751
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Chen LQ, Lin IW, Qu XQ, Sosso D, McFarlane HE, Londoño A, Samuels AL, Frommer WB. A cascade of sequentially expressed sucrose transporters in the seed coat and endosperm provides nutrition for the Arabidopsis embryo. THE PLANT CELL 2015; 27:607-19. [PMID: 25794936 PMCID: PMC4558658 DOI: 10.1105/tpc.114.134585] [Citation(s) in RCA: 252] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 02/06/2015] [Accepted: 02/26/2015] [Indexed: 05/18/2023]
Abstract
Developing plant embryos depend on nutrition from maternal tissues via the seed coat and endosperm, but the mechanisms that supply nutrients to plant embryos have remained elusive. Sucrose, the major transport form of carbohydrate in plants, is delivered via the phloem to the maternal seed coat and then secreted from the seed coat to feed the embryo. Here, we show that seed filling in Arabidopsis thaliana requires the three sucrose transporters SWEET11, 12, and 15. SWEET11, 12, and 15 exhibit specific spatiotemporal expression patterns in developing seeds, but only a sweet11;12;15 triple mutant showed severe seed defects, which include retarded embryo development, reduced seed weight, and reduced starch and lipid content, causing a "wrinkled" seed phenotype. In sweet11;12;15 triple mutants, starch accumulated in the seed coat but not the embryo, implicating SWEET-mediated sucrose efflux in the transfer of sugars from seed coat to embryo. This cascade of sequentially expressed SWEETs provides the feeding pathway for the plant embryo, an important feature for yield potential.
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Affiliation(s)
- Li-Qing Chen
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - I Winnie Lin
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 Department of Biology, Stanford University, Stanford, California 94305
| | - Xiao-Qing Qu
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Davide Sosso
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Heather E McFarlane
- Department of Botany, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Alejandra Londoño
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - A Lacey Samuels
- Department of Botany, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Wolf B Frommer
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
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752
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The host plant metabolite glucose is the precursor of diffusible signal factor (DSF) family signals in Xanthomonas campestris. Appl Environ Microbiol 2015; 81:2861-8. [PMID: 25681189 DOI: 10.1128/aem.03813-14] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Plant pathogen Xanthomonas campestris pv. campestris produces cis-11-methyl-2-dodecenoic acid (diffusible signal factor [DSF]) as a cell-cell communication signal to regulate biofilm dispersal and virulence factor production. Previous studies have demonstrated that DSF biosynthesis is dependent on the presence of RpfF, an enoyl-coenzyme A (CoA) hydratase, but the DSF synthetic mechanism and the influence of the host plant on DSF biosynthesis are still not clear. We show here that exogenous addition of host plant juice or ethanol extract to the growth medium of X. campestris pv. campestris could significantly boost DSF family signal production. It was subsequently revealed that X. campestris pv. campestris produces not only DSF but also BDSF (cis-2-dodecenoic acid) and another novel DSF family signal, which was designated DSF-II. BDSF was originally identified in Burkholderia cenocepacia to be involved in regulation of motility, biofilm formation, and virulence in B. cenocepacia. Functional analysis suggested that DSF-II plays a role equal to that of DSF in regulation of biofilm dispersion and virulence factor production in X. campestris pv. campestris. Furthermore, chromatographic separation led to identification of glucose as a specific molecule stimulating DSF family signal biosynthesis in X. campestris pv. campestris. (13)C-labeling experiments demonstrated that glucose acts as a substrate to provide a carbon element for DSF biosynthesis. The results of this study indicate that X. campestris pv. campestris could utilize a common metabolite of the host plant to enhance DSF family signal synthesis and therefore promote virulence.
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753
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Williams JS, Wu L, Li S, Sun P, Kao TH. Insight into S-RNase-based self-incompatibility in Petunia: recent findings and future directions. FRONTIERS IN PLANT SCIENCE 2015; 6:41. [PMID: 25699069 PMCID: PMC4318427 DOI: 10.3389/fpls.2015.00041] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 01/15/2015] [Indexed: 05/29/2023]
Abstract
S-RNase-based self-incompatibility in Petunia is a self/non-self recognition system that allows the pistil to reject self-pollen to prevent inbreeding and to accept non-self pollen for outcrossing. Cloning of S-RNase in 1986 marked the beginning of nearly three decades of intensive research into the mechanism of this complex system. S-RNase was shown to be the sole female determinant in 1994, and the first male determinant, S-locus F-box protein1 (SLF1), was identified in 2004. It was discovered in 2010 that additional SLF proteins are involved in pollen specificity, and recently two S-haplotypes of Petunia inflata were found to possess 17 SLF genes based on pollen transcriptome analysis, further increasing the complexity of the system. Here, we first summarize the current understanding of how the interplay between SLF proteins and S-RNase in the pollen tube allows cross-compatible pollination, but results in self-incompatible pollination. We then discuss some of the aspects that are not yet elucidated, including uptake of S-RNase into the pollen tube, nature, and assembly of SLF-containing complexes, the biochemical basis for differential interactions between SLF proteins and S-RNase, and fate of non-self S-RNases in the pollen tube.
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Affiliation(s)
- Justin S. Williams
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA, USA
| | - Lihua Wu
- Intercollege Graduate Degree Program in Plant Biology, Pennsylvania State University, University Park, PA, USA
| | - Shu Li
- Intercollege Graduate Degree Program in Plant Biology, Pennsylvania State University, University Park, PA, USA
| | - Penglin Sun
- Intercollege Graduate Degree Program in Plant Biology, Pennsylvania State University, University Park, PA, USA
| | - Teh-Hui Kao
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA, USA
- Intercollege Graduate Degree Program in Plant Biology, Pennsylvania State University, University Park, PA, USA
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754
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Wang C, Zhang X, Fan Y, Gao Y, Zhu Q, Zheng C, Qin T, Li Y, Che J, Zhang M, Yang B, Liu Y, Zhao K. XA23 is an executor R protein and confers broad-spectrum disease resistance in rice. MOLECULAR PLANT 2015; 8:290-302. [PMID: 25616388 DOI: 10.1016/j.molp.2014.10.010] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Revised: 10/10/2014] [Accepted: 10/28/2014] [Indexed: 05/03/2023]
Abstract
The majority of plant disease resistance (R) genes encode proteins that share common structural features. However, the transcription activator-like effector (TALE)-associated executor type R genes show no considerable sequence homology to any known R genes. We adopted a map-based cloning approach and TALE-based technology to isolate and characterize Xa23, a new executor R gene derived from wild rice (Oryza rufipogon) that confers an extremely broad spectrum of resistance to bacterial blight caused by Xanthomonas oryzae pv. oryzae (Xoo). Xa23 encodes a 113 amino acid protein that shares 50% identity with the known executor R protein XA10. The predicted transmembrane helices in XA23 also overlap with those of XA10. Unlike Xa10, however, Xa23 transcription is specifically activated by AvrXa23, a TALE present in all examined Xoo field isolates. Moreover, the susceptible xa23 allele has an identical open reading frame of Xa23 but differs in promoter region by lacking the TALE binding element (EBE) for AvrXa23. XA23 can trigger a strong hypersensitive response in rice, tobacco, and tomato. Our results provide the first evidence that plant genomes have an executor R gene family of which members execute their function and spectrum of disease resistance by recognizing the cognate TALEs in the pathogen.
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Affiliation(s)
- Chunlian Wang
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Institute of Crop Science, Chinese Academy of Agriculture Sciences (CAAS), Beijing 100081, China
| | - Xiaoping Zhang
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Institute of Crop Science, Chinese Academy of Agriculture Sciences (CAAS), Beijing 100081, China
| | - Yinglun Fan
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Institute of Crop Science, Chinese Academy of Agriculture Sciences (CAAS), Beijing 100081, China
| | - Ying Gao
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Institute of Crop Science, Chinese Academy of Agriculture Sciences (CAAS), Beijing 100081, China
| | - Qinlong Zhu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
| | - Chongke Zheng
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Institute of Crop Science, Chinese Academy of Agriculture Sciences (CAAS), Beijing 100081, China
| | - Tengfei Qin
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Institute of Crop Science, Chinese Academy of Agriculture Sciences (CAAS), Beijing 100081, China
| | - Yanqiang Li
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Institute of Crop Science, Chinese Academy of Agriculture Sciences (CAAS), Beijing 100081, China
| | - Jinying Che
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Institute of Crop Science, Chinese Academy of Agriculture Sciences (CAAS), Beijing 100081, China
| | - Mingwei Zhang
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Institute of Crop Science, Chinese Academy of Agriculture Sciences (CAAS), Beijing 100081, China
| | - Bing Yang
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA
| | - Yaoguang Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
| | - Kaijun Zhao
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Institute of Crop Science, Chinese Academy of Agriculture Sciences (CAAS), Beijing 100081, China.
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755
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Lee Y, Nishizawa T, Yamashita K, Ishitani R, Nureki O. Structural basis for the facilitative diffusion mechanism by SemiSWEET transporter. Nat Commun 2015; 6:6112. [PMID: 25598322 PMCID: PMC4309421 DOI: 10.1038/ncomms7112] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 12/15/2014] [Indexed: 02/07/2023] Open
Abstract
SWEET family proteins mediate sugar transport across biological membranes and play crucial roles in plants and animals. The SWEETs and their bacterial homologues, the SemiSWEETs, are related to the PQ-loop family, which is characterized by highly conserved proline and glutamine residues (PQ-loop motif). Although the structures of the bacterial SemiSWEETs were recently reported, the conformational transition and the significance of the conserved motif in the transport cycle have remained elusive. Here we report crystal structures of SemiSWEET from Escherichia coli, in the both inward-open and outward-open states. A structural comparison revealed that SemiSWEET undergoes an intramolecular conformational change in each protomer. The conserved PQ-loop motif serves as a molecular hinge that enables the 'binder clip-like' motion of SemiSWEET. The present work provides the framework for understanding the overall transport cycles of SWEET and PQ-loop family proteins.
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Affiliation(s)
- Yongchan Lee
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Tomohiro Nishizawa
- 1] Department of Biological Sciences, Graduate School of Science, University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan [2] Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | | | - Ryuichiro Ishitani
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Osamu Nureki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
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756
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Jung B, Ludewig F, Schulz A, Meißner G, Wöstefeld N, Flügge UI, Pommerrenig B, Wirsching P, Sauer N, Koch W, Sommer F, Mühlhaus T, Schroda M, Cuin TA, Graus D, Marten I, Hedrich R, Neuhaus HE. Identification of the transporter responsible for sucrose accumulation in sugar beet taproots. NATURE PLANTS 2015; 1:14001. [PMID: 27246048 DOI: 10.1038/nplants.2014.1] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 09/24/2014] [Indexed: 05/21/2023]
Abstract
Sugar beet provides around one third of the sugar consumed worldwide and serves as a significant source of bioenergy in the form of ethanol. Sucrose accounts for up to 18% of plant fresh weight in sugar beet. Most of the sucrose is concentrated in the taproot, where it accumulates in the vacuoles. Despite 30 years of intensive research, the transporter that facilitates taproot sucrose accumulation has escaped identification. Here, we combine proteomic analyses of the taproot vacuolar membrane, the tonoplast, with electrophysiological analyses to show that the transporter BvTST2.1 is responsible for vacuolar sucrose uptake in sugar beet taproots. We show that BvTST2.1 is a sucrose-specific transporter, and present evidence to suggest that it operates as a proton antiporter, coupling the import of sucrose into the vacuole to the export of protons. BvTST2.1 exhibits a high amino acid sequence similarity to members of the tonoplast monosaccharide transporter family in Arabidopsis, prompting us to rename this group of proteins 'tonoplast sugar transporters'. The identification of BvTST2.1 could help to increase sugar yields from sugar beet and other sugar-storing plants in future breeding programs.
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Affiliation(s)
- Benjamin Jung
- Pflanzenphysiologie, University Kaiserslautern, Erwin Schrödinger Straße, D-67653 Kaiserslautern, Germany
| | - Frank Ludewig
- Biocenter Cologne, Botanical Institute II and Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, Zülpicher Straße 47b, D-50674, Germany
| | - Alexander Schulz
- Biophysics and Molecular Plant Physiology, University Würzburg, Julius von Sachs Platz 2, D-97082 Würzburg, Germany
| | - Garvin Meißner
- Pflanzenphysiologie, University Kaiserslautern, Erwin Schrödinger Straße, D-67653 Kaiserslautern, Germany
| | - Nicole Wöstefeld
- Biocenter Cologne, Botanical Institute II and Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, Zülpicher Straße 47b, D-50674, Germany
| | - Ulf-Ingo Flügge
- Biocenter Cologne, Botanical Institute II and Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, Zülpicher Straße 47b, D-50674, Germany
| | - Benjamin Pommerrenig
- Molecular Plant Physiology, University Erlangen-Nuremberg, Staudtstraße 5, D-91058 Erlangen, Germany
| | - Petra Wirsching
- Molecular Plant Physiology, University Erlangen-Nuremberg, Staudtstraße 5, D-91058 Erlangen, Germany
| | - Norbert Sauer
- Molecular Plant Physiology, University Erlangen-Nuremberg, Staudtstraße 5, D-91058 Erlangen, Germany
| | - Wolfgang Koch
- KWS Saat AG, Grimsehlstr.31, D37555 Einbeck, Germany
| | - Frederik Sommer
- Molecular Biotechnology and Systems Biology, University Kaiserslautern, Paul-Ehrlich-Straße, D-67653 Kaiserslautern Germany
| | - Timo Mühlhaus
- Molecular Biotechnology and Systems Biology, University Kaiserslautern, Paul-Ehrlich-Straße, D-67653 Kaiserslautern Germany
| | - Michael Schroda
- Molecular Biotechnology and Systems Biology, University Kaiserslautern, Paul-Ehrlich-Straße, D-67653 Kaiserslautern Germany
| | - Tracey Ann Cuin
- Biophysics and Molecular Plant Physiology, University Würzburg, Julius von Sachs Platz 2, D-97082 Würzburg, Germany
| | - Dorothea Graus
- Biophysics and Molecular Plant Physiology, University Würzburg, Julius von Sachs Platz 2, D-97082 Würzburg, Germany
| | - Irene Marten
- Biophysics and Molecular Plant Physiology, University Würzburg, Julius von Sachs Platz 2, D-97082 Würzburg, Germany
| | - Rainer Hedrich
- Biophysics and Molecular Plant Physiology, University Würzburg, Julius von Sachs Platz 2, D-97082 Würzburg, Germany
| | - H Ekkehard Neuhaus
- Pflanzenphysiologie, University Kaiserslautern, Erwin Schrödinger Straße, D-67653 Kaiserslautern, Germany
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757
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Hutin M, Pérez-Quintero AL, Lopez C, Szurek B. MorTAL Kombat: the story of defense against TAL effectors through loss-of-susceptibility. FRONTIERS IN PLANT SCIENCE 2015. [PMID: 26236326 DOI: 10.3389/fpls.2015.0053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Many plant-pathogenic xanthomonads rely on Transcription Activator-Like (TAL) effectors to colonize their host. This particular family of type III effectors functions as specific plant transcription factors via a programmable DNA-binding domain. Upon binding to the promoters of plant disease susceptibility genes in a sequence-specific manner, the expression of these host genes is induced. However, plants have evolved specific strategies to counter the action of TAL effectors and confer resistance. One mechanism is to avoid the binding of TAL effectors by mutations of their DNA binding sites, resulting in resistance by loss-of-susceptibility. This article reviews our current knowledge of the susceptibility hubs targeted by Xanthomonas TAL effectors, possible evolutionary scenarios for plants to combat the pathogen with loss-of-function alleles, and how this knowledge can be used overall to develop new pathogen-informed breeding strategies and improve crop resistance.
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Affiliation(s)
- Mathilde Hutin
- UMR IPME, Institut de Recherche Pour le Développement, IRD-CIRAD-Université Montpellier 2 Montpellier, France
| | - Alvaro L Pérez-Quintero
- UMR IPME, Institut de Recherche Pour le Développement, IRD-CIRAD-Université Montpellier 2 Montpellier, France
| | - Camilo Lopez
- UMR IPME, Institut de Recherche Pour le Développement, IRD-CIRAD-Université Montpellier 2 Montpellier, France ; Biology Department, Universidad Nacional de Colombia Bogota, Colombia
| | - Boris Szurek
- UMR IPME, Institut de Recherche Pour le Développement, IRD-CIRAD-Université Montpellier 2 Montpellier, France
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758
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Niks RE, Qi X, Marcel TC. Quantitative resistance to biotrophic filamentous plant pathogens: concepts, misconceptions, and mechanisms. ANNUAL REVIEW OF PHYTOPATHOLOGY 2015; 53:445-70. [PMID: 26047563 DOI: 10.1146/annurev-phyto-080614-115928] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Quantitative resistance (QR) refers to a resistance that is phenotypically incomplete and is based on the joined effect of several genes, each contributing quantitatively to the level of plant defense. Often, QR remains durably effective, which is the primary driver behind the interest in it. The various terms that are used to refer to QR, such as field resistance, adult plant resistance, and basal resistance, reflect the many properties attributed to it. In this article, we discuss aspects connected to those attributions, in particular the hypothesis that much of the QR to biotrophic filamentous pathogens is basal resistance, i.e., poor suppression of PAMP-triggered defense by effectors. We discuss what role effectors play in suppressing defense or improving access to nutrients. Based on the functions of the few plant proteins identified as involved in QR, vesicle trafficking and protein/metabolite transportation are likely to be common physiological processes relevant to QR.
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Affiliation(s)
- Rients E Niks
- Laboratory of Plant Breeding, Wageningen University and Research Centre, 6700 AJ Wageningen, The Netherlands;
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759
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Mesarich CH, Bowen JK, Hamiaux C, Templeton MD. Repeat-containing protein effectors of plant-associated organisms. FRONTIERS IN PLANT SCIENCE 2015; 6:872. [PMID: 26557126 PMCID: PMC4617103 DOI: 10.3389/fpls.2015.00872] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 10/01/2015] [Indexed: 05/10/2023]
Abstract
Many plant-associated organisms, including microbes, nematodes, and insects, deliver effector proteins into the apoplast, vascular tissue, or cell cytoplasm of their prospective hosts. These effectors function to promote colonization, typically by altering host physiology or by modulating host immune responses. The same effectors however, can also trigger host immunity in the presence of cognate host immune receptor proteins, and thus prevent colonization. To circumvent effector-triggered immunity, or to further enhance host colonization, plant-associated organisms often rely on adaptive effector evolution. In recent years, it has become increasingly apparent that several effectors of plant-associated organisms are repeat-containing proteins (RCPs) that carry tandem or non-tandem arrays of an amino acid sequence or structural motif. In this review, we highlight the diverse roles that these repeat domains play in RCP effector function. We also draw attention to the potential role of these repeat domains in adaptive evolution with regards to RCP effector function and the evasion of effector-triggered immunity. The aim of this review is to increase the profile of RCP effectors from plant-associated organisms.
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Affiliation(s)
- Carl H. Mesarich
- School of Biological Sciences, The University of AucklandAuckland, New Zealand
- Host–Microbe Interactions, Bioprotection, The New Zealand Institute for Plant & Food Research LtdAuckland, New Zealand
- *Correspondence: Carl H. Mesarich
| | - Joanna K. Bowen
- Host–Microbe Interactions, Bioprotection, The New Zealand Institute for Plant & Food Research LtdAuckland, New Zealand
| | - Cyril Hamiaux
- Human Responses, The New Zealand Institute for Plant & Food Research LimitedAuckland, New Zealand
| | - Matthew D. Templeton
- School of Biological Sciences, The University of AucklandAuckland, New Zealand
- Host–Microbe Interactions, Bioprotection, The New Zealand Institute for Plant & Food Research LtdAuckland, New Zealand
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760
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Hutin M, Pérez-Quintero AL, Lopez C, Szurek B. MorTAL Kombat: the story of defense against TAL effectors through loss-of-susceptibility. FRONTIERS IN PLANT SCIENCE 2015; 6:535. [PMID: 26236326 PMCID: PMC4500901 DOI: 10.3389/fpls.2015.00535] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 06/30/2015] [Indexed: 05/21/2023]
Abstract
Many plant-pathogenic xanthomonads rely on Transcription Activator-Like (TAL) effectors to colonize their host. This particular family of type III effectors functions as specific plant transcription factors via a programmable DNA-binding domain. Upon binding to the promoters of plant disease susceptibility genes in a sequence-specific manner, the expression of these host genes is induced. However, plants have evolved specific strategies to counter the action of TAL effectors and confer resistance. One mechanism is to avoid the binding of TAL effectors by mutations of their DNA binding sites, resulting in resistance by loss-of-susceptibility. This article reviews our current knowledge of the susceptibility hubs targeted by Xanthomonas TAL effectors, possible evolutionary scenarios for plants to combat the pathogen with loss-of-function alleles, and how this knowledge can be used overall to develop new pathogen-informed breeding strategies and improve crop resistance.
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Affiliation(s)
- Mathilde Hutin
- UMR IPME, Institut de Recherche Pour le Développement, IRD-CIRAD-Université Montpellier 2Montpellier, France
| | - Alvaro L. Pérez-Quintero
- UMR IPME, Institut de Recherche Pour le Développement, IRD-CIRAD-Université Montpellier 2Montpellier, France
| | - Camilo Lopez
- UMR IPME, Institut de Recherche Pour le Développement, IRD-CIRAD-Université Montpellier 2Montpellier, France
- Biology Department, Universidad Nacional de ColombiaBogota, Colombia
| | - Boris Szurek
- UMR IPME, Institut de Recherche Pour le Développement, IRD-CIRAD-Université Montpellier 2Montpellier, France
- *Correspondence: Boris Szurek, UMR IPME, Institut de Recherche Pour le Développement, IRD-CIRAD-Université Montpellier 2, 911 Avenue Agropolis BP 64501, 34394 Montpellier Cedex 5, France,
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761
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Sulpice R, McKeown PC. Moving toward a comprehensive map of central plant metabolism. ANNUAL REVIEW OF PLANT BIOLOGY 2015; 66:187-210. [PMID: 25621519 DOI: 10.1146/annurev-arplant-043014-114720] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Decades of intensive study have led to the discovery of the main pathways involved in central metabolism but only some of the pathways and regulatory networks in which they are embedded. In this review, we discuss techniques used to assemble these pathways into a systems biology framework that can enable accurate modeling of the response of central metabolism to changes, including ways to perturb metabolic systems and assemble the resulting data into a meaningful network. Critically, these networks are of such size and complexity that it is possible to derive them only if data from different groups can be comprehensively and meaningfully combined. We conclude that it is essential to establish common standards for the description of experimental conditions and data collection and to store this information in databases to which the whole community can contribute.
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762
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A Ralstonia solanacearum type III effector directs the production of the plant signal metabolite trehalose-6-phosphate. mBio 2014; 5:mBio.02065-14. [PMID: 25538193 PMCID: PMC4278537 DOI: 10.1128/mbio.02065-14] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The plant pathogen Ralstonia solanacearum possesses two genes encoding a trehalose-6-phosphate synthase (TPS), an enzyme of the trehalose biosynthetic pathway. One of these genes, named ripTPS, was found to encode a protein with an additional N-terminal domain which directs its translocation into host plant cells through the type 3 secretion system. RipTPS is a conserved effector in the R. solanacearum species complex, and homologues were also detected in other bacterial plant pathogens. Functional analysis of RipTPS demonstrated that this type 3 effector synthesizes trehalose-6-phosphate and identified residues essential for this enzymatic activity. Although trehalose-6-phosphate is a key signal molecule in plants that regulates sugar status and carbon assimilation, the disruption of ripTPS did not alter the virulence of R. solanacearum on plants. However, heterologous expression assays showed that this effector specifically elicits a hypersensitive-like response on tobacco that is independent of its enzymatic activity and is triggered by the C-terminal half of the protein. Recognition of this effector by the plant immune system is suggestive of a role during the infectious process. Ralstonia solanacearum, the causal agent of bacterial wilt disease, infects more than two hundred plant species, including economically important crops. The type III secretion system plays a major role in the pathogenicity of this bacterium, and approximately 70 effector proteins have been shown to be translocated into host plant cells. This study provides the first description of a type III effector endowed with a trehalose-6-phosphate synthase enzymatic activity and illustrates a new mechanism by which the bacteria may manipulate the plant metabolism upon infection. In recent years, trehalose-6-phosphate has emerged as an essential signal molecule in plants, connecting plant metabolism and development. The finding that a bacterial pathogen could induce the production of trehalose-6-phosphate in plant cells further highlights the importance of this metabolite in multiple aspects of the molecular physiology of plants.
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763
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Chen Y, Ren X, Zhou X, Huang L, Yan L, Lei Y, Liao B, Huang J, Huang S, Wei W, Jiang H. Dynamics in the resistant and susceptible peanut (Arachis hypogaea L.) root transcriptome on infection with the Ralstonia solanacearum. BMC Genomics 2014; 15:1078. [PMID: 25481772 PMCID: PMC4300042 DOI: 10.1186/1471-2164-15-1078] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Accepted: 11/05/2014] [Indexed: 11/29/2022] Open
Abstract
Background Bacterial wilt caused by Ralstonia solanacearum is a serious soil-borne disease of peanut (Arachis hypogaea L). The molecular basis of peanut response to R. solanacearum remains unknown. To understand the resistance mechanism behind peanut resistance to R. solanacearum, we used RNA-Seq to perform global transcriptome profiling on the roots of peanut resistant (R) and susceptible (S) genotypes under R. solanacearum infection. Results A total of 4.95 x 108 raw sequence reads were generated and subsequently assembled into 271, 790 unigenes with an average length of 890 bp and a N50 of 1, 665 bp. 179, 641 unigenes could be annotated by public protein databases. The pairwise transcriptome comparsions of time course (6, 12, 24, 48 and 72 h post inoculation) were conducted 1) between inoculated and control samples of each genotype, 2) between inoculated samples of R and S genotypes. The linear dynamics of transcriptome profile was observed between adjacent samples for each genotype, two genotypes shared similar transcriptome pattern at early time points with most significant up regulation at 12 hour, and samples from R genotype at 24 h and S genotype at 48 h showed similar transcriptome pattern, significant differences of transcriptional profile were observed in pairwise comparisons between R and S genotypes. KEGG analysis showed that the primary metabolisms were inhibited in both genotypes and stronger inhibition in R genotype post inoculation. The defense related genes (R gene, LRR-RLK, cell wall genes, etc.) generally showed a genotype-specific down regulation and different expression between both genotypes. Conclusion This transcriptome profiling provided the largest data set that explores the dynamic in crosstalk between peanut and R. solanacearum. The results suggested that the down-regulation of primary metabolism is contributed to the resistance difference between R and S genotypes. The genotype-specific expression pattern of defense related DEGs also contributed to the resistance difference between R and S genotype. This study will strongly contribute to better understand the molecular interaction between plant and R. solanacearum. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-1078) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Huifang Jiang
- Oil Crop Research Institute, Chinese Academy of Agricultural Sciences/Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, No 2 Xudong Second Road, Wuhan 430062, P,R, China.
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764
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Liu H, Chang Q, Feng W, Zhang B, Wu T, Li N, Yao F, Ding X, Chu Z. Domain dissection of AvrRxo1 for suppressor, avirulence and cytotoxicity functions. PLoS One 2014; 9:e113875. [PMID: 25437277 PMCID: PMC4250038 DOI: 10.1371/journal.pone.0113875] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 11/01/2014] [Indexed: 12/27/2022] Open
Abstract
AvrRxo1, a type III effector from Xanthomonas oryzae pv. oryzicola (Xoc) which causes bacterial leaf streak (BLS) in rice, can be recognised by non-host resistance protein Rxo1. It triggers a hypersensitive response (HR) in maize. Little is known regarding the virulence function of AvrRxo1. In this study, we determined that AvrRxo1 is able to suppress the HR caused by the non-host resistance recognition of Xanthomonas oryzae pv. oryzae (Xoo) by Nicotiana benthamiana. It is toxic, inducing cell death from transient expression in N. benthamiana, as well as in yeast. Among the four AvrRxo1 alleles from different Xoc strains, we concluded that the toxicity is abolished by a single amino acid substitution at residue 344 in two AvrRxo1 alleles. A series of truncations from the carboxyl terminus (C-terminus) indicate that the complete C-terminus of AvrRxo1 plays an essential role as a suppressor or cytotoxic protein. The C-terminus was also required for the avirulence function, but the last two residues were not necessary. The first 52 amino acids of N-terminus are unessential for toxicity. Point mutagenesis experiments indicate that the ATP/GTP binding site motif A is required for all three functions of AvrRxo1, and NLS is required for both the avirulence and the suppression of non-host resistance. The putative thiol protease site is only required for the cytotoxicity function. These results determine that AvrRxo1 plays a role in the complex interaction with host proteins after delivery into plant cells.
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Affiliation(s)
- Haifeng Liu
- State Key Laboratory of Crop Biology, Shandong Provincial Key Laboratory of Agricultural Microbiology, Shandong Agricultural University, Tai an, Shandong, PR China
| | - Qingle Chang
- State Key Laboratory of Crop Biology, Shandong Provincial Key Laboratory of Agricultural Microbiology, Shandong Agricultural University, Tai an, Shandong, PR China
| | - Wenjie Feng
- State Key Laboratory of Crop Biology, Shandong Provincial Key Laboratory of Agricultural Microbiology, Shandong Agricultural University, Tai an, Shandong, PR China
| | - Baogang Zhang
- State Key Laboratory of Crop Biology, Shandong Provincial Key Laboratory of Agricultural Microbiology, Shandong Agricultural University, Tai an, Shandong, PR China
| | - Tao Wu
- State Key Laboratory of Crop Biology, Shandong Provincial Key Laboratory of Agricultural Microbiology, Shandong Agricultural University, Tai an, Shandong, PR China
| | - Ning Li
- State Key Laboratory of Crop Biology, Shandong Provincial Key Laboratory of Agricultural Microbiology, Shandong Agricultural University, Tai an, Shandong, PR China
| | - Fangyin Yao
- Biotechnology Research Center, Shandong Academy of Agricultural Science, Jinan, Shandong, PR China
| | - Xinhua Ding
- State Key Laboratory of Crop Biology, Shandong Provincial Key Laboratory of Agricultural Microbiology, Shandong Agricultural University, Tai an, Shandong, PR China
| | - Zhaohui Chu
- State Key Laboratory of Crop Biology, Shandong Provincial Key Laboratory of Agricultural Microbiology, Shandong Agricultural University, Tai an, Shandong, PR China
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765
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Wang J, Yan C, Li Y, Hirata K, Yamamoto M, Yan N, Hu Q. Crystal structure of a bacterial homologue of SWEET transporters. Cell Res 2014; 24:1486-9. [PMID: 25378180 PMCID: PMC4260346 DOI: 10.1038/cr.2014.144] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Affiliation(s)
- Jing Wang
- State Key Laboratory of Bio-membrane and Membrane Biotechnology, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China
- Center for Structural Biology, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Chuangye Yan
- State Key Laboratory of Bio-membrane and Membrane Biotechnology, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China
- Center for Structural Biology, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Yini Li
- State Key Laboratory of Bio-membrane and Membrane Biotechnology, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China
- Center for Structural Biology, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Kunio Hirata
- Advanced Photon Technology Division, Research Infrastructure Group, SR Life Science Instrumentation Unit, 1-1-1 Kouto Sayo-cho Sayo-gun, Hyogo 679-5148, Japan
| | - Masaki Yamamoto
- Advanced Photon Technology Division, Research Infrastructure Group, SR Life Science Instrumentation Unit, 1-1-1 Kouto Sayo-cho Sayo-gun, Hyogo 679-5148, Japan
| | - Nieng Yan
- State Key Laboratory of Bio-membrane and Membrane Biotechnology, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China
- Center for Structural Biology, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Qi Hu
- State Key Laboratory of Bio-membrane and Membrane Biotechnology, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China
- Center for Structural Biology, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
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766
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Chong J, Piron MC, Meyer S, Merdinoglu D, Bertsch C, Mestre P. The SWEET family of sugar transporters in grapevine: VvSWEET4 is involved in the interaction with Botrytis cinerea. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:6589-601. [PMID: 25246444 DOI: 10.1093/jxb/eru375] [Citation(s) in RCA: 143] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
During plant development, sugar export is determinant in multiple processes such as nectar production, pollen development and long-distance sucrose transport. The plant SWEET family of sugar transporters is a recently identified protein family of sugar uniporters. In rice, SWEET transporters are the target of extracellular bacteria, which have evolved sophisticated mechanisms to modify their expression and acquire sugars to sustain their growth. Here we report the characterization of the SWEET family of sugar transporters in Vitis vinifera. We identified 17 SWEET genes in the V. vinifera 40024 genome and show that they are differentially expressed in vegetative and reproductive organs. Inoculation with the biotrophic pathogens Erysiphe necator and Plasmopara viticola did not result in significant induction of VvSWEET gene expression. However, infection with the necrotroph Botrytis cinerea triggered a strong up-regulation of VvSWEET4 expression. Further characterization of VvSWEET4 revealed that it is a glucose transporter localized in the plasma membrane that is up-regulated by inducers of reactive oxygen species and virulence factors from necrotizing pathogens. Finally, Arabidopsis knockout mutants in the orthologous AtSWEET4 were found to be less susceptible to B. cinerea. We propose that stimulation of expression of a developmentally regulated glucose uniporter by reactive oxygen species production and extensive cell death after necrotrophic fungal infection could facilitate sugar acquisition from plant cells by the pathogen.
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Affiliation(s)
- Julie Chong
- Laboratoire Vigne, Biotechnologies et Environnement (LVBE, EA3991), Université de Haute Alsace, 33 rue de Herrlisheim, 68000 Colmar, France
| | - Marie-Christine Piron
- INRA, UMR 1131 Santé de la Vigne et Qualité du Vin, F-68000 Colmar, France Université de Strasbourg, UMR 1131 Santé de la Vigne et Qualité du Vin, F-68000 Colmar, France
| | - Sophie Meyer
- INRA, UMR 1131 Santé de la Vigne et Qualité du Vin, F-68000 Colmar, France Université de Strasbourg, UMR 1131 Santé de la Vigne et Qualité du Vin, F-68000 Colmar, France
| | - Didier Merdinoglu
- INRA, UMR 1131 Santé de la Vigne et Qualité du Vin, F-68000 Colmar, France Université de Strasbourg, UMR 1131 Santé de la Vigne et Qualité du Vin, F-68000 Colmar, France
| | - Christophe Bertsch
- Laboratoire Vigne, Biotechnologies et Environnement (LVBE, EA3991), Université de Haute Alsace, 33 rue de Herrlisheim, 68000 Colmar, France
| | - Pere Mestre
- INRA, UMR 1131 Santé de la Vigne et Qualité du Vin, F-68000 Colmar, France Université de Strasbourg, UMR 1131 Santé de la Vigne et Qualité du Vin, F-68000 Colmar, France
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767
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Tian F, Wang Y, Zhu X, Chen L, Duan Y. Effect of Sinorhizobium fredii strain Sneb183 on the biological control of soybean cyst nematode in soybean. J Basic Microbiol 2014; 54:1258-63. [PMID: 24912826 DOI: 10.1002/jobm.201301014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 03/18/2014] [Indexed: 01/06/2023]
Abstract
The soybean cyst nematode (SCN; Heterodera glycines) is a major detriment to soybean production. The endophytic bacterium Sinorhizobium fredii strain Sneb183 is known to inhibit the activity of SCN. In the present study, soybean seedlings were inoculated with Sneb183, to study the penetration juveniles, and their development inside the roots. The number of cysts in the soybean roots was also examined. The induced systemic resistance in soybean was also examined through the split-root system. Our results revealed that the number of juveniles and cysts significantly decreased as a result of Sneb183 inoculation. Sneb183 also prolonged the developmental stage of SCN in the root to 30 days as compared to 27 days in the control. Furthermore, the number of nematodes in each stage was lower in the Sneb183 treated plants than control plants. We also used a split-root system to show that the S. fredii strain Sneb183 induced a systemic resistance to SCN infection in soybean. The repression rate of SCN penetration was 38.75%. Our study showed that Sneb183 can be an effective biocontrol agent for managing SCN infestation in soybean.
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Affiliation(s)
- Feng Tian
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
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768
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Muñoz-Bodnar A, Perez-Quintero AL, Gomez-Cano F, Gil J, Michelmore R, Bernal A, Szurek B, Lopez C. RNAseq analysis of cassava reveals similar plant responses upon infection with pathogenic and non-pathogenic strains of Xanthomonas axonopodis pv. manihotis. PLANT CELL REPORTS 2014; 33:1901-12. [PMID: 25120000 DOI: 10.1007/s00299-014-1667-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Revised: 06/25/2014] [Accepted: 07/23/2014] [Indexed: 05/28/2023]
Abstract
An RNAseq-based analysis of the cassava plants inoculated with Xam allowed the identification of transcriptional upregulation of genes involved in jasmonate metabolism, phenylpropanoid biosynthesis and putative targets for a TALE. Cassava bacterial blight, a disease caused by the gram-negative bacterium Xanthomonas axonopodis pv. manihotis (Xam), is a major limitation to cassava production worldwide and especially in developing countries. The molecular mechanisms underlying cassava susceptibility to Xam are currently unknown. To identify host genes and pathways leading to plant susceptibility, we analyzed the transcriptomic responses occurring in cassava plants challenged with either the non-pathogenic Xam strain ORST4, or strain ORST4(TALE1 Xam ) which is pathogenic due to the major virulence transcription activator like effector TALE1 Xam . Both strains triggered similar responses, i.e., induction of genes related to photosynthesis and phenylpropanoid biosynthesis, and repression of genes related to jasmonic acid signaling. Finally, to search for TALE1 Xam virulence targets, we scanned the list of cassava genes induced upon inoculation of ORST4(TALE1 Xam ) for candidates harboring a predicted TALE1 Xam effector binding element in their promoter. Among the six genes identified as potential candidate targets of TALE1 Xam a gene coding for a heat shock transcription factor stands out as the best candidate based on their induction in presence of TALE1 Xam and contain a sequence putatively recognized by TALE1 Xam .
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Affiliation(s)
- Alejandra Muñoz-Bodnar
- Manihot Biotec Group, Department of Biology, Universidad Nacional de Colombia, Bogotá, Colombia
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769
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Cohn M, Bart RS, Shybut M, Dahlbeck D, Gomez M, Morbitzer R, Hou BH, Frommer WB, Lahaye T, Staskawicz BJ. Xanthomonas axonopodis virulence is promoted by a transcription activator-like effector-mediated induction of a SWEET sugar transporter in cassava. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2014; 27:1186-98. [PMID: 25083909 DOI: 10.1094/mpmi-06-14-0161-r] [Citation(s) in RCA: 149] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The gene-for-gene concept has historically been applied to describe a specific resistance interaction wherein single genes from the host and the pathogen dictate the outcome. These interactions have been observed across the plant kingdom and all known plant microbial pathogens. In recent years, this concept has been extended to susceptibility phenotypes in the context of transcription activator-like (TAL) effectors that target SWEET sugar transporters. However, because this interaction has only been observed in rice, it was not clear whether the gene-for-gene susceptibility was unique to that system. Here, we show, through a combined systematic analysis of the TAL effector complement of Xanthomonas axonopodis pv. manihotis and RNA sequencing to identify targets in cassava, that TAL20Xam668 specifically induces the sugar transporter MeSWEET10a to promote virulence. Designer TAL effectors (dTALE) complement TAL20Xam668 mutant phenotypes, demonstrating that MeSWEET10a is a susceptibility gene in cassava. Sucrose uptake-deficient X. axonopodis pv. manihotis bacteria do not lose virulence, indicating that sucrose may be cleaved extracellularly and taken up as hexoses into X. axonopodis pv. manihotis. Together, our data suggest that pathogen hijacking of plant nutrients is not unique to rice blight but also plays a role in bacterial blight of the dicot cassava.
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770
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Jaehme M, Guskov A, Slotboom DJ. Crystal structure of the vitamin B3 transporter PnuC, a full-length SWEET homolog. Nat Struct Mol Biol 2014; 21:1013-5. [PMID: 25291599 DOI: 10.1038/nsmb.2909] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 09/30/2014] [Indexed: 12/31/2022]
Abstract
PnuC transporters catalyze cellular uptake of the NAD+ precursor nicotinamide riboside (NR) and belong to a large superfamily that includes the SWEET sugar transporters. We present a crystal structure of Neisseria mucosa PnuC, which adopts a highly symmetrical fold with 3+1+3 membrane topology not previously observed in any protein. The high symmetry of PnuC with a single NR bound in the center suggests a simple alternating-access translocation mechanism.
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Affiliation(s)
- Michael Jaehme
- University of Groningen, Groningen Biomolecular Sciences and Biotechnology Institute, Groningen, the Netherlands
| | - Albert Guskov
- University of Groningen, Groningen Biomolecular Sciences and Biotechnology Institute, Groningen, the Netherlands
| | - Dirk Jan Slotboom
- University of Groningen, Groningen Biomolecular Sciences and Biotechnology Institute, Groningen, the Netherlands
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771
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O’Rourke JA, Iniguez LP, Fu F, Bucciarelli B, Miller SS, Jackson SA, McClean PE, Li J, Dai X, Zhao PX, Hernandez G, Vance CP. An RNA-Seq based gene expression atlas of the common bean. BMC Genomics 2014; 15:866. [PMID: 25283805 PMCID: PMC4195886 DOI: 10.1186/1471-2164-15-866] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 09/24/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Common bean (Phaseolus vulgaris) is grown throughout the world and comprises roughly 50% of the grain legumes consumed worldwide. Despite this, genetic resources for common beans have been lacking. Next generation sequencing, has facilitated our investigation of the gene expression profiles associated with biologically important traits in common bean. An increased understanding of gene expression in common bean will improve our understanding of gene expression patterns in other legume species. RESULTS Combining recently developed genomic resources for Phaseolus vulgaris, including predicted gene calls, with RNA-Seq technology, we measured the gene expression patterns from 24 samples collected from seven tissues at developmentally important stages and from three nitrogen treatments. Gene expression patterns throughout the plant were analyzed to better understand changes due to nodulation, seed development, and nitrogen utilization. We have identified 11,010 genes differentially expressed with a fold change ≥ 2 and a P-value < 0.05 between different tissues at the same time point, 15,752 genes differentially expressed within a tissue due to changes in development, and 2,315 genes expressed only in a single tissue. These analyses identified 2,970 genes with expression patterns that appear to be directly dependent on the source of available nitrogen. Finally, we have assembled this data in a publicly available database, The Phaseolus vulgaris Gene Expression Atlas (Pv GEA), http://plantgrn.noble.org/PvGEA/ . Using the website, researchers can query gene expression profiles of their gene of interest, search for genes expressed in different tissues, or download the dataset in a tabular form. CONCLUSIONS These data provide the basis for a gene expression atlas, which will facilitate functional genomic studies in common bean. Analysis of this dataset has identified genes important in regulating seed composition and has increased our understanding of nodulation and impact of the nitrogen source on assimilation and distribution throughout the plant.
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Affiliation(s)
- Jamie A O’Rourke
- />Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, MN 55108 USA
- />USDA-ARS, Corn Insect Crop Genetics Research Unit, Iowa State University, Ames, IA 50011 USA
| | - Luis P Iniguez
- />Centro de Ciencias Genomicas, Universidad Nacional Autonoma de Mexico, 66210 Cuernavaca, Mor Mexico
| | - Fengli Fu
- />Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, MN 55108 USA
| | - Bruna Bucciarelli
- />Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, MN 55108 USA
- />USDA-Agricultural Research Service, Plant Science Research Unit, St. Paul, MN 55108 USA
| | - Susan S Miller
- />Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, MN 55108 USA
- />USDA-Agricultural Research Service, Plant Science Research Unit, St. Paul, MN 55108 USA
| | - Scott A Jackson
- />Center for Applied Genetic Technologies, University of Georgia, Athens, GA 30602 USA
| | - Philip E McClean
- />Department of Plant Sciences, North Dakota State University, Fargo, ND 58105 USA
| | - Jun Li
- />Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK 73401 USA
| | - Xinbin Dai
- />Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK 73401 USA
| | - Patrick X Zhao
- />Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK 73401 USA
| | - Georgina Hernandez
- />Centro de Ciencias Genomicas, Universidad Nacional Autonoma de Mexico, 66210 Cuernavaca, Mor Mexico
| | - Carroll P Vance
- />Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, MN 55108 USA
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772
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Li M, Sack FD. Myrosin idioblast cell fate and development are regulated by the Arabidopsis transcription factor FAMA, the auxin pathway, and vesicular trafficking. THE PLANT CELL 2014; 26:4053-66. [PMID: 25304201 PMCID: PMC4247575 DOI: 10.1105/tpc.114.129726] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 08/27/2014] [Accepted: 09/23/2014] [Indexed: 05/20/2023]
Abstract
Crucifer shoots harbor a glucosinolate-myrosinase system that defends against insect predation. Arabidopsis thaliana myrosinase (thioglucoside glucohydrolase [TGG]) accumulates in stomata and in myrosin idioblasts (MIs). This work reports that the basic helix-loop-helix transcription factor FAMA that is key to stomatal development is also expressed in MIs. The loss of FAMA function abolishes MI fate as well as the expression of the myrosinase genes TGG1 and TGG2. MI cells have previously been reported to be located in the phloem. Instead, we found that MIs arise from the ground meristem rather than provascular tissues and thus are not homologous with phloem. Moreover, MI patterning and morphogenesis are abnormal when the function of the ARF-GEF gene GNOM is lost as well as when auxin efflux and vesicular trafficking are chemically disrupted. Stomata and MI cells constitute part of a wider system that reduces plant predation, the so-called "mustard oil bomb," in which vacuole breakage in cells harboring myrosinase and glucosinolate yields a brew toxic to many animals, especially insects. This identification of the gene that confers the fate of MIs, as well as stomata, might facilitate the development of strategies for engineering crops to mitigate predation.
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Affiliation(s)
- Meng Li
- Department of Botany, University of British Columbia, Vancouver V6T 1Z4, Canada
| | - Fred D Sack
- Department of Botany, University of British Columbia, Vancouver V6T 1Z4, Canada
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773
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Proels RK, Hückelhoven R. Cell-wall invertases, key enzymes in the modulation of plant metabolism during defence responses. MOLECULAR PLANT PATHOLOGY 2014; 15:858-64. [PMID: 24646208 PMCID: PMC6638650 DOI: 10.1111/mpp.12139] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Most plant-pathogen interactions do not result in pathogenesis because of pre-formed defensive plant barriers or pathogen-triggered activation of effective plant immune responses. The mounting of defence reactions is accompanied by a profound modulation of plant metabolism. Common metabolic changes are the repression of photosynthesis, the increase in heterotrophic metabolism and the synthesis of secondary metabolites. This enhanced metabolic activity is accompanied by the reduced export of sucrose or enhanced import of hexoses at the site of infection, which is mediated by an induced activity of cell-wall invertase (Cw-Inv). Cw-Inv cleaves sucrose, the major transport sugar in plants, irreversibly yielding glucose and fructose, which can be taken up by plant cells via hexose transporters. These hexose sugars not only function in metabolism, but also act as signalling molecules. The picture of Cw-Inv regulation in plant-pathogen interactions has recently been broadened and is discussed in this review. An interesting emerging feature is the link between Cw-Inv and the circadian clock and new modes of Cw-Inv regulation at the post-translational level.
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Affiliation(s)
- Reinhard Korbinian Proels
- Lehrstuhl für Phytopathologie, Technische Universität München, D-85350, Freising-Weihenstephan, Germany
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774
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Structures of bacterial homologues of SWEET transporters in two distinct conformations. Nature 2014; 515:448-452. [PMID: 25186729 DOI: 10.1038/nature13670] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2014] [Accepted: 07/10/2014] [Indexed: 01/15/2023]
Abstract
SWEETs and their prokaryotic homologues are monosaccharide and disaccharide transporters that are present from Archaea to plants and humans. SWEETs play crucial roles in cellular sugar efflux processes: that is, in phloem loading, pollen nutrition and nectar secretion. Their bacterial homologues, which are called SemiSWEETs, are among the smallest known transporters. Here we show that SemiSWEET molecules, which consist of a triple-helix bundle, form symmetrical, parallel dimers, thereby generating the translocation pathway. Two SemiSWEET isoforms were crystallized, one in an apparently open state and one in an occluded state, indicating that SemiSWEETs and SWEETs are transporters that undergo rocking-type movements during the transport cycle. The topology of the triple-helix bundle is similar yet distinct to that of the basic building block of animal and plant major facilitator superfamily (MFS) transporters (for example, GLUTs and SUTs). This finding indicates two possibilities: that SWEETs and MFS transporters evolved from an ancestral triple-helix bundle or that the triple-helix bundle represents convergent evolution. In SemiSWEETs and SWEETs, two triple-helix bundles are arranged in a parallel configuration to produce the 6- and 6 + 1-transmembrane-helix pores, respectively. In the 12-transmembrane-helix MFS transporters, four triple-helix bundles are arranged into an alternating antiparallel configuration, resulting in a much larger 2 × 2 triple-helix bundle forming the pore. Given the similarity of SemiSWEETs and SWEETs to PQ-loop amino acid transporters and to mitochondrial pyruvate carriers (MPCs), the structures characterized here may also be relevant to other transporters in the MtN3 clan. The insight gained from the structures of these transporters and from the analysis of mutations of conserved residues will improve the understanding of the transport mechanism, as well as allow comparative studies of the different superfamilies involved in sugar transport and the evolution of transporters in general.
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775
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Anderson VA, Haley SD, Peairs FB, van Eck L, Leach JE, Lapitan NLV. Virus-induced gene silencing suggests (1,3;1,4)-β-glucanase is a susceptibility factor in the compatible russian wheat aphid-wheat interaction. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2014; 27:913-922. [PMID: 24964057 DOI: 10.1094/mpmi-05-13-0141-r] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The Russian wheat aphid (RWA), Diuraphis noxia (Kurdjumov), is a significant insect pest of wheat (Triticum aestivum L.) and has a major economic impact worldwide, especially on winter wheat in the western United States. The continuing emergence of new RWA biotypes virulent to existing resistance genes reinforces the need for more durable resistance. Studies have indicated that resistance in previously susceptible plants can be produced by knock-down of susceptibility genes or other genes involved in host plant susceptibility. Therefore, investigation into genes involved in compatible RWA-wheat interactions could be a feasible approach to achieving durable RWA resistance. The objective of this study was to test whether silencing (1,3;1,4)-β-glucanase, previously observed to be highly induced in susceptible compared with resistant wheat during aphid infestation, would confer resistance to a susceptible wheat genotype. Barley stripe mosaic virus-mediated virus-induced gene silencing was employed to test whether (1,3;1,4)-β-glucanase is involved in the susceptible reaction of 'Gamtoos-S' (GS). Controlled infestation with U.S. biotype RWA2 was done to assess aphid reproduction and host symptom development. Aphids on (1,3;1,4)-β-glucanase-silenced plants reproduced less per day and had longer prenymphipositional periods than those on control GS plants. Furthermore, the (1,3;1,4)-β-glucanase-silenced plants exhibited less chlorosis and greater dry weight compared with GS. Aphid reproduction and host plant symptom development showed linear relationships with (1,3;1,4)-β-glucanase transcript levels. Our results suggest that (1,3;1,4)-β-glucanase is required for successful infestation by the RWA and may be a susceptibility factor that could be exploited as a potential target for RWA resistance breeding.
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776
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Buscaill P, Rivas S. Transcriptional control of plant defence responses. CURRENT OPINION IN PLANT BIOLOGY 2014; 20:35-46. [PMID: 24840291 DOI: 10.1016/j.pbi.2014.04.004] [Citation(s) in RCA: 140] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 04/17/2014] [Accepted: 04/24/2014] [Indexed: 05/22/2023]
Abstract
Mounting of efficient plant defence responses depends on the ability to trigger a rapid defence reaction after recognition of the invading microbe. Activation of plant resistance is achieved by modulation of the activity of multiple transcriptional regulators, both DNA-binding transcription factors and their regulatory proteins, that are able to reprogram transcription in the plant cell towards the activation of defence signalling. Here we provide an overview of recent developments on the transcriptional control of plant defence responses and discuss defence-related hormone signalling, the role of WRKY transcription factors during the regulation of plant responses to pathogens, nuclear functions of plant immune receptor proteins, as well as varied ways by which microbial effectors subvert plant transcriptional reprogramming to promote disease.
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Affiliation(s)
- Pierre Buscaill
- INRA, Laboratoire des Interactions Plantes-Microorganismes (LIPM), UMR441, F-31326 Castanet-Tolosan, France
| | - Susana Rivas
- CNRS, Laboratoire des Interactions Plantes-Microorganismes (LIPM), UMR2594, F-31326 Castanet-Tolosan, France.
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777
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Okmen B, Doehlemann G. Inside plant: biotrophic strategies to modulate host immunity and metabolism. CURRENT OPINION IN PLANT BIOLOGY 2014; 20:19-25. [PMID: 24780462 DOI: 10.1016/j.pbi.2014.03.011] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 03/17/2014] [Accepted: 03/31/2014] [Indexed: 05/23/2023]
Abstract
Filamentous plant pathogens that establish biotrophic interactions need to avoid plant immune responses. Recent findings from different pathosystems suggest that sufficient suppression of host immunity is based on the modulation of a rather limited number of host targets. Microbial strategies to target host physiology dependent on the duration of biotrophy, the style of host tissue colonization and the degree of interference with plant development. In this article, we present current concepts in biotrophic virulence strategies and discuss mechanisms of pathogen adaptation and effector specialization.
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Affiliation(s)
- Bilal Okmen
- Max-Planck-Institute for Terrestrial Microbiology, Department for Organismic Interactions, Marburg, Germany
| | - Gunther Doehlemann
- Max-Planck-Institute for Terrestrial Microbiology, Department for Organismic Interactions, Marburg, Germany.
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778
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Ji ZY, Zakria M, Zou LF, Xiong L, Li Z, Ji GH, Chen GY. Genetic diversity of transcriptional activator-like effector genes in Chinese isolates of Xanthomonas oryzae pv. oryzicola. PHYTOPATHOLOGY 2014; 104:672-82. [PMID: 24423401 DOI: 10.1094/phyto-08-13-0232-r] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Xanthomonas oryzae pv. oryzicola causes bacterial leaf streak (BLS), a devastating disease of rice in Asia countries. X. oryzae pv. oryzicola utilizes repertoires of transcriptional activator-like effectors (TALEs) to manipulate host resistance or susceptibility; thus, TALEs can determine the outcome of BLS. In this report, we studied genetic diversity in putative tale genes of 65 X. oryzae pv. oryzicola strains that originated from nine provinces of southern China. Genomic DNAs from the 65 strains were digested with BamHI and hybridized with an internal fragment of avrXa3, a tale gene originating from the related pathogen, X. oryzae pv. oryzae, which causes bacterial leaf blight (BLB). Southern blot analysis indicated that the strains contained a variable number (9 to 22) of avrXa3-hybridizing fragments (e.g., putative tale genes). Based on the number and size of hybridizing bands, strains were classified into 14 genotypes (designated 1 to 14), and genotypes 3 and 10 represented 29.23 and 24.64% of the total, respectively. A high molecular weight BamHI fragment (HMWB; ≈6.0 kb) was present in 12 of the 14 genotypes, and sequence analysis of the HMWB revealed the presence of a C-terminally truncated tale, an insertion element related to IS1403, and genes encoding phosphoglycerate mutase and endonuclease V. Primers were developed from the 6.0-kb HMWB fragment and showed potential in genotyping X. oryzae pv. oryzicola strains by polymerase chain reaction. Virulence of X. oryzae pv. oryzicola strains was assessed on 23 rice cultivars containing different resistance genes for BLB. The X. oryzae pv. oryzicola strains could be grouped into 14 pathotypes (I to XIV), and the grouping of strains was almost identical to the categories determined by genotypic analysis. In general, strains containing higher numbers of putative tale genes were more virulent on rice than strains containing fewer tales. The results also indicate that there are no gene-for-gene relationships between the tested rice lines and X. oryzae pv. oryzicola strains. To our knowledge, this is the first description of genetic diversity of X. oryzae pv. oryzicola strains based on tale gene analysis.
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779
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San Martín A, Sotelo-Hitschfeld T, Lerchundi R, Fernández-Moncada I, Ceballo S, Valdebenito R, Baeza-Lehnert F, Alegría K, Contreras-Baeza Y, Garrido-Gerter P, Romero-Gómez I, Barros LF. Single-cell imaging tools for brain energy metabolism: a review. NEUROPHOTONICS 2014; 1:011004. [PMID: 26157964 PMCID: PMC4478754 DOI: 10.1117/1.nph.1.1.011004] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2014] [Revised: 04/09/2014] [Accepted: 04/10/2014] [Indexed: 05/03/2023]
Abstract
Neurophotonics comes to light at a time in which advances in microscopy and improved calcium reporters are paving the way toward high-resolution functional mapping of the brain. This review relates to a parallel revolution in metabolism. We argue that metabolism needs to be approached both in vitro and in vivo, and that it does not just exist as a low-level platform but is also a relevant player in information processing. In recent years, genetically encoded fluorescent nanosensors have been introduced to measure glucose, glutamate, ATP, NADH, lactate, and pyruvate in mammalian cells. Reporting relative metabolite levels, absolute concentrations, and metabolic fluxes, these sensors are instrumental for the discovery of new molecular mechanisms. Sensors continue to be developed, which together with a continued improvement in protein expression strategies and new imaging technologies, herald an exciting era of high-resolution characterization of metabolism in the brain and other organs.
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Affiliation(s)
- Alejandro San Martín
- Centro de Estudios Científicos, Arturo Prat 514, Valdivia, 5110466, Chile
- Universidad Austral de Chile, Valdivia, Chile
| | - Tamara Sotelo-Hitschfeld
- Centro de Estudios Científicos, Arturo Prat 514, Valdivia, 5110466, Chile
- Universidad Austral de Chile, Valdivia, Chile
| | - Rodrigo Lerchundi
- Centro de Estudios Científicos, Arturo Prat 514, Valdivia, 5110466, Chile
- Universidad Austral de Chile, Valdivia, Chile
| | - Ignacio Fernández-Moncada
- Centro de Estudios Científicos, Arturo Prat 514, Valdivia, 5110466, Chile
- Universidad Austral de Chile, Valdivia, Chile
| | - Sebastian Ceballo
- Centro de Estudios Científicos, Arturo Prat 514, Valdivia, 5110466, Chile
| | - Rocío Valdebenito
- Centro de Estudios Científicos, Arturo Prat 514, Valdivia, 5110466, Chile
| | | | - Karin Alegría
- Centro de Estudios Científicos, Arturo Prat 514, Valdivia, 5110466, Chile
| | - Yasna Contreras-Baeza
- Centro de Estudios Científicos, Arturo Prat 514, Valdivia, 5110466, Chile
- Universidad Austral de Chile, Valdivia, Chile
| | - Pamela Garrido-Gerter
- Centro de Estudios Científicos, Arturo Prat 514, Valdivia, 5110466, Chile
- Universidad Austral de Chile, Valdivia, Chile
| | - Ignacio Romero-Gómez
- Centro de Estudios Científicos, Arturo Prat 514, Valdivia, 5110466, Chile
- Universidad Austral de Chile, Valdivia, Chile
| | - L. Felipe Barros
- Centro de Estudios Científicos, Arturo Prat 514, Valdivia, 5110466, Chile
- Address all correspondence to: L. Felipe Barros, E-mail:
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780
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Perotto S, Rodda M, Benetti A, Sillo F, Ercole E, Rodda M, Girlanda M, Murat C, Balestrini R. Gene expression in mycorrhizal orchid protocorms suggests a friendly plant-fungus relationship. PLANTA 2014; 239:1337-49. [PMID: 24760407 DOI: 10.1007/s00425-014-2062-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 03/06/2014] [Indexed: 05/03/2023]
Abstract
Orchids fully depend on symbiotic interactions with specific soil fungi for seed germination and early development. Germinated seeds give rise to a protocorm, a heterotrophic organ that acquires nutrients, including organic carbon, from the mycorrhizal partner. It has long been debated if this interaction is mutualistic or antagonistic. To investigate the molecular bases of the orchid response to mycorrhizal invasion, we developed a symbiotic in vitro system between Serapias vomeracea, a Mediterranean green meadow orchid, and the rhizoctonia-like fungus Tulasnella calospora. 454 pyrosequencing was used to generate an inventory of plant and fungal genes expressed in mycorrhizal protocorms, and plant genes could be reliably identified with a customized bioinformatic pipeline. A small panel of plant genes was selected and expression was assessed by real-time quantitative PCR in mycorrhizal and non-mycorrhizal protocorm tissues. Among these genes were some markers of mutualistic (e.g. nodulins) as well as antagonistic (e.g. pathogenesis-related and wound/stress-induced) genes. None of the pathogenesis or wound/stress-related genes were significantly up-regulated in mycorrhizal tissues, suggesting that fungal colonization does not trigger strong plant defence responses. In addition, the highest expression fold change in mycorrhizal tissues was found for a nodulin-like gene similar to the plastocyanin domain-containing ENOD55. Another nodulin-like gene significantly more expressed in the symbiotic tissues of mycorrhizal protocorms was similar to a sugar transporter of the SWEET family. Two genes coding for mannose-binding lectins were significantly up-regulated in the presence of the mycorrhizal fungus, but their role in the symbiosis is unclear.
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Affiliation(s)
- Silvia Perotto
- Department of Life Sciences and Systems Biology, University of Turin, Viale Mattioli 25, 10125, Turin, Italy,
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781
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Abstract
Over the last 300 years, plant science research has provided important knowledge and technologies for advancing the sustainability of agriculture. In this Essay, I describe how basic research advances have been translated into crop improvement, explore some lessons learned, and discuss the potential for current and future contribution of plant genetic improvement technologies to continue to enhance food security and agricultural sustainability.
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Affiliation(s)
- Pamela C. Ronald
- Department of Plant Pathology and the Genome Center, University of California, Davis, Davis, California, United States of America
- The Joint Bioenergy Institute, Emeryville, California, United States of America
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782
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Reuscher S, Akiyama M, Yasuda T, Makino H, Aoki K, Shibata D, Shiratake K. The sugar transporter inventory of tomato: genome-wide identification and expression analysis. PLANT & CELL PHYSIOLOGY 2014; 55:1123-41. [PMID: 24833026 DOI: 10.1093/pcp/pcu052] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The mobility of sugars between source and sink tissues in plants depends on sugar transport proteins. Studying the corresponding genes allows the manipulation of the sink strength of developing fruits, thereby improving fruit quality for human consumption. Tomato (Solanum lycopersicum) is both a major horticultural crop and a model for the development of fleshy fruits. In this article we provide a comprehensive inventory of tomato sugar transporters, including the SUCROSE TRANSPORTER family, the SUGAR TRANSPORTER PROTEIN family, the SUGAR FACILITATOR PROTEIN family, the POLYOL/MONOSACCHARIDE TRANSPORTER family, the INOSITOL TRANSPORTER family, the PLASTIDIC GLUCOSE TRANSLOCATOR family, the TONOPLAST MONOSACCHARIDE TRANSPORTER family and the VACUOLAR GLUCOSE TRANSPORTER family. Expressed sequence tag (EST) sequencing and phylogenetic analyses established a nomenclature for all analyzed tomato sugar transporters. In total we identified 52 genes in tomato putatively encoding sugar transporters. The expression of 29 sugar transporter genes in vegetative tissues and during fruit development was analyzed. Several sugar transporter genes were expressed in a tissue- or developmental stage-specific manner. This information will be helpful to better understand source to sink movement of photoassimilates in tomato. Identification of fruit-specific sugar transporters might be a first step to find novel genes contributing to tomato fruit sugar accumulation.
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Affiliation(s)
- Stefan Reuscher
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, 464-8601 JapanThese authors contributed equally to this work
| | - Masahito Akiyama
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, 464-8601 JapanThese authors contributed equally to this work
| | - Tomohide Yasuda
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, 464-8601 Japan
| | - Haruko Makino
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, 464-8601 Japan
| | - Koh Aoki
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Gakuen-cho, Sakai, 599-8531 Japan
| | - Daisuke Shibata
- Kazusa DNA Research Institute, Kazusa-kamatari, Kisarazu, 292-0818 Japan
| | - Katsuhiro Shiratake
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, 464-8601 Japan
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783
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Yuan M, Zhao J, Huang R, Li X, Xiao J, Wang S. Rice MtN3/saliva/SWEET gene family: Evolution, expression profiling, and sugar transport. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2014; 56:559-70. [PMID: 24456138 DOI: 10.1111/jipb.12173] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 01/06/2014] [Indexed: 05/06/2023]
Abstract
The rice MtN3/saliva/SWEET gene family consists of 21 paralogs. However, their functions in physiological processes are largely unknown, although at least three of the 21 paralogs are used by pathogenic bacteria to infect rice. Here, we report the evolutionary features, transcriptional characteristics, and putative functions in sugar transport of this gene family. The wild rice accessions in this study included those with AA, BB, CC, BBCC, CCDD, EE, and GG genomes, which appeared approximately 0.58-14.6 million years ago. The structures, chromosomal locations, phylogenetic relationships, and homologous distribution among the accessions suggest that the number of rice MtN3/saliva/SWEET paralogs gradually increased as the Oryza genus evolved, and one third of the paralogs may have originated recently. These paralogs are differentially expressed in vegetative and reproductive tissues, in the leaf senescence process, and in signaling dependent on gibberellic acid, cytokinin, or 1-naphthalene acetic acid (an analog of auxin), suggesting that they may be associated with multiple physiological processes. Four paralogs could transport galactose in yeast, which suggests that they may have a similar function in rice. These results will help to elucidate their roles and biochemical functions in rice development, adaptation to environment, host-pathogen interaction, and so forth.
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Affiliation(s)
- Meng Yuan
- National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China
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784
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Kissoudis C, van de Wiel C, Visser RGF, van der Linden G. Enhancing crop resilience to combined abiotic and biotic stress through the dissection of physiological and molecular crosstalk. FRONTIERS IN PLANT SCIENCE 2014; 5:207. [PMID: 24904607 PMCID: PMC4032886 DOI: 10.3389/fpls.2014.00207] [Citation(s) in RCA: 152] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 04/28/2014] [Indexed: 05/18/2023]
Abstract
Plants growing in their natural habitats are often challenged simultaneously by multiple stress factors, both abiotic and biotic. Research has so far been limited to responses to individual stresses, and understanding of adaptation to combinatorial stress is limited, but indicative of non-additive interactions. Omics data analysis and functional characterization of individual genes has revealed a convergence of signaling pathways for abiotic and biotic stress adaptation. Taking into account that most data originate from imposition of individual stress factors, this review summarizes these findings in a physiological context, following the pathogenesis timeline and highlighting potential differential interactions occurring between abiotic and biotic stress signaling across the different cellular compartments and at the whole plant level. Potential effects of abiotic stress on resistance components such as extracellular receptor proteins, R-genes and systemic acquired resistance will be elaborated, as well as crosstalk at the levels of hormone, reactive oxygen species, and redox signaling. Breeding targets and strategies are proposed focusing on either manipulation and deployment of individual common regulators such as transcription factors or pyramiding of non- (negatively) interacting components such as R-genes with abiotic stress resistance genes. We propose that dissection of broad spectrum stress tolerance conferred by priming chemicals may provide an insight on stress cross regulation and additional candidate genes for improving crop performance under combined stress. Validation of the proposed strategies in lab and field experiments is a first step toward the goal of achieving tolerance to combinatorial stress in crops.
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785
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Siamer S, Guillas I, Shimobayashi M, Kunz C, Hall MN, Barny MA. Expression of the bacterial type III effector DspA/E in Saccharomyces cerevisiae down-regulates the sphingolipid biosynthetic pathway leading to growth arrest. J Biol Chem 2014; 289:18466-77. [PMID: 24828506 DOI: 10.1074/jbc.m114.562769] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Erwinia amylovora, the bacterium responsible for fire blight, relies on a type III secretion system and a single injected effector, DspA/E, to induce disease in host plants. DspA/E belongs to the widespread AvrE family of type III effectors that suppress plant defense responses and promote bacterial growth following infection. Ectopic expression of DspA/E in plant or in Saccharomyces cerevisiae is toxic, indicating that DspA/E likely targets a cellular process conserved between yeast and plant. To unravel the mode of action of DspA/E, we screened the Euroscarf S. cerevisiae library for mutants resistant to DspA/E-induced growth arrest. The most resistant mutants (Δsur4, Δfen1, Δipt1, Δskn1, Δcsg1, Δcsg2, Δorm1, and Δorm2) were impaired in the sphingolipid biosynthetic pathway. Exogenously supplied sphingolipid precursors such as the long chain bases (LCBs) phytosphingosine and dihydrosphingosine also suppressed the DspA/E-induced yeast growth defect. Expression of DspA/E in yeast down-regulated LCB biosynthesis and induced a rapid decrease in LCB levels, indicating that serine palmitoyltransferase (SPT), the first and rate-limiting enzyme of the sphingolipid biosynthetic pathway, was repressed. SPT down-regulation was mediated by dephosphorylation and activation of Orm proteins that negatively regulate SPT. A Δcdc55 mutation affecting Cdc55-PP2A protein phosphatase activity prevented Orm dephosphorylation and suppressed DspA/E-induced growth arrest.
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Affiliation(s)
- Sabrina Siamer
- From the Institut National de la Recherche Agronomique UMR1392, Institut d'Ecologie et des Sciences de l'Environnement, Université Pierre et Marie Curie (UPMC), Bât A 7ème Etage Case 237, 7 Quai St.-Bernard, 75252 Paris, France, Biozentrum, University of Basel, CH-4056 Basel, Switzerland
| | - Isabelle Guillas
- Sorbonne Universités, UMR1166, Institut National de la Santé et de la recherche médicale-UPMC, Pitié-Salpétrière University Hospital, F75013, Paris, France
| | | | - Caroline Kunz
- Sorbonne Universités, UPMC University Paris 06, UFR 927, F-75005 Paris, France, and Muséum National d'Histoire Naturelle, UMR7245, Molécules de Communication et Adaptation des Micro-organismes, F-75005 Paris, France
| | - Michael N Hall
- Biozentrum, University of Basel, CH-4056 Basel, Switzerland
| | - Marie-Anne Barny
- From the Institut National de la Recherche Agronomique UMR1392, Institut d'Ecologie et des Sciences de l'Environnement, Université Pierre et Marie Curie (UPMC), Bât A 7ème Etage Case 237, 7 Quai St.-Bernard, 75252 Paris, France,
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786
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Mezhoud N, Zili F, Bouzidi N, Helaoui F, Ammar J, Ouada HB. The effects of temperature and light intensity on growth, reproduction and EPS synthesis of a thermophilic strain related to the genus Graesiella. Bioprocess Biosyst Eng 2014; 37:2271-80. [DOI: 10.1007/s00449-014-1204-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2013] [Accepted: 04/22/2014] [Indexed: 10/25/2022]
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787
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Li Z, Zou L, Ye G, Xiong L, Ji Z, Zakria M, Hong N, Wang G, Chen G. A potential disease susceptibility gene CsLOB of citrus is targeted by a major virulence effector PthA of Xanthomonas citri subsp. citri. MOLECULAR PLANT 2014; 7:912-5. [PMID: 24398629 DOI: 10.1093/mp/sst176] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Affiliation(s)
- Zheng Li
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
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788
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Kuhn H, Panstruga R. Introduction to a Virtual Special Issue on phytopathogen effector proteins. THE NEW PHYTOLOGIST 2014; 202:727-730. [PMID: 24716512 DOI: 10.1111/nph.12804] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Affiliation(s)
- Hannah Kuhn
- Institute for Biology I, Unit of Plant Molecular Cell Biology, RWTH Aachen University, Aachen, Germany
| | - Ralph Panstruga
- Institute for Biology I, Unit of Plant Molecular Cell Biology, RWTH Aachen University, Aachen, Germany
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789
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Lin IW, Sosso D, Chen LQ, Gase K, Kim SG, Kessler D, Klinkenberg PM, Gorder MK, Hou BH, Qu XQ, Carter CJ, Baldwin IT, Frommer WB. Nectar secretion requires sucrose phosphate synthases and the sugar transporter SWEET9. Nature 2014; 508:546-9. [PMID: 24670640 DOI: 10.1038/nature13082] [Citation(s) in RCA: 241] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 01/27/2014] [Indexed: 01/09/2023]
Abstract
Angiosperms developed floral nectaries that reward pollinating insects. Although nectar function and composition have been characterized, the mechanism of nectar secretion has remained unclear. Here we identify SWEET9 as a nectary-specific sugar transporter in three eudicot species: Arabidopsis thaliana, Brassica rapa (extrastaminal nectaries) and Nicotiana attenuata (gynoecial nectaries). We show that SWEET9 is essential for nectar production and can function as an efflux transporter. We also show that sucrose phosphate synthase genes, encoding key enzymes for sucrose biosynthesis, are highly expressed in nectaries and that their expression is also essential for nectar secretion. Together these data are consistent with a model in which sucrose is synthesized in the nectary parenchyma and subsequently secreted into the extracellular space via SWEET9, where sucrose is hydrolysed by an apoplasmic invertase to produce a mixture of sucrose, glucose and fructose. The recruitment of SWEET9 for sucrose export may have been a key innovation, and could have coincided with the evolution of core eudicots and contributed to the evolution of nectar secretion to reward pollinators.
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Affiliation(s)
- I Winnie Lin
- 1] Department of Biology, Stanford University, Stanford, California 94305, USA [2] Carnegie Institution for Science, 260 Panama Street, Stanford, California 94305, USA
| | - Davide Sosso
- 1] Department of Biology, Stanford University, Stanford, California 94305, USA [2] Carnegie Institution for Science, 260 Panama Street, Stanford, California 94305, USA
| | - Li-Qing Chen
- Carnegie Institution for Science, 260 Panama Street, Stanford, California 94305, USA
| | - Klaus Gase
- Max Planck Institute for Chemical Ecology, Jena D-07745, Germany
| | - Sang-Gyu Kim
- Max Planck Institute for Chemical Ecology, Jena D-07745, Germany
| | - Danny Kessler
- Max Planck Institute for Chemical Ecology, Jena D-07745, Germany
| | - Peter M Klinkenberg
- 1] Department of Biology, University of Minnesota Duluth, Duluth, Minnesota 55812, USA [2] Department of Plant Biology, University of Minnesota, St Paul, Minnesota 55108, USA
| | - Molly K Gorder
- 1] Department of Biology, University of Minnesota Duluth, Duluth, Minnesota 55812, USA [2] Department of Plant Biology, University of Minnesota, St Paul, Minnesota 55108, USA
| | - Bi-Huei Hou
- Carnegie Institution for Science, 260 Panama Street, Stanford, California 94305, USA
| | - Xiao-Qing Qu
- 1] Carnegie Institution for Science, 260 Panama Street, Stanford, California 94305, USA [2] Key Laboratory of Plant and Soil Interactions, College of Resources and Environmental Sciences, China Agricultural University, 100193 Beijing, China
| | - Clay J Carter
- 1] Department of Biology, University of Minnesota Duluth, Duluth, Minnesota 55812, USA [2] Department of Plant Biology, University of Minnesota, St Paul, Minnesota 55108, USA
| | - Ian T Baldwin
- Max Planck Institute for Chemical Ecology, Jena D-07745, Germany
| | - Wolf B Frommer
- 1] Department of Biology, Stanford University, Stanford, California 94305, USA [2] Carnegie Institution for Science, 260 Panama Street, Stanford, California 94305, USA
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790
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Bodenhausen N, Bortfeld-Miller M, Ackermann M, Vorholt JA. A synthetic community approach reveals plant genotypes affecting the phyllosphere microbiota. PLoS Genet 2014; 10:e1004283. [PMID: 24743269 PMCID: PMC3990490 DOI: 10.1371/journal.pgen.1004283] [Citation(s) in RCA: 238] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 02/18/2014] [Indexed: 12/12/2022] Open
Abstract
The identity of plant host genetic factors controlling the composition of the plant microbiota and the extent to which plant genes affect associated microbial populations is currently unknown. Here, we use a candidate gene approach to investigate host effects on the phyllosphere community composition and abundance. To reduce the environmental factors that might mask genetic factors, the model plant Arabidopsis thaliana was used in a gnotobiotic system and inoculated with a reduced complexity synthetic bacterial community composed of seven strains representing the most abundant phyla in the phyllosphere. From a panel of 55 plant mutants with alterations in the surface structure, cell wall, defense signaling, secondary metabolism, and pathogen recognition, a small number of single host mutations displayed an altered microbiota composition and/or abundance. Host alleles that resulted in the strongest perturbation of the microbiota relative to the wild-type were lacs2 and pec1. These mutants affect cuticle formation and led to changes in community composition and an increased bacterial abundance relative to the wild-type plants, suggesting that different bacteria can benefit from a modified cuticle to different extents. Moreover, we identified ein2, which is involved in ethylene signaling, as a host factor modulating the community's composition. Finally, we found that different Arabidopsis accessions exhibited different communities, indicating that plant host genetic factors shape the associated microbiota, thus harboring significant potential for the identification of novel plant factors affecting the microbiota of the communities. The leaves of plants are inhabited by a diverse community of microorganisms. These leaf inhabitants influence their hosts with respect to growth and resistance to abiotic and biotic stresses. Recent studies revealed that the bacterial communities associated with leaves undergo selection, resulting in conserved microbial communities. However, the factors that are involved in structuring of bacterial communities are not well understood. In order to uncover host genetic factors that determine the community composition and to exclude confounding environmental effects, we inoculated Arabidopsis thaliana with a synthetic bacterial community under controlled conditions We screened a panel of Arabidopsis mutants defective in various traits for alterations in community structure and abundance and were able to show that cuticle synthesis and ethylene perception affect the bacterial community. In addition, we identified plant ecotypes with drastic differences in the community composition. Our system can thus be used to identify additional host genes and to broaden insights into plant microbe interactions, potentially providing a basis for applied plant protection through the identification of traits that enhance growth of plant probiotic bacteria.
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Affiliation(s)
| | | | - Martin Ackermann
- Department of Environmental Sciences, ETH Zurich, Zurich, Switzerland
- Department of Environmental Microbiology, Eawag, Dubendorf, Switzerland
| | - Julia A. Vorholt
- Institute of Microbiology, ETH Zurich, Zurich, Switzerland
- * E-mail:
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791
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Jones AM, Danielson JA, Manojkumar SN, Lanquar V, Grossmann G, Frommer WB. Abscisic acid dynamics in roots detected with genetically encoded FRET sensors. eLife 2014; 3:e01741. [PMID: 24737862 PMCID: PMC3985517 DOI: 10.7554/elife.01741] [Citation(s) in RCA: 168] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Cytosolic hormone levels must be tightly controlled at the level of influx, efflux, synthesis, degradation and compartmentation. To determine ABA dynamics at the single cell level, FRET sensors (ABACUS) covering a range ∼0.2–800 µM were engineered using structure-guided design and a high-throughput screening platform. When expressed in yeast, ABACUS1 detected concentrative ABA uptake mediated by the AIT1/NRT1.2 transporter. Arabidopsis roots expressing ABACUS1-2µ (Kd∼2 µM) and ABACUS1-80µ (Kd∼80 µM) respond to perfusion with ABA in a concentration-dependent manner. The properties of the observed ABA accumulation in roots appear incompatible with the activity of known ABA transporters (AIT1, ABCG40). ABACUS reveals effects of external ABA on homeostasis, that is, ABA-triggered induction of ABA degradation, modification, or compartmentation. ABACUS can be used to study ABA responses in mutants and quantitatively monitor ABA translocation and regulation, and identify missing components. The sensor screening platform promises to enable rapid fine-tuning of the ABA sensors and engineering of plant and animal hormone sensors to advance our understanding of hormone signaling. DOI:http://dx.doi.org/10.7554/eLife.01741.001 Plants are able to respond to detrimental changes in their environment—when, for example, water becomes scarce or the soil becomes too salty—in ways that minimize stress and damage caused by these changes. Hormones are chemicals that trigger the plant’s response under these circumstances. Abscisic acid is the hormone that regulates how plants respond to drought and salt stress, and also controls growth and development. In the past, it was possible to measure the average level of this hormone in a given tissue, but not the level in individual cells in a living plant, nor in specific compartments within a cell. Moreover, it was difficult to follow directly how abscisic acid moved between the plant cells, tissues or organs. Now, Jones et al. (and independently Waadt et al.) have developed tools that can measure the levels of abscisic acid within defined compartments of individual cells in living plants and in real time. The plants were genetically engineered to produce sensor proteins with two properties: they can bind to abscisic acid in a reversible manner, and they contain two ‘reporters’ that fluoresce at different wavelengths. Shining light onto the plant at a specific wavelength that is only absorbed by one of the reporters causes both of the reporters on the sensor proteins to fluoresce. However, the two reporters fluoresce differently when the sensor binds to abscisic acid. Specifically, one reporter fluoresces more and the other less. Hence, measuring the ratio of these two wavelengths in the light that is given off by the sensor proteins can be used as a measure of the concentration of abscisic acid in a plant cell. Jones et al. used a high-throughput platform to engineer five sensor proteins that detect abscisic acid over a wide range of concentrations. Using these ‘ABACUS’ sensors in living plants could track the uptake of abscisic acid into root cells, and revealed that the concentration of the hormone inside the cell stayed below the levels provided on the outside. Since known abscisic acid-transporters are capable of raising the hormone concentration inside a cell above that provided on the outside, abscisic acid transport into plant roots may occur via as-yet-undiscovered transporter proteins. Jones et al. also show that root cells rapidly eliminate abscisic acid, and that adding extra abscisic acid to the roots increases the rate of elimination within minutes. Plants were also engineered to target the sensor proteins specifically to the cell nucleus. In the future, targeting these sensors to the cell wall should allow tracking of the cell-to-cell movement of this hormone. Further aims include using ABACUS to track abscisic acid in plants undergoing stress, and to use the high-throughput platform to develop new sensors to track other hormones in living organisms (including animals). DOI:http://dx.doi.org/10.7554/eLife.01741.002
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Affiliation(s)
- Alexander M Jones
- Department of Plant Biology, Carnegie Institution for Science, Stanford, United States
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792
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Zhou Y, Liu L, Huang W, Yuan M, Zhou F, Li X, Lin Y. Overexpression of OsSWEET5 in rice causes growth retardation and precocious senescence. PLoS One 2014; 9:e94210. [PMID: 24709840 PMCID: PMC3978035 DOI: 10.1371/journal.pone.0094210] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 03/13/2014] [Indexed: 01/07/2023] Open
Abstract
As a novel sugar transporter family, SWEETs play important roles in plant growth and development. Here, we characterized a SWEET gene named OsSWEET5 through its overexpression in rice. Heterologous expression assay indicated that OsSWEET5 encoded a galactose transporter in yeast. OsSWEET5-overexpressing plants displayed the phenotypes of growth retardation and precocious senescence at seedling stage. GC-MS analysis showed that the sugar levels were largely altered in the leaves of the OsSWEET5-overexpressing plants. Molecular analysis revealed that these phenotypes might be due to the transcriptional changes of the genes involved in sugar metabolism and transport. In addition, the transgenic plants showed a lower level of auxin with altered transcription of genes involved in auxin signaling and translocation pathways. However, no obvious phenotype was observed between the amiRNA-OsSWEET5 transgenic lines and WT plants, which could be a result of the functional redundancy of the galactose transporters in rice. Taken together, our findings suggest that OsSWEET5 plays a crucial role in regulating the crosstalk between sugar and auxin in rice.
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Affiliation(s)
- Yong Zhou
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China
| | - Li Liu
- Plant Reproductive Biology, University of California Davis, Davis, California, United States of America
| | - Weifeng Huang
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China
| | - Meng Yuan
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China
| | - Fei Zhou
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China
| | - Xianghua Li
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China
| | - Yongjun Lin
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China
- * E-mail:
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793
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Affiliation(s)
- Michael J Haydon
- Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK
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794
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Lanquar V, Grossmann G, Vinkenborg JL, Merkx M, Thomine S, Frommer WB. Dynamic imaging of cytosolic zinc in Arabidopsis roots combining FRET sensors and RootChip technology. THE NEW PHYTOLOGIST 2014; 202:198-208. [PMID: 24372442 DOI: 10.1111/nph.12652] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 11/18/2013] [Indexed: 05/03/2023]
Abstract
Zinc plays a central role in all living cells as a cofactor for enzymes and as a structural element enabling the adequate folding of proteins. In eukaryotic cells, metals are highly compartmentalized and chelated. Although essential to characterize the mechanisms of Zn(2+) homeostasis, the measurement of free metal concentrations in living cells has proved challenging and the dynamics are difficult to determine. Our work combines the use of genetically encoded Förster resonance energy transfer (FRET) sensors and a novel microfluidic technology, the RootChip, to monitor the dynamics of cytosolic Zn(2+) concentrations in Arabidopsis root cells. Our experiments provide estimates of cytosolic free Zn(2+) concentrations in Arabidopsis root cells grown under sufficient (0.4 nM) and excess (2 nM) Zn(2+) supply. In addition, monitoring the dynamics of cytosolic [Zn(2+) ] in response to external supply suggests the involvement of high- and low-affinity uptake systems as well as release from internal stores. In this study, we demonstrate that the combination of genetically encoded FRET sensors and microfluidics provides an attractive tool to monitor the dynamics of cellular metal ion concentrations over a wide concentration range in root cells.
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Affiliation(s)
- Viviane Lanquar
- Department of Plant Biology, Carnegie Institution for Science, 260 Panama St, Stanford, CA, 94305, USA
- CNRS, Institut des Sciences du Végétal, Saclay Plant Sciences, Avenue de la Terrasse, 91198, Gif-sur-Yvette, France
| | - Guido Grossmann
- Department of Plant Biology, Carnegie Institution for Science, 260 Panama St, Stanford, CA, 94305, USA
| | - Jan L Vinkenborg
- Laboratory of Chemical Biology, Eindhoven University of Technology, PO Box 513, 5600 MB, Eindhoven, the Netherlands
| | - Maarten Merkx
- Laboratory of Chemical Biology, Eindhoven University of Technology, PO Box 513, 5600 MB, Eindhoven, the Netherlands
| | - Sébastien Thomine
- CNRS, Institut des Sciences du Végétal, Saclay Plant Sciences, Avenue de la Terrasse, 91198, Gif-sur-Yvette, France
| | - Wolf B Frommer
- Department of Plant Biology, Carnegie Institution for Science, 260 Panama St, Stanford, CA, 94305, USA
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795
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Braun DM, Wang L, Ruan YL. Understanding and manipulating sucrose phloem loading, unloading, metabolism, and signalling to enhance crop yield and food security. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:1713-35. [PMID: 24347463 DOI: 10.1093/jxb/ert416] [Citation(s) in RCA: 227] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Sucrose is produced in, and translocated from, photosynthetically active leaves (sources) to support non-photosynthetic tissues (sinks), such as developing seeds, fruits, and tubers. Different plants can utilize distinct mechanisms to transport sucrose into the phloem sieve tubes in source leaves. While phloem loading mechanisms have been extensively studied in dicot plants, there is less information about phloem loading in monocots. Maize and rice are major dietary staples, which have previously been proposed to use different cellular routes to transport sucrose from photosynthetic cells into the translocation stream. The anatomical, physiological, and genetic evidence supporting these conflicting hypotheses is examined. Upon entering sink cells, sucrose often is degraded into hexoses for a wide range of metabolic and storage processes, including biosynthesis of starch, protein, and cellulose, which are all major constituents for food, fibre, and fuel. Sucrose, glucose, fructose, and their derivate, trehalose-6-phosphate, also serve as signalling molecules to regulate gene expression either directly or through cross-talk with other signalling pathways. As such, sugar transport and metabolism play pivotal roles in plant development and realization of crop yield that needs to be increased substantially to meet the projected population demand in the foreseeable future. This review will discuss the current understanding of the control of carbon partitioning from the cellular to whole-plant levels, focusing on (i) the pathways employed for phloem loading in source leaves, particularly in grasses, and the routes used in sink organs for phloem unloading; (ii) the transporter proteins responsible for sugar efflux and influx across plasma membranes; and (iii) the key enzymes regulating sucrose metabolism, signalling, and utilization. Examples of how sugar transport and metabolism can be manipulated to improve crop productivity and stress tolerance are discussed.
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Affiliation(s)
- David M Braun
- Division of Biological Sciences, Interdisciplinary Plant Group, and Missouri Maize Center, University of Missouri, Columbia, MO 65211, USA
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796
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Klemens PAW, Patzke K, Trentmann O, Poschet G, Büttner M, Schulz A, Marten I, Hedrich R, Neuhaus HE. Overexpression of a proton-coupled vacuolar glucose exporter impairs freezing tolerance and seed germination. THE NEW PHYTOLOGIST 2014; 202:188-197. [PMID: 24329902 DOI: 10.1111/nph.12642] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 11/13/2013] [Indexed: 05/18/2023]
Abstract
Arabidopsis vacuoles harbor, besides sugar transporter of the TMT-type, an early response to dehydration like 6 (ERDL6) protein involved in glucose export into the cytosol. However, the mode of transport of ERDL6 and the plant's feedback to overexpression of its activity on essential properties such as, for example, seed germination or freezing tolerance, remain unexplored. Using patch-clamp studies on vacuoles expressing AtERDL6 we demonstrated directly that this carrier operates as a proton-driven glucose exporter. Overexpression of BvIMP, the closest sugar beet (Beta vulgaris) homolog to AtERDL6, in Arabidopsis leads surprisingly to impaired seed germination under both conditions, sugar application and low environmental temperatures, but not under standard conditions. Upon cold treatment, BvIMP overexpressor plants accumulated lower quantities of monosaccharides than the wild-type, a response in line with the reduced frost tolerance of the transgenic Arabidopsis plants, and the fact that cold temperatures inhibits BvIMP transcription in sugar beet leaves. With these findings we show that the tight control of vacuolar sugar import and export is a key requisite for cold tolerance and seed germination of plants.
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Affiliation(s)
- Patrick A W Klemens
- Plant Physiology, University of Kaiserslautern, Erwin-Schrödinger-Str., D-67653, Kaiserslautern, Germany
| | - Kathrin Patzke
- Plant Physiology, University of Kaiserslautern, Erwin-Schrödinger-Str., D-67653, Kaiserslautern, Germany
| | - Oliver Trentmann
- Plant Physiology, University of Kaiserslautern, Erwin-Schrödinger-Str., D-67653, Kaiserslautern, Germany
| | - Gernot Poschet
- Centre for Organismal Studies (COS), University of Heidelberg, Im Neuenheimer Feld 360, 69120, Heidelberg, Germany
| | - Michael Büttner
- Centre for Organismal Studies (COS), University of Heidelberg, Im Neuenheimer Feld 360, 69120, Heidelberg, Germany
| | - Alexander Schulz
- Institute for Molecular Plant Physiology and Biophysics, University of Würzburg, Julius-von-Sachs Platz 2, D-97082, Würzburg, Germany
| | - Irene Marten
- Institute for Molecular Plant Physiology and Biophysics, University of Würzburg, Julius-von-Sachs Platz 2, D-97082, Würzburg, Germany
| | - Rainer Hedrich
- Institute for Molecular Plant Physiology and Biophysics, University of Würzburg, Julius-von-Sachs Platz 2, D-97082, Würzburg, Germany
| | - H Ekkehard Neuhaus
- Plant Physiology, University of Kaiserslautern, Erwin-Schrödinger-Str., D-67653, Kaiserslautern, Germany
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797
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Bartlem DG, Jones MGK, Hammes UZ. Vascularization and nutrient delivery at root-knot nematode feeding sites in host roots. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:1789-98. [PMID: 24336493 DOI: 10.1093/jxb/ert415] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Plants are constantly challenged by pathogens and pests, which can have a profound impact on the yield and quality of produce in agricultural systems. The vascular system of higher plants is critical for growth and for their ability to counteract changing external conditions, serving as a distribution network for water, nutrients, and photosynthates from the source organs to regions where they are in demand. Unfortunately, these features also make it an attractive target for pathogens and pests that demand access to a reliable supply of host resources. The vascular tissue of plants therefore often plays a central role in pathogen and parasite interactions. One of the more striking rearrangements of the host vascular system occurs during root-knot nematode infestation of plant roots. These sedentary endoparasites induce permanent feeding sites that are comprised of 'giant cells' and are subject to extensive changes in vascularization, resulting in the giant cells being encaged within a network of de novo formed xylem and phloem cells. Despite being considered critical to the function of the feeding site, the mechanisms underlying this vascularization have received surprisingly little attention when compared with the amount of research on giant cell development and function. An overview of the current knowledge on vascularization of root-knot nematode feeding sites is provided here and recent advances in our understanding of the transport mechanisms involved in nutrient delivery to these parasite-induced sinks are described.
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Affiliation(s)
- Derek G Bartlem
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
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798
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Kliebenstein DJ. Orchestration of plant defense systems: genes to populations. TRENDS IN PLANT SCIENCE 2014; 19:250-255. [PMID: 24486317 DOI: 10.1016/j.tplants.2014.01.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 11/21/2013] [Accepted: 01/08/2014] [Indexed: 06/03/2023]
Abstract
Research over the past decades has made immense progress in identifying some genes and mechanisms underlying plant defense against biotic organisms. The recent movement towards systems biology approaches has increased mechanistic knowledge, revealing a need for understanding how all the genes and mechanisms integrate to create a response to any given biotic interaction. This begins with evidence that diverse molecular patterns converge, suggesting that the plant perceives signals not the interacting species. These signals then coordinate across regulatory networks via molecular interactions and cause non-cell autonomous responses in neighboring and systemic cells. Finally, the identification of transporters is showing that plant defenses are harmonized across tissues and even show the potential for coordination across individuals within a population.
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Affiliation(s)
- Daniel J Kliebenstein
- Department of Plant Sciences, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA; DynaMo Center of Excellence, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg C, Denmark.
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799
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Chao J, Jin J, Wang D, Han R, Zhu R, Zhu Y, Li S. Cytological and transcriptional dynamics analysis of host plant revealed stage-specific biological processes related to compatible rice-Ustilaginoidea virens interaction. PLoS One 2014; 9:e91391. [PMID: 24646527 PMCID: PMC3960121 DOI: 10.1371/journal.pone.0091391] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 02/09/2014] [Indexed: 01/22/2023] Open
Abstract
Rice false smut, a fungal disease caused by Ustilaginoidea virens is becoming a severe detriment to rice production worldwide. However, little is known about the molecular response of rice to attacks by the smut pathogen. In this article, we define the initial infection process as having three stages: initial colonization on the pistil (stage 1, S1), amplification on the anther (stage 2, S2) and sporulation in the anther chambers (stage 3, S3). Based on the transcriptome of rice hosts in response to U. virens in two separate years, we identified 126, 204, and 580 specific regulated genes in their respective stages S1, S2, and S3, respectively, by excluding common expression patterns in other openly biotic/abiotic databases using bioinformatics. As the disease progresses, several stage-specific biological processes (BP) terms were distinctively enriched: "Phosphorylation" in stage S1, "PCD" in S2, and "Cell wall biogenesis" in S3, implying a concise signal cascade indicative of the tactics that smut pathogens use to control host rice cells during infection. 113 regulated genes were coexpressed among the three stages. They shared highly conserved promoter cis-element in the promoters in response to the regulation of WRKY and Myb for up-regulation, and ABA and Ca2+ for down regulation, indicating their potentially critical roles in signal transduction during rice-U. virens interaction. We further analyzed seven highly regulated unique genes; four were specific to pollen development, implying that pollen-related genes play critical roles in the establishment of rice susceptibility to U. virens. To my knowledge, this is the first report about probing of molecular response of rice to smut pathogen infection, which will greatly expand our understanding of the molecular events surrounding infection by rice false smut.
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Affiliation(s)
- Jinquan Chao
- State Key Laboratory for Hybrid Rice, College of Life Science, Wuhan University, Wuhan, China
| | - Jie Jin
- State Key Laboratory for Hybrid Rice, College of Life Science, Wuhan University, Wuhan, China
| | - Dong Wang
- Department of Statistics, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Ran Han
- State Key Laboratory for Hybrid Rice, College of Life Science, Wuhan University, Wuhan, China
| | - Renshan Zhu
- State Key Laboratory for Hybrid Rice, College of Life Science, Wuhan University, Wuhan, China
| | - Yingguo Zhu
- State Key Laboratory for Hybrid Rice, College of Life Science, Wuhan University, Wuhan, China
| | - Shaoqing Li
- State Key Laboratory for Hybrid Rice, College of Life Science, Wuhan University, Wuhan, China
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800
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Chen LQ. SWEET sugar transporters for phloem transport and pathogen nutrition. THE NEW PHYTOLOGIST 2014; 201:1150-5. [PMID: 24649486 DOI: 10.1111/nph.12445] [Citation(s) in RCA: 209] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Many intercellular solute transport processes require an apoplasmic step, that is, efflux from one cell and subsequent uptake by an adjacent cell. Cellular uptake transporters have been identified for many solutes, including sucrose; however, efflux transporters have remained elusive for a long time. Cellular efflux of sugars plays essential roles in many processes, such as sugar efflux as the first step in phloem loading, sugar efflux for nectar secretion, and sugar efflux for supplying symbionts such as mycorrhiza, and maternal efflux for filial tissue development. Furthermore, sugar efflux systems can be hijacked by pathogens for access to nutrition from hosts. Mutations that block recruitment of the efflux mechanism by the pathogen thus cause pathogen resistance. Until recently, little was known regarding the underlying mechanism of sugar efflux. The identification of sugar efflux carriers, SWEETs (Sugars Will Eventually be Exported Transporters), has shed light on cellular sugar efflux. SWEETs appear to function as uniporters, facilitating diffusion of sugars across cell membranes. Indeed, SWEETs probably mediate sucrose efflux from putative phloem parenchyma into the phloem apoplasm, a key step proceeding phloem loading. Engineering of SWEET mutants using transcriptional activator-like effector nuclease (TALEN)-based genomic editing allowed the engineering of pathogen resistance. The widespread expression of the SWEET family promises to provide insights into many other cellular efflux mechanisms.
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