy Conversion, Inner Mongolia University of Science and Technology, Neimenggu, Baotou, 014010, China
| | - Junkang Guo
- School of Environmental Science and Engineering, Shaanxi University of Science & Technology, Xi'an, Shaanxi, 710021, China
| | - Jisheng Li
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China.
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25
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Zhu J, Nan Q, Qin T, Qian D, Mao T, Yuan S, Wu X, Niu Y, Bai Q, An L, Xiang Y. Higher-Ordered Actin Structures Remodeled by Arabidopsis ACTIN-DEPOLYMERIZING FACTOR5 Are Important for Pollen Germination and Pollen Tube Growth. MOLECULAR PLANT 2017; 10:1065-1081. [PMID: 28606871 DOI: 10.1016/j.molp.2017.06.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 06/02/2017] [Accepted: 06/05/2017] [Indexed: 06/07/2023]
Abstract
Dynamics of the actin cytoskeleton are essential for pollen germination and pollen tube growth. ACTIN-DEPOLYMERIZING FACTORs (ADFs) typically contribute to actin turnover by severing/depolymerizing actin filaments. Recently, we demonstrated that Arabidopsis subclass III ADFs (ADF5 and ADF9) evolved F-actin-bundling function from conserved F-actin-depolymerizing function. However, little is known about the physiological function, the evolutional significance, and the actin-bundling mechanism of these neofunctionalized ADFs. Here, we report that loss of ADF5 function caused delayed pollen germination, retarded pollen tube growth, and increased sensitive to latrunculin B (LatB) treatment by affecting the generation and maintenance of actin bundles. Examination of actin filament dynamics in living cells revealed that the bundling frequency was significantly decreased in adf5 pollen tubes, consistent with its biochemical functions. Further biochemical and genetic complementation analyses demonstrated that both the N- and C-terminal actin-binding domains of ADF5 are required for its physiological and biochemical functions. Interestingly, while both are atypical actin-bundling ADFs, ADF5, but not ADF9, plays an important role in mature pollen physiological activities. Taken together, our results suggest that ADF5 has evolved the function of bundling actin filaments and plays an important role in the formation, organization, and maintenance of actin bundles during pollen germination and pollen tube growth.
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Affiliation(s)
- Jingen Zhu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Qiong Nan
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Tao Qin
- State Key Laboratory of Plant Physiology and Biochemistry, Department of Plant Sciences, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Dong Qian
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Tonglin Mao
- State Key Laboratory of Plant Physiology and Biochemistry, Department of Plant Sciences, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Shunjie Yuan
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Xiaorong Wu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Yue Niu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Qifeng Bai
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Lizhe An
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Yun Xiang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
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26
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Hu C, Vogler H, Aellen M, Shamsudhin N, Jang B, Burri JT, Läubli N, Grossniklaus U, Pané S, Nelson BJ. Correction: High precision, localized proton gradients and fluxes generated by a microelectrode device induce differential growth behaviors of pollen tubes. LAB ON A CHIP 2017; 17:1678. [PMID: 28426092 DOI: 10.1039/c7lc90041d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Correction for 'High precision, localized proton gradients and fluxes generated by a microelectrode device induce differential growth behaviors of pollen tubes' by Chengzhi Hu et al., Lab Chip, 2017, 17, 671-680.
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Affiliation(s)
- Chengzhi Hu
- Institute of Robotics and Intelligent Systems, ETH Zurich, Tannenstrasse 3, CH-8092 Zurich, Switzerland.
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Broz AK, Guerrero RF, Randle AM, Baek YS, Hahn MW, Bedinger PA. Transcriptomic analysis links gene expression to unilateral pollen-pistil reproductive barriers. BMC PLANT BIOLOGY 2017; 17:81. [PMID: 28438120 PMCID: PMC5402651 DOI: 10.1186/s12870-017-1032-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 04/12/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND Unilateral incompatibility (UI) is an asymmetric reproductive barrier that unidirectionally prevents gene flow between species and/or populations. UI is characterized by a compatible interaction between partners in one direction, but in the reciprocal cross fertilization fails, generally due to pollen tube rejection by the pistil. Although UI has long been observed in crosses between different species, the underlying molecular mechanisms are only beginning to be characterized. The wild tomato relative Solanum habrochaites provides a unique study system to investigate the molecular basis of this reproductive barrier, as populations within the species exhibit both interspecific and interpopulation UI. Here we utilized a transcriptomic approach to identify genes in both pollen and pistil tissues that may be key players in UI. RESULTS We confirmed UI at the pollen-pistil level between a self-incompatible population and a self-compatible population of S. habrochaites. A comparison of gene expression between pollinated styles exhibiting the incompatibility response and unpollinated controls revealed only a small number of differentially expressed transcripts. Many more differences in transcript profiles were identified between UI-competent versus UI-compromised reproductive tissues. A number of intriguing candidate genes were highly differentially expressed, including a putative pollen arabinogalactan protein, a stylar Kunitz family protease inhibitor, and a stylar peptide hormone Rapid ALkalinization Factor. Our data also provide transcriptomic evidence that fundamental processes including reactive oxygen species (ROS) signaling are likely key in UI pollen-pistil interactions between both populations and species. CONCLUSIONS Gene expression analysis of reproductive tissues allowed us to better understand the molecular basis of interpopulation incompatibility at the level of pollen-pistil interactions. Our transcriptomic analysis highlighted specific genes, including those in ROS signaling pathways that warrant further study in investigations of UI. To our knowledge, this is the first report to identify candidate genes involved in unilateral barriers between populations within a species.
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Affiliation(s)
- Amanda K. Broz
- Department of Biology, Colorado State University, Fort Collins, CO 80523-1878 USA
| | | | - April M. Randle
- Department of Biology, Colorado State University, Fort Collins, CO 80523-1878 USA
- Department of Environmental Science, University of San Francisco, San Francisco, CA 94117 USA
| | - You Soon Baek
- Department of Biology, Colorado State University, Fort Collins, CO 80523-1878 USA
| | - Matthew W. Hahn
- Department of Biology, Indiana University, Bloomington, IN 47405 USA
- School of Informatics and Computing, Indiana University, Bloomington, IN 47405 USA
| | - Patricia A. Bedinger
- Department of Biology, Colorado State University, Fort Collins, CO 80523-1878 USA
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Khatun K, Robin AHK, Park JI, Kim CK, Lim KB, Kim MB, Lee DJ, Nou IS, Chung MY. Genome-Wide Identification, Characterization and Expression Profiling of ADF Family Genes in Solanum lycopersicum L. Genes (Basel) 2016; 7:E79. [PMID: 27690110 PMCID: PMC5083918 DOI: 10.3390/genes7100079] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 09/12/2016] [Accepted: 09/22/2016] [Indexed: 12/15/2022] Open
Abstract
The actin depolymerizing factor (ADF) proteins have growth, development, defense-related and growth regulatory functions in plants. The present study used genome-wide analysis to investigate ADF family genes in tomato. Eleven tomato ADF genes were identified and differential expression patterns were found in different organs. SlADF6 was preferentially expressed in roots, suggesting its function in root development. SlADF1, SlADF3 and SlADF10 were predominately expressed in the flowers compared to the other organs and specifically in the stamen compared to other flower parts, indicating their potential roles in pollen development. The comparatively higher expression of SlADF3 and SlADF11 at early fruit developmental stages might implicate them in determining final fruit size. SlADF5 and SlADF8 had relatively higher levels of expression five days after the breaker stage of fruit development, suggesting their possible role in fruit ripening. Notably, six genes were induced by cold and heat, seven by drought, five by NaCl, and four each by abscisic acid (ABA), jasmonic acid (JA) and wounding treatments. The differential expression patterns of the SlADF genes under different types of stresses suggested their function in stress tolerance in tomato plants. Our results will be helpful for the functional characterization of ADF genes during organ and fruit development of tomato under different stresses.
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Affiliation(s)
- Khadiza Khatun
- Department of Agricultural Industry Economy and Education, Sunchon National University, 413 Jungangno, Suncheon, Jeonnam 540-950, Korea.
| | - Arif Hasan Khan Robin
- Department of Horticulture, Sunchon National University, 413 Jungangno, Suncheon, Jeonnam 540-950, Korea.
| | - Jong-In Park
- Department of Horticulture, Sunchon National University, 413 Jungangno, Suncheon, Jeonnam 540-950, Korea.
| | - Chang Kil Kim
- Department of Horticultural Science, Kyungpook National University, Daegu 702-701, Korea.
| | - Ki-Byung Lim
- Department of Horticultural Science, Kyungpook National University, Daegu 702-701, Korea.
| | - Min-Bae Kim
- Department of Agricultural Industry Economy and Education, Sunchon National University, 413 Jungangno, Suncheon, Jeonnam 540-950, Korea.
- Department of Agricultural Education, Sunchon National University, 413 Jungangno, Suncheon, Jeonnam 540-950, Korea.
| | - Do-Jin Lee
- Department of Agricultural Industry Economy and Education, Sunchon National University, 413 Jungangno, Suncheon, Jeonnam 540-950, Korea.
- Department of Agricultural Education, Sunchon National University, 413 Jungangno, Suncheon, Jeonnam 540-950, Korea.
| | - Ill Sup Nou
- Department of Horticulture, Sunchon National University, 413 Jungangno, Suncheon, Jeonnam 540-950, Korea.
| | - Mi-Young Chung
- Department of Agricultural Industry Economy and Education, Sunchon National University, 413 Jungangno, Suncheon, Jeonnam 540-950, Korea.
- Department of Agricultural Education, Sunchon National University, 413 Jungangno, Suncheon, Jeonnam 540-950, Korea.
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Wang W, Sheng X, Shu Z, Li D, Pan J, Ye X, Chang P, Li X, Wang Y. Combined Cytological and Transcriptomic Analysis Reveals a Nitric Oxide Signaling Pathway Involved in Cold-Inhibited Camellia sinensis Pollen Tube Growth. FRONTIERS IN PLANT SCIENCE 2016; 7:456. [PMID: 27148289 PMCID: PMC4830839 DOI: 10.3389/fpls.2016.00456] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 03/24/2016] [Indexed: 05/05/2023]
Abstract
Nitric oxide (NO) as a signaling molecule plays crucial roles in many abiotic stresses in plant development processes, including pollen tube growth. Here, the signaling networks dominated by NO during cold stress that inhibited Camellia sinensis pollen tube growth are investigated in vitro. Cytological analysis show that cold-induced NO is involved in the inhibition of pollen tube growth along with disruption of the cytoplasmic Ca(2+) gradient, increase in ROS content, acidification of cytoplasmic pH and abnormalities in organelle ultrastructure and cell wall component distribution in the pollen tube tip. Furthermore, differentially expressed genes (DEGs)-related to signaling pathway, such as NO synthesis, cGMP, Ca(2+), ROS, pH, actin, cell wall, and MAPK cascade signal pathways, are identified and quantified using transcriptomic analyses and qRT-PCR, which indicate a potential molecular mechanism for the above cytological results. Taken together, these findings suggest that a complex signaling network dominated by NO, including Ca(2+), ROS, pH, RACs signaling and the crosstalk among them, is stimulated in the C. sinensis pollen tube in response to cold stress, which further causes secondary and tertiary alterations, such as ultrastructural abnormalities in organelles and cell wall construction, ultimately resulting in perturbed pollen tube extension.
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Affiliation(s)
- Weidong Wang
- College of Horticulture, Nanjing Agricultural UniversityNanjing, China
| | - Xianyong Sheng
- College of Life Sciences, Capital Normal UniversityBeijing, China
| | - Zaifa Shu
- College of Horticulture, Nanjing Agricultural UniversityNanjing, China
| | - Dongqin Li
- College of Horticulture, Nanjing Agricultural UniversityNanjing, China
| | - Junting Pan
- College of Horticulture, Nanjing Agricultural UniversityNanjing, China
| | - Xiaoli Ye
- College of Horticulture, Nanjing Agricultural UniversityNanjing, China
| | - Pinpin Chang
- College of Horticulture, Nanjing Agricultural UniversityNanjing, China
| | - Xinghui Li
- College of Horticulture, Nanjing Agricultural UniversityNanjing, China
| | - Yuhua Wang
- College of Horticulture, Nanjing Agricultural UniversityNanjing, China
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Lv F, Li P, Zhang R, Li N, Guo W. Functional divergence of GhCFE5 homoeologs revealed in cotton fiber and Arabidopsis root cell development. PLANT CELL REPORTS 2016; 35:867-81. [PMID: 26759310 DOI: 10.1007/s00299-015-1928-0] [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: 07/12/2015] [Revised: 12/19/2015] [Accepted: 12/29/2015] [Indexed: 05/20/2023]
Abstract
In GhCFE5 homoeologs, GhCFE5D interacted with more actin homologs and stronger interaction activity than GhCFE5A. GhCFE5D - but not GhCFE5A -overexpression severely disrupted actin cytoskeleton organization and significantly suppressed cell elongation. Homoeologous genes are common in polyploid plants; however, their functional divergence is poorly elucidated. Allotetraploid Upland cotton (Gossypium hirsutum, AADD) is the most widely cultivated cotton; accounting for more than 90 % of the world's cotton production. Here, we characterized GhCFE5A and GhCFE5D homoeologs from G. hirsutum acc TM-1. GhCFE5 homoeologs are expressed preferentially in fiber cells; and a significantly greater accumulation of GhCFE5A mRNA than GhCFE5D mRNA was found in all tested tissues. Overexpression of GhCFE5D but not GhCFE5A seriously inhibits the Arabidopsis hypocotyl and root cell elongation. Yeast two-hybrid assay and bimolecular fluorescence complementation (BiFC) analysis showed that compared with GhCFE5A, GhCFE5D interacts with more actin homologs and has a stronger interaction activity both from Arabidopsis and Upland cotton. Interestingly, subcellular localization showed that GhCFE5 resides on the cortical endoplasmic reticulum (ER) network and is colocalized with actin cables. The interaction activities between GhCFE5 homoeologs and actin differ in their effects on F-actin structure in transgenic Arabidopsis root cells. The F-actin changed direction from vertical to lateral, and the actin cytoskeleton organization was severely disrupted in GhCFE5D-overexpressing root cells. These data support the functional divergence of GhCFE5 homoeologs in the actin cytoskeleton structure and cell elongation, implying an important role for GhCFE5 in the evolution and selection of cotton fiber.
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Affiliation(s)
- Fenni Lv
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Hybrid Cotton R&D Engineering Research Center, MOE, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, People's Republic of China
| | - Peng Li
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Hybrid Cotton R&D Engineering Research Center, MOE, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, People's Republic of China
| | - Rui Zhang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Hybrid Cotton R&D Engineering Research Center, MOE, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, People's Republic of China
| | - Nina Li
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Hybrid Cotton R&D Engineering Research Center, MOE, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, People's Republic of China
| | - Wangzhen Guo
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Hybrid Cotton R&D Engineering Research Center, MOE, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, People's Republic of China.
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Tang C, Deng L, Chang D, Chen S, Wang X, Kang Z. TaADF3, an Actin-Depolymerizing Factor, Negatively Modulates Wheat Resistance Against Puccinia striiformis. FRONTIERS IN PLANT SCIENCE 2016; 6:1214. [PMID: 26834758 PMCID: PMC4716666 DOI: 10.3389/fpls.2015.01214] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 12/17/2015] [Indexed: 05/23/2023]
Abstract
The actin cytoskeleton has been implicated in plant defense against pathogenic fungi, oomycetes, and bacteria. Actin depolymerizing factors (ADFs) are stimulus responsive actin cytoskeleton modulators. However, there is limited evidence linking ADFs with plant defense against pathogens. In this study, we have isolated and functionally characterized a stress-responsive ADF gene (TaADF3) from wheat, which was detectable in all examined wheat tissues. TaADF3 is a three-copy gene located on chromosomes 5AL, 5BL, and 5DL. A particle bombardment assay in onion epidermal cells revealed the cytoplasmic and nuclear localization of TaADF3. The expression of TaADF3 was inducible by abscisic acid (ABA), as well as various abiotic stresses (drought and cold) and virulent Puccinia striiformis f. sp. tritici (Pst) but was down regulated in response to avirulent Pst. Virus-induced silencing of TaADF3 copies enhanced wheat resistance to avirulent Pst, with decreased reactive oxygen species (ROS) accumulation and hypersensitive response (HR). Upon treatment with virulent Pst, TaADF3-knockdown plants exhibited reduced susceptibility, which was accompanied by increased ROS production and HR. Interestingly, the silencing of TaADF3 resulted in hindered pathogen penetration and haustoria formation for both avirulent and virulent Pst. Moreover, the array and distribution of actin filaments was transformed in TaADF3-knockdown epidermal cells, which possibly facilitated attenuating the fungus penetration. Thus, our findings suggest that TaADF3 positively regulates wheat tolerance to abiotic stresses and negatively regulates wheat resistance to Pst in an ROS-dependent manner, possibly underlying the mechanism of impeding fungal penetration dependent on the actin architecture dynamics.
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Affiliation(s)
| | | | | | | | - Xiaojie Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F UniversityYangling, China
| | - Zhensheng Kang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F UniversityYangling, China
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Gong F, Wu X, Wang W. Diversity and function of maize pollen coat proteins: from biochemistry to proteomics. FRONTIERS IN PLANT SCIENCE 2015; 6:199. [PMID: 25870606 PMCID: PMC4378360 DOI: 10.3389/fpls.2015.00199] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 03/12/2015] [Indexed: 05/23/2023]
Abstract
Maize (Zea mays L.) is globally cultivated as one of the most important grain crops. As a wind-pollinated species, maize produces a large quantity of pollen grains that heavier and larger compared to Arabidopsis. Maize is an important model plant in pollen biology of monocots. The pollen coat, the outermost layer of pollen, plays a vital role in pollen-stigma interactions and successful fertilization. Pollen coat proteins (PCPs), which confer species specificity, are required for pollen adhesion, recognition, hydration, and germination on the stigma. Thus, PCPs have attracted intensive research efforts in plant science for decades. However, only a few PCPs in maize have been characterized to date, whereas the functions of most maize PCPs remain unclear. In this review, we summarize the current knowledge of maize PCPs with regard to protein constituents, synthesis and transport, and functions by comparison with the model plant Arabidopsis thaliana and Brassica plants. An understanding of the comprehensive knowledge of maize PCPs will help to illuminate the mechanism by which PCPs are involved in pollen-stigma interactions in maize and other crop plants.
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33
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Li L, Li Y, Wang NN, Li Y, Lu R, Li XB. Cotton LIM domain-containing protein GhPLIM1 is specifically expressed in anthers and participates in modulating F-actin. PLANT BIOLOGY (STUTTGART, GERMANY) 2015; 17:528-534. [PMID: 25294521 DOI: 10.1111/plb.12243] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 06/23/2014] [Indexed: 06/03/2023]
Abstract
As one form of actin binding protein (ABP), LIM domain protein can trigger the formation of actin bundles during plant growth and development. In this study, a cDNA (designated GhPLIM1) encoding a LIM domain protein with 216 amino acid residues was identified from a cotton flower cDNA library. Quantitative RT-PCR indicated that GhPLIM1 is specifically expressed in cotton anthers, and its expression levels are regulated during anther development of cotton. GhPLIM1:eGFP transformed cotton cells display a distributed network of eGFP fluorescence, suggesting that GhPLIM1 protein is mainly localised to the cell cytoskeleton. In vitro high-speed co-sedimentation and low co-sedimentation assays indicate that GhPLIM1 protein not only directly binds actin filaments but also bundles F-actin. Further biochemical experiments verified that GhPLIM1 protein can protect F-actin against depolymerisation by Lat B. Thus, our data demonstrate that GhPLIM1 functions as an actin binding protein (ABP) in modulating actin filaments in vitro, suggesting that GhPLIM1 may be involved in regulating the actin cytoskeleton required for pollen development in cotton.
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Affiliation(s)
- L Li
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, China
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34
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Nagawa S, Xu T, Yang Z. RHO GTPase in plants: Conservation and invention of regulators and effectors. Small GTPases 2014; 1:78-88. [PMID: 21686259 DOI: 10.4161/sgtp.1.2.14544] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Revised: 12/13/2010] [Accepted: 12/20/2010] [Indexed: 12/30/2022] Open
Abstract
Plants possess a single subfamily of Rho GTPases, ROP, which does usual things as do Rho-family GTPases in animal and fungal systems, namely participating in the spatial control of cellular processes by signaling to the cytoskeleton and vesicular trafficking. As one would expect, ROPs are modulated by conserved regulators such as DHR2-type GEFs, RhoGAPs and Rho GDIs. What is surprising is that plants have invented new regulators such as PRONE-type GEFs (known as RopGEFs) and effectors such as RICs and ICRs/RIPs in the regulation of the cytoskeleton and vesicular trafficking. This review will discuss recent work on characterizing ROP regulators and effectors as well as addressing why and how a mixture of conserved and novel Rho signaling mechanisms is utilized to modulate fundamental cellular processes such as cytoskeletal dynamics/reorganization and vesicular trafficking.
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Affiliation(s)
- Shingo Nagawa
- Center for Plant Cell Biology; Department of Botany and Plant Sciences; University of California; Riverside, CA USA
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35
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Fu Y, Duan X, Tang C, Li X, Voegele RT, Wang X, Wei G, Kang Z. TaADF7, an actin-depolymerizing factor, contributes to wheat resistance against Puccinia striiformis f. sp. tritici. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 78:16-30. [PMID: 24635700 DOI: 10.1111/tpj.12457] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2013] [Revised: 12/10/2013] [Accepted: 01/09/2014] [Indexed: 05/21/2023]
Abstract
The actin cytoskeleton is involved in plant defense responses; however, the role of the actin-depolymerizing factor (ADF) family, which regulates actin cytoskeletal dynamics, in plant disease resistance, is largely unknown. Here, we characterized a wheat (Triticum aestivum) ADF gene, TaADF7, with three copies located on chromosomes 1A, 1B, and 1D, respectively. All three copies encoded the same protein, although there were variations in 19 nucleotide positions in the open reading frame. Transcriptional expression of the three TaADF7 copies were all sharply elevated in response to avirulent Puccinia striiformis f. sp. tritici (Pst) infection, with similar expression patterns. TaADF7 regulated the actin cytoskeletal dynamics by targeting the actin cytoskeleton to execute actin binding/severing activities. When the TaADF7 copies were all silenced by virus-induced gene silencing, the growth of Pst hypha increased and sporadic urediniospores were observed, as compared with control plants, upon inoculation with avirulent Pst. In addition, the accumulation of reactive oxygen species (ROS) and the hypersensitive response (HR) were greatly weakened, whereas cytochalasin B partially rescued the HR in TaADF7 knock-down plants. Together, these findings suggest that TaADF7 is likely to contribute to wheat resistance against Pst infection by modulating the actin cytoskeletal dynamics to influence ROS accumulation and the HR.
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Affiliation(s)
- Yanping Fu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China
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Zepeda I, Sánchez-López R, Kunkel JG, Bañuelos LA, Hernández-Barrera A, Sánchez F, Quinto C, Cárdenas L. Visualization of highly dynamic F-actin plus ends in growing phaseolus vulgaris root hair cells and their responses to Rhizobium etli nod factors. PLANT & CELL PHYSIOLOGY 2014; 55:580-592. [PMID: 24399235 DOI: 10.1093/pcp/pct202] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Legume plants secrete signaling molecules called flavonoids into the rhizosphere. These molecules activate the transcription of rhizobial nod genes, which encode proteins involved in the synthesis of signaling compounds named Nod factors (NFs). NFs, in turn, trigger changes in plant gene expression, cortical cell dedifferentiation and mitosis, depolarization of the root hair cell membrane potential and rearrangement of the actin cytoskeleton. Actin polymerization plays an important role in apical growth in hyphae and pollen tubes. Using sublethal concentrations of fluorescently labeled cytochalasin D (Cyt-Fl), we visualized the distribution of filamentous actin (F-actin) plus ends in living Phaseolus vulgaris and Arabidopsis root hairs during apical growth. We demonstrated that Cyt-Fl specifically labeled the newly available plus ends of actin microfilaments, which probably represent sites of polymerization. The addition of unlabeled competing cytochalasin reduced the signal, suggesting that the labeled and unlabeled forms of the drug bind to the same site on F-actin. Exposure to Rhizobium etli NFs resulted in a rapid increase in the number of F-actin plus ends in P. vulgaris root hairs and in the re-localization of F-actin plus ends to infection thread initiation sites. These data suggest that NFs promote the formation of F-actin plus ends, which results in actin cytoskeleton rearrangements that facilitate infection thread formation.
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Affiliation(s)
- Isaac Zepeda
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, UNAM, Apdo. Postal 510-3, Cuernavaca, Morelos 62250, Mexico
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Arora D, Gross T, Brueggeman R. Allele characterization of genes required for rpg4-mediated wheat stem rust resistance identifies Rpg5 as the R gene. PHYTOPATHOLOGY 2013; 103:1153-1161. [PMID: 23841622 DOI: 10.1094/phyto-01-13-0030-r] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A highly virulent form of the wheat stem rust pathogen Puccinia graminis f. sp. tritici race TTKSK is virulent on both wheat and barley, presenting a major threat to world food security. The recessive and temperature-sensitive rpg4 gene is the only effective source of resistance identified in barley (Hordeum vulgare) against P. graminis f. sp. tritici race TTKSK. Efforts to position clone rpg4 localized resistance to a small interval on barley chromosome 5HL, tightly linked to the rye stem rust (P. graminis f. sp. secalis) resistance (R) gene Rpg5. High-resolution genetic analysis and post-transcriptional gene silencing of the genes at the rpg4/Rpg5 locus determined that three tightly linked genes (Rpg5, HvRga1, and HvAdf3) are required together for rpg4-mediated wheat stem rust resistance. Alleles of the three genes were analyzed from a diverse set of 14 domesticated barley lines (H. vulgare) and 8 wild barley accessions (H. vulgare subsp. spontaneum) to characterize diversity that may determine incompatibility (resistance). The analysis determined that HvAdf3 and HvRga1 code for predicted functional proteins that do not appear to contain polymorphisms determining the compatible (susceptible) interactions with the wheat stem rust pathogen and were expressed at the transcriptional level from both resistant and susceptible barley lines. The HvAdf3 alleles shared 100% amino acid identity among all 22 genotypes examined. The P. graminis f. sp. tritici race QCCJ-susceptible barley lines with HvRga1 alleles containing the limited amino acid substitutions unique to the susceptible varieties also contained predicted nonfunctional rpg5 alleles. Thus, susceptibility in these lines is likely due to the nonfunctional RPG5 proteins. The Rpg5 allele analysis determined that 9 of the 13 P. graminis f. sp. tritici race QCCJ-susceptible barley lines contain alleles that either code for predicted truncated proteins as the result of a single nucleotide substitution, resulting in a stop codon at amino acid 161, a single cytosine indel causing a frame shift, and a stop codon at amino acid 217, or an indel that deleted the entire STPK domain. The three P. graminis f. sp. tritici race QCCJ-susceptible lines (Swiss landraces Hv489, Hv492, and Hv611) and the wild barley accession WBDC160 contain rpg5 alleles predicted to encode full-length proteins containing a nonsynonomous nucleotide substitution that results in the amino acid substitution E1287A. This amino acid substitution present in the uncharacterized C-terminal domain is not found in any resistant line and may be important to elicit the resistance reaction. These data suggest that rpg4-mediated resistance against many wheat stem rust pathogen races, including P. graminis f. sp. tritici race TTKSK, rely on the Rpg5 R gene; thus, rpg4- and Rpg5-mediated resistance rely on a common R gene and should not be considered completely distinct. The data also determined that Rpg5 gene-specific molecular markers could be used to detect rpg4-mediated wheat stem rust resistance for marker-assisted selection.
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Dong CH, Hong Y. Arabidopsis CDPK6 phosphorylates ADF1 at N-terminal serine 6 predominantly. PLANT CELL REPORTS 2013; 32:1715-28. [PMID: 23903947 DOI: 10.1007/s00299-013-1482-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 06/26/2013] [Accepted: 07/15/2013] [Indexed: 05/20/2023]
Abstract
KEY MESSAGE We found that Arabidopsis AtADF1 was phosphorylated by AtCDPK6 at serine 6 predominantly and the phosphoregulation plays a key role in the regulation of ADF1-mediated depolymerization of actin filaments. ABSTRACT Since actin-depolymerizing factor (ADF) is highly conserved among eukaryotes, it is one of the key modulators for actin organization. In plants, ADF is directly involved in the depolymerization of actin filaments, and therefore important for F-actin-dependent cellular activities. The activity of ADF is tightly controlled through a number of molecular mechanisms, including phosphorylation-mediated inactivation of ADF. To investigate Arabidopsis ADF1 phosphoregulation, we generated AtADF1 phosphorylation site-specific mutants. Using transient expression and stable transgenic approaches, we analyzed the ADF1 phosphorylation mutants in the regulation of actin filament organizations in plant cells. By in vitro phosphorylation assay, we showed that AtADF1 is phosphorylated by AtCDPK6 at serine 6 predominantly. Chemically induced expression of AtCDPK6 can negatively regulate the wild-type AtADF1 in depolymerizing actin filaments, but not those of the mutants AtADF1(S6A) and AtADF1(S6D). These results demonstrate a regulatory function of Arabidopsis CDPK6 in the N-terminal phosphorylation of AtADF1.
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Affiliation(s)
- Chun-Hai Dong
- College of Life Sciences, Qingdao Agricultural University, Qingdao, 266109, People's Republic of China,
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Wang H, Zhuang X, Cai Y, Cheung AY, Jiang L. Apical F-actin-regulated exocytic targeting of NtPPME1 is essential for construction and rigidity of the pollen tube cell wall. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2013; 76:367-79. [PMID: 23906068 DOI: 10.1111/tpj.12300] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 07/15/2013] [Accepted: 07/18/2013] [Indexed: 05/03/2023]
Abstract
In tip-confined growing pollen tubes, delivery of newly synthesized cell wall materials to the rapidly expanding apical surface requires spatial organization and temporal regulation of the apical F-actin filament and exocytosis. In this study, we demonstrate that apical F-actin is essential for the rigidity and construction of the pollen tube cell wall by regulating exocytosis of Nicotiana tabacum pectin methylesterase (NtPPME1). Wortmannin disrupts the spatial organization of apical F-actin in the pollen tube tip and inhibits polar targeting of NtPPME1, which subsequently alters the rigidity and pectic composition of the pollen tube cell wall, finally causing growth arrest of the pollen tube. In addition to mechanistically linking cell wall construction and apical F-actin, wortmannin can be used as a useful tool for studying endomembrane trafficking and cytoskeletal organization in pollen tubes.
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Affiliation(s)
- Hao Wang
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
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Durst S, Nick P, Maisch J. Nicotiana tabacum actin-depolymerizing factor 2 is involved in actin-driven, auxin-dependent patterning. JOURNAL OF PLANT PHYSIOLOGY 2013; 170:1057-66. [PMID: 23545293 DOI: 10.1016/j.jplph.2013.03.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 03/07/2013] [Accepted: 03/07/2013] [Indexed: 05/27/2023]
Abstract
Polar transport of auxin has been identified as a central element of pattern formation. To address the underlying cellular mechanisms, we use the tobacco cell line (Nicotiana tabacum L. cv. Bright Yellow 2; BY-2) as model. We showed previously that cell divisions within a cell file are synchronized by polar auxin flow, linked to the organization of actin filaments (AF) which, in turn, is modified via actin-binding proteins (ABPs). From a preparatory study for disturbed division synchrony in cell lines overexpressing different ABPs, we identified the actin depolymerizing factor 2 (ADF2). A cell line overexpressing GFP-NtADF2 was specifically affected in division synchrony. The cell division pattern could be rescued by addition of Phosphatidylinositol 4,5-bisphosphate (PIP2) or by phalloidin. These observations allow to draw first conclusions on the pathway linking auxin signalling via actin reorganization to synchronized cell division placing the regulation of cortical actin turnover by ADF2 into the focus.
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Affiliation(s)
- Steffen Durst
- Botanical Institute, Molecular Cell Biology, Karlsruhe Institute of Technology (KIT), Kaiserstrasse 2, D-76131 Karlsruhe, Germany
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Chen CYH, Zheng WG, Cheung AY, Wu HM. Pollen germination activates the apical membrane-located RAC/ROP GTPase switch. MOLECULAR PLANT 2013; 6:1358-61. [PMID: 23686947 DOI: 10.1093/mp/sst074] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
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Venus Y, Oelmüller R. Arabidopsis ROP1 and ROP6 influence germination time, root morphology, the formation of F-actin bundles, and symbiotic fungal interactions. MOLECULAR PLANT 2013; 6:872-86. [PMID: 23118477 DOI: 10.1093/mp/sss101] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The RHO-related GTPases ROP1 and ROP6 and the ROP1-interacting protein RIC4 in Arabidopsis are involved in various processes of F-actin dynamics, cell growth, and plant/microbe interactions. The knockout rop1 and rop1 rop6 seeds germinate earlier and are impaired in root hair development. Also root hair branching is strongly affected by manipulation of the RHO-related GTPase (ROP) levels. Furthermore, in the double knockout line rop1 rop6, no actin bundle formation can be detected. We demonstrate that these proteins are required for establishing a mutualistic interaction between the root-colonizing endophytic fungus Piriformospora indica and Arabidopsis. The fungus promotes growth of wild-type plants. rop1, rop6, rop1 rop6, ric4, 35S::ROP1, and 35S::ROP6 seedlings are impaired in the response to the fungus. Since the different root architectures have no effect on root colonization, the impaired response to P. indica should be caused by ROP-mediated events in the root cells. In wild-type roots, P. indica stimulates the formation of F-actin bundles and this does not occur in the rop1 rop6 knockout line. Furthermore, the fungus stimulates the expression of the calmodulin-binding protein gene Cbp60g, and this response is severely reduced in the rop mutants. We propose that ROP1 and ROP6 are required for F-actin bundle formation in the roots, which is required for P. indica-mediated growth promotion in Arabidopsis.
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Affiliation(s)
- Yvonne Venus
- Institut für Allgemeine Botanik und Pflanzenphysiologie, Friedrich-Schiller-Universität Jena, Dornburger Straβe 159, D-07743 Jena, Germany
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Wang X, Richards J, Gross T, Druka A, Kleinhofs A, Steffenson B, Acevedo M, Brueggeman R. The rpg4-mediated resistance to wheat stem rust (Puccinia graminis) in barley (Hordeum vulgare) requires Rpg5, a second NBS-LRR gene, and an actin depolymerization factor. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2013; 26:407-18. [PMID: 23216085 DOI: 10.1094/mpmi-06-12-0146-r] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The rpg4 gene confers recessive resistance to several races of wheat stem rust (Puccinia graminis f. sp. tritici) and Rpg5 provides dominant resistance against isolates of the rye stem rust (P. graminis f. sp. secalis) in barley. The rpg4 and Rpg5 genes are tightly linked on chromosome 5H, and positional cloning using high-resolution populations clearly separated the genes, unambiguously identifying Rpg5; however, the identity of rpg4 remained unclear. High-resolution genotyping of critical recombinants at the rpg4/Rpg5 locus, designated here as rpg4-mediated resistance locus (RMRL) delimited two distinct yet tightly linked loci required for resistance, designated as RMRL1 and RMRL2. Utilizing virus-induced gene silencing, each gene at RMRL1, i.e., HvRga1 (a nucleotide-binding site leucine-rich repeat [NBS-LRR] domain gene), Rpg5 (an NBS-LRR-protein kinase domain gene), and HvAdf3 (an actin depolymerizing factor-like gene), was individually silenced followed by inoculation with P. graminis f. sp. tritici race QCCJ. Silencing each gene changed the reaction type from incompatible to compatible, indicating that all three genes are required for rpg4-mediated resistance. This stem rust resistance mechanism in barley follows the emerging theme of unrelated pairs of genetically linked NBS-LRR genes required for specific pathogen recognition and resistance. It also appears that actin cytoskeleton dynamics may play an important role in determining resistance against several races of stem rust in barley.
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Affiliation(s)
- X Wang
- Department of Plant Pathology, North Dakota State University, Fargo, ND, USA
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Comparative proteomic analysis reveals differentially expressed proteins correlated with fuzz fiber initiation in diploid cotton (Gossypium arboreum L.). J Proteomics 2013; 82:113-29. [PMID: 23474080 DOI: 10.1016/j.jprot.2013.02.020] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2012] [Revised: 02/16/2013] [Accepted: 02/21/2013] [Indexed: 01/10/2023]
Abstract
UNLABELLED In this study, a comparative proteomic analysis was employed to identify fuzz fiber initiation-related proteins in wild-type diploid cotton (Gossypium arboreum L.) and its fuzzless mutant. Temporal changes in global proteomes were examined using 2-DE at five developmental time points for fuzz fiber initiation, and 71 differentially expressed protein species were identified by MS, 45 of which were preferentially accumulated in the wild-type. These proteins were assigned to several functional categories, mainly in cell response/signal transduction, redox homeostasis, protein metabolism and energy/carbohydrate metabolism. It was remarkable that more than ten key proteins with high-abundance were involved in gibberellic acid (GA) signaling and ROS scavenging, and increasing concentrations of active GAs and H2O2 were also detected approximately 5dpa in wild type ovules. Furthermore, in vivo GA and H2O2 treatments of ovules inside young bolls showed that these compounds can synergistically promote fuzz fiber initiation. Our findings not only described a dynamic protein network supporting fuzz initiation in diploid cotton fiber ovules, but also deepened our understanding of the molecular basis of cotton fiber initiation. BIOLOGICAL SIGNIFICANCE Our study reported the identification of differentially expressed proteins in wild-type diploid cotton (G. arboreum L.) and its fuzzless mutant by comparative proteomic approach. In total, 71 protein species related to fuzz initiation were identified by MS. These proteins were assigned to several functional categories, mainly in energy/carbohydrate metabolism, protein metabolism, signal transduction, redox homeostasis etc. Importantly, a number of key proteins were found to be associated with GA signaling and ROS scavenging. In consistence with these findings, we detected the increase of GAs and H2O2 concentrations during fiber initiation, and our in vivo ovule experiments with GA and H2O2 injection and following microscopy observation of fuzz fiber initiation supported promoting effects of GA and H2O2 on cotton fiber initiation. These findings depicted a dynamic protein network supporting cotton fiber initiation in diploid cotton ovules. Our study is of major significance for understanding the molecular mechanisms controlling fuzz initiation and also provides a solid basis for further functional research of single nodes of this network in relation to cotton fiber initiation.
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Zhu L, Zhang Y, Kang E, Xu Q, Wang M, Rui Y, Liu B, Yuan M, Fu Y. MAP18 regulates the direction of pollen tube growth in Arabidopsis by modulating F-actin organization. THE PLANT CELL 2013; 25:851-67. [PMID: 23463774 PMCID: PMC3634693 DOI: 10.1105/tpc.113.110528] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
For fertilization to occur in plants, the pollen tube must be guided to enter the ovule via the micropyle. Previous reports have implicated actin filaments, actin binding proteins, and the tip-focused calcium gradient as key contributors to polar growth of pollen tubes; however, the regulation of directional pollen tube growth is largely unknown. We reported previously that Arabidopsis thaliana MICROTUBULE-ASSOCIATED PROTEIN18 (MAP18) contributes to directional cell growth and cortical microtubule organization. The preferential expression of MAP18 in pollen and in pollen tubes suggests that MAP18 also may function in pollen tube growth. In this study, we demonstrate that MAP18 functions in pollen tubes by influencing actin organization, rather than microtubule assembly. In vitro biochemical results indicate that MAP18 exhibits Ca(2+)-dependent filamentous (F)-actin-severing activity. Abnormal expression of MAP18 in map18 and MAP18 OX plants was associated with disorganization of the actin cytoskeleton in the tube apex, resulting in aberrant pollen tube growth patterns and morphologies, inaccurate micropyle targeting, and fewer fertilization events. Experiments with MAP18 mutants created by site-directed mutagenesis suggest that F-actin-severing activity is essential to the effects of MAP18 on pollen tube growth direction. Our study demonstrates that in Arabidopsis, MAP18 guides the direction of pollen tube growth by modulating actin filaments.
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Ye J, Zhang W, Guo Y. Arabidopsis SOS3 plays an important role in salt tolerance by mediating calcium-dependent microfilament reorganization. PLANT CELL REPORTS 2013; 32:139-48. [PMID: 23052592 DOI: 10.1007/s00299-012-1348-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 09/11/2012] [Accepted: 09/11/2012] [Indexed: 05/23/2023]
Abstract
KEY MESSAGE : SOS3 mediates calcium dependent actin filament reorganization that plays important roles in plant responses to salt stress. Arabidopsis salt overly sensitive 3 (SOS3) plays an important role in plant salt tolerance by regulation of Na(+)/K(+) homeostasis. Plants lacking SOS3 are hypersensitive to salt stress and this phenomenon can be partially rescued by the addition of calcium. However the mechanism underlying remains elusive. We here report that the organization of actin filaments in sos3 mutant differs from that in wild-type plant. Under salt stress abnormal actin assembly and arrangement in sos3 are more pronounced, which can be partially complemented by addition of external calcium or low concentration of latrunculin A, an actin monomer-sequestering agent. The effects of calcium and Lat A on actin filament organization of sos3 mutant are accordant with their effects on sos3 salt sensitivity under salt stress. These findings indicate that the salt-hypersensitivity of sos3 mutant partially results from its disordered actin filaments, and SOS3 mediated actin filament reorganization plays important roles in plant responses to salt stress.
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Affiliation(s)
- Jiamin Ye
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
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Wen F, Wang J, Xing D. A protein phosphatase 2A catalytic subunit modulates blue light-induced chloroplast avoidance movements through regulating actin cytoskeleton in Arabidopsis. PLANT & CELL PHYSIOLOGY 2012; 53:1366-1379. [PMID: 22642987 DOI: 10.1093/pcp/pcs081] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Chloroplast avoidance movements mediated by phototropin 2 (phot2) are one of most important physiological events in the response to high-fluence blue light (BL), which reduces damage to the photosynthetic machinery under excess light. Protein phosphatase 2A-2 (PP2A-2) is an isoform of the catalytic subunit of PP2A, which regulates a number of developmental processes. To investigate whether PP2A-2 was involved in high-fluence BL-induced chloroplast avoidance movements, we first analyzed chloroplast migration in the leaves of the pp2a-2 mutant in response to BL. The data showed that PP2A-2 might act as a positive regulator in phot2-mediated chloroplast avoidance movements, but not in phot1-mediated chloroplast accumulation movements. Then, the effect of okadaic acid (OA) and cantharidin (selective PP2A inhibitors) on high-fluence BL response was further investigated in Arabidopsis thaliana mesophyll cells. Within a certain concentration range, exogenously applied OA or cantharidin inhibited the high-fluence BL-induced chloroplast movements in a concentration-dependent manner. Actin depolymerizing factor (ADF)/cofilin phosphorylation assays demonstrated that PP2A-2 can activate/dephosphorylate ADF/cofilin, an actin-binding protein, in Arabidopsis mesophyll cells. Consistent with this observation, the experiments showed that OA could inhibit ADF1 binding to the actin and suppress the reorganization of the actin cytoskeleton after high-fluence BL irradiation. The adf1 and adf3 mutants also exhibited reduced high-fluence BL-induced chloroplast avoidance movements. In conclusion, we identified that PP2A-2 regulated the activation of ADF/cofilin, which, in turn, regulated actin cytoskeleton remodeling and was involved in phot2-mediated chloroplast avoidance movements.
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Affiliation(s)
- Feng Wen
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China
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Keskin BC, Yuca E, Ertekin O, Yüksel B, Memon AR. Expression characteristics of ARF1 and SAR1 during development and the de-etiolation process. PLANT BIOLOGY (STUTTGART, GERMANY) 2012; 14:24-32. [PMID: 21973219 DOI: 10.1111/j.1438-8677.2011.00482.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
ARF1 (ADP-ribosylation factor 1) and SAR1 (secretion-associated RAS super family) are involved in the formation and budding of vesicles throughout plant endomembrane systems. The molecular mechanisms of this transport have been studied extensively in mammalian and yeast cells. However, very little is known about the mechanisms of coat protein complex (COP) formation and recruitment of COP-vesicle cargoes in plants. To provide insights into vesicular trafficking in Pisum sativum L., we investigated mRNA and protein expression patterns of ARF1 and SAR1 in roots and shoots at early growth stages and in the de-etiolation process. We showed that ARF1 was concentrated mostly in the crude Golgi fractions, and SAR1 was concentrated predominantly in the crude ER fractions of de-etiolated shoots. ARF1 and SAR1 proteins were several times more abundant in shoots relative to roots. In total protein homogenates, the expression level of SAR1 and ARF1 was higher in shoots of dark-grown pea plants than light-grown plants. In contrast, ARF1 was higher in roots of light-grown pea relative to roots of dark-grown pea. With ageing, the ARF1 mRNA in roots was reduced, while SAR1 expression increased. Unlike ARF1 transcripts, ARF1 protein levels did not fluctuate significantly in root and shoot tissue during early development. The relative abundance of SAR1 protein in root tissues may suggest a high level of vesicular transport from the ER to the Golgi. Experimental results suggested that white light probably affects the regulation of ARF1 and SAR1 protein levels. On the other hand, short-term white light affects SAR1 but not ARF1.
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Affiliation(s)
- B Cevher Keskin
- Plant Molecular Biology Laboratory, TUBITAK, The Scientific and Technological Research Council of Turkey, Marmara Research Center, Genetic Engineering and Biotechnology Institute, Gebze, Kocaeli, Turkey.
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Ontivero M, Zamora GM, Salazar S, Ricci JCD, Castagnaro AP. Isolation of a strawberry gene fragment encoding an actin depolymerizing factor-like protein from genotypes resistant to Colletotrichum acutatum. Genome 2011; 54:1041-4. [DOI: 10.1139/g11-068] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Actin depolymerizing factors (ADFs) have been recently implicated in plant defense against pathogenic fungi, associated with the cytoskeletal rearrangements that contribute to establish an effective barrier against fungal ingress. In this work, we identified a DNA fragment corresponding to a part of a gene predicted to encode an ADF-like protein in genotypes of Fragaria ananassa resistant to the fungus Colletotrichum acutatum . Bulked segregant analysis combined with AFLP was used to identify polymorphisms linked to resistance in hybrids derived from the cross between the resistant cultivar ‘Sweet Charlie’ and the susceptible cultivar ‘Pájaro’. The sequence of one out of three polymorphic bands detected showed significant BLASTX hits to ADF proteins from other plants. Two possible exons were identified and bioinformatic analysis revealed the presence of the ADF homology domain with two actin-binding sites, an N-terminal phosphorylation site, and a nuclear localization signal. In addition to its possible application in strawberry breeding programs, these finding may contribute to investigate the role of ADFs in plant resistance against fungi.
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Affiliation(s)
- Marta Ontivero
- Sección Biotecnología, Estación Experimental Agroindustrial Obispo Colombres-Unidad Asociada al INSIBIO, Av. William Cross 3150, 4101 Las Talitas, Tucumán, Argentina
| | - Gustavo Martínez Zamora
- Instituto Superior de Investigaciones Biológicas (INSIBIO; CONICET- UNT) and Instituto de Química Biológica “Dr. Bernabé Bloj”, Universidad Nacional de Tucumán. Chacabuco 461, 4000 Tucumán. Argentina
| | - Sergio Salazar
- Estación Experimental Agropecuaria Famaillá-INTA. Ruta Prov. 301 km 32. 4132 Famaillá, Tucumán, Argentina. Facultad de Agronomía y Zootecnia, Universidad Nacional de Tucumán. Av. Roca 1900. 4000 Tucumán. Argentina
| | - Juan Carlos Díaz Ricci
- Instituto Superior de Investigaciones Biológicas (INSIBIO; CONICET- UNT) and Instituto de Química Biológica “Dr. Bernabé Bloj”, Universidad Nacional de Tucumán. Chacabuco 461, 4000 Tucumán. Argentina
| | - Atilio Pedro Castagnaro
- Sección Biotecnología, Estación Experimental Agroindustrial Obispo Colombres-Unidad Asociada al INSIBIO, Av. William Cross 3150, 4101 Las Talitas, Tucumán, Argentina
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Rahman LN, Smith GST, Bamm VV, Voyer-Grant JAM, Moffatt BA, Dutcher JR, Harauz G. Phosphorylation of Thellungiella salsuginea dehydrins TsDHN-1 and TsDHN-2 facilitates cation-induced conformational changes and actin assembly. Biochemistry 2011; 50:9587-604. [PMID: 21970344 DOI: 10.1021/bi201205m] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Group 2 late embryogenesis abundant (LEA) proteins, also known as dehydrins, are intrinsically disordered proteins that are expressed in plants experiencing extreme environmental conditions such as drought or low temperatures. These proteins are characterized by the presence of at least one conserved, lysine-rich K-segment and sometimes by one or more serine-rich S-segments that are phosphorylated. Dehydrins may stabilize proteins and membrane structures during environmental stress and can sequester and scavenge metal ions. Here, we investigate how the conformations of two dehydrins from Thellungiella salsuginea, denoted as TsDHN-1 (acidic) and TsDHN-2 (basic), are affected by pH, interactions with cations and membranes, and phosphorylation. Both TsDHN-1 and TsDHN-2 were expressed as SUMO fusion proteins for in vitro phosphorylation by casein kinase II (CKII), and structural analysis by circular dichroism and attenuated total reflection-Fourier transform infrared spectroscopy. We show that the polyproline II conformation can be induced in the dehydrins by their environmental conditions, including changes in the concentration of divalent cations such as Ca(2+). The assembly of actin by these dehydrins was assessed by sedimentation assays and viewed by transmission electron and atomic force microscopy. Phosphorylation allowed both dehydrins to polymerize actin filaments. These results support the hypothesis that dehydrins stabilize the cytoskeleton under stress conditions and further that phosphorylation may be an important feature of this stabilization.
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Affiliation(s)
- Luna N Rahman
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
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