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Chen X, Li WW, Gao J, Wu Z, Du J, Zhang X, Zhu YX. Arabidopsis PDLP7 modulated plasmodesmata function is related to BG10-dependent glucosidase activity required for callose degradation. Sci Bull (Beijing) 2024; 69:3075-3088. [PMID: 38735789 DOI: 10.1016/j.scib.2024.04.063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 04/01/2024] [Accepted: 04/25/2024] [Indexed: 05/14/2024]
Abstract
The microdomains of plasmodesmata, specialized cell-wall channels responsible for communications between neighboring cells, are composed of various plasmodesmata-located proteins (PDLPs) and lipids. Here, we found that, among all PDLP or homologous proteins in Arabidopsis thaliana genome, PDLP5 and PDLP7 possessed a C-terminal sphingolipid-binding motif, with the latter being the only member that was significantly upregulated upon turnip mosaic virus and cucumber mosaic virus infections. pdlp7 mutant plants exhibited significantly reduced callose deposition, larger plasmodesmata diameters, and faster viral transmission. These plants exhibited increased glucosidase activity but no change in callose synthase activity. PDLP7 interacted specifically with glucan endo-1,3-β-glucosidase 10 (BG10). Consistently, higher levels of callose deposition and slower virus transmission in bg10 mutants were observed. The interaction between PDLP7 and BG10 was found to depend on the presence of the Gnk2-homologous 1 (GnK2-1) domain at the N terminus of PDLP7 with Asp-35, Cys-42, Gln-44, and Leu-116 being essential. In vitro supplementation of callose was able to change the conformation of the GnK2-1 domain. Our data suggest that the GnK2-1 domain of PDLP7, in conjunction with callose and BG10, plays a key role in plasmodesmata opening and closure, which is necessary for intercellular movement of various molecules.
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Affiliation(s)
- Xin Chen
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China
| | - Wan-Wan Li
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China
| | - Jin Gao
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China
| | - Zhiguo Wu
- Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Juan Du
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiaoming Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yu-Xian Zhu
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China; Institute for Advanced Studies, Wuhan University, Wuhan 430072, China.
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2
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Zanini AA, Burch-Smith TM. New insights into plasmodesmata: complex 'protoplasmic connecting threads'. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:5557-5567. [PMID: 39001658 PMCID: PMC11427835 DOI: 10.1093/jxb/erae307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Accepted: 07/12/2024] [Indexed: 09/28/2024]
Abstract
Intercellular communication in plants, as in other multicellular organisms, allows cells in tissues to coordinate their responses for development and in response to environmental stimuli. Much of this communication is facilitated by plasmodesmata (PD), consisting of membranes and cytoplasm, that connect adjacent cells to each other. PD have long been viewed as passive conduits for the movement of a variety of metabolites and molecular cargoes, but this perception has been changing over the last two decades or so. Research from the last few years has revealed the importance of PD as signaling hubs and as crucial players in hormone signaling. The adoption of advanced biochemical approaches, molecular tools, and high-resolution imaging modalities has led to several recent breakthroughs in our understanding of the roles of PD, revealing the structural and regulatory complexity of these 'protoplasmic connecting threads'. We highlight several of these findings that we think well illustrate the current understanding of PD as functioning at the nexus of plant physiology, development, and acclimation to the environment.
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Affiliation(s)
- Andrea A Zanini
- Donald Danforth Plant Science Center, Saint Louis, MO 63132, USA
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3
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Gu X, Cao Z, Li Z, Yu H, Liu W. Plant immunity suppression by an β-1,3-glucanase of the maize anthracnose pathogen Colletotrichum graminicola. BMC PLANT BIOLOGY 2024; 24:339. [PMID: 38671375 PMCID: PMC11046878 DOI: 10.1186/s12870-024-05053-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 04/19/2024] [Indexed: 04/28/2024]
Abstract
BACKGROUND Many phytopathogens secrete a large number of cell wall degrading enzymes (CWDEs) to decompose host cell walls in order to penetrate the host, obtain nutrients and accelerate colonization. There is a wide variety of CWDEs produced by plant pathogens, including glycoside hydrolases (GHs), which determine the virulence, pathogenicity, and host specificity of phytopathogens. The specific molecular mechanisms by which pathogens suppress host immunity remain obscure. RESULT In this study, we found that CgEC124 encodes a glycosyl hydrolase with a signal peptide and a conserved Glyco_hydro_cc domain which belongs to glycoside hydrolase 128 family. The expression of CgEC124 was significantly induced in the early stage of Colletotrichum graminicola infection, especially at 12 hpi. Furthermore, CgEC124 positively regulated the pathogenicity, but it did not impact the vegetative growth of mycelia. Ecotopic transient expression of CgEC124 decreased the disease resistance and callose deposition in maize. Moreover, CgEC124 exhibited the β-1,3-glucanase activity and suppresses glucan-induced ROS burst in maize leaves. CONCLUSIONS Our results indicate that CgEC124 is required for full virulence of C. graminicola but not for vegetative growth. CgEC124 increases maize susceptibility by inhibiting host reactive oxygen species burst as well as callose deposition. Meanwhile, our data suggests that CgEC124 explores its β-1,3-glucanase activity to prevent induction of host defenses.
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Affiliation(s)
- Xiaoyu Gu
- College of Plant Protection, Hebei Agricultural University, Baoding, 071001, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Zhiyan Cao
- College of Plant Protection, Hebei Agricultural University, Baoding, 071001, China
| | - Zhiqiang Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Haiyue Yu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
| | - Wende Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
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4
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Schreiber JM, Limpens E, de Keijzer J. Distributing Plant Developmental Regulatory Proteins via Plasmodesmata. PLANTS (BASEL, SWITZERLAND) 2024; 13:684. [PMID: 38475529 DOI: 10.3390/plants13050684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 02/21/2024] [Accepted: 02/22/2024] [Indexed: 03/14/2024]
Abstract
During plant development, mobile proteins, including transcription factors, abundantly serve as messengers between cells to activate transcriptional signaling cascades in distal tissues. These proteins travel from cell to cell via nanoscopic tunnels in the cell wall known as plasmodesmata. Cellular control over this intercellular movement can occur at two likely interdependent levels. It involves regulation at the level of plasmodesmata density and structure as well as at the level of the cargo proteins that traverse these tunnels. In this review, we cover the dynamics of plasmodesmata formation and structure in a developmental context together with recent insights into the mechanisms that may control these aspects. Furthermore, we explore the processes involved in cargo-specific mechanisms that control the transport of proteins via plasmodesmata. Instead of a one-fits-all mechanism, a pluriform repertoire of mechanisms is encountered that controls the intercellular transport of proteins via plasmodesmata to control plant development.
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Affiliation(s)
- Joyce M Schreiber
- Laboratory of Cell and Developmental Biology, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Erik Limpens
- Laboratory of Molecular Biology, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Jeroen de Keijzer
- Laboratory of Cell and Developmental Biology, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
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5
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Hunt H, Leape S, Sidhu JS, Ajmera I, Lynch JP, Ratcliffe RG, Sweetlove LJ. A role for fermentation in aerobic conditions as revealed by computational analysis of maize root metabolism during growth by cell elongation. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 116:1553-1570. [PMID: 37831626 DOI: 10.1111/tpj.16478] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 09/07/2023] [Accepted: 09/11/2023] [Indexed: 10/15/2023]
Abstract
The root is a well-studied example of cell specialisation, yet little is known about the metabolism that supports the transport functions and growth of different root cell types. To address this, we used computational modelling to study metabolism in the elongation zone of a maize lateral root. A functional-structural model captured the cell-anatomical features of the root and modelled how they changed as the root elongated. From these data, we derived constraints for a flux balance analysis model that predicted metabolic fluxes of the 11 concentric rings of cells in the root. We discovered a distinct metabolic flux pattern in the cortical cell rings, endodermis and pericycle (but absent in the epidermis) that involved a high rate of glycolysis and production of the fermentation end-products lactate and ethanol. This aerobic fermentation was confirmed experimentally by metabolite analysis. The use of fermentation in the model was not obligatory but was the most efficient way to meet the specific demands for energy, reducing power and carbon skeletons of expanding cells. Cytosolic acidification was avoided in the fermentative mode due to the substantial consumption of protons by lipid synthesis. These results expand our understanding of fermentative metabolism beyond that of hypoxic niches and suggest that fermentation could play an important role in the metabolism of aerobic tissues.
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Affiliation(s)
- Hilary Hunt
- Department of Biology, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
| | - Stefan Leape
- Department of Biology, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
| | - Jagdeep Singh Sidhu
- Department of Plant Science, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
| | - Ishan Ajmera
- Department of Plant Science, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
| | - Jonathan P Lynch
- Department of Plant Science, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
| | - R George Ratcliffe
- Department of Biology, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
| | - Lee J Sweetlove
- Department of Biology, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
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6
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Suraby EJ, Agisha VN, Dhandapani S, Sng YH, Lim SH, Naqvi NI, Sarojam R, Yin Z, Park BS. Plant growth promotion under phosphate deficiency and improved phosphate acquisition by new fungal strain, Penicillium olsonii TLL1. Front Microbiol 2023; 14:1285574. [PMID: 37965551 PMCID: PMC10642178 DOI: 10.3389/fmicb.2023.1285574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 09/28/2023] [Indexed: 11/16/2023] Open
Abstract
Microbiomes in soil ecosystems play a significant role in solubilizing insoluble inorganic and organic phosphate sources with low availability and mobility in the soil. They transfer the phosphate ion to plants, thereby promoting plant growth. In this study, we isolated an unidentified fungal strain, POT1 (Penicillium olsonii TLL1) from indoor dust samples, and confirmed its ability to promote root growth, especially under phosphate deficiency, as well as solubilizing activity for insoluble phosphates such as AlPO4, FePO4·4H2O, Ca3(PO4)2, and hydroxyapatite. Indeed, in vermiculite containing low and insoluble phosphate, the shoot fresh weight of Arabidopsis and leafy vegetables increased by 2-fold and 3-fold, respectively, with POT1 inoculation. We also conducted tests on crops in Singapore's local soil, which contains highly insoluble phosphate. We confirmed that with POT1, Bok Choy showed a 2-fold increase in shoot fresh weight, and Rice displayed a 2-fold increase in grain yield. Furthermore, we demonstrated that plant growth promotion and phosphate solubilizing activity of POT1 were more effective than those of four different Penicillium strains such as Penicillium bilaiae, Penicillium chrysogenum, Penicillium janthinellum, and Penicillium simplicissimum under phosphate-limiting conditions. Our findings uncover a new fungal strain, provide a better understanding of symbiotic plant-fungal interactions, and suggest the potential use of POT1 as a biofertilizer to improve phosphate uptake and use efficiency in phosphate-limiting conditions.
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Affiliation(s)
- Erinjery Jose Suraby
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore
| | | | - Savitha Dhandapani
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore
| | - Yee Hwui Sng
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore
| | - Shi Hui Lim
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore
| | - Naweed I. Naqvi
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Rajani Sarojam
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore
| | - Zhongchao Yin
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Bong Soo Park
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore
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7
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Wegner L, Porth ML, Ehlers K. Multicellularity and the Need for Communication-A Systematic Overview on (Algal) Plasmodesmata and Other Types of Symplasmic Cell Connections. PLANTS (BASEL, SWITZERLAND) 2023; 12:3342. [PMID: 37765506 PMCID: PMC10536634 DOI: 10.3390/plants12183342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 09/14/2023] [Accepted: 09/15/2023] [Indexed: 09/29/2023]
Abstract
In the evolution of eukaryotes, the transition from unicellular to simple multicellular organisms has happened multiple times. For the development of complex multicellularity, characterized by sophisticated body plans and division of labor between specialized cells, symplasmic intercellular communication is supposed to be indispensable. We review the diversity of symplasmic connectivity among the eukaryotes and distinguish between distinct types of non-plasmodesmatal connections, plasmodesmata-like structures, and 'canonical' plasmodesmata on the basis of developmental, structural, and functional criteria. Focusing on the occurrence of plasmodesmata (-like) structures in extant taxa of fungi, brown algae (Phaeophyceae), green algae (Chlorophyta), and streptophyte algae, we present a detailed critical update on the available literature which is adapted to the present classification of these taxa and may serve as a tool for future work. From the data, we conclude that, actually, development of complex multicellularity correlates with symplasmic connectivity in many algal taxa, but there might be alternative routes. Furthermore, we deduce a four-step process towards the evolution of canonical plasmodesmata and demonstrate similarity of plasmodesmata in streptophyte algae and land plants with respect to the occurrence of an ER component. Finally, we discuss the urgent need for functional investigations and molecular work on cell connections in algal organisms.
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Affiliation(s)
- Linus Wegner
- Institute of Botany, Justus-Liebig University, D-35392 Giessen, Germany;
| | | | - Katrin Ehlers
- Institute of Botany, Justus-Liebig University, D-35392 Giessen, Germany;
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8
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Mendieta JP, Sangra A, Yan H, Minow MAA, Schmitz RJ. Exploring plant cis-regulatory elements at single-cell resolution: overcoming biological and computational challenges to advance plant research. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 115:1486-1499. [PMID: 37309871 PMCID: PMC10598807 DOI: 10.1111/tpj.16351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/06/2023] [Accepted: 06/08/2023] [Indexed: 06/14/2023]
Abstract
Cis-regulatory elements (CREs) are important sequences for gene expression and for plant biological processes such as development, evolution, domestication, and stress response. However, studying CREs in plant genomes has been challenging. The totipotent nature of plant cells, coupled with the inability to maintain plant cell types in culture and the inherent technical challenges posed by the cell wall has limited our understanding of how plant cell types acquire and maintain their identities and respond to the environment via CRE usage. Advances in single-cell epigenomics have revolutionized the field of identifying cell-type-specific CREs. These new technologies have the potential to significantly advance our understanding of plant CRE biology, and shed light on how the regulatory genome gives rise to diverse plant phenomena. However, there are significant biological and computational challenges associated with analyzing single-cell epigenomic datasets. In this review, we discuss the historical and foundational underpinnings of plant single-cell research, challenges, and common pitfalls in the analysis of plant single-cell epigenomic data, and highlight biological challenges unique to plants. Additionally, we discuss how the application of single-cell epigenomic data in various contexts stands to transform our understanding of the importance of CREs in plant genomes.
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Affiliation(s)
| | - Ankush Sangra
- Department of Genetics, University of Georgia, Athens, 30602, Georgia, USA
| | - Haidong Yan
- Department of Genetics, University of Georgia, Athens, 30602, Georgia, USA
| | - Mark A A Minow
- Department of Genetics, University of Georgia, Athens, 30602, Georgia, USA
| | - Robert J Schmitz
- Department of Genetics, University of Georgia, Athens, 30602, Georgia, USA
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9
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Tessmer MA, Ribeiro BG, Kluge RA, Salvador A, Appezzato-da-Glória B. Characterization of the Epidermis and Cuticle of the Cashew Pseudofruit during Its Development and Maturation. PLANTS (BASEL, SWITZERLAND) 2023; 12:293. [PMID: 36679007 PMCID: PMC9866660 DOI: 10.3390/plants12020293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/03/2023] [Accepted: 01/06/2023] [Indexed: 06/17/2023]
Abstract
The epidermis and cuticle play an important role in reducing dehydration and protecting the cashew pseudofruit in both the production environment and the postharvest stage. This study analyzes the alterations on the epidermis and cuticle of CCP 76 cashew pseudofruits harvested in five developmental and maturation stages (S1, S2, S3, S4, and S5). The epidermis and cuticle of the samples were analyzed under light microscopy (LM) (quantitative analysis), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The epidermal cells at S3 reached maximum outer periclinal wall thickness, which reduced during ripening (S4 and S5), while the cuticle increased in thickness during the same period. These changes coincided with the rapid initial growth of the cashew pseudofruit when the epidermis and cuticle need to accompany the expansion of internal tissues. At the ultrastructural level, lipid material is transported via vesicles through the cell wall to the cuticle, increasing its thickness. Epicuticular waxes, previously deposited as plates and globules, began to develop an amorphous shape during maturation. This process possibly occurs due to changes in wax composition that can be related to the development of greasiness on the fruit skin. These findings provide a better understanding of cashew pseudofruit skin, which will aid future studies and strategies to preserve quality during the postharvest stage.
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Affiliation(s)
- Magda Andréia Tessmer
- Biological Science Department, Luiz de Queiroz College of Agriculture, University of São Paulo, Piracicaba 13418-900, SP, Brazil
| | - Bruno Geraldelli Ribeiro
- Biological Science Department, Luiz de Queiroz College of Agriculture, University of São Paulo, Piracicaba 13418-900, SP, Brazil
| | - Ricardo Alfredo Kluge
- Biological Science Department, Luiz de Queiroz College of Agriculture, University of São Paulo, Piracicaba 13418-900, SP, Brazil
| | - Alejandra Salvador
- Postharvest Department, Instituto Valenciano de Investigaciones Agrarias, 46113 Valencia, Spain
| | - Beatriz Appezzato-da-Glória
- Biological Science Department, Luiz de Queiroz College of Agriculture, University of São Paulo, Piracicaba 13418-900, SP, Brazil
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10
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Ershova N, Sheshukova E, Kamarova K, Arifulin E, Tashlitsky V, Serebryakova M, Komarova T. Nicotiana benthamiana Kunitz peptidase inhibitor-like protein involved in chloroplast-to-nucleus regulatory pathway in plant-virus interaction. FRONTIERS IN PLANT SCIENCE 2022; 13:1041867. [PMID: 36438111 PMCID: PMC9685412 DOI: 10.3389/fpls.2022.1041867] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Accepted: 10/24/2022] [Indexed: 06/16/2023]
Abstract
Plant viruses use a variety of strategies to infect their host. During infection, viruses cause symptoms of varying severity, which are often associated with altered leaf pigmentation due to structural and functional damage to chloroplasts that are affected by viral proteins. Here we demonstrate that Nicotiana benthamiana Kunitz peptidase inhibitor-like protein (KPILP) gene is induced in response to potato virus X (PVX) infection. Using reverse genetic approach, we have demonstrated that KPILP downregulates expression of LHCB1 and LHCB2 genes of antenna light-harvesting complex proteins, HEMA1 gene encoding glutamyl-tRNA reductase, which participates in tetrapyrrole biosynthesis, and RBCS1A gene encoding RuBisCO small subunit isoform involved in the antiviral immune response. Thus, KPILP is a regulator of chloroplast retrograde signaling system during developing PVX infection. Moreover, KPILP was demonstrated to affect carbon partitioning: reduced glucose levels during PVX infection were associated with KPILP upregulation. Another KPILP function is associated with plasmodesmata permeability control. Its ability to stimulate intercellular transport of reporter 2xGFP molecules indicates that KPILP is a positive plasmodesmata regulator. Moreover, natural KPILP glycosylation is indispensable for manifestation of this function. During PVX infection KPILP increased expression leads to the reduction of plasmodesmata callose deposition. These results could indicate that KPILP affects plasmodesmata permeability via callose-dependent mechanism. Thus, virus entering a cell and starting reproduction triggers KPILP expression, which leads to downregulation of nuclear-encoded chloroplast genes associated with retrograde signaling, reduction in photoassimilates accumulation and increase in intercellular transport, creating favorable conditions for reproduction and spread of viral infection.
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Affiliation(s)
- Natalia Ershova
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russia
| | - Ekaterina Sheshukova
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russia
| | - Kamila Kamarova
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russia
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
| | - Evgenii Arifulin
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Vadim Tashlitsky
- Chemistry Department, Lomonosov Moscow State University, Moscow, Russia
| | - Marina Serebryakova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Tatiana Komarova
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russia
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
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11
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Kehr J, Morris RJ, Kragler F. Long-Distance Transported RNAs: From Identity to Function. ANNUAL REVIEW OF PLANT BIOLOGY 2022; 73:457-474. [PMID: 34910585 DOI: 10.1146/annurev-arplant-070121-033601] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
There is now a wealth of data, from different plants and labs and spanning more than two decades, which unequivocally demonstrates that RNAs can be transported over long distances, from the cell where they are transcribed to distal cells in other tissues. Different types of RNA molecules are transported, including micro- and messenger RNAs. Whether these RNAs are selected for transport and, if so, how they are selected and transported remain, in general, open questions. This aspect is likely not independent of the biological function and relevance of the transported RNAs, which are in most cases still unclear. In this review, we summarize the experimental data supporting selectivity or nonselectivity of RNA translocation and review the evidence for biological functions. After discussing potential issues regarding the comparability between experiments, we propose criteria that need to be critically evaluated to identify important signaling RNAs.
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Affiliation(s)
- Julia Kehr
- Department of Biology, Institute for Plant Sciences and Microbiology, Universität Hamburg, Hamburg, Germany;
| | - Richard J Morris
- Computational and Systems Biology, John Innes Centre, Norwich, United Kingdom;
| | - Friedrich Kragler
- Department II, Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany;
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12
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Godel-J Drychowska K, Kurczy Ska E. Qualitative and quantitative analyses of the plasmodesmata that accompany cell fate changes during the somatic embryogenesis of Arabidopsis thaliana. FUNCTIONAL PLANT BIOLOGY : FPB 2022; 49:186-200. [PMID: 34838155 DOI: 10.1071/fp21243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Accepted: 11/10/2021] [Indexed: 06/13/2023]
Abstract
Plasmodesmata (PD) are cytoplasmic and membrane-lined microchannels that enable symplasmic communication in plants, which is involved in the regulation of cell differentiation. The presented results emphasise the qualitative and quantitative analyses of PD, which are the basis of the symplasmic communication. The cells that initiate various development programmes create symplasmic domains that are characterised by different degrees of symplasmic communication. Changes in symplasmic communication are caused by the presence or absence of PD and/or the ability of signals to move through them. In the presented studies, somatic embryogenesis was used to describe the characteristics of the PD within and between the symplasmic domains in explants of the Arabidopsis thaliana (L.) Heynh ecotype Columbia-0 and 35S:BBM transgenic line. Transmission electron microscopy was used to describe the cells that regain totipotency/pluripotency during somatic embryogenesis, as well as the number and shape of the PD in the different symplasmic domains of the explants and somatic embryos. Array tomography was used to create a 3D reconstruction of the protodermal cells of the somatic embryos with particular emphasis on the PD distribution in the cell walls. The results showed that there were different frequencies of the PD within and between the symplasmic domain that emerges during somatic embryogenesis and between the Col-0 and 35S:BBM somatic embryos with regard to the differences in the shape of the PD.
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Affiliation(s)
- Kamila Godel-J Drychowska
- Faculty of Natural Sciences, Institute of Biology, Biotechnology and Environmental Protection, The University of Silesia, 28 Jagiellonska Street, 40-032 Katowice, Poland
| | - Ewa Kurczy Ska
- Faculty of Natural Sciences, Institute of Biology, Biotechnology and Environmental Protection, The University of Silesia, 28 Jagiellonska Street, 40-032 Katowice, Poland
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13
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Dmitrieva VA, Domashkina VV, Ivanova AN, Sukhov VS, Tyutereva EV, Voitsekhovskaja OV. Regulation of plasmodesmata in Arabidopsis leaves: ATP, NADPH and chlorophyll b levels matter. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:5534-5552. [PMID: 33974689 DOI: 10.1093/jxb/erab205] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 05/07/2021] [Indexed: 06/12/2023]
Abstract
In mature leaves, cell-to-cell transport via plasmodesmata between mesophyll cells links the production of assimilates by photosynthesis with their export to sink organs. This study addresses the question of how signals derived from chloroplasts and photosynthesis influence plasmodesmata permeability. Cell-to-cell transport was analyzed in leaves of the Arabidopsis chlorophyll b-less ch1-3 mutant, the same mutant complemented with a cyanobacterial CAO gene (PhCAO) overaccumulating chlorophyll b, the trxm3 mutant lacking plastidial thioredoxin m3, and the ntrc mutant lacking functional NADPH:thioredoxin reductase C. The regulation of plasmodesmata permeability in these lines could not be traced back to the reduction state of the thioredoxin system or the types and levels of reactive oxygen species produced in chloroplasts; however, it could be related to chloroplast ATP and NADPH production. The results suggest that light enables plasmodesmata closure via an increase in the ATP and NADPH levels produced in photosynthesis, providing a control mechanism for assimilate export based on the rate of photosynthate production in the Calvin-Benson cycle. The level of chlorophyll b influences plasmodesmata permeability via as-yet-unidentified signals. The data also suggest a role of thioredoxin m3 in the regulation of cyclic electron flow around photosystem I.
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Affiliation(s)
- Valeria A Dmitrieva
- Laboratory of Molecular and Ecological Physiology, Komarov Botanical Institute, Russian Academy of Sciences, St. Petersburg, Russia
| | - Valentina V Domashkina
- Laboratory of Molecular and Ecological Physiology, Komarov Botanical Institute, Russian Academy of Sciences, St. Petersburg, Russia
| | - Alexandra N Ivanova
- Laboratory of Plant Anatomy, Komarov Botanical Institute, Russian Academy of Sciences, St. Petersburg, Russia
- Research Park, St. Petersburg State University, St. Petersburg, Russia
| | - Vladimir S Sukhov
- Department of Biophysics, N.I. Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Elena V Tyutereva
- Laboratory of Molecular and Ecological Physiology, Komarov Botanical Institute, Russian Academy of Sciences, St. Petersburg, Russia
| | - Olga V Voitsekhovskaja
- Laboratory of Molecular and Ecological Physiology, Komarov Botanical Institute, Russian Academy of Sciences, St. Petersburg, Russia
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14
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Horner W, Brunkard JO. Cytokinins Stimulate Plasmodesmatal Transport in Leaves. FRONTIERS IN PLANT SCIENCE 2021; 12:674128. [PMID: 34135930 PMCID: PMC8201399 DOI: 10.3389/fpls.2021.674128] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 04/28/2021] [Indexed: 06/12/2023]
Abstract
Plant cells are connected by plasmodesmata (PD), nanoscopic channels in cell walls that allow diverse cytosolic molecules to move between neighboring cells. PD transport is tightly coordinated with physiology and development, although the range of signaling pathways that influence PD transport has not been comprehensively defined. Several plant hormones, including salicylic acid (SA) and auxin, are known to regulate PD transport, but the effects of other hormones have not been established. In this study, we provide evidence that cytokinins promote PD transport in leaves. Using a green fluorescent protein (GFP) movement assay in the epidermis of Nicotiana benthamiana, we have shown that PD transport significantly increases when leaves are supplied with exogenous cytokinins at physiologically relevant concentrations or when a positive regulator of cytokinin responses, ARABIDOPSIS HISTIDINE PHOSPHOTRANSFER PROTEIN 5 (AHP5), is overexpressed. We then demonstrated that silencing cytokinin receptors, ARABIDOPSIS HISTIDINE KINASE 3 (AHK3) or AHK4 or overexpressing a negative regulator of cytokinin signaling, AAHP6, significantly decreases PD transport. These results are supported by transcriptomic analysis of mutants with increased PD transport (ise1-4), which show signs of enhanced cytokinin signaling. We concluded that cytokinins contribute to dynamic changes in PD transport in plants, which will have implications in several aspects of plant biology, including meristem patterning and development, regulation of the sink-to-source transition, and phytohormone crosstalk.
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Affiliation(s)
- Wilson Horner
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, United States
- Plant Gene Expression Center, USDA Agricultural Research Service, Albany, CA, United States
- Laboratory of Genetics, University of Wisconsin – Madison, Madison, WI, United States
| | - Jacob O. Brunkard
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, United States
- Plant Gene Expression Center, USDA Agricultural Research Service, Albany, CA, United States
- Laboratory of Genetics, University of Wisconsin – Madison, Madison, WI, United States
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15
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Peters WS, Jensen KH, Stone HA, Knoblauch M. Plasmodesmata and the problems with size: Interpreting the confusion. JOURNAL OF PLANT PHYSIOLOGY 2021; 257:153341. [PMID: 33388666 DOI: 10.1016/j.jplph.2020.153341] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/04/2020] [Accepted: 12/07/2020] [Indexed: 05/14/2023]
Abstract
Plant tissues exhibit a symplasmic organization; the individual protoplasts are connected to their neighbors via cytoplasmic bridges that extend through pores in the cell walls. These bridges may have diameters of a micrometer or more, as in the sieve pores of the phloem, but in most cell types they are smaller. Historically, botanists referred to cytoplasmic bridges of all sizes as plasmodesmata. The meaning of the term began to shift when the transmission electron microscope (TEM) became the preferred tool for studying these structures. Today, a plasmodesma is widely understood to be a 'nano-scale' pore. Unfortunately, our understanding of these nanoscopic channels suffers from methodological limitations. This is exemplified by the fact that state-of-the-art EM techniques appear to reveal plasmodesmal pore structures that are much smaller than the tracer molecules known to diffuse through these pores. In general, transport processes in pores that have dimensions in the size range of the transported molecules are governed by different physical parameters than transport process in the macroscopic realm. This can lead to unexpected effects, as experience in nanofluidic technologies demonstrates. Our discussion of problems of size in plasmodesma research leads us to conclude that the field will benefit from technomimetic reasoning - the utilization of concepts developed in applied nanofluidics for the interpretation of biological systems.
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Affiliation(s)
- Winfried S Peters
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA; Department of Biology, Purdue University Fort Wayne, Fort Wayne, IN, 46805, USA.
| | - Kaare H Jensen
- Department of Physics, Technical University of Denmark, DK-2800 Kgs., Lyngby, Denmark.
| | - Howard A Stone
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ, 08544, USA.
| | - Michael Knoblauch
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA.
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16
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Veerabagu M, Rinne PLH, Skaugen M, Paul LK, van der Schoot C. Lipid Body Dynamics in Shoot Meristems: Production, Enlargement, and Putative Organellar Interactions and Plasmodesmal Targeting. FRONTIERS IN PLANT SCIENCE 2021; 12:674031. [PMID: 34367200 PMCID: PMC8335594 DOI: 10.3389/fpls.2021.674031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 06/14/2021] [Indexed: 05/20/2023]
Abstract
Post-embryonic cells contain minute lipid bodies (LBs) that are transient, mobile, engage in organellar interactions, and target plasmodesmata (PD). While LBs can deliver γ-clade 1,3-β-glucanases to PD, the nature of other cargo is elusive. To gain insight into the poorly understood role of LBs in meristems, we investigated their dynamics by microscopy, gene expression analyzes, and proteomics. In developing buds, meristems accumulated LBs, upregulated several LB-specific OLEOSIN genes and produced OLEOSINs. During bud maturation, the major gene OLE6 was strongly downregulated, OLEOSINs disappeared from bud extracts, whereas lipid biosynthesis genes were upregulated, and LBs were enlarged. Proteomic analyses of the LB fraction of dormant buds confirmed that OLEOSINs were no longer present. Instead, we identified the LB-associated proteins CALEOSIN (CLO1), Oil Body Lipase 1 (OBL1), Lipid Droplet Interacting Protein (LDIP), Lipid Droplet Associated Protein1a/b (LDAP1a/b) and LDAP3a/b, and crucial components of the OLEOSIN-deubiquitinating and degradation machinery, such as PUX10 and CDC48A. All mRFP-tagged LDAPs localized to LBs when transiently expressed in Nicotiana benthamiana. Together with gene expression analyzes, this suggests that during bud maturation, OLEOSINs were replaced by LDIP/LDAPs at enlarging LBs. The LB fraction contained the meristem-related actin7 (ACT7), "myosin XI tail-binding" RAB GTPase C2A, an LB/PD-associated γ-clade 1,3-β-glucanase, and various organelle- and/or PD-localized proteins. The results are congruent with a model in which LBs, motorized by myosin XI-k/1/2, traffic on F-actin, transiently interact with other organelles, and deliver a diverse cargo to PD.
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Affiliation(s)
- Manikandan Veerabagu
- Faculty of Biosciences, Department of Plant Sciences, Norwegian University of Life Sciences, Ås, Norway
| | - Päivi L. H. Rinne
- Faculty of Biosciences, Department of Plant Sciences, Norwegian University of Life Sciences, Ås, Norway
| | - Morten Skaugen
- Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Laju K. Paul
- Faculty of Biosciences, Department of Plant Sciences, Norwegian University of Life Sciences, Ås, Norway
| | - Christiaan van der Schoot
- Faculty of Biosciences, Department of Plant Sciences, Norwegian University of Life Sciences, Ås, Norway
- *Correspondence: Christiaan van der Schoot
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17
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Azim MF, Burch-Smith TM. Organelles-nucleus-plasmodesmata signaling (ONPS): an update on its roles in plant physiology, metabolism and stress responses. CURRENT OPINION IN PLANT BIOLOGY 2020; 58:48-59. [PMID: 33197746 DOI: 10.1016/j.pbi.2020.09.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 09/26/2020] [Accepted: 09/27/2020] [Indexed: 05/03/2023]
Abstract
Plasmodesmata allow movement of metabolites and signaling molecules between plant cells and are, therefore, critical players in plant development and physiology, and in responding to environmental signals and stresses. There is emerging evidence that plasmodesmata are controlled by signaling originating from other organelles, primarily the chloroplasts and mitochondria. These signals act in the nucleus to alter expression of genetic pathways that control both trafficking via plasmodesmata and the plasmodesmatal pores themselves. This control circuit was dubbed organelle-nucleus-plasmodesmata signaling (ONPS). Here we discuss how ONPS arose during plant evolution and highlight the discovery of an ONPS-like module for regulating stomata. We also consider recent findings that illuminate details of the ONPS circuit and its roles in plant physiology, metabolism, and defense.
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Affiliation(s)
- Mohammad F Azim
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, United States
| | - Tessa M Burch-Smith
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, United States.
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18
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García-Gómez ML, Castillo-Jiménez A, Martínez-García JC, Álvarez-Buylla ER. Multi-level gene regulatory network models to understand complex mechanisms underlying plant development. CURRENT OPINION IN PLANT BIOLOGY 2020; 57:171-179. [PMID: 33171396 DOI: 10.1016/j.pbi.2020.09.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 08/12/2020] [Accepted: 09/24/2020] [Indexed: 05/07/2023]
Abstract
Patterning in plant development is the emergent outcome of the feedback-based interplay between tissue-coupled intracellular regulatory networks and physicochemical fields. This interplay gives rise to dynamics that evolve on a wide spectrum of spatiotemporal scales. This imposes important challenges for computational approaches to model the dynamics of plant development. These challenges are being tackled in recent times by computational and mathematical advances that have made progress in the modelling of regulatory networks, as well as in approaches to couple the latter to physicochemical fields. Efforts in this direction are fundamental to identify the dynamical constraints that emerge from non-cellular autonomous activity in cell-fate decisions and patterning, and requires an understanding of how multi-level and multi-scale processes are coupled. Here, we discuss the use of multi-level modeling and simulation tools for the study of multicellular systems, with emphasis on plants. As illustrative examples, we discuss recent works elucidating the mechanisms that underlie patterning in the root meristem of Arabidopsis thaliana, and in plant responses to environmental conditions.
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Affiliation(s)
- Mónica L García-Gómez
- Departamento de Ecología Funcional, Instituto de Ecología, Universidad Nacional Autónoma de México, Coyoacán, Ciudad de México, Mexico; Centro de Ciencias de la Complejidad, Universidad Nacional Autónoma de México, Coyoacán, Ciudad de México, Mexico
| | - Aaron Castillo-Jiménez
- Centro de Ciencias de la Complejidad, Universidad Nacional Autónoma de México, Coyoacán, Ciudad de México, Mexico; PhD Program on Biomedical Science, Universidad Nacional Autónoma de México, Coyoacán, Ciudad de México, Mexico
| | | | - Elena R Álvarez-Buylla
- Departamento de Ecología Funcional, Instituto de Ecología, Universidad Nacional Autónoma de México, Coyoacán, Ciudad de México, Mexico; Centro de Ciencias de la Complejidad, Universidad Nacional Autónoma de México, Coyoacán, Ciudad de México, Mexico.
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19
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Intercellular trafficking via plasmodesmata: molecular layers of complexity. Cell Mol Life Sci 2020; 78:799-816. [PMID: 32920696 PMCID: PMC7897608 DOI: 10.1007/s00018-020-03622-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 07/28/2020] [Accepted: 08/13/2020] [Indexed: 12/12/2022]
Abstract
Plasmodesmata are intercellular pores connecting together most plant cells. These structures consist of a central constricted form of the endoplasmic reticulum, encircled by some cytoplasmic space, in turn delimited by the plasma membrane, itself ultimately surrounded by the cell wall. The presence and structure of plasmodesmata create multiple routes for intercellular trafficking of a large spectrum of molecules (encompassing RNAs, proteins, hormones and metabolites) and also enable local signalling events. Movement across plasmodesmata is finely controlled in order to balance processes requiring communication with those necessitating symplastic isolation. Here, we describe the identities and roles of the molecular components (specific sets of lipids, proteins and wall polysaccharides) that shape and define plasmodesmata structural and functional domains. We highlight the extensive and dynamic interactions that exist between the plasma/endoplasmic reticulum membranes, cytoplasm and cell wall domains, binding them together to effectively define plasmodesmata shapes and purposes.
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20
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Kleinow T, Happle A, Kober S, Linzmeier L, Rehm TM, Fritze J, Buchholz PCF, Kepp G, Jeske H, Wege C. Phosphorylations of the Abutilon Mosaic Virus Movement Protein Affect Its Self-Interaction, Symptom Development, Viral DNA Accumulation, and Host Range. FRONTIERS IN PLANT SCIENCE 2020; 11:1155. [PMID: 32849713 PMCID: PMC7411133 DOI: 10.3389/fpls.2020.01155] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 07/15/2020] [Indexed: 06/11/2023]
Abstract
The genome of bipartite geminiviruses in the genus Begomovirus comprises two circular DNAs: DNA-A and DNA-B. The DNA-B component encodes a nuclear shuttle protein (NSP) and a movement protein (MP), which cooperate for systemic spread of infectious nucleic acids within host plants and affect pathogenicity. MP mediates multiple functions during intra- and intercellular trafficking, such as binding of viral nucleoprotein complexes, targeting to and modification of plasmodesmata, and release of the cargo after cell-to-cell transfer. For Abutilon mosaic virus (AbMV), phosphorylation of MP expressed in bacteria, yeast, and Nicotiana benthamiana plants, respectively, has been demonstrated in previous studies. Three phosphorylation sites (T221, S223, and S250) were identified in its C-terminal oligomerization domain by mass spectrometry, suggesting a regulation of MP by posttranslational modification. To examine the influence of the three sites on the self-interaction in more detail, MP mutants were tested for their interaction in yeast by two-hybrid assays, or by Förster resonance energy transfer (FRET) techniques in planta. Expression constructs with point mutations leading to simultaneous (triple) exchange of T221, S223, and S250 to either uncharged alanine (MPAAA), or phosphorylation charge-mimicking aspartate residues (MPDDD) were compared. MPDDD interfered with MP-MP binding in contrast to MPAAA. The roles of the phosphorylation sites for the viral life cycle were studied further, using plant-infectious AbMV DNA-B variants with the same triple mutants each. When co-inoculated with wild-type DNA-A, both mutants infected N. benthamiana plants systemically, but were unable to do so for some other plant species of the families Solanaceae or Malvaceae. Systemically infected plants developed symptoms and viral DNA levels different from those of wild-type AbMV for most virus-plant combinations. The results indicate a regulation of diverse MP functions by posttranslational modifications and underscore their biological relevance for a complex host plant-geminivirus interaction.
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21
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Wu J, Zhou C, Li J, Li C, Tao X, Leontis NB, Zirbel CL, Bisaro DM, Ding B. Functional analysis reveals G/U pairs critical for replication and trafficking of an infectious non-coding viroid RNA. Nucleic Acids Res 2020; 48:3134-3155. [PMID: 32083649 PMCID: PMC7102988 DOI: 10.1093/nar/gkaa100] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 02/03/2020] [Accepted: 02/18/2020] [Indexed: 01/19/2023] Open
Abstract
While G/U pairs are present in many RNAs, the lack of molecular studies to characterize the roles of multiple G/U pairs within a single RNA limits our understanding of their biological significance. From known RNA 3D structures, we observed that the probability a G/U will form a Watson-Crick (WC) base pair depends on sequence context. We analyzed 17 G/U pairs in the 359-nucleotide genome of Potato spindle tuber viroid (PSTVd), a circular non-coding RNA that replicates and spreads systemically in host plants. Most putative G/U base pairs were experimentally supported by selective 2'-hydroxyl acylation analyzed by primer extension (SHAPE). Deep sequencing PSTVd genomes from plants inoculated with a cloned master sequence revealed naturally occurring variants, and showed that G/U pairs are maintained to the same extent as canonical WC base pairs. Comprehensive mutational analysis demonstrated that nearly all G/U pairs are critical for replication and/or systemic spread. Two selected G/U pairs were found to be required for PSTVd entry into, but not for exit from, the host vascular system. This study identifies critical roles for G/U pairs in the survival of an infectious RNA, and increases understanding of structure-based regulation of replication and trafficking of pathogen and cellular RNAs.
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Affiliation(s)
- Jian Wu
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, and Infectious Diseases Institute, The Ohio State University, Columbus, OH 43210, USA.,Graduate Program in Molecular, Cellular, and Developmental Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Cuiji Zhou
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, and Infectious Diseases Institute, The Ohio State University, Columbus, OH 43210, USA
| | - James Li
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, and Infectious Diseases Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Chun Li
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaorong Tao
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Neocles B Leontis
- Department of Chemistry, Bowling Green State University, Bowling Green, OH 43403, USA
| | - Craig L Zirbel
- Department of Mathematics and Statistics, Bowling Green State University, Bowling Green, OH 43403, USA
| | - David M Bisaro
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, and Infectious Diseases Institute, The Ohio State University, Columbus, OH 43210, USA.,Graduate Program in Molecular, Cellular, and Developmental Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Biao Ding
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, and Infectious Diseases Institute, The Ohio State University, Columbus, OH 43210, USA.,Graduate Program in Molecular, Cellular, and Developmental Biology, The Ohio State University, Columbus, OH 43210, USA
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22
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Ganusova EE, Reagan BC, Fernandez JC, Azim MF, Sankoh AF, Freeman KM, McCray TN, Patterson K, Kim C, Burch-Smith TM. Chloroplast-to-nucleus retrograde signalling controls intercellular trafficking via plasmodesmata formation. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190408. [PMID: 32362251 DOI: 10.1098/rstb.2019.0408] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The signalling pathways that regulate intercellular trafficking via plasmodesmata (PD) remain largely unknown. Analyses of mutants with defects in intercellular trafficking led to the hypothesis that chloroplasts are important for controlling PD, probably by retrograde signalling to the nucleus to regulate expression of genes that influence PD formation and function, an idea encapsulated in the organelle-nucleus-PD signalling (ONPS) hypothesis. ONPS is supported by findings that point to chloroplast redox state as also modulating PD. Here, we have attempted to further elucidate details of ONPS. Through reverse genetics, expression of select nucleus-encoded genes with known or predicted roles in chloroplast gene expression was knocked down, and the effects on intercellular trafficking were then assessed. Silencing most genes resulted in chlorosis, and the expression of several photosynthesis and tetrapyrrole biosynthesis associated nuclear genes was repressed in all silenced plants. PD-mediated intercellular trafficking was changed in the silenced plants, consistent with predictions of the ONPS hypothesis. One striking observation, best exemplified by silencing the PNPase homologues, was that the degree of chlorosis of silenced leaves was not correlated with the capacity for intercellular trafficking. Finally, we measured the distribution of PD in silenced leaves and found that intercellular trafficking was positively correlated with the numbers of PD. Together, these results not only provide further support for ONPS but also point to a genetic mechanism for PD formation, clarifying a longstanding question about PD and intercellular trafficking. This article is part of the theme issue 'Retrograde signalling from endosymbiotic organelles'.
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Affiliation(s)
- Elena E Ganusova
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Brandon C Reagan
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Jessica C Fernandez
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Mohammad F Azim
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Amie F Sankoh
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | | | - Tyra N McCray
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Kelsey Patterson
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Chinkee Kim
- Departments of Science and Mathematics, RIT/National Technical Institute for the Deaf (NTID), Rochester, NY 14623, USA
| | - Tessa M Burch-Smith
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
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23
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Brunkard JO, Xu M, Scarpin MR, Chatterjee S, Shemyakina EA, Goodman HM, Zambryski P. TOR dynamically regulates plant cell-cell transport. Proc Natl Acad Sci U S A 2020; 117:5049-5058. [PMID: 32051250 PMCID: PMC7060719 DOI: 10.1073/pnas.1919196117] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The coordinated redistribution of sugars from mature "source" leaves to developing "sink" leaves requires tight regulation of sugar transport between cells via plasmodesmata (PD). Although fundamental to plant physiology, the mechanisms that control PD transport and thereby support development of new leaves have remained elusive. From a forward genetic screen for altered PD transport, we discovered that the conserved eukaryotic glucose-TOR (TARGET OF RAPAMYCIN) metabolic signaling network restricts PD transport in leaves. Genetic approaches and chemical or physiological treatments to either promote or disrupt TOR activity demonstrate that glucose-activated TOR decreases PD transport in leaves. We further found that TOR is significantly more active in mature leaves photosynthesizing excess sugars than in young, growing leaves, and that this increase in TOR activity correlates with decreased rates of PD transport. We conclude that leaf cells regulate PD trafficking in response to changing carbohydrate availability monitored by the TOR pathway.
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Affiliation(s)
- Jacob O Brunkard
- Department of Plant and Microbial Biology, University of California, Berkeley CA 94720;
- Plant Gene Expression Center, US Department of Agriculture, Agricultural Research Service, Albany, CA 94710
- Innovative Genomics Institute, Berkeley, CA 94720
| | - Min Xu
- Department of Plant and Microbial Biology, University of California, Berkeley CA 94720
- Department of Biology, Northwest University, 710069 Xi'an, China
| | - M Regina Scarpin
- Department of Plant and Microbial Biology, University of California, Berkeley CA 94720
- Plant Gene Expression Center, US Department of Agriculture, Agricultural Research Service, Albany, CA 94710
| | - Snigdha Chatterjee
- Department of Plant and Microbial Biology, University of California, Berkeley CA 94720
- Plant Gene Expression Center, US Department of Agriculture, Agricultural Research Service, Albany, CA 94710
- Innovative Genomics Institute, Berkeley, CA 94720
| | - Elena A Shemyakina
- Department of Plant and Microbial Biology, University of California, Berkeley CA 94720
- Plant Gene Expression Center, US Department of Agriculture, Agricultural Research Service, Albany, CA 94710
| | - Howard M Goodman
- Department of Plant and Microbial Biology, University of California, Berkeley CA 94720
| | - Patricia Zambryski
- Department of Plant and Microbial Biology, University of California, Berkeley CA 94720;
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24
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Hernández-Hernández V, Benítez M, Boudaoud A. Interplay between turgor pressure and plasmodesmata during plant development. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:768-777. [PMID: 31563945 DOI: 10.1093/jxb/erz434] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 09/09/2019] [Indexed: 06/10/2023]
Abstract
Plasmodesmata traverse cell walls, generating connections between neighboring cells. They allow intercellular movement of molecules such as transcription factors, hormones, and sugars, and thus create a symplasmic continuity within a tissue. One important factor that determines plasmodesmal permeability is their aperture, which is regulated during developmental and physiological processes. Regulation of aperture has been shown to affect developmental events such as vascular differentiation in the root, initiation of lateral roots, or transition to flowering. Extensive research has unraveled molecular factors involved in the regulation of plasmodesmal permeability. Nevertheless, many plant developmental processes appear to involve feedbacks mediated by mechanical forces, raising the question of whether mechanical forces and plasmodesmal permeability affect each other. Here, we review experimental data on how one of these forces, turgor pressure, and plasmodesmal permeability may mutually influence each other during plant development, and we discuss the questions raised by these data. Addressing such questions will improve our knowledge of how cellular patterns emerge during development, shedding light on the evolution of complex multicellular plants.
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Affiliation(s)
- Valeria Hernández-Hernández
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, Lyon, France
| | - Mariana Benítez
- Laboratorio Nacional de Ciencias de la Sostenibilidad, Instituto de Ecología & Centro de Ciencias de la Complejidad, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Arezki Boudaoud
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, Lyon, France
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25
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The dynamic response of the Arabidopsis root metabolome to auxin and ethylene is not predicted by changes in the transcriptome. Sci Rep 2020; 10:679. [PMID: 31959762 PMCID: PMC6971091 DOI: 10.1038/s41598-019-57161-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 12/19/2019] [Indexed: 12/27/2022] Open
Abstract
While the effects of phytohormones on plant gene expression have been well characterized, comparatively little is known about how hormones influence metabolite profiles. This study examined the effects of elevated auxin and ethylene on the metabolome of Arabidopsis roots using a high-resolution 24 h time course, conducted in parallel to time-matched transcriptomic analyses. Mass spectrometry using orthogonal UPLC separation strategies (reversed phase and HILIC) in both positive and negative ionization modes was used to maximize identification of metabolites with altered levels. The findings show that the root metabolome responds rapidly to hormone stimulus and that compounds belonging to the same class of metabolites exhibit similar changes. The responses were dominated by changes in phenylpropanoid, glucosinolate, and fatty acid metabolism, although the nature and timing of the response was unique for each hormone. These alterations in the metabolome were not directly predicted by the corresponding transcriptome data, suggesting that post-transcriptional events such as changes in enzyme activity and/or transport processes drove the observed changes in the metabolome. These findings underscore the need to better understand the biochemical mechanisms underlying the temporal reconfiguration of plant metabolism, especially in relation to the hormone-metabolome interface and its subsequent physiological and morphological effects.
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26
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Reagan BC, Burch-Smith TM. Viruses Reveal the Secrets of Plasmodesmal Cell Biology. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2020; 33:26-39. [PMID: 31715107 DOI: 10.1094/mpmi-07-19-0212-fi] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Plasmodesmata (PD) are essential for intercellular trafficking of molecules required for plant life, from small molecules like sugars and ions to macromolecules including proteins and RNA molecules that act as signals to regulate plant development and defense. As obligate intracellular pathogens, plant viruses have evolved to manipulate this communication system to facilitate the initial cell-to-cell and eventual systemic spread in their plant hosts. There has been considerable interest in how viruses manipulate the PD that connect the protoplasts of neighboring cells, and viruses have yielded invaluable tools for probing the structure and function of PD. With recent advances in biochemistry and imaging, we have gained new insights into the composition and structure of PD in the presence and absence of viruses. Here, we first discuss viral strategies for manipulating PD for their intercellular movement and examine how this has shed light on our understanding of native PD function. We then address the controversial role of the cytoskeleton in trafficking to and through PD. Finally, we address how viruses could alter PD structure and consider possible mechanisms of the phenomenon described as 'gating'. This discussion supports the significance of virus research in elucidating the properties of PD, these persistently enigmatic plant organelles.
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Affiliation(s)
- Brandon C Reagan
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, U.S.A
| | - Tessa M Burch-Smith
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, U.S.A
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27
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Abstract
The coordination of cell fate decisions within complex multicellular structures rests on intercellular communication. To generate ordered patterns, cells need to know their relative positions within the growing structure. This is commonly achieved via the production and perception of mobile signaling molecules. In animal systems, such positional signals often act as morphogens and subdivide a field of cells into domains of discrete cell identities using a threshold-based readout of their mobility gradient. Reflecting the independent origin of multicellularity, plants evolved distinct signaling mechanisms to drive cell fate decisions. Many of the basic principles underlying developmental patterning are, however, shared between animals and plants, including the use of signaling gradients to provide positional information. In plant development, small RNAs can act as mobile instructive signals, and similar to classical morphogens in animals, employ a threshold-based readout of their mobility gradient to generate precisely defined cell fate boundaries. Given the distinctive nature of peptide morphogens and small RNAs, how might mechanisms underlying the function of traditionally morphogens be adapted to create morphogen-like behavior using small RNAs? In this review, we highlight the contributions of mobile small RNAs to pattern formation in plants and summarize recent studies that have advanced our understanding regarding the formation, stability, and interpretation of small RNA gradients.
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Affiliation(s)
- Simon Klesen
- Center for Plant Molecular Biology, University of Tübingen, Tübingen, Germany
| | - Kristine Hill
- Center for Plant Molecular Biology, University of Tübingen, Tübingen, Germany
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28
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Plasmodesmata Conductivity Regulation: A Mechanistic Model. PLANTS 2019; 8:plants8120595. [PMID: 31842374 PMCID: PMC6963776 DOI: 10.3390/plants8120595] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 12/03/2019] [Accepted: 12/10/2019] [Indexed: 01/16/2023]
Abstract
Plant cells form a multicellular symplast via cytoplasmic bridges called plasmodesmata (Pd) and the endoplasmic reticulum (ER) that crosses almost all plant tissues. The Pd proteome is mainly represented by secreted Pd-associated proteins (PdAPs), the repertoire of which quickly adapts to environmental conditions and responds to biotic and abiotic stresses. Although the important role of Pd in stress-induced reactions is universally recognized, the mechanisms of Pd control are still not fully understood. The negative role of callose in Pd permeability has been convincingly confirmed experimentally, yet the roles of cytoskeletal elements and many PdAPs remain unclear. Here, we discuss the contribution of each protein component to Pd control. Based on known data, we offer mechanistic models of mature leaf Pd regulation in response to stressful effects.
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29
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Wu J, Leontis NB, Zirbel CL, Bisaro DM, Ding B. A three-dimensional RNA motif mediates directional trafficking of Potato spindle tuber viroid from epidermal to palisade mesophyll cells in Nicotiana benthamiana. PLoS Pathog 2019; 15:e1008147. [PMID: 31644572 PMCID: PMC6827988 DOI: 10.1371/journal.ppat.1008147] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 11/04/2019] [Accepted: 10/14/2019] [Indexed: 12/15/2022] Open
Abstract
Potato spindle tuber viroid (PSTVd) is a circular non-coding RNA of 359 nucleotides that replicates and spreads systemically in host plants, thus all functions required to establish an infection are mediated by sequence and structural elements in the genome. The PSTVd secondary structure contains 26 Watson-Crick base-paired stems and 27 loops. Most of the loops are believed to form three-dimensional (3D) structural motifs through non-Watson-Crick base pairing, base stacking, and other local interactions. Homology-based prediction using the JAR3D online program revealed that loop 27 (nucleotides 177-182) most likely forms a 3D structure similar to the loop of a conserved hairpin located in the 3' untranslated region of histone mRNAs in animal cells. This stem-loop, which is involved in 3'-end maturation, is not found in polyadenylated plant histone mRNAs. Mutagenesis showed that PSTVd genomes containing base substitutions in loop 27 predicted by JAR3D to disrupt the 3D structure were unable to replicate in Nicotiana benthamiana leaves following mechanical rub inoculation, with one exception: a U178G/U179G double mutant was replication-competent and able to spread within the upper epidermis of inoculated leaves, but was confined to this cell layer. Remarkably, direct delivery of the U178G/U179G mutant into the vascular system by needle puncture inoculation allowed it to spread systemically and enter mesophyll cells and epidermal cells of upper leaves. These findings highlight the importance of RNA 3D structure for PSTVd replication and intercellular trafficking and indicate that loop 27 is required for epidermal exit, but not epidermal entry or transit between other cell types. Thus, requirements for RNA trafficking between epidermal and underlying palisade mesophyll cells are unique and directional. Our findings further suggest that 3D structure and RNA-protein interactions constrain RNA sequence evolution, and validate JAR3D as a tool to predict RNA 3D structure.
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Affiliation(s)
- Jian Wu
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, Infectious Diseases Institute, and Graduate Program in Molecular, Cellular, and Developmental Biology, The Ohio State University, Columbus, Ohio, United States of America
| | - Neocles B. Leontis
- Department of Chemistry and Center for Biomolecular Sciences, Bowling Green State University, Bowling Green, Ohio, United States of America
| | - Craig L. Zirbel
- Department of Mathematics and Statistics, Bowling Green State University, Bowling Green, Ohio, United States of America
| | - David M. Bisaro
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, Infectious Diseases Institute, and Graduate Program in Molecular, Cellular, and Developmental Biology, The Ohio State University, Columbus, Ohio, United States of America
| | - Biao Ding
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, Infectious Diseases Institute, and Graduate Program in Molecular, Cellular, and Developmental Biology, The Ohio State University, Columbus, Ohio, United States of America
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30
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Tran TM, McCubbin TJ, Bihmidine S, Julius BT, Baker RF, Schauflinger M, Weil C, Springer N, Chomet P, Wagner R, Woessner J, Grote K, Peevers J, Slewinski TL, Braun DM. Maize Carbohydrate Partitioning Defective33 Encodes an MCTP Protein and Functions in Sucrose Export from Leaves. MOLECULAR PLANT 2019; 12:1278-1293. [PMID: 31102785 DOI: 10.1016/j.molp.2019.05.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 04/09/2019] [Accepted: 05/03/2019] [Indexed: 05/29/2023]
Abstract
To sustain plant growth, development, and crop yield, sucrose must be transported from leaves to distant parts of the plant, such as seeds and roots. To identify genes that regulate sucrose accumulation and transport in maize (Zea mays), we isolated carbohydrate partitioning defective33 (cpd33), a recessive mutant that accumulated excess starch and soluble sugars in mature leaves. The cpd33 mutants also exhibited chlorosis in the leaf blades, greatly diminished plant growth, and reduced fertility. Cpd33 encodes a protein containing multiple C2 domains and transmembrane regions. Subcellular localization experiments showed the CPD33 protein localized to plasmodesmata (PD), the plasma membrane, and the endoplasmic reticulum. We also found that a loss-of-function mutant of the CPD33 homolog in Arabidopsis, QUIRKY, had a similar carbohydrate hyperaccumulation phenotype. Radioactively labeled sucrose transport assays showed that sucrose export was significantly lower in cpd33 mutant leaves relative to wild-type leaves. However, PD transport in the adaxial-abaxial direction was unaffected in cpd33 mutant leaves. Intriguingly, transmission electron microscopy revealed fewer PD at the companion cell-sieve element interface in mutant phloem tissue, providing a possible explanation for the reduced sucrose export in mutant leaves. Collectively, our results suggest that CPD33 functions to promote symplastic transport into sieve elements.
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Affiliation(s)
- Thu M Tran
- Division of Biological Sciences, Interdisciplinary Plant Group, Missouri Maize Center, University of Missouri, Columbia, MO 65211, USA; Division of Plant Sciences, University of Missouri, Columbia, MO 65211, USA; National Key Laboratory for Plant Cell Technology, Agricultural Genetics Institute, Hanoi, Vietnam
| | - Tyler J McCubbin
- Division of Biological Sciences, Interdisciplinary Plant Group, Missouri Maize Center, University of Missouri, Columbia, MO 65211, USA; Division of Plant Sciences, University of Missouri, Columbia, MO 65211, USA
| | - Saadia Bihmidine
- Division of Biological Sciences, Interdisciplinary Plant Group, Missouri Maize Center, University of Missouri, Columbia, MO 65211, USA
| | - Benjamin T Julius
- Division of Biological Sciences, Interdisciplinary Plant Group, Missouri Maize Center, University of Missouri, Columbia, MO 65211, USA
| | - R Frank Baker
- Division of Biological Sciences, Interdisciplinary Plant Group, Missouri Maize Center, University of Missouri, Columbia, MO 65211, USA
| | - Martin Schauflinger
- Electron Microscopy Core Facility, University of Missouri, Columbia, MO 65211, USA
| | - Clifford Weil
- Department of Agronomy, Purdue University, West Lafayette, IN 47907, USA
| | - Nathan Springer
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN 55108, USA
| | - Paul Chomet
- NRGene Inc., 8910 University Center Lane, ∖r∖nSuite 400, San Diego, CA 92122, USA
| | - Ruth Wagner
- Bayer Crop Science, Chesterfield, MO 63017, USA
| | | | - Karen Grote
- Bayer Crop Science, Chesterfield, MO 63017, USA
| | | | | | - David M Braun
- Division of Biological Sciences, Interdisciplinary Plant Group, Missouri Maize Center, University of Missouri, Columbia, MO 65211, USA.
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31
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Navarro JA, Sanchez-Navarro JA, Pallas V. Key checkpoints in the movement of plant viruses through the host. Adv Virus Res 2019; 104:1-64. [PMID: 31439146 DOI: 10.1016/bs.aivir.2019.05.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Plant viruses cannot exploit any of the membrane fusion-based routes of entry described for animal viruses. In addition, one of the distinctive structures of plant cells, the cell wall, acts as the first barrier against the invasion of pathogens. To overcome the rigidity of the cell wall, plant viruses normally take advantage of the way of life of different biological vectors. Alternatively, the physical damage caused by environmental stresses can facilitate virus entry. Once inside the cell and taking advantage of the characteristic symplastic continuity of plant cells, viruses need to remodel and/or modify the restricted pore size of the plasmodesmata (channels that connect plant cells). In a successful interaction for the virus, it can reach the vascular tissue to systematically invade the plant. The connections between the different cell types in this path are not designed to allow the passage of molecules with the complexity of viruses. During this process, viruses face different cell barriers that must be overcome to reach the distal parts of the plant. In this review, we highlight the current knowledge about how plant RNA viruses enter plant cells, move between them to reach vascular cells and overcome the different physical and cellular barriers that the phloem imposes. Finally, we update the current research on cellular organelles as key regulator checkpoints in the long-distance movement of plant viruses.
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Affiliation(s)
- Jose A Navarro
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Valencia, Spain
| | - Jesus A Sanchez-Navarro
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Valencia, Spain
| | - Vicente Pallas
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Valencia, Spain.
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32
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Enkavi G, Javanainen M, Kulig W, Róg T, Vattulainen I. Multiscale Simulations of Biological Membranes: The Challenge To Understand Biological Phenomena in a Living Substance. Chem Rev 2019; 119:5607-5774. [PMID: 30859819 PMCID: PMC6727218 DOI: 10.1021/acs.chemrev.8b00538] [Citation(s) in RCA: 184] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Indexed: 12/23/2022]
Abstract
Biological membranes are tricky to investigate. They are complex in terms of molecular composition and structure, functional over a wide range of time scales, and characterized by nonequilibrium conditions. Because of all of these features, simulations are a great technique to study biomembrane behavior. A significant part of the functional processes in biological membranes takes place at the molecular level; thus computer simulations are the method of choice to explore how their properties emerge from specific molecular features and how the interplay among the numerous molecules gives rise to function over spatial and time scales larger than the molecular ones. In this review, we focus on this broad theme. We discuss the current state-of-the-art of biomembrane simulations that, until now, have largely focused on a rather narrow picture of the complexity of the membranes. Given this, we also discuss the challenges that we should unravel in the foreseeable future. Numerous features such as the actin-cytoskeleton network, the glycocalyx network, and nonequilibrium transport under ATP-driven conditions have so far received very little attention; however, the potential of simulations to solve them would be exceptionally high. A major milestone for this research would be that one day we could say that computer simulations genuinely research biological membranes, not just lipid bilayers.
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Affiliation(s)
- Giray Enkavi
- Department
of Physics, University of
Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - Matti Javanainen
- Department
of Physics, University of
Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
- Institute
of Organic Chemistry and Biochemistry of the Czech Academy
of Sciences, Flemingovo naḿesti 542/2, 16610 Prague, Czech Republic
- Computational
Physics Laboratory, Tampere University, P.O. Box 692, FI-33014 Tampere, Finland
| | - Waldemar Kulig
- Department
of Physics, University of
Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - Tomasz Róg
- Department
of Physics, University of
Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
- Computational
Physics Laboratory, Tampere University, P.O. Box 692, FI-33014 Tampere, Finland
| | - Ilpo Vattulainen
- Department
of Physics, University of
Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
- Computational
Physics Laboratory, Tampere University, P.O. Box 692, FI-33014 Tampere, Finland
- MEMPHYS-Center
for Biomembrane Physics
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33
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Milewska-Hendel A, Witek W, Rypień A, Zubko M, Baranski R, Stróż D, Kurczyńska EU. The development of a hairless phenotype in barley roots treated with gold nanoparticles is accompanied by changes in the symplasmic communication. Sci Rep 2019; 9:4724. [PMID: 30886208 PMCID: PMC6423127 DOI: 10.1038/s41598-019-41164-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 02/26/2019] [Indexed: 11/09/2022] Open
Abstract
Uptake of water and nutrients by roots affects the ontogenesis of the whole plant. Nanoparticles, e.g. gold nanoparticles, have a broad range of applications in many fields which leads to the transfer of these materials into the environment. Thus, the understanding of their impact on the growth and development of the root system is an emerging issue. During our studies on the effect of positively charged gold nanoparticles on the barley roots, a hairless phenotype was found. We investigated whether this phenotype correlates with changes in symplasmic communication, which is an important factor that regulates, among others, differentiation of the rhizodermis into hair and non-hair cells. The results showed no restriction in symplasmic communication in the treated roots, in contrast to the control roots, in which the trichoblasts and atrichoblasts were symplasmically isolated during their differentiation. Moreover, differences concerning the root morphology, histology, ultrastructure and the cell wall composition were detected between the control and the treated roots. These findings suggest that the harmful effect of nanoparticles on plant growth may, among others, consist in disrupting the symplasmic communication/isolation, which leads to the development of a hairless root phenotype, thus limiting the functioning of the roots.
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Affiliation(s)
- Anna Milewska-Hendel
- Department of Cell Biology, Faculty of Biology and Environmental Protection, University of Silesia in Katowice, 28 Jagiellońska Street, 40-032, Katowice, Poland.
| | - Weronika Witek
- Department of Cell Biology, Faculty of Biology and Environmental Protection, University of Silesia in Katowice, 28 Jagiellońska Street, 40-032, Katowice, Poland
| | - Aleksandra Rypień
- Laboratory of Microscopy Techniques, Faculty of Biology and Environmental Protection, University of Silesia in Katowice, 28 Jagiellońska Street, 40-032, Katowice, Poland
| | - Maciej Zubko
- Institute of Materials Science, Faculty of Computer Science and Materials Science, University of Silesia in Katowice, 75 Pułku Piechoty Street 1a, Chorzów, 41-500, Poland
- Department of Physics, University of Hradec Králové, Hradec Králové, Czech Republic
| | - Rafal Baranski
- Institute of Plant Biology and Biotechnology, Faculty of Biotechnology and Horticulture, University of Agriculture in Krakow, Al. 29 Listopada 54, 31-425, Krakow, Poland
| | - Danuta Stróż
- Institute of Materials Science, Faculty of Computer Science and Materials Science, University of Silesia in Katowice, 75 Pułku Piechoty Street 1a, Chorzów, 41-500, Poland
| | - Ewa U Kurczyńska
- Department of Cell Biology, Faculty of Biology and Environmental Protection, University of Silesia in Katowice, 28 Jagiellońska Street, 40-032, Katowice, Poland.
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34
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Bobik K, Fernandez JC, Hardin SR, Ernest B, Ganusova EE, Staton ME, Burch-Smith TM. The essential chloroplast ribosomal protein uL15c interacts with the chloroplast RNA helicase ISE2 and affects intercellular trafficking through plasmodesmata. THE NEW PHYTOLOGIST 2019; 221:850-865. [PMID: 30192000 DOI: 10.1111/nph.15427] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 07/24/2018] [Indexed: 05/07/2023]
Abstract
Chloroplasts retain part of their ancestral genomes and the machinery for expression of those genomes. The nucleus-encoded chloroplast RNA helicase INCREASED SIZE EXCLUSION LIMIT2 (ISE2) is required for chloroplast ribosomal RNA processing and chloro-ribosome assembly. To further elucidate ISE2's role in chloroplast translation, two independent approaches were used to identify its potential protein partners. Both a yeast two-hybrid screen and a pull-down assay identified plastid ribosomal protein L15, uL15c (formerly RPL15), as interacting with ISE2. The interaction was confirmed in vivo by co-immunoprecipitation. Interestingly, we found that rpl15 null mutants do not complete embryogenesis, indicating that RPL15 is an essential gene for autotrophic growth of Arabidopsis thaliana. Arabidopsis and Nicotiana benthamiana plants with reduced expression of RPL15 developed chlorotic leaves, had reduced photosynthetic capacity and exhibited defective chloroplast development. Processing of chloroplast ribosomal RNAs and assembly of ribosomal subunits were disrupted by reduced expression of RPL15. Chloroplast translation was also decreased, reducing accumulation of chloroplast-encoded proteins, in such plants compared to wild-type plants. Notably, knockdown of RPL15 expression increased intercellular trafficking, a phenotype also observed in plants with reduced ISE2 expression. This finding provides further evidence for chloroplast function in modulating intercellular trafficking via plasmodesmata.
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Affiliation(s)
- Krzysztof Bobik
- Department of Biochemistry and Cellular & Molecular Biology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Jessica C Fernandez
- Department of Biochemistry and Cellular & Molecular Biology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Sara R Hardin
- Department of Biochemistry and Cellular & Molecular Biology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Ben Ernest
- School of Genome Science and Technology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Elena E Ganusova
- Department of Biochemistry and Cellular & Molecular Biology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Margaret E Staton
- Department of Entomology and Plant Pathology, University of Tennessee Institute of Agriculture, Knoxville, TN, 37996, USA
| | - Tessa M Burch-Smith
- Department of Biochemistry and Cellular & Molecular Biology, University of Tennessee, Knoxville, TN, 37996, USA
- School of Genome Science and Technology, University of Tennessee, Knoxville, TN, 37996, USA
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35
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Wu SW, Kumar R, Iswanto ABB, Kim JY. Callose balancing at plasmodesmata. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:5325-5339. [PMID: 30165704 DOI: 10.1093/jxb/ery317] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 08/20/2018] [Indexed: 05/19/2023]
Abstract
In plants, communication and molecular exchanges between different cells and tissues are dependent on the apoplastic and symplastic pathways. Symplastic molecular exchanges take place through the plasmodesmata, which connect the cytoplasm of neighboring cells in a highly controlled manner. Callose, a β-1,3-glucan polysaccharide, is a plasmodesmal marker molecule that is deposited in cell walls near the neck zone of plasmodesmata and controls their permeability. During cell differentiation and plant development, and in response to diverse stresses, the level of callose in plasmodesmata is highly regulated by two antagonistic enzymes, callose synthase or glucan synthase-like and β-1,3-glucanase. The diverse modes of regulation by callose synthase and β-1,3-glucanase have been uncovered in the past decades through biochemical, molecular, genetic, and omics methods. This review highlights recent findings regarding the function of plasmodesmal callose and the molecular players involved in callose metabolism, and provides new insight into the mechanisms maintaining plasmodesmal callose homeostasis.
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Affiliation(s)
- Shu-Wei Wu
- Division of Applied Life Science (BK21 Plus program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Republic of Korea
| | - Ritesh Kumar
- Division of Applied Life Science (BK21 Plus program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Republic of Korea
| | - Arya Bagus Boedi Iswanto
- Division of Applied Life Science (BK21 Plus program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Republic of Korea
| | - Jae-Yean Kim
- Division of Applied Life Science (BK21 Plus program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Republic of Korea
- Division of Life Science (CK1 program), Gyeongsang National University, Jinju, Republic of Korea
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36
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Reagan BC, Ganusova EE, Fernandez JC, McCray TN, Burch-Smith TM. RNA on the move: The plasmodesmata perspective. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2018; 275:1-10. [PMID: 30107876 DOI: 10.1016/j.plantsci.2018.07.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 05/25/2018] [Accepted: 07/04/2018] [Indexed: 05/11/2023]
Abstract
It is now widely accepted that plant RNAs can have effects at sites far away from their sites of synthesis. Cellular mRNA transcripts, endogenous small RNAs and defense-related small RNAs all move from cell to cell via plasmodesmata (PD), and may even move long distances in the phloem. Despite their small size, PD have complicated substructures, and the area of the pore available for RNA trafficking can be remarkably small. The intent of this review is to bring into focus the role of PD in cell-to-cell and long distance communication in plants. We consider how cellular RNAs could move through the cell to the PD and thence through PD. The protein composition of PD and the possible roles of PD proteins in RNA trafficking are also discussed. Recent evidence for RNA metabolism in organelles acting as a factor in controlling PD flux is also presented, highlighting new aspects of plant intra- and intercellular communication. It is clear that while the phenomenon of RNA mobility is common and essential, many questions remain, and these have been highlighted throughout this review.
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Affiliation(s)
- Brandon C Reagan
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, United States
| | - Elena E Ganusova
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, United States
| | - Jessica C Fernandez
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, United States
| | - Tyra N McCray
- School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37996, United States
| | - Tessa M Burch-Smith
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, United States; School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37996, United States.
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37
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Gating of miRNA movement at defined cell-cell interfaces governs their impact as positional signals. Nat Commun 2018; 9:3107. [PMID: 30082703 PMCID: PMC6079027 DOI: 10.1038/s41467-018-05571-0] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 07/13/2018] [Indexed: 01/02/2023] Open
Abstract
Mobile small RNAs serve as local positional signals in development and coordinate stress responses across the plant. Despite its central importance, an understanding of how the cell-to-cell movement of small RNAs is governed is lacking. Here, we show that miRNA mobility is precisely regulated through a gating mechanism polarised at defined cell–cell interfaces. This generates directional movement between neighbouring cells that limits long-distance shoot-to-root trafficking, and underpins domain-autonomous behaviours of small RNAs within stem cell niches. We further show that the gating of miRNA mobility occurs independent of mechanisms controlling protein movement, identifying the small RNA as the mobile unit. These findings reveal gate-keepers of cell-to-cell small RNA mobility generate selectivity in long-distance signalling, and help safeguard functional domains within dynamic stem cell niches while mitigating a ‘signalling gridlock’ in contexts where developmental patterning events occur in close spatial and temporal vicinity. Movement of small RNA between cells is critical to plant development and stress responses. Here the authors uncover a gate-keeping mechanism that can restrict small RNA movement at cell-cell interfaces, providing selectivity in long-distance signalling and limiting the scope of local mobility.
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38
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Liang D. A Salutary Role of Reactive Oxygen Species in Intercellular Tunnel-Mediated Communication. Front Cell Dev Biol 2018; 6:2. [PMID: 29503816 PMCID: PMC5821100 DOI: 10.3389/fcell.2018.00002] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 01/18/2018] [Indexed: 12/17/2022] Open
Abstract
The reactive oxygen species, generally labeled toxic due to high reactivity without target specificity, are gradually uncovered as signaling molecules involved in a myriad of biological processes. But one important feature of ROS roles in macromolecule movement has not caught attention until recent studies with technique advance and design elegance have shed lights on ROS signaling for intercellular and interorganelle communication. This review begins with the discussions of genetic and chemical studies on the regulation of symplastic dye movement through intercellular tunnels in plants (plasmodesmata), and focuses on the ROS regulatory mechanisms concerning macromolecule movement including small RNA-mediated gene silencing movement and protein shuttling between cells. Given the premise that intercellular tunnels (bridges) in mammalian cells are the key physical structures to sustain intercellular communication, movement of macromolecules and signals is efficiently facilitated by ROS-induced membrane protrusions formation, which is analogously applied to the interorganelle communication in plant cells. Although ROS regulatory differences between plant and mammalian cells exist, the basis for ROS-triggered conduit formation underlies a unifying conservative theme in multicellular organisms. These mechanisms may represent the evolutionary advances that have enabled multicellularity to gain the ability to generate and utilize ROS to govern material exchanges between individual cells in oxygenated environment.
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Affiliation(s)
- Dacheng Liang
- Hubei Collaborative Innovation Center for Grain Industry, School of Agriculture, Yangtze University, Jingzhou, China.,Engineering Research Center of Ecology and Agricultural Use of Wetland, Ministry of Education, Yangtze University, Jingzhou, China
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39
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Lu KJ, De Rybel B, van Mourik H, Weijers D. Regulation of intercellular TARGET OF MONOPTEROS 7 protein transport in the Arabidopsis root. Development 2018; 145:dev.152892. [PMID: 29358212 DOI: 10.1242/dev.152892] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 12/13/2017] [Indexed: 01/24/2023]
Abstract
Intercellular communication coordinates hypophysis establishment in the Arabidopsis embryo. Previously, TARGET OF MONOPTEROS 7 (TMO7) was reported to be transported to the hypophysis, the founder cell of the root cap, and RNA suppression experiments implicated its function in embryonic root development. However, the protein properties and mechanisms mediating TMO7 protein transport, and the role the movement plays in development remained unclear. Here, we report that in the post-embryonic root, TMO7 and its close relatives are transported into the root cap through plasmodesmata in a sequence-dependent manner. We also show that nuclear residence is crucial for TMO7 transport, and postulate that modification, potentially phosphorylation, labels TMO7 for transport. Additionally, three novel CRISPR/Cas9-induced tmo7 alleles confirmed a role in hypophysis division, but suggest complex redundancies with close relatives in root formation. Finally, we demonstrate that TMO7 transport is biologically meaningful, as local expression partially restores hypophysis division in a plasmodesmal protein transport mutant. Our study identifies motifs and amino acids that are pivotal for TMO7 protein transport, and establishes the importance of TMO7 in hypophysis and root development.
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Affiliation(s)
- Kuan-Ju Lu
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Bert De Rybel
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, The Netherlands.,Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 927, 9052 Ghent, Belgium.,VIB Center for Plant Systems Biology, Technologiepark 927, 9052 Ghent, Belgium
| | - Hilda van Mourik
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Dolf Weijers
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
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40
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Canales J, Henriquez-Valencia C, Brauchi S. The Integration of Electrical Signals Originating in the Root of Vascular Plants. FRONTIERS IN PLANT SCIENCE 2018; 8:2173. [PMID: 29375591 PMCID: PMC5767606 DOI: 10.3389/fpls.2017.02173] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 12/12/2017] [Indexed: 05/07/2023]
Abstract
Plants have developed different signaling systems allowing for the integration of environmental cues to coordinate molecular processes associated to both early development and the physiology of the adult plant. Research on systemic signaling in plants has traditionally focused on the role of phytohormones as long-distance signaling molecules, and more recently the importance of peptides and miRNAs in building up this communication process has also been described. However, it is well-known that plants have the ability to generate different types of long-range electrical signals in response to different stimuli such as light, temperature variations, wounding, salt stress, or gravitropic stimulation. Presently, it is unclear whether short or long-distance electrical communication in plants is linked to nutrient uptake. This review deals with aspects of sensory input in plant roots and the propagation of discrete signals to the plant body. We discuss the physiological role of electrical signaling in nutrient uptake and how nutrient variations may become an electrical signal propagating along the plant.
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Affiliation(s)
- Javier Canales
- Facultad de Ciencias, Instituto de Bioquimica y Microbiologia, Universidad Austral de Chile, Valdivia, Chile
- Millennium Institute for Integrative Systems and Synthetic Biology, Santiago, Chile
| | - Carlos Henriquez-Valencia
- Facultad de Ciencias, Instituto de Bioquimica y Microbiologia, Universidad Austral de Chile, Valdivia, Chile
| | - Sebastian Brauchi
- Facultad de Medicina, Instituto de Fisiologia, Universidad Austral de Chile, Valdivia, Chile
- Millennium Nucleus of Ion Channels-Associated Diseases, Valdivia, Chile
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41
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Reagan BC, Kim PJY, Perry PD, Dunlap JR, Burch-Smith TM. Spatial distribution of organelles in leaf cells and soybean root nodules revealed by focused ion beam-scanning electron microscopy. FUNCTIONAL PLANT BIOLOGY : FPB 2018; 45:180-191. [PMID: 32291032 DOI: 10.1071/fp16347] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Accepted: 12/23/2016] [Indexed: 06/11/2023]
Abstract
Analysis of cellular ultrastructure has been dominated by transmission electron microscopy (TEM), so images collected by this technique have shaped our current understanding of cellular structure. More recently, three-dimensional (3D) analysis of organelle structures has typically been conducted using TEM tomography. However, TEM tomography application is limited by sample thickness. Focused ion beam-scanning electron microscopy (FIB-SEM) uses a dual beam system to perform serial sectioning and imaging of a sample. Thus FIB-SEM is an excellent alternative to TEM tomography and serial section TEM tomography. Animal tissue samples have been more intensively investigated by this technique than plant tissues. Here, we show that FIB-SEM can be used to study the 3D ultrastructure of plant tissues in samples previously prepared for TEM via commonly used fixation and embedding protocols. Reconstruction of FIB-SEM sections revealed ultra-structural details of the plant tissues examined. We observed that organelles packed tightly together in Nicotiana benthamiana Domin leaf cells may form membrane contacts. 3D models of soybean nodule cells suggest that the bacteroids in infected cells are contained within one large membrane-bound structure and not the many individual symbiosomes that TEM thin-sections suggest. We consider the implications of these organelle arrangements for intercellular signalling.
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Affiliation(s)
- Brandon C Reagan
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, 1414 Cumberland Avenue , Knoxville ,TN 37996, USA
| | - Paul J-Y Kim
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, 1414 Cumberland Avenue , Knoxville ,TN 37996, USA
| | - Preston D Perry
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, 1414 Cumberland Avenue , Knoxville ,TN 37996, USA
| | - John R Dunlap
- Advanced Microscopy and Imaging Center, University of Tennessee, Knoxville, 1499 Circle Dr Knoxville, TN 37996, USA
| | - Tessa M Burch-Smith
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, 1414 Cumberland Avenue , Knoxville ,TN 37996, USA
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42
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Leijon F, Melzer M, Zhou Q, Srivastava V, Bulone V. Proteomic Analysis of Plasmodesmata From Populus Cell Suspension Cultures in Relation With Callose Biosynthesis. FRONTIERS IN PLANT SCIENCE 2018; 9:1681. [PMID: 30510561 PMCID: PMC6252348 DOI: 10.3389/fpls.2018.01681] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 10/29/2018] [Indexed: 05/19/2023]
Abstract
Plasmodesmata are channels that link adjacent cells in plant tissues through which molecular exchanges take place. They are involved in multiple processes vital to plant cells, such as responses to hormonal signaling or environmental challenges including osmotic stress, wounding and pathogen attack. Despite the importance of plasmodesmata, their proteome is not well-defined. Here, we have isolated fractions enriched in plasmodesmata from cell suspension cultures of Populus trichocarpa and identified 201 proteins that are enriched in these fractions, thereby providing further insight on the multiple functions of plasmodesmata. Proteomics analysis revealed an enrichment of proteins specifically involved in responses to stress, transport, metabolism and signal transduction. Consistent with the role of callose deposition and turnover in the closure and aperture of the plasmodesmata and our proteomic analysis, we demonstrate the enrichment of callose synthase activity in the plasmodesmata represented by several gene products. A new form of calcium-independent callose synthase activity was detected, in addition to the typical calcium-dependent enzyme activity, suggesting a role of calcium in the regulation of plasmodesmata through two forms of callose synthase activities. Our report provides the first proteomic investigation of the plasmodesmata from a tree species and the direct biochemical evidence for the occurrence of several forms of active callose synthases in these structures. Data are available via ProteomeXchange with identifier PXD010692.
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Affiliation(s)
- Felicia Leijon
- Division of Glycoscience, School of Engineering Sciences in Chemistry, Biotechnology and Health, Royal Institute of Technology, AlbaNova University Centre, Stockholm, Sweden
| | - Michael Melzer
- Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany
| | - Qi Zhou
- Division of Glycoscience, School of Engineering Sciences in Chemistry, Biotechnology and Health, Royal Institute of Technology, AlbaNova University Centre, Stockholm, Sweden
| | - Vaibhav Srivastava
- Division of Glycoscience, School of Engineering Sciences in Chemistry, Biotechnology and Health, Royal Institute of Technology, AlbaNova University Centre, Stockholm, Sweden
- *Correspondence: Vaibhav Srivastava, Vincent Bulone,
| | - Vincent Bulone
- Division of Glycoscience, School of Engineering Sciences in Chemistry, Biotechnology and Health, Royal Institute of Technology, AlbaNova University Centre, Stockholm, Sweden
- ARC Centre of Excellence in Plant Cell Walls and School of Agriculture, Food and Wine, The University of Adelaide, Adelaide, SA, Australia
- *Correspondence: Vaibhav Srivastava, Vincent Bulone,
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Dorokhov YL, Sheshukova EV, Komarova TV. Methanol in Plant Life. FRONTIERS IN PLANT SCIENCE 2018; 9:1623. [PMID: 30473703 PMCID: PMC6237831 DOI: 10.3389/fpls.2018.01623] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 10/18/2018] [Indexed: 05/19/2023]
Abstract
Until recently, plant-emitted methanol was considered a biochemical by-product, but studies in the last decade have revealed its role as a signal molecule in plant-plant and plant-animal communication. Moreover, methanol participates in metabolic biochemical processes during growth and development. The purpose of this review is to determine the impact of methanol on the growth and immunity of plants. Plants generate methanol in the reaction of the demethylation of macromolecules including DNA and proteins, but the main source of plant-derived methanol is cell wall pectins, which are demethylesterified by pectin methylesterases (PMEs). Methanol emissions increase in response to mechanical wounding or other stresses due to damage of the cell wall, which is the main source of methanol production. Gaseous methanol from the wounded plant induces defense reactions in intact leaves of the same and neighboring plants, activating so-called methanol-inducible genes (MIGs) that regulate plant resistance to biotic and abiotic factors. Since PMEs are the key enzymes in methanol production, their expression increases in response to wounding, but after elimination of the stress factor effects, the plant cell should return to the original state. The amount of functional PMEs in the cell is strictly regulated at both the gene and protein levels. There is negative feedback between one of the MIGs, aldose epimerase-like protein, and PME gene transcription; moreover, the enzymatic activity of PMEs is modulated and controlled by PME inhibitors (PMEIs), which are also induced in response to pathogenic attack.
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Affiliation(s)
- Yuri L. Dorokhov
- N.I. Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russia
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- *Correspondence: Yuri L. Dorokhov,
| | | | - Tatiana V. Komarova
- N.I. Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russia
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
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Park SH, Li F, Renaud J, Shen W, Li Y, Guo L, Cui H, Sumarah M, Wang A. NbEXPA1, an α-expansin, is plasmodesmata-specific and a novel host factor for potyviral infection. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 92:846-861. [PMID: 28941316 DOI: 10.1111/tpj.13723] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 09/01/2017] [Accepted: 09/07/2017] [Indexed: 05/23/2023]
Abstract
Plasmodesmata (PD), unique to the plant kingdom, are structurally complex microchannels that cross the cell wall to establish symplastic communication between neighbouring cells. Viral intercellular movement occurs through PD. To better understand the involvement of PD in viral infection, we conducted a quantitative proteomic study on the PD-enriched fraction from Nicotiana benthamiana leaves in response to infection by Turnip mosaic virus (TuMV). We report the identification of a total of 1070 PD protein candidates, of which 100 (≥2-fold increase) and 48 (≥2-fold reduction) are significantly differentially accumulated in the PD-enriched fraction, when compared with protein levels in the corresponding healthy control. Among the differentially accumulated PD protein candidates, we show that an α-expansin designated NbEXPA1, a cell wall loosening protein, is PD-specific. TuMV infection downregulates NbEXPA1 mRNA expression and protein accumulation. We further demonstrate that NbEXPA1 is recruited to the viral replication complex via the interaction with NIb, the only RNA-dependent RNA polymerase of TuMV. Silencing of NbEXPA1 inhibits plant growth and TuMV infection, whereas overexpression of NbEXPA1 promotes viral replication and intercellular movement. These data suggest that NbEXPA1 is a host factor for potyviral infection. This study not only generates a PD-proteome dataset that is useful in future studies to expound PD biology and PD-mediated virus-host interactions but also characterizes NbEXPA1 as the first PD-specific cell wall loosening protein and its essential role in potyviral infection.
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Affiliation(s)
- Sang-Ho Park
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, N5V 4T3, Canada
- Department of Biology, Western University, London, ON, N6A 5B7, Canada
| | - Fangfang Li
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, N5V 4T3, Canada
| | - Justin Renaud
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, N5V 4T3, Canada
| | - Wentao Shen
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, N5V 4T3, Canada
- Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, Hainan, 571101, China
| | - Yinzi Li
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, N5V 4T3, Canada
- Department of Biology, Western University, London, ON, N6A 5B7, Canada
| | - Lihua Guo
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, N5V 4T3, Canada
- Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Hongguang Cui
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, N5V 4T3, Canada
| | - Mark Sumarah
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, N5V 4T3, Canada
| | - Aiming Wang
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, N5V 4T3, Canada
- Department of Biology, Western University, London, ON, N6A 5B7, Canada
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45
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Maurya JP, Bhalerao RP. Photoperiod- and temperature-mediated control of growth cessation and dormancy in trees: a molecular perspective. ANNALS OF BOTANY 2017; 120:351-360. [PMID: 28605491 PMCID: PMC5591416 DOI: 10.1093/aob/mcx061] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Indexed: 05/03/2023]
Abstract
BACKGROUND How plants adapt their developmental patterns to regular seasonal changes is an important question in biology. The annual growth cycle in perennial long-lived trees is yet another example of how plants can adapt to seasonal changes. The two main signals that plants rely on to respond to seasonal changes are photoperiod and temperature, and these signals have critical roles in the temporal regulation of the annual growth cycle of trees. SCOPE This review presents the latest findings to provide insight into the molecular mechanisms that underlie how photoperiodic and temperature signals regulate seasonal growth in trees. CONCLUSION The results point to a high level of conservation in the signalling pathways that mediate photoperiodic control of seasonal growth in trees and flowering in annual plants such as arabidopsis. Furthermore, the data indicate that symplastic communication may mediate certain aspects of seasonal growth. Although considerable insight into the control of phenology in model plants such as poplar and spruce has been obtained, the future challenge is extending these studies to other, non-model trees.
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Affiliation(s)
- Jay P Maurya
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden
| | - Rishikesh P Bhalerao
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden
- For correspondence. E-mail
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Ye ZW, Chen QF, Chye ML. Arabidopsis thaliana Acyl-CoA-binding protein ACBP6 interacts with plasmodesmata-located protein PDLP8. PLANT SIGNALING & BEHAVIOR 2017; 12:e1359365. [PMID: 28786767 PMCID: PMC5616145 DOI: 10.1080/15592324.2017.1359365] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 07/19/2017] [Accepted: 07/20/2017] [Indexed: 05/22/2023]
Abstract
In Arabidopsis thaliana, six acyl-CoA-binding proteins (ACBPs), designated as AtACBP1 to AtACBP6, have been identified to function in various events related to plant stress and development. The 10-kDa AtACBP6 is the smallest in this protein family, and recombinant AtACBP6 interacts with lipids in vitro by binding to acyl-CoA esters and phosphatidylcholine. Using anti-AtACBP6 antibodies in immunoelectron microscopy, we have localized AtACBP6 in the Arabidopsis phloem. The detection of immunogold grains in the plasmodesmata suggested that AtACBP6 could move from the companion cells to the sieve elements via the plasmodesmata. As AtACBP6 has been identified in a membrane-based interactome analysis to be a potential protein partner of Plasmodesmata-Localized Protein, PDLP8, AtACBP6-PDLP8 interaction was investigated herein utilizing isothermal titration calorimetry, as well as pull-down and bimolecular fluorescence complementation assays (BiFC). Notably, BiFC data revealed that AtACBP6-PDLP8 interaction occurred at the plasma membrane, which was unexpected as AtACBP6 has been previously identified in the cytosol. AtACBP6 expression was generally higher than PDLP8 in β-glucuronidase (GUS) assays on transgenic Arabidopsis transformed with AtACBP6 or PDLP8 promoter-driven GUS, consistent with qRT-PCR and microarray results. Furthermore, western blot analysis using anti-AtACBP6 antibodies showed a reduction in AtACBP6 expression in the pdlp8 T-DNA insertional mutant, suggesting that PDLP8 may possibly influence AtACBP6 accumulation in the sieve elements, probably in the plasmodesmata, where PDLP8 is confined and to where AtACBP6 has been immunodetected.
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Affiliation(s)
- Zi-Wei Ye
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Qin-Fang Chen
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Mee-Len Chye
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
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Dmitrieva VA, Ivanova AN, Tyutereva EV, Evkaikina AI, Klimova EA, Voitsekhovskaja OV. Chlorophyllide-a-Oxygenase (CAO) deficiency affects the levels of singlet oxygen and formation of plasmodesmata in leaves and shoot apical meristems of barley. PLANT SIGNALING & BEHAVIOR 2017; 12:e1300732. [PMID: 28272988 PMCID: PMC5437820 DOI: 10.1080/15592324.2017.1300732] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 02/20/2017] [Accepted: 02/21/2017] [Indexed: 05/19/2023]
Abstract
In plants, organogenesis and specification of cell layers and tissues rely on precise symplastic delivery of regulatory molecules via plasmodesmata. Accordingly, abundance and aperture of plasmodesmata at individual cell boundaries should be controlled by the plant. Recently, studies in Arabidopsis established reactive oxygen species as major regulators of plasmodesmata formation and gating. We show that in a barley mutant deficient in the synthesis of chlorophyll b, the numbers of plasmodesmata in leaves and in the shoot apical meristem are significantly higher than in the corresponding wild type, probably due to redox imbalance in the mutant. The resulting disturbance of symplasmic transport is likely to be the reason for the observed delayed floral transition in these mutants.
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Affiliation(s)
- Valeria A. Dmitrieva
- Laboratory of Plant Ecological Physiology, Komarov Botanical Institute, Russian Academy of Sciences, St.-Petersburg, Russia
| | - Alexandra N. Ivanova
- Laboratory of Plant Ecological Physiology, Komarov Botanical Institute, Russian Academy of Sciences, St.-Petersburg, Russia
- Laboratory of Plant Anatomy and Morphology, Komarov Botanical Institute, Russian Academy of Sciences, St.-Petersburg, Russia
| | - Elena V. Tyutereva
- Laboratory of Plant Ecological Physiology, Komarov Botanical Institute, Russian Academy of Sciences, St.-Petersburg, Russia
| | - Anastasiia I. Evkaikina
- Laboratory of Plant Ecological Physiology, Komarov Botanical Institute, Russian Academy of Sciences, St.-Petersburg, Russia
| | - Ekaterina A. Klimova
- Laboratory of Plant Ecological Physiology, Komarov Botanical Institute, Russian Academy of Sciences, St.-Petersburg, Russia
| | - Olga V. Voitsekhovskaja
- Laboratory of Plant Ecological Physiology, Komarov Botanical Institute, Russian Academy of Sciences, St.-Petersburg, Russia
- CONTACT Olga V. Voitsekhovskaja Plant Ecological Physiology, Komarov Botanical Institute RAS, ul. Professora Popova, 2, Saint Petersburg, 197376, Russia
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48
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Kitagawa M, Jackson D. Plasmodesmata-Mediated Cell-to-Cell Communication in the Shoot Apical Meristem: How Stem Cells Talk. PLANTS (BASEL, SWITZERLAND) 2017; 6:E12. [PMID: 28257070 PMCID: PMC5371771 DOI: 10.3390/plants6010012] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 02/23/2017] [Indexed: 01/30/2023]
Abstract
Positional information is crucial for the determination of plant cell fates, and it is established based on coordinated cell-to-cell communication, which in turn is essential for plant growth and development. Plants have evolved a unique communication pathway, with tiny channels called plasmodesmata (PD) spanning the cell wall. PD interconnect most cells in the plant and generate a cytoplasmic continuum, to mediate short- and long-distance trafficking of various molecules. Cell-to-cell communication through PD plays a role in transmitting positional signals, however, the regulatory mechanisms of PD-mediated trafficking are still largely unknown. The induction and maintenance of stem cells in the shoot apical meristem (SAM) depends on PDmediated cell-to-cell communication, hence, it is an optimal model for dissecting the regulatory mechanisms of PD-mediated cell-to-cell communication and its function in specifying cell fates. In this review, we summarize recent knowledge of PD-mediated cell-to-cell communication in the SAM, and discuss mechanisms underlying molecular trafficking through PD and its role in plant development.
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Affiliation(s)
- Munenori Kitagawa
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA.
| | - David Jackson
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA.
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49
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Wróbel-Marek J, Kurczyńska E, Płachno BJ, Kozieradzka-Kiszkurno M. Identification of symplasmic domains in the embryo and seed of Sedum acre L. (Crassulaceae). PLANTA 2017; 245:491-505. [PMID: 27888360 PMCID: PMC5310571 DOI: 10.1007/s00425-016-2619-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 11/16/2016] [Indexed: 05/10/2023]
Abstract
MAIN CONCLUSION Our study demonstrated that symplasmic communication between Sedum acre seed compartments and the embryo proper is not uniform. The presence of plasmodesmata (PD) constitutes the structural basis for information exchange between cells, and symplasmic communication is involved in the regulation of cell differentiation and plant development. Most recent studies concerning an analysis of symplasmic communication between seed compartments and the embryo have been predominantly performed on Arabidopsis thaliana. The results presented in this paper describe the analysis of symplasmic communication on the example of Sedum acre seeds, because the ultrastructure of the seed compartments and the embryo proper, including the PD, have already been described, and this species represents an embryonic type of development different to Arabidopsis. Moreover, in this species, an unusual electron-dense dome associated with plasmodesmata on the border between the basal cell/chalazal suspensor cells and the basal cell/the endosperm has been described. This prompted the question as to whether these plasmodesmata are functional. Thus, the aim of this study was to describe the movement of symplasmic transport fluorochromes between different Sedum seed compartments, with particular emphasis on the movement between the basal cell and the embryo proper and endosperm, to answer the following questions: (1) are seeds divided into symplasmic domains; (2) if so, are they stable or do they change with the development? The results have shown that symplasmic tracers movement: (a) from the external integument to internal integument is restricted; (b) from the basal cell to the other part of the embryo proper and from the basal cell to the endosperm is also restricted;
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Affiliation(s)
- Justyna Wróbel-Marek
- Department of Cell Biology, University of Silesia, Jagiellońska 28, 40-032, Katowice, Poland
| | - Ewa Kurczyńska
- Department of Cell Biology, University of Silesia, Jagiellońska 28, 40-032, Katowice, Poland
| | - Bartosz J Płachno
- Department of Plant Cytology and Embryology, Jagiellonian University in Kraków, Gronostajowa 9, 30-387, Kraków, Poland
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Brunkard JO, Zambryski PC. Plasmodesmata enable multicellularity: new insights into their evolution, biogenesis, and functions in development and immunity. CURRENT OPINION IN PLANT BIOLOGY 2017; 35:76-83. [PMID: 27889635 DOI: 10.1016/j.pbi.2016.11.007] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 11/04/2016] [Accepted: 11/08/2016] [Indexed: 05/19/2023]
Abstract
Plant cells are connected by plasmodesmata (PD), cytosolic bridges that allow molecules to freely move across the cell wall. Recently resolved relationships among land plants and their algal relatives reveal that land plants evolved PD independently from algae. Proteomic and genetic screens illuminate new dimensions of the structural and regulatory pathways that control PD biogenesis. Biochemical studies demonstrate that immunological signals induce systemic defenses by moving from diseased cells through PD; subsequently, PD transport is restricted to quarantine diseased cells. Here, we review our expanding knowledge of the roles of PD in plant development, physiology, and immunity.
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Affiliation(s)
- Jacob O Brunkard
- Plant Gene Expression Center, USDA Agricultural Research Service, 800 Buchanan Street, Albany, CA 94710, USA
| | - Patricia C Zambryski
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA.
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