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Opitz MW, Díaz-Manzano FE, Ruiz-Ferrer V, Daneshkhah R, Ludwig R, Lorenz C, Escobar C, Steinkellner S, Wieczorek K. The other side of the coin: systemic effects of Serendipita indica root colonization on development of sedentary plant-parasitic nematodes in Arabidopsis thaliana. PLANTA 2024; 259:121. [PMID: 38615288 PMCID: PMC11016515 DOI: 10.1007/s00425-024-04402-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 04/01/2024] [Indexed: 04/15/2024]
Abstract
MAIN CONCLUSION Upon systemic S. indica colonization in split-root system cyst and root-knot nematodes benefit from endophyte-triggered carbon allocation and altered defense responses what significantly facilitates their development in A. thaliana. Serendipita indica is an endophytic fungus that establishes mutualistic relationships with different plants including Arabidopsis thaliana. It enhances host's growth and resistance to different abiotic and biotic stresses such as infestation by the cyst nematode Heterodera schachtii (CN). In this work, we show that S. indica also triggers similar direct reduction in development of the root-knot nematode Meloidogyne javanica (RKN) in A. thaliana. Further, to mimick the natural situation occurring frequently in soil where roots are unequally colonized by endophytes we used an in vitro split-root system with one half of A. thaliana root inoculated with S. indica and the other half infected with CN or RKN, respectively. Interestingly, in contrast to direct effects, systemic effects led to an increase in number of both nematodes. To elucidate this phenomenon, we focused on sugar metabolism and defense responses in systemic non-colonized roots of plants colonized by S. indica. We analyzed the expression of several SUSs and INVs as well as defense-related genes and measured sugar pools. The results show a significant downregulation of PDF1.2 as well as slightly increased sucrose levels in the non-colonized half of the root in three-chamber dish. Thus, we speculate that, in contrast to direct effects, both nematode species benefit from endophyte-triggered carbon allocation and altered defense responses in the systemic part of the root, which promotes their development. With this work, we highlight the complexity of this multilayered tripartite relationship and deliver new insights into sugar metabolism and plant defense responses during S. indica-nematode-plant interaction.
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Affiliation(s)
- Michael W Opitz
- Department of Crop Sciences, Institute of Plant Protection, University of Natural Resources and Life Sciences, Vienna, Tulln an der Donau, Austria
| | - Fernando Evaristo Díaz-Manzano
- Área de Fisiología Vegetal, Facultad de Ciencias Ambientales y Bioquímica, Universidad de Castilla-La Mancha, Toledo, Spain
| | - Virginia Ruiz-Ferrer
- Área de Fisiología Vegetal, Facultad de Ciencias Ambientales y Bioquímica, Universidad de Castilla-La Mancha, Toledo, Spain
| | - Roshanak Daneshkhah
- Department of Crop Sciences, Institute of Plant Protection, University of Natural Resources and Life Sciences, Vienna, Tulln an der Donau, Austria
| | - Roland Ludwig
- Department of Food Science and Technology, Institute of Food Technology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Cindy Lorenz
- Department of Food Science and Technology, Institute of Food Technology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Carolina Escobar
- Área de Fisiología Vegetal, Facultad de Ciencias Ambientales y Bioquímica, Universidad de Castilla-La Mancha, Toledo, Spain
| | - Siegrid Steinkellner
- Department of Crop Sciences, Institute of Plant Protection, University of Natural Resources and Life Sciences, Vienna, Tulln an der Donau, Austria
| | - Krzysztof Wieczorek
- Department of Crop Sciences, Institute of Plant Protection, University of Natural Resources and Life Sciences, Vienna, Tulln an der Donau, Austria.
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Xiao L, Gheysen G, Yang M, Xiao X, Xu L, Guo X, Yang L, Liu W, He Y, Peng D, Peng H, Ma K, Long H, Wang G, Xiao Y. Brown planthopper infestation on rice reduces plant susceptibility to Meloidogyne graminicola by reducing root sugar allocation. THE NEW PHYTOLOGIST 2024; 242:262-277. [PMID: 38332248 DOI: 10.1111/nph.19570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 01/16/2024] [Indexed: 02/10/2024]
Abstract
Plants are simultaneously attacked by different pests that rely on sugars uptake from plants. An understanding of the role of plant sugar allocation in these multipartite interactions is limited. Here, we characterized the expression patterns of sucrose transporter genes and evaluated the impact of targeted transporter gene mutants and brown planthopper (BPH) phloem-feeding and oviposition on root sugar allocation and BPH-reduced rice susceptibility to Meloidogyne graminicola. We found that the sugar transporter genes OsSUT1 and OsSUT2 are induced at BPH oviposition sites. OsSUT2 mutants showed a higher resistance to gravid BPH than to nymph BPH, and this was correlated with callose deposition, as reflected in a different effect on M. graminicola infection. BPH phloem-feeding caused inhibition of callose deposition that was counteracted by BPH oviposition. Meanwhile, this pivotal role of sugar allocation in BPH-reduced rice susceptibility to M. graminicola was validated on rice cultivar RHT harbouring BPH resistance genes Bph3 and Bph17. In conclusion, we demonstrated that rice susceptibility to M. graminicola is regulated by BPH phloem-feeding and oviposition on rice through differences in plant sugar allocation.
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Affiliation(s)
- Liying Xiao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Godelieve Gheysen
- Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University, Proeftuinstraat 86, Ghent, 9000, Belgium
| | - Mingwei Yang
- Hubei Key Laboratory of Insect Resources Utilization and Sustainable Pest Management, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xueqiong Xiao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Lihe Xu
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xiaoli Guo
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Lijie Yang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Wen Liu
- Hubei Key Laboratory of Insect Resources Utilization and Sustainable Pest Management, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yueping He
- Hubei Key Laboratory of Insect Resources Utilization and Sustainable Pest Management, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Deliang Peng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Science, Beijing, 100193, China
| | - Huan Peng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Science, Beijing, 100193, China
| | - Kangsheng Ma
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Haibo Long
- Institute of Environment and Plant Protection, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, China
| | - Gaofeng Wang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yannong Xiao
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, 430070, China
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Zhou Y, Zhao D, Duan Y, Chen L, Fan H, Wang Y, Liu X, Chen LQ, Xuan Y, Zhu X. AtSWEET1 negatively regulates plant susceptibility to root-knot nematode disease. FRONTIERS IN PLANT SCIENCE 2023; 14:1010348. [PMID: 36824200 PMCID: PMC9941640 DOI: 10.3389/fpls.2023.1010348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 01/20/2023] [Indexed: 06/18/2023]
Abstract
The root-knot nematode Meloidogyne incognita is a pathogenic pest that causes severe economic loss to agricultural production by forming a parasitic relationship with its hosts. During the development of M. incognita in the host plant roots, giant cells are formed as a nutrient sink. However, the roles of sugar transporters during the giant cells gain sugar from the plant cells are needed to improve. Meanwhile, the eventual function of sugars will eventually be exported transporters (SWEETs) in nematode-plant interactions remains unclear. In this study, the expression patterns of Arabidopsis thaliana SWEETs were examined by inoculation with M. incognita at 3 days post inoculation (dpi) (penetration stage) and 18 dpi (developing stage). We found that few AtSWEETs responded sensitively to M. incognita inoculation, with the highest induction of AtSWEET1 (AT1G21460), a glucose transporter gene. Histological analyses indicated that the β-glucuronidase (GUS) and green fluorescent protein (GFP) signals were observed specifically in the galls of AtSWEET1-GUS and AtSWEET1-GFP transgenic plant roots, suggesting that AtSWEET1 was induced specifically in the galls. Genetic studies have shown that parasitism of M. incognita was significantly affected in atsweet1 compared to wild-type and complementation plants. In addition, parasitism of M. incognita was significantly affected in atsweet10 but not in atsweet13 and atsweet14, expression of which was induced by inoculation with M. incognita. Taken together, these data prove that SWEETs play important roles in plant and nematode interactions.
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Affiliation(s)
- Yuan Zhou
- Nematology Institute of Northern China, College of Plant Protection, Shenyang Agriculture University, Shenyang, China
| | - Dan Zhao
- College of Plant Protection, Jilin Agricultural University, Changchun, China
| | - Yuxi Duan
- Nematology Institute of Northern China, College of Plant Protection, Shenyang Agriculture University, Shenyang, China
| | - Lijie Chen
- Nematology Institute of Northern China, College of Plant Protection, Shenyang Agriculture University, Shenyang, China
| | - Haiyan Fan
- Nematology Institute of Northern China, College of Plant Protection, Shenyang Agriculture University, Shenyang, China
| | - Yuanyuan Wang
- College of Biological Science and Technology, Shenyang Agriculture University, Shenyang, China
| | - Xiaoyu Liu
- College of Sciences, Shenyang Agriculture University, Shenyang, China
| | - Li-Qing Chen
- Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Yuanhu Xuan
- Nematology Institute of Northern China, College of Plant Protection, Shenyang Agriculture University, Shenyang, China
| | - Xiaofeng Zhu
- Nematology Institute of Northern China, College of Plant Protection, Shenyang Agriculture University, Shenyang, China
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4
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Xu Q, Liesche J. Sugar export from Arabidopsis leaves: actors and regulatory strategies. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:5275-5284. [PMID: 34037757 DOI: 10.1093/jxb/erab241] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 05/22/2021] [Indexed: 06/12/2023]
Abstract
Plant acclimation and stress responses depend on the dynamic optimization of carbon balance between source and sink organs. This optimization also applies to the leaf export rate of photosynthetically produced sugars. So far, investigations into the molecular mechanisms of how the rate is controlled have focused on sugar transporters responsible for loading sucrose into the phloem sieve element-companion cell complex of leaf veins. Here, we take a broader view of the various proteins with potential direct influence on the leaf sugar export rate in the model plant Arabidopsis thaliana, helped by the cell type-specific transcriptome data that have recently become available. Furthermore, we integrate current information on the regulation of these potential target proteins. Our analysis identifies putative control points and units of transcriptionally and post-transcriptionally co-regulated genes. Most notable is the potential regulatory unit of sucrose transporters (SUC2, SWEET11, SWEET12, and SUC4) and proton pumps (AHA3 and AVP1). Our analysis can guide future research aimed at understanding the regulatory network controlling leaf sugar export by providing starting points for characterizing regulatory strategies and identifying regulatory factors that link sugar export rate to the major signaling pathways.
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Affiliation(s)
- Qiyu Xu
- College of Life Sciences, Northwest A&F University, Yangling, China
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, China
- Biomass Energy Center for Arid and Semiarid Lands, Northwest A&F University, Yangling, China
| | - Johannes Liesche
- College of Life Sciences, Northwest A&F University, Yangling, China
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, China
- Biomass Energy Center for Arid and Semiarid Lands, Northwest A&F University, Yangling, China
- Institute for Molecular Physiology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
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5
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Xu L, Xiao L, Xiao Y, Peng D, Xiao X, Huang W, Gheysen G, Wang G. Plasmodesmata play pivotal role in sucrose supply to Meloidogyne graminicola-caused giant cells in rice. MOLECULAR PLANT PATHOLOGY 2021; 22:539-550. [PMID: 33723908 PMCID: PMC8035636 DOI: 10.1111/mpp.13042] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 01/24/2021] [Accepted: 01/28/2021] [Indexed: 05/20/2023]
Abstract
On infection, plant-parasitic nematodes establish feeding sites in roots from which they take up carbohydrates among other nutrients. Knowledge on how carbohydrates are supplied to the nematodes' feeding sites is limited. Here, gene expression analyses showed that RNA levels of OsSWEET11 to OsSWEET15 were extremely low in both Meloidogyne graminicola (Mg)-caused galls and noninoculated roots. All the rice sucrose transporter genes, OsSUT1 to OsSUT5, were either down-regulated in Mg-caused galls compared with noninoculated rice roots or had very low transcript abundance. OsSUT1 was the only gene up-regulated in galls, at 14 days postinoculation (dpi), after being highly down-regulated at 3 and 7 dpi. OsSUT4 was down-regulated at 3 dpi. No noticeable OsSUTs promoter activities were detected in Mg-caused galls of pOsSUT1 to -5::GUS rice lines. Loading experiments with carboxyfluorescein diacetate (CFDA) demonstrated that symplastic connections exist between phloem and Mg-caused giant cells (GCs). According to data from OsGNS5- and OsGSL2-overexpressing rice plants that had decreased and increased callose deposition, respectively, callose negatively affected Mg parasitism and sucrose supply to Mg-caused GCs. Our results suggest that plasmodesmata-mediated sucrose transport plays a pivotal role in sucrose supply from rice root phloem to Mg-caused GCs, and OsSWEET11 to -15 and OsSUTs are not major players in it, although further functional analysis is needed for OsSUT1 and OsSUT4.
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Affiliation(s)
- Li‐he Xu
- Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science & TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Li‐ying Xiao
- Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science & TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Yan‐nong Xiao
- Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science & TechnologyHuazhong Agricultural UniversityWuhanChina
| | - De‐liang Peng
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural ScienceBeijingChina
| | - Xue‐qiong Xiao
- Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science & TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Wen‐kun Huang
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural ScienceBeijingChina
| | - Godelieve Gheysen
- Department of BiotechnologyFaculty of Bioscience EngineeringGhent UniversityGhentBelgium
| | - Gao‐feng Wang
- Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science & TechnologyHuazhong Agricultural UniversityWuhanChina
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6
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Stadler R, Sauer N. The AtSUC2 Promoter: A Powerful Tool to Study Phloem Physiology and Development. Methods Mol Biol 2019; 2014:267-287. [PMID: 31197803 DOI: 10.1007/978-1-4939-9562-2_22] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The sucrose carrier AtSUC2 of Arabidopsis thaliana is localized in the phloem, where it catalyzes the uptake of sucrose from the apoplast into companion cells. Imported sucrose moves passively via plasmodesmata from the companion cells into the neighboring sieve elements that distribute this disaccharide to the different sink organs. Phloem loading of sucrose by the AtSUC2 protein is an essential process, and mutants lacking this protein stay tiny, develop no or only few flowers, and have a strongly reduced root system. The promoter of the AtSUC2 gene is active exclusively in companion cells of the phloem. Moreover, it drives very strong expression not only in Arabidopsis, but also in all plant species tested so far, including monocot species. Due to these features, the AtSUC2 promoter has become an important tool in diverse areas of plant research during the last two decades. It was used to study phloem development and function including phloem loading and unloading. Furthermore, it was helpful in analyzing the pathways of posttranscriptional silencing by RNA interference, the regulation of flowering, mechanisms of nutrient withdrawal by phloem-feeding pathogens, and other physiological functions that are related to long distance transport. The present paper gives an overview of different approaches in plant research that utilized the strong and companion cell-specific expression of own or foreign genes driven by the AtSUC2 promoter.
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Affiliation(s)
- Ruth Stadler
- Molecular Plant Physiology, Department of Biology, University of Erlangen-Nuremberg, Erlangen, Germany.
| | - Norbert Sauer
- Molecular Plant Physiology, Department of Biology, University of Erlangen-Nuremberg, Erlangen, Germany
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7
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Redding NW, Agudelo P, Wells CE. Multiple Nodulation Genes Are Up-Regulated During Establishment of Reniform Nematode Feeding Sites in Soybean. PHYTOPATHOLOGY 2018; 108:275-291. [PMID: 28945515 DOI: 10.1094/phyto-04-17-0154-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The semi-endoparastic reniform nematode (Rotylenchulus reniformis) infects over 300 plant species. Females penetrate host roots and induce formation of complex, multinucleate feeding sites called syncytia. While anatomical changes associated with reniform nematode infection are well documented, little is known about their molecular basis. We grew soybean (Glycine max) in a split-root growth system, inoculated half of each root system with R. reniformis, and quantified gene expression in infected and control root tissue at four dates after inoculation. Over 6,000 genes were differentially expressed between inoculated and control roots on at least one date (false discovery rate [FDR] = 0.01, |log2FC| ≥ 1), and 507 gene sets were significantly enriched or depleted in inoculated roots (FDR = 0.05). Numerous genes up-regulated during syncytium formation had previously been associated with rhizobia nodulation. These included the nodule-initiating transcription factors CYCLOPS, NSP1, NSP2, and NIN, as well as multiple nodulins associated with the plant-derived peribacteroid membrane. Nodulation-related NIP aquaporins and SWEET sugar transporters were induced, as were plant CLAVATA3/ESR-related (CLE) signaling proteins and cell cycle regulators such as CCS52A and E2F. Nodulins and nodule-associated genes may have ancestral functions in normal root development and mycorrhization that have been co-opted by both parasitic nematodes and rhizobial bacteria to promote feeding site and nodule formation.
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Affiliation(s)
- Nathan W Redding
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC 29634
| | - Paula Agudelo
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC 29634
| | - Christina E Wells
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC 29634
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8
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Smant G, Helder J, Goverse A. Parallel adaptations and common host cell responses enabling feeding of obligate and facultative plant parasitic nematodes. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 93:686-702. [PMID: 29277939 DOI: 10.1111/tpj.13811] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Revised: 12/10/2017] [Accepted: 12/14/2017] [Indexed: 05/08/2023]
Abstract
Parallel adaptations enabling the use of plant cells as the primary food source have occurred multiple times in distinct nematode clades. The hallmark of all extant obligate and facultative plant-feeding nematodes is the presence of an oral stylet, which is required for penetration of plant cell walls, delivery of pharyngeal gland secretions into host cells and selective uptake of plant assimilates. Plant parasites from different clades, and even within a single clade, display a large diversity in feeding behaviours ranging from short feeding cycles on single cells to prolonged feeding on highly sophisticated host cell complexes. Despite these differences, feeding of nematodes frequently (but certainly not always) induces common responses in host cells (e.g. endopolyploidization and cellular hypertrophy). It is thought that these host cell responses are brought about by the interplay of effectors and other biological active compounds in stylet secretions of feeding nematodes, but this has only been studied for the most advanced sedentary plant parasites. In fact, these responses are thought to be fundamental for prolonged feeding of sedentary plant parasites on host cells. However, as we discuss in this review, some of these common plant responses to independent lineages of plant parasitic nematodes might also be generic reactions to cell stress and as such their onset may not require specific inputs from plant parasitic nematodes. Sedentary plant parasitic nematodes may utilize effectors and their ability to synthesize other biologically active compounds to tailor these common responses for prolonged feeding on host cells.
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Affiliation(s)
- Geert Smant
- Laboratory of Nematology, Wageningen University, Droevendaalsesteeg 1, Wageningen, 6708PB, The Netherlands
| | - Johannes Helder
- Laboratory of Nematology, Wageningen University, Droevendaalsesteeg 1, Wageningen, 6708PB, The Netherlands
| | - Aska Goverse
- Laboratory of Nematology, Wageningen University, Droevendaalsesteeg 1, Wageningen, 6708PB, The Netherlands
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9
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The Role of Sugar Transporter Genes during Early Infection by Root-Knot Nematodes. Int J Mol Sci 2018; 19:ijms19010302. [PMID: 29351253 PMCID: PMC5796247 DOI: 10.3390/ijms19010302] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2017] [Revised: 01/16/2018] [Accepted: 01/17/2018] [Indexed: 12/28/2022] Open
Abstract
Although pathogens such as nematodes are known to hijack nutrients from host plants, the mechanisms whereby nematodes obtain sugars from plants remain largely unknown. To determine the effects of nematode infection on host plant sugar allocation, soluble sugar (fructose, glucose, sucrose) content was investigated using high-performance liquid chromatography with refractive index detection and was found to increase significantly in tomato (Solanum lycopersicum, Sl) leaves and roots during early infection by root-knot nematodes (RKNs). To further analyze whether sugar transporters played a role in this process, the expression levels of sucrose transporter (SUT/SUC), Sugars Will Eventually be Exported Transporter (SWEET), tonoplast monosaccharide transporter (TMT), and vacuolar glucose transporter (VGT) gene family members were examined by qRT-PCR analysis after RKN infection. The results showed that three SlSUTs, 17 SlSWEETs, three SlTMTs, and SlVGT1 were upregulated in the leaves, whereas three SlSUTs, 17 SlSWEETs, two SlTMTs, and SlVGT1 were induced in the roots. To determine the function of the sugar transporters in the RKN infection process, we examined post-infection responses in the Atsuc2 mutant and pAtSUC2-GUS lines. β-glucuronidase expression was strongly induced at the infection sites, and RKN development was significantly arrested in the Atsuc2 mutant. Taken together, our analyses provide useful information for understanding the sugar transporter responses during early infection by RKNs in tomato.
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10
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Rottmann TM, Fritz C, Lauter A, Schneider S, Fischer C, Danzberger N, Dietrich P, Sauer N, Stadler R. Protoplast-Esculin Assay as a New Method to Assay Plant Sucrose Transporters: Characterization of AtSUC6 and AtSUC7 Sucrose Uptake Activity in Arabidopsis Col-0 Ecotype. FRONTIERS IN PLANT SCIENCE 2018; 9:430. [PMID: 29740457 PMCID: PMC5925572 DOI: 10.3389/fpls.2018.00430] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 03/20/2018] [Indexed: 05/20/2023]
Abstract
The best characterized function of sucrose transporters of the SUC family in plants is the uptake of sucrose into the phloem for long-distance transport of photoassimilates. This important step is usually performed by one specific SUC in every species. However, plants possess small families of several different SUCs which are less well understood. Here, we report on the characterization of AtSUC6 and AtSUC7, two members of the SUC family in Arabidopsis thaliana. Heterologous expression in yeast (Saccharomyces cerevisiae) revealed that AtSUC6Col-0 is a high-affinity H+-symporter that mediates the uptake of sucrose and maltose across the plasma membrane at exceptionally low pH values. Reporter gene analyses revealed a strong expression of AtSUC6Col-0 in reproductive tissues, where the protein product might contribute to sugar uptake into pollen tubes and synergid cells. A knockout of AtSUC6 did not interfere with vegetative development or reproduction, which points toward physiological redundancy of AtSUC6Col-0 with other sugar transporters. Reporter gene analyses showed that AtSUC7Col-0 is expressed in roots and pollen tubes and that this sink specific expression of AtSUC7Col-0 is regulated by intragenic regions. Transport activity of AtSUC7Col-0 could not be analyzed in baker's yeast or Xenopus oocytes because the protein was not correctly targeted to the plasma membrane in both heterologous expression systems. Therefore, a novel approach to analyze sucrose transporters in planta was developed. Plasma membrane localized SUCs including AtSUC6Col-0 and also sucrose specific SWEETs were able to mediate transport of the fluorescent sucrose analog esculin in transformed mesophyll protoplasts. In contrast, AtSUC7Col-0 is not able to mediate esculin transport across the plasma membrane which implicates that AtSUC7Col-0 might be a non-functional pseudogene. The novel protoplast assay provides a useful tool for the quick and quantitative analysis of sucrose transporters in an in planta expression system.
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11
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Ohtsu M, Sato Y, Kurihara D, Suzaki T, Kawaguchi M, Maruyama D, Higashiyama T. Spatiotemporal deep imaging of syncytium induced by the soybean cyst nematode Heterodera glycines. PROTOPLASMA 2017; 254:2107-2115. [PMID: 28343256 DOI: 10.1007/s00709-017-1105-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Accepted: 03/13/2017] [Indexed: 05/17/2023]
Abstract
Parasite infections cause dramatic anatomical and ultrastructural changes in host plants. Cyst nematodes are parasites that invade host roots and induce a specific feeding structure called a syncytium. A syncytium is a large multinucleate cell formed by cell wall dissolution-mediated cell fusion. The soybean cyst nematode (SCN), Heterodera glycines, is a major soybean pathogen. To investigate SCN infection and the syncytium structure, we established an in planta deep imaging system using a clearing solution ClearSee and two-photon excitation microscopy (2PEM). Using this system, we found that several cells were incorporated into the syncytium; the nuclei increased in size and the cell wall openings began to be visible at 2 days after inoculation (DAI). Moreover, at 14 DAI, in the syncytium developed in the cortex, there were thickened concave cell wall pillars that resembled "Parthenon pillars." In contrast, there were many thick board-like cell walls and rarely Parthenon pillars in the syncytium developed in the stele. We revealed that the syncytia were classified into two types based on the pattern of the cell wall structures, which appeared to be determined by the position of the syncytium inside roots. Our results provide new insights into the developmental process of syncytium induced by cyst nematode and a better understanding of the three-dimensional structure of the syncytium in host roots.
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Affiliation(s)
- Mina Ohtsu
- Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602, Japan.
| | - Yoshikatsu Sato
- Institute of Transformative Bio-Molecules (ITbM), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8601, Japan
| | - Daisuke Kurihara
- Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602, Japan
- JST ERATO Higashiyama Live-Holonics Project, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602, Japan
| | - Takuya Suzaki
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tennodai, Tsukuba, Ibaraki, 305-8577, Japan
| | - Masayoshi Kawaguchi
- Division of Symbiotic Systems, National Institute for Basic Biology (NIBB), Okazaki, Aichi, 444-8585, Japan
| | - Daisuke Maruyama
- Kihara Institute for Biological Research, Yokohama City University, 641-12 Maioka-cho, Totsuka-ku, Yokohama, Kanagawa, 244-0813, Japan
| | - Tetsuya Higashiyama
- Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602, Japan
- Institute of Transformative Bio-Molecules (ITbM), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8601, Japan
- JST ERATO Higashiyama Live-Holonics Project, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602, Japan
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Kooliyottil R, Dandurand LM, Kuhl JC, Caplan A, Xiao F. Microaspiration of Solanum tuberosum root cells at early stages of infection by Globodera pallida. PLANT METHODS 2017; 13:68. [PMID: 28855955 PMCID: PMC5571573 DOI: 10.1186/s13007-017-0219-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 08/16/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND Sedentary endoparasitic cyst nematodes form a feeding structure in plant roots, called a syncytium. Syncytium formation involves extensive transcriptional modifications, which leads to cell modifications such as increased cytoplasmic streaming, enlarged nuclei, increased numbers of organelles, and replacement of a central vacuole by many small vacuoles. When whole root RNA is isolated and analyzed, transcript changes manifested in the infected plant cells are overshadowed by gene expression from cells of the entire root system. Use of microaspiration allows isolation of the content of nematode infected cells from a heterogeneous cell population. However, one challenge with this method is identifying the nematode infected cells under the microscope at early stages of infection. This problem was addressed by staining nematode juveniles with a fluorescent dye prior to infection so that the infected cells could be located and microaspirated. RESULTS In the present study, we used the fluorescent vital stain PKH26 coupled with a micro-rhizosphere chamber to locate the infected nematode Globodera pallida in Solanum tuberosum root cells. This enabled microaspiration of nematode-infected root cells during the early stages of parasitism. To study the transcriptional events occurring in these cells, an RNA isolation method from microaspirated samples was optimized, and subsequently the RNA was purified using magnetic beads. With this method, we obtained an RNA quality number of 7.8. For transcriptome studies, cDNA was synthesized from the isolated RNA and assessed by successfully amplifying several pathogenesis related protein coding genes. CONCLUSION The use of PKH26 stained nematode juveniles enabled early detection of nematode infected cells for microaspiration. To investigate transcriptional changes in low yielding RNA samples, bead-based RNA extraction procedures minimized RNA degradation and provided high quality RNA. This protocol provides a robust procedure to analyze gene expression in nematode-infected cells.
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Affiliation(s)
- Rinu Kooliyottil
- Department of Plant Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844 USA
| | - Louise-Marie Dandurand
- Department of Plant Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844 USA
| | - Joseph C. Kuhl
- Department of Plant Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844 USA
| | - Allan Caplan
- Department of Plant Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844 USA
| | - Fangming Xiao
- Department of Plant Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844 USA
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Ohtsu M, Kurihara D, Sato Y, Suzaki T, Kawaguchi M, Maruyama D, Higashiyama T. Fluorescent Labeling of the Cyst Nematode Heterodera glycines in Deep-Tissue Live Imaging. CYTOLOGIA 2017. [DOI: 10.1508/cytologia.82.251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Mina Ohtsu
- Graduate School of Science, Nagoya University
| | - Daisuke Kurihara
- Graduate School of Science, Nagoya University
- JST ERATO Higashiyama Live-Holonics Project, Nagoya University
| | - Yoshikatsu Sato
- Institute of Transformative Bio-Molecules (ITbM), Nagoya University
| | - Takuya Suzaki
- Graduate School of Life and Environmental Sciences, University of Tsukuba
| | | | - Daisuke Maruyama
- Kihara Institute for Biological Research, Yokohama City University
| | - Tetsuya Higashiyama
- Graduate School of Science, Nagoya University
- JST ERATO Higashiyama Live-Holonics Project, Nagoya University
- Institute of Transformative Bio-Molecules (ITbM), Nagoya University
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Rodiuc N, Vieira P, Banora MY, de Almeida Engler J. On the track of transfer cell formation by specialized plant-parasitic nematodes. FRONTIERS IN PLANT SCIENCE 2014; 5:160. [PMID: 24847336 PMCID: PMC4017147 DOI: 10.3389/fpls.2014.00160] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 04/07/2014] [Indexed: 05/02/2023]
Abstract
Transfer cells are ubiquitous plant cells that play an important role in plant development as well as in responses to biotic and abiotic stresses. They are highly specialized and differentiated cells playing a central role in the acquisition, distribution and exchange of nutrients. Their unique structural traits are characterized by augmented ingrowths of invaginated secondary wall material, unsheathed by an amplified area of plasma membrane enriched in a suite of solute transporters. Similar morphological features can be perceived in vascular root feeding cells induced by sedentary plant-parasitic nematodes, such as root-knot and cyst nematodes, in a wide range of plant hosts. Despite their close phylogenetic relationship, these obligatory biotrophic plant pathogens engage different approaches when reprogramming root cells into giant cells or syncytia, respectively. Both nematode feeding-cells types will serve as the main source of nutrients until the end of the nematode life cycle. In both cases, these nematodes are able to remarkably maneuver and reprogram plant host cells. In this review we will discuss the structure, function and formation of these specialized multinucleate cells that act as nutrient transfer cells accumulating and synthesizing components needed for survival and successful offspring of plant-parasitic nematodes. Plant cells with transfer-like functions are also a renowned subject of interest involving still poorly understood molecular and cellular transport processes.
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Affiliation(s)
- Natalia Rodiuc
- Laboratório de Interação Molecular Planta-Praga, Embrapa Recursos Genéticos e Biotecnologia, PqEBBrasília, Brasil
| | - Paulo Vieira
- NemaLab – Instituto de Ciências Agrárias e Ambientais Mediterrânicas, Universidade de ÉvoraÉvora, Portugal
| | | | - Janice de Almeida Engler
- Laboratório de Interação Molecular Planta-Praga, Embrapa Recursos Genéticos e Biotecnologia, PqEBBrasília, Brasil
- Institut National de la Recherche Agronomique, Plant, Health and Environment, Plant-Nematodes Interaction Team, UMR 1355 ISA/Centre National de la Recherche Scientifique, UMR 7254 ISA/Université de Nice-Sophia Antipolis, UMR ISASophia-Antipolis, France
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15
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Cabello S, Lorenz C, Crespo S, Cabrera J, Ludwig R, Escobar C, Hofmann J. Altered sucrose synthase and invertase expression affects the local and systemic sugar metabolism of nematode-infected Arabidopsis thaliana plants. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:201-12. [PMID: 24187419 PMCID: PMC3883288 DOI: 10.1093/jxb/ert359] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Sedentary endoparasitic nematodes of plants induce highly specific feeding cells in the root central cylinder. From these, the obligate parasites withdraw all required nutrients. The feeding cells were described as sink tissues in the plant's circulation system that are supplied with phloem-derived solutes such as sugars. Currently, there are several publications describing mechanisms of sugar import into the feeding cells. However, sugar processing has not been studied so far. Thus, in the present work, the roles of the sucrose-cleaving enzymes sucrose synthases (SUS) and invertases (INV) in the development of Heterodera schachtii were studied. Gene expression analyses indicate that both enzymes are regulated transcriptionally. Nematode development was enhanced on multiple INV and SUS mutants. Syncytia of these mutants were characterized by altered enzyme activity and changing sugar pool sizes. Further, the analyses revealed systemically affected sugar levels and enzyme activities in the shoots of the tested mutants, suggesting changes in the source-sink relationship. Finally, the development of the root-knot nematode Meloidogyne javanica was studied in different INV and SUS mutants and wild-type Arabidopsis plants. Similar effects on the development of both sedentary endoparasitic nematode species (root-knot and cyst nematode) were observed, suggesting a more general role of sucrose-degrading enzymes during plant-nematode interactions.
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Affiliation(s)
- Susana Cabello
- University of Natural Resources and Applied Life Sciences, Department of Crop Sciences, Konrad Lorenz Str. 24, Tulln a. d. Donau A-3430, Austria
| | - Cindy Lorenz
- University of Natural Resources and Applied Life Sciences, Department of Food Sciences and Technology, Vienna, Austria
| | - Sara Crespo
- University of Natural Resources and Applied Life Sciences, Department of Crop Sciences, Konrad Lorenz Str. 24, Tulln a. d. Donau A-3430, Austria
| | - Javier Cabrera
- Universidad de Castilla-La Mancha, Facultad de Ciencias del Medio Ambiente, Avenida de Carlos III s/n, 45071 Toledo, Spain
| | - Roland Ludwig
- University of Natural Resources and Applied Life Sciences, Department of Food Sciences and Technology, Vienna, Austria
| | - Carolina Escobar
- Universidad de Castilla-La Mancha, Facultad de Ciencias del Medio Ambiente, Avenida de Carlos III s/n, 45071 Toledo, Spain
| | - Julia Hofmann
- University of Natural Resources and Applied Life Sciences, Department of Crop Sciences, Konrad Lorenz Str. 24, Tulln a. d. Donau A-3430, Austria
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Le Hir R, Bellini C. The plant-specific dof transcription factors family: new players involved in vascular system development and functioning in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2013; 4:164. [PMID: 23755058 PMCID: PMC3665933 DOI: 10.3389/fpls.2013.00164] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 05/10/2013] [Indexed: 05/02/2023]
Abstract
In higher plants phloem and xylem are responsible for long-distance transport of water, nutrients, and signals that act systemically at short or long-distance to coordinate developmental processes. The formation of the plant vascular system is a complex process that integrates signaling events and gene regulation at transcriptional and posttranscriptional levels. Thanks to transcriptomic and proteomic analysis we start to better understand the mechanisms underlying the formation and the functioning of the vascular system. The role of the DNA-binding with one finger (Dof TFs), a group of plant-specific transcription factors, recently emerged as part of the transcriptional regulatory networks acting on the formation and functioning of the vascular tissues. More than half of the members of this TF family are expressed in the vascular system. In addition some of them have been proposed to be mobile proteins, suggesting a possible role in the control of short- or long-distance signaling as well. This review summarizes the current knowledge on Dof TFs family in Arabidopsis with a special focus on their role in vascular development and functioning.
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Affiliation(s)
- Rozenn Le Hir
- UMR1318 Institut Jean-Pierre Bourgin, INRA-AgroParisTech, INRA Centre de Versailles, Versailles, France
- *Correspondence: Rozenn Le Hir, UMR1318 Institut Jean-Pierre Bourgin, INRA-AgroParisTech, INRA Centre de Versailles, Route de Saint-Cyr (RD10), 78026 Versailles Cedex, France. e-mail:
| | - Catherine Bellini
- UMR1318 Institut Jean-Pierre Bourgin, INRA-AgroParisTech, INRA Centre de Versailles, Versailles, France
- Department of Plant Physiology, Umeå Plant Science Centre, Umeå University, Umeå, Sweden
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17
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Ludewig F, Flügge UI. Role of metabolite transporters in source-sink carbon allocation. FRONTIERS IN PLANT SCIENCE 2013; 4:231. [PMID: 23847636 PMCID: PMC3698459 DOI: 10.3389/fpls.2013.00231] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 06/13/2013] [Indexed: 05/18/2023]
Abstract
Plants assimilate carbon dioxide during photosynthesis in chloroplasts. Assimilated carbon is subsequently allocated throughout the plant. Generally, two types of organs can be distinguished, mature green source leaves as net photoassimilate exporters, and net importers, the sinks, e.g., roots, flowers, small leaves, and storage organs like tubers. Within these organs, different tissue types developed according to their respective function, and cells of either tissue type are highly compartmentalized. Photoassimilates are allocated to distinct compartments of these tissues in all organs, requiring a set of metabolite transporters mediating this intercompartmental transfer. The general route of photoassimilates can be briefly described as follows. Upon fixation of carbon dioxide in chloroplasts of mesophyll cells, triose phosphates either enter the cytosol for mainly sucrose formation or remain in the stroma to form transiently stored starch which is degraded during the night and enters the cytosol as maltose or glucose to be further metabolized to sucrose. In both cases, sucrose enters the phloem for long distance transport or is transiently stored in the vacuole, or can be degraded to hexoses which also can be stored in the vacuole. In the majority of plant species, sucrose is actively loaded into the phloem via the apoplast. Following long distance transport, it is released into sink organs, where it enters cells as source of carbon and energy. In storage organs, sucrose can be stored, or carbon derived from sucrose can be stored as starch in plastids, or as oil in oil bodies, or - in combination with nitrogen - as protein in protein storage vacuoles and protein bodies. Here, we focus on transport proteins known for either of these steps, and discuss the implications for yield increase in plants upon genetic engineering of respective transporters.
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Affiliation(s)
- Frank Ludewig
- *Correspondence: Frank Ludewig, Botanical Institute II, Cologne Biocenter, University of Cologne, Zülpicher Str. 47b, 50674 Cologne, Germany e-mail:
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18
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Davies LJ, Lilley CJ, Paul Knox J, Urwin PE. Syncytia formed by adult female Heterodera schachtii in Arabidopsis thaliana roots have a distinct cell wall molecular architecture. THE NEW PHYTOLOGIST 2012; 196:238-246. [PMID: 22803660 DOI: 10.1111/j.1469-8137.2012.04238.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
• Plant-parasitic cyst nematodes form a feeding site, termed a syncytium, through which the nematode obtains nutrients from the host plant to support nematode development. The structural features of cell walls of syncytial cells have yet to be elucidated. • Monoclonal antibodies to defined glycans and a cellulose-binding module were used to determine the cell wall architectures of syncytial and surrounding cells in the roots of Arabidopsis thaliana infected with the cyst nematode Heterodera schachtii. • Fluorescence imaging revealed that the cell walls of syncytia contain cellulose and the hemicelluloses xyloglucan and heteromannan. Heavily methyl-esterified pectic homogalacturonan and arabinan are abundant in syncytial cell walls; galactan could not be detected. This is suggestive of highly flexible syncytial cell walls. • This work provides important information on the structural architecture of the cell walls of this novel cell type and reveals factors that enable the feeding site to perform its functional requirements to support nematode development.
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Affiliation(s)
- Laura J Davies
- Centre for Plant Sciences, University of Leeds, Leeds, West Yorkshire LS2 9JT, UK
| | - Catherine J Lilley
- Centre for Plant Sciences, University of Leeds, Leeds, West Yorkshire LS2 9JT, UK
| | - J Paul Knox
- Centre for Plant Sciences, University of Leeds, Leeds, West Yorkshire LS2 9JT, UK
| | - P E Urwin
- Centre for Plant Sciences, University of Leeds, Leeds, West Yorkshire LS2 9JT, UK
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Nakabayashi K, Bartsch M, Xiang Y, Miatton E, Pellengahr S, Yano R, Seo M, Soppe WJJ. The time required for dormancy release in Arabidopsis is determined by DELAY OF GERMINATION1 protein levels in freshly harvested seeds. THE PLANT CELL 2012; 24:2826-38. [PMID: 22829147 PMCID: PMC3426117 DOI: 10.1105/tpc.112.100214] [Citation(s) in RCA: 154] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Revised: 06/21/2012] [Accepted: 07/02/2012] [Indexed: 05/18/2023]
Abstract
Seed dormancy controls the start of a plant's life cycle by preventing germination of a viable seed in an unfavorable season. Freshly harvested seeds usually show a high level of dormancy, which is gradually released during dry storage (after-ripening). Abscisic acid (ABA) has been identified as an essential factor for the induction of dormancy, whereas gibberellins (GAs) are required for germination. The molecular mechanisms controlling seed dormancy are not well understood. DELAY OF GERMINATION1 (DOG1) was recently identified as a major regulator of dormancy in Arabidopsis thaliana. Here, we show that the DOG1 protein accumulates during seed maturation and remains stable throughout seed storage and imbibition. The levels of DOG1 protein in freshly harvested seeds highly correlate with dormancy. The DOG1 protein becomes modified during after-ripening, and its levels in stored seeds do not correlate with germination potential. Although ABA levels in dog1 mutants are reduced and GA levels enhanced, we show that DOG1 does not regulate dormancy primarily via changes in hormone levels. We propose that DOG1 protein abundance in freshly harvested seeds acts as a timer for seed dormancy release, which functions largely independent from ABA.
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Affiliation(s)
- Kazumi Nakabayashi
- Department of Plant Breeding and Genetics, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany.
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Abstract
Obligate plant-parasitic nematodes, such as cyst nematodes (Heterodera and Globodera spp.) and root-knot nematodes (Meloidogyne spp.), form specialized feeding cells in host plant roots. These feeding cells provide the sole source of nutrition for the growth and reproduction of the nematode to complete its life cycle. Feeding cell formation involves complex physiological and morphological changes to normal root cells and is accompanied by dramatic changes in plant gene expression. The distinct features of feeding cells suggest that their formation entails a unique gene expression profile, a better understanding of which will assist in building models to explain signaling pathways that modulate transcriptional changes in response to nematodes. Ultimately, this knowledge can be used to design strategies to develop resistance against nematodes in crop plants. Feeding cells comprise a small fraction of the total root cell population, and identification of plant gene expression changes specific to these cells is difficult. Until recently, the specific isolation of nematode feeding cells could be accomplished only by manual dissection or microaspiration. These approaches are limited in that only mature feeding cells can be isolated. These limitations in tissue accessibility for macromolecule isolation at different stages of feeding cell development can be overcome through the use of laser microdissection (LM), a technique that enables the specific isolation of feeding cells from early to late stages for RNA isolation, amplification, and downstream analysis.
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Affiliation(s)
- Nagabhushana Ithal
- Division of Plant Sciences, Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
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21
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Dusotoit-Coucaud A, Brunel N, Kongsawadworakul P, Viboonjun U, Lacointe A, Julien JL, Chrestin H, Sakr S. Sucrose importation into laticifers of Hevea brasiliensis, in relation to ethylene stimulation of latex production. ANNALS OF BOTANY 2009; 104:635-47. [PMID: 19567416 PMCID: PMC2729633 DOI: 10.1093/aob/mcp150] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
BACKGROUND AND AIMS The major economic product of Hevea brasiliensis is a rubber-containing cytoplasm (latex), which flows out of laticifers (latex cells) when the bark is tapped. The latex yield is stimulated by ethylene. Sucrose, the unique precursor of rubber synthesis, must cross the plasma membrane through specific sucrose transporters before being metabolized in the laticifers. The relative importance of sucrose transporters in determining latex yield is unknown. Here, the effects of ethylene (by application of Ethrel on sucrose transporter gene expression in the inner bark tissues and latex cells of H. brasiliensis are described. METHODS Experiments, including cloning sucrose transporters, real time RT-PCR and in situ hybridization, were carried out on virgin (untapped) trees, treated or untreated with the latex yield stimulant Ethrel. KEY RESULTS Seven putative full-length cDNAs of sucrose transporters were cloned from a latex-specific cDNA library. These transporters belong to all SUT (sucrose transporter) groups and differ by their basal gene expression in latex and inner soft bark, with a predominance of HbSUT1A and HbSUT1B. Of these sucrose transporters, only HbSUT1A and HbSUT2A were distinctly increased by ethylene. Moreover, this increase was shown to be specific to laticifers and to ethylene application. CONCLUSION The data and all previous information on sucrose transport show that HbSUT1A and HbSUT2A are related to the increase in sucrose import into laticifers, required for the stimulation of latex yield by ethylene in virgin trees.
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Affiliation(s)
- Anaïs Dusotoit-Coucaud
- UMR 547 PIAF, INRA, Université Blaise Pascal, 24 avenue des Landais, 63177 Aubière Cedex, France
| | - Nicole Brunel
- UMR 547 PIAF, INRA, Université Blaise Pascal, 24 avenue des Landais, 63177 Aubière Cedex, France
| | - Panida Kongsawadworakul
- Department of Plant Science, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand
| | - Unchera Viboonjun
- Department of Plant Science, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand
| | - André Lacointe
- UMR 547 PIAF, INRA, Université Blaise Pascal, 24 avenue des Landais, 63177 Aubière Cedex, France
| | - Jean-Louis Julien
- UMR 547 PIAF, INRA, Université Blaise Pascal, 24 avenue des Landais, 63177 Aubière Cedex, France
| | - Hervé Chrestin
- Department of Plant Science, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand
- Institut de Recherche pour le Developpement (IRD), UR 060 CLIFA/CEFE-CNRS, 1919 route de Mende, F34293, Montpellier Cedex 5, France
| | - Soulaïman Sakr
- UMR 547 PIAF, INRA, Université Blaise Pascal, 24 avenue des Landais, 63177 Aubière Cedex, France
- Agrocampus Ouest, Centre d'Angers, UMR SAGAH, IFR QUASAV 149, 2 rue le Nôtre, 49045 Angers Cedex, France
- For correspondence. E-mail
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Szakasits D, Heinen P, Wieczorek K, Hofmann J, Wagner F, Kreil DP, Sykacek P, Grundler FMW, Bohlmann H. The transcriptome of syncytia induced by the cyst nematode Heterodera schachtii in Arabidopsis roots. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2009; 57:771-84. [PMID: 18980640 PMCID: PMC2667683 DOI: 10.1111/j.1365-313x.2008.03727.x] [Citation(s) in RCA: 162] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2008] [Revised: 07/10/2008] [Accepted: 09/23/2008] [Indexed: 05/18/2023]
Abstract
Arabidopsis thaliana is a host for the sugar beet cyst nematode Heterodera schachtii. Juvenile nematodes invade the roots and induce the development of a syncytium, which functions as a feeding site for the nematode. Here, we report on the transcriptome of syncytia induced in the roots of Arabidopsis. Microaspiration was employed to harvest pure syncytium material, which was then used to prepare RNA for hybridization to Affymetrix GeneChips. Initial data analysis showed that the gene expression in syncytia at 5 and 15 days post-infection did not differ greatly, and so both time points were compared together with control roots. Out of a total of 21 138 genes, 18.4% (3893) had a higher expression level and 15.8% (3338) had a lower expression level in syncytia, as compared with control roots, using a multiple-testing corrected false discovery rate of below 5%. A gene ontology (GO) analysis of up- and downregulated genes showed that categories related to high metabolic activity were preferentially upregulated. A principal component analysis was applied to compare the transcriptome of syncytia with the transcriptome of different Arabidopsis organs (obtained by the AtGenExpress project), and with specific root tissues. This analysis revealed that syncytia are transcriptionally clearly different from roots (and all other organs), as well as from other root tissues.
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Affiliation(s)
- Dagmar Szakasits
- Institute of Plant Protection, Department of Applied Plant Sciences and Plant Biotechnology, University of Natural Resources and Applied Life SciencesVienna, Austria
| | - Petra Heinen
- Institute of Plant Protection, Department of Applied Plant Sciences and Plant Biotechnology, University of Natural Resources and Applied Life SciencesVienna, Austria
| | - Krzysztof Wieczorek
- Institute of Plant Protection, Department of Applied Plant Sciences and Plant Biotechnology, University of Natural Resources and Applied Life SciencesVienna, Austria
| | - Julia Hofmann
- Institute of Plant Protection, Department of Applied Plant Sciences and Plant Biotechnology, University of Natural Resources and Applied Life SciencesVienna, Austria
| | - Florian Wagner
- RZPD German Resource Center for Genome ResearchBerlin, Germany
| | - David P Kreil
- WWTF Chair of Bioinformatics, Department of Biotechnology, University of Natural Resources and Applied Life SciencesVienna, Austria
| | - Peter Sykacek
- WWTF Chair of Bioinformatics, Department of Biotechnology, University of Natural Resources and Applied Life SciencesVienna, Austria
| | - Florian M W Grundler
- Institute of Plant Protection, Department of Applied Plant Sciences and Plant Biotechnology, University of Natural Resources and Applied Life SciencesVienna, Austria
| | - Holger Bohlmann
- Institute of Plant Protection, Department of Applied Plant Sciences and Plant Biotechnology, University of Natural Resources and Applied Life SciencesVienna, Austria
- * For correspondence (fax: +43 1 47654 3359; e-mail )
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Fosu-Nyarko J, Jones MGK, Wang Z. Functional characterization of transcripts expressed in early-stage Meloidogyne javanica-induced giant cells isolated by laser microdissection. MOLECULAR PLANT PATHOLOGY 2009; 10:237-48. [PMID: 19236572 PMCID: PMC6640526 DOI: 10.1111/j.1364-3703.2008.00526.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The root-knot nematode Meloidogyne javanica induces giant cells and feeds from them during its development and reproduction. To study the cellular processes underlying the formation of giant cells, laser microdissection was used to isolate the contents of early-stage giant cells 4 and 7 days post-infection (dpi) from tomato, and cDNA libraries from both stages were generated with 87 [250 expressed sequence tag (EST) clones] and 54 (309 EST clones) individual transcripts identified, respectively. These transcripts have roles in metabolism, stress response, protein synthesis, cell division and morphogenesis, transport, signal transduction, protein modification and fate, and regulation of cellular processes. The expression of 25 selected transcripts was studied further by real-time quantitative reverse transcriptase-polymerase chain reaction. Among them, 13 showed continuous up-regulation in giant cells from 4 to 7 dpi. The expression of two transcripts was higher than in controls at 4 dpi and remained at the same level at 7 dpi; a further five transcripts were highly expressed only at 7 dpi. The Phi-1 protein gene, a cell cycle-related homologue in tobacco, was expressed 8.5 times more strongly in giant cells than in control cells at 4 dpi, but was reduced to 6.7 times at 7 dpi. Using in situ hybridization, the expression of the Phi-1 gene was preferentially localized in the cytoplasm of giant cells at 4 dpi, together with a pectinesterase U1 precursor gene. The identification of highly expressed transcripts in developing giant cells adds to the knowledge of the plant genes responsive to nematode infection, and may provide candidate genes for nematode control strategies.
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Affiliation(s)
- John Fosu-Nyarko
- Plant Biotechnology Research Group, Western Australian State Agricultural Biotechnology Centre (SABC), School of Biological Sciences and Biotechnology, Murdoch University, Perth, WA6150, Australia
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Molecular Approaches Toward Resistance to Plant-Parasitic Nematodes. CELL BIOLOGY OF PLANT NEMATODE PARASITISM 2009. [DOI: 10.1007/978-3-540-85215-5_9] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Li Y, Fester T, Taylor CG. Transcriptomic Analysis of Nematode Infestation. CELL BIOLOGY OF PLANT NEMATODE PARASITISM 2009. [DOI: 10.1007/978-3-540-85215-5_7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Hofmann J, Hess PH, Szakasits D, Blöchl A, Wieczorek K, Daxböck-Horvath S, Bohlmann H, van Bel AJE, Grundler FMW. Diversity and activity of sugar transporters in nematode-induced root syncytia. JOURNAL OF EXPERIMENTAL BOTANY 2009; 60:3085-95. [PMID: 19487386 PMCID: PMC2718214 DOI: 10.1093/jxb/erp138] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2009] [Revised: 04/04/2009] [Accepted: 04/06/2009] [Indexed: 05/18/2023]
Abstract
The plant-parasitic nematode Heterodera schachtii stimulates plant root cells to form syncytial feeding structures which synthesize all nutrients required for successful nematode development. Cellular re-arrangements and modified metabolism of the syncytia are accompanied by massive intra- and intercellular solute allocations. In this study the expression of all genes annotated as sugar transporters in the Arabidopsis Membrane Protein Library was investigated by Affymetrix gene chip analysis in young and fully developed syncytia compared with non-infected Arabidopsis thaliana roots. The expression of three highly up-regulated (STP12, MEX1, and GTP2) and three highly down-regulated genes (SFP1, STP7, and STP4) was analysed by quantitative RT-PCR (qRT-PCR). The most up-regulated gene (STP12) was chosen for further in-depth studies using in situ RT-PCR and a nematode development assay with a T-DNA insertion line revealing a significant reduction of male nematode development. The specific role of STP12 expression in syncytia of male juveniles compared with those of female juveniles was further shown by qRT-PCR. In order to provide evidence for sugar transporter activity across the plasma membrane of syncytia, fluorescence-labelled glucose was used and membrane potential recordings following the application of several sugars were performed. Analyses of soluble sugar pools revealed a highly specific composition in syncytia. The presented work demonstrates that sugar transporters are specifically expressed and active in syncytia, indicating a profound role in inter- and intracelluar transport processes.
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Affiliation(s)
- Julia Hofmann
- Institute of Plant Protection, Department of Applied Plant Sciences and Plant Biotechnology, BOKU-University of Natural Resources and Applied Life Sciences Vienna, Peter Jordan-Str. 82, A-1190 Vienna, Austria
| | - Paul H. Hess
- Plant Cell Biology Research Group, Institute of General Botany, Justus-Liebig-University, Senckenbergstr. 17, D-35390 Giessen, Germany
| | - Dagmar Szakasits
- Institute of Plant Protection, Department of Applied Plant Sciences and Plant Biotechnology, BOKU-University of Natural Resources and Applied Life Sciences Vienna, Peter Jordan-Str. 82, A-1190 Vienna, Austria
| | - Andreas Blöchl
- Department of Chemical Ecology and Ecosystem Research, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria
| | - Krzysztof Wieczorek
- Institute of Plant Protection, Department of Applied Plant Sciences and Plant Biotechnology, BOKU-University of Natural Resources and Applied Life Sciences Vienna, Peter Jordan-Str. 82, A-1190 Vienna, Austria
| | - Sabine Daxböck-Horvath
- Institute of Plant Protection, Department of Applied Plant Sciences and Plant Biotechnology, BOKU-University of Natural Resources and Applied Life Sciences Vienna, Peter Jordan-Str. 82, A-1190 Vienna, Austria
| | - Holger Bohlmann
- Institute of Plant Protection, Department of Applied Plant Sciences and Plant Biotechnology, BOKU-University of Natural Resources and Applied Life Sciences Vienna, Peter Jordan-Str. 82, A-1190 Vienna, Austria
| | - Aart J. E. van Bel
- Plant Cell Biology Research Group, Institute of General Botany, Justus-Liebig-University, Senckenbergstr. 17, D-35390 Giessen, Germany
| | - Florian M. W. Grundler
- Institute of Plant Protection, Department of Applied Plant Sciences and Plant Biotechnology, BOKU-University of Natural Resources and Applied Life Sciences Vienna, Peter Jordan-Str. 82, A-1190 Vienna, Austria
- To whom correspondence should be addressed. E-mail:
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Hofmann J, Grundler FM. Starch as a sugar reservoir for nematode-induced syncytia. PLANT SIGNALING & BEHAVIOR 2008; 3:961-962. [PMID: 19704419 PMCID: PMC2633742 DOI: 10.4161/psb.6075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2008] [Accepted: 04/09/2008] [Indexed: 05/28/2023]
Abstract
The plant parasitic nematode Heterodera schachtii invades the roots of Arabidopsis thaliana to induce nematode feeding structures in the central cylinder. During nematode development, the parasites feed exclusively from these structures. Thus, high sugar import and specific sugar processing of the affected plant cells is crucial for nematode development. In the present work, we found starch accumulation in nematode feeding structures and therefore studied the expression genes involved in the starch metabolic pathway. The importance of starch synthesis was further shown using the Atss1 mutant line. As it is rather surprising to find starch accumulation in cells characterised by a high nutrient loss, we speculate that starch serves as long- and short-term carbohydrate storage to compensate the staggering feeding behaviour of the parasites.
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Affiliation(s)
- Julia Hofmann
- Institute of Plant Protection; Department of Applied Plant Sciences and Plant Biotechnology; BOKU-University of Natural Resources and Applied Life Sciences Vienna; Vienna Austria
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Fudali S, Sobczak M, Janakowski S, Griesser M, Grundler FMW, Golinowski W. Expansins are among plant cell wall modifying agents specifically expressed during development of nematode-induced syncytia. PLANT SIGNALING & BEHAVIOR 2008; 3:969-71. [PMID: 19704422 PMCID: PMC2633745 DOI: 10.4161/psb.6169] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Accepted: 04/21/2008] [Indexed: 05/20/2023]
Abstract
Cyst nematodes are economically important pests. As obligatory biotrophic endoparasites they invade host roots and induce formation of syncytia, structures that serve them as the only source of nutrients. During syncytium development, extensive cell wall modifications take place. Cell wall dissolution occurs during cell wall opening formation, cell walls expand during hypertrophy of syncytial elements and local cell wall synthesis leads to the thickening of syncytial cell wall and the formation of cell wall ingrowths. Numerous studies revealed that nematodes change expression of plant genes encoding cell wall modifying proteins including expansins. Expansins poses unique abilities to induce cell wall extension in acidic pH. Recently, we demonstrated that two alpha-expansin genes LeEXPA4 and LeEXPA5 are upregulated in tomato roots infected with potato cyst nematode (Globodera rostochiensis). In this addendum, we present the most recent results concerning involvement of plant cell wall modifying genes in syncytium development and discuss possible practical applications of this knowledge for developing plants with resistance against nematodes.
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Affiliation(s)
- Sylwia Fudali
- Department of Botany; Warsaw University of Life Sciences (SGGW); Warsaw Poland
| | - Miroslaw Sobczak
- Department of Botany; Warsaw University of Life Sciences (SGGW); Warsaw Poland
| | - Slawomir Janakowski
- Department of Botany; Warsaw University of Life Sciences (SGGW); Warsaw Poland
| | - Michaela Griesser
- Institute of Plant Protection; Department of Applied Plant Sciences and Plant Biotechnology; University of Natural Resources and Applied Life Sciences; Vienna Austria
| | - Florian MW Grundler
- Institute of Plant Protection; Department of Applied Plant Sciences and Plant Biotechnology; University of Natural Resources and Applied Life Sciences; Vienna Austria
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Schmitt B, Stadler R, Sauer N. Immunolocalization of solanaceous SUT1 proteins in companion cells and xylem parenchyma: new perspectives for phloem loading and transport. PLANT PHYSIOLOGY 2008; 148:187-99. [PMID: 18614713 PMCID: PMC2528081 DOI: 10.1104/pp.108.120410] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2008] [Accepted: 06/22/2008] [Indexed: 05/18/2023]
Abstract
Leaf sucrose (Suc) transporters are essential for phloem loading and long-distance partitioning of assimilates in plants that load their phloem from the apoplast. Suc loading into the phloem is indispensable for the generation of the osmotic potential difference that drives phloem bulk flow and is central for the long-distance movement of phloem sap compounds, including hormones and signaling molecules. In previous analyses, solanaceous SUT1 Suc transporters from tobacco (Nicotiana tabacum), potato (Solanum tuberosum), and tomato (Solanum lycopersicum) were immunolocalized in plasma membranes of enucleate sieve elements. Here, we present data that identify solanaceous SUT1 proteins with high specificity in phloem companion cells. Moreover, comparisons of SUT1 localization in the abaxial and adaxial phloem revealed higher levels of SUT1 protein in the abaxial phloem of all three solanaceous species, suggesting different physiological roles for these two types of phloem. Finally, SUT1 proteins were identified in files of xylem parenchyma cells, mainly in the bicollateral veins. Together, our data provide new insight into the role of SUT1 proteins in solanaceous species.
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Affiliation(s)
- Bianca Schmitt
- Molekulare Pflanzenphysiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91058 Erlangen, Germany
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32
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Schneidereit A, Imlau A, Sauer N. Conserved cis-regulatory elements for DNA-binding-with-one-finger and homeo-domain-leucine-zipper transcription factors regulate companion cell-specific expression of the Arabidopsis thaliana SUCROSE TRANSPORTER 2 gene. PLANTA 2008; 228:651-62. [PMID: 18551303 DOI: 10.1007/s00425-008-0767-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2008] [Revised: 05/26/2008] [Accepted: 05/30/2008] [Indexed: 05/18/2023]
Abstract
The transition from young carbon-importing sink leaves of higher plants to mature carbon-exporting source leaves is paralleled by a complete reversal of phloem function. While sink-leaf phloem mediates the influx of reduced carbon from older source leaves and the release of this imported carbon to the sink-leaf mesophyll, source-leaf phloem catalyzes the uptake of photoassimilates into companion cells (CCs) and sieve elements (SEs) and the net carbon export from the leaf. Phloem loading in source leaves with sucrose, the main or exclusive transport form for fixed carbon in most higher plants, is catalyzed by plasma membrane-localized sucrose transporters. Consistent with the described physiological switch from sink to source, the promoter of the Arabidopsis AtSUC2 gene is active only in source-leaf CCs of Arabidopsis or of transgenic tobacco (Nicotiana tabacum). For the identification of regulatory elements involved in this companion cell-specific and source-specific gene expression, we performed detailed analyses of the AtSUC2 promoter by truncation and mutagenesis. A 126-bp promoter fragment was identified, which seems to contain these fragments and which drives AtSUC2-typical expression when combined with a 35S minimal promoter. Within this fragment, linker-scanning analyses revealed two cis-regulatory elements that were further characterized as putative binding sites for transcription factors of the DNA-binding-with-one-finger or the homeo-domain-leucine-zipper families. Similar or identical binding sites are found in other genes and in different plant species, suggesting an ancient regulatory mechanism for this important physiological switch.
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Affiliation(s)
- Alexander Schneidereit
- Molekulare Pflanzenphysiologie, Universität Erlangen-Nürnberg, Staudtstrasse 5, 91058 Erlangen, Germany
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Abstract
Sedentary nematodes are destructive plant pathogens that cause significant yield losses. In the roots of their host plants, cyst nematodes (CNs) and root-knot nematodes (RKNs) induce different, highly specialized feeding sites--syncytia or giant cells (GCs), respectively--to optimize nutrient uptake. We compared the mechanisms by which nutrients are delivered from the model host plant, Arabidopsis, to GCs induced by the RKN Meloidogyne incognita or to syncytia induced by the CN Heterodera schachtii. From previous work, syncytia were known to be symplastically connected to newly formed host phloem composed of sieve elements (SEs) and companion cells. Here we studied the formation of plasmodesmata (PD) during GC and syncytia development by monitoring a viral movement protein that targets branched PD and the development of host phloem during GC formation by applying confocal laser scanning microscopy and immunocytochemistry. Analyses of plants expressing soluble or membrane-anchored green fluorescent protein in their phloem demonstrated symplastic isolation of GCs. GCs were found to be embedded in a tissue that consists exclusively of SEs. These de novo-formed SEs, contained nuclei and were interconnected by secondary PD. A similar interconnection of SEs was observed around syncytia. However, these secondary PD were also present at the SE-syncytium interface, demonstrating the postulated symplastic connection. Our results show that CNs and RKNs, despite their close phylogenetic relatedness, employ fundamentally different strategies to withdraw nutrients from host plants.
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Hofmann J, Szakasits D, Blöchl A, Sobczak M, Daxböck-Horvath S, Golinowski W, Bohlmann H, Grundler FMW. Starch serves as carbohydrate storage in nematode-induced syncytia. PLANT PHYSIOLOGY 2008; 146:228-35. [PMID: 17981988 PMCID: PMC2230564 DOI: 10.1104/pp.107.107367] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2007] [Accepted: 10/24/2007] [Indexed: 05/18/2023]
Abstract
The plant parasitic nematode Heterodera schachtii induces specific syncytial feeding sites in the roots of Arabidopsis thaliana from where it withdraws all required nutrients. Therefore, syncytia have to be well supplied with assimilates and generate strong sinks in the host plant's transport system. Import mechanisms and consequent accumulation of sucrose in syncytia were described recently. In this work, we studied the starch metabolism of syncytia. Using high-performance liquid chromatography and microscopic analyses, we demonstrated that syncytia store carbohydrates by starch accumulation. Further, we monitored the expression of genes involved in the starch metabolic pathway by gene chip analysis and quantitative reverse transcription-PCR. Finally, we provide functional proof of the importance of starch synthesis for nematode development using T-DNA insertion lines. We conclude that syncytia accumulate starch as a carbohydrate buffer to compensate for changing solute uptake by the nematode and as long-term storage during juvenile development.
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Affiliation(s)
- Julia Hofmann
- Institute of Plant Protection, Department of Applied Plant Sciences and Plant Biotechnology, University of Natural Resources and Applied Life Sciences, A-1190, Vienna, Austria
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Wang X, Replogle A, Davis EL, Mitchum MG. The tobacco Cel7 gene promoter is auxin-responsive and locally induced in nematode feeding sites of heterologous plants. MOLECULAR PLANT PATHOLOGY 2007; 8:423-36. [PMID: 20507511 DOI: 10.1111/j.1364-3703.2007.00403.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Emerging evidence suggests that plant cell-wall-modifying enzymes induced by root-parasitic nematodes play important roles in feeding cell formation. We previously identified a tobacco endo-beta-1,4-glucanase (cellulase) gene, NtCel7, that was strongly induced in both root-knot and cyst nematode feeding cells. To characterize further the developmental and nematode-responsive regulation of NtCel7, we isolated the NtCel7 promoter and analysed its expression over a time course of nematode infection and in response to auxin, gibberellin, ethylene and sucrose in soybean and tomato hairy roots and in Arabidopsis containing the NtCel7 promoter fused to the beta-glucuronidase (GUS) reporter gene. Histochemical analyses of transgenic plant materials revealed that the NtCel7 promoter exhibited a unique organ-specific expression pattern during plant development suggestive of important roles for NtCel7 in both vegetative and reproductive growth. In all plant species tested, strong GUS expression was observed in root tips and lateral root primordia of uninfected roots with weaker expression in the root vasculature. Further analyses of transgenic Arabidopsis plants revealed expression in shoot and root meristems and the vasculature of most organs during plant development. We also determined that the NtCel7 promoter was induced by auxin, but not gibberellin, ethylene or sucrose. Moreover, strong GUS activity was observed in both cyst and root-knot nematode-induced feeding sites in transgenic roots of soybean, tomato and Arabidopsis. The conserved developmental and nematode-responsive expression of the NtCel7 promoter in heterologous plants indicates that motifs of this regulatory element play a fundamental role in regulating NtCel7 gene expression within nematode feeding sites and that this regulation may be mediated by auxin.
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Affiliation(s)
- Xiaohong Wang
- USDA-ARS Plant Protection Research Unit, Department of Plant Pathology, Cornell University, Ithaca, NY 14853, USA
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Ithal N, Recknor J, Nettleton D, Maier T, Baum TJ, Mitchum MG. Developmental transcript profiling of cyst nematode feeding cells in soybean roots. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2007; 20:510-25. [PMID: 17506329 DOI: 10.1094/mpmi-20-5-0510] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Cyst nematodes of the genus Heterodera are obligate, sedentary endoparasites that have developed highly evolved relationships with specific host plant species. Successful parasitism involves significant physiological and morphological changes to plant root cells for the formation of specialized feeding cells called syncytia. To better understand the molecular mechanisms that lead to the development of nematode feeding cells, transcript profiling was conducted on developing syncytia induced by the soybean cyst nematode Heterodera glycines in soybean roots by coupling laser capture microdissection with high-density oligonucleotide microarray analysis. This approach has identified pathways that may play intrinsic roles in syncytium induction, formation, and function. Our data suggest interplay among phytohormones that likely regulates synchronized changes in the expression of genes encoding cell-wall-modifying proteins. This process appears to be tightly controlled and coordinately regulated with cell wall rigidification processes that may involve lignification of feeding cell walls. Our data also show local downregulation of jasmonic acid biosynthesis and responses in developing syncytia, which suggest a local suppression of plant defense mechanisms. Moreover, we identified genes encoding putative transcription factors and components of signal transduction pathways that may be important in the regulatory processes governing syncytium formation and function. Our analysis provides a broad mechanistic picture that forms the basis for future hypothesis-driven research to understand cyst nematode parasitism and to develop effective management tools against these pathogens.
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Affiliation(s)
- Nagabhushana Ithal
- Division of Plant Sciences and Bord Life Sciences Center, University of Missouri, Columbia 65211, USA
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Uehara T, Sugiyama S, Masuta C. Comparative serial analysis of gene expression of transcript profiles of tomato roots infected with cyst nematode. PLANT MOLECULAR BIOLOGY 2007; 63:185-94. [PMID: 16983456 DOI: 10.1007/s11103-006-9081-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2006] [Accepted: 08/18/2006] [Indexed: 05/11/2023]
Abstract
We analyzed global transcripts for tomato roots infected with the cyst nematode Globodera rostochiensis using serial analysis of gene expression (SAGE). SAGE libraries were made from nematode-infected roots and uninfected roots at 14 days after inoculation, and the clones including SAGE tags were sequenced. Genes were identified by matching the SAGE tags to tomato expressed sequence tags and cDNA databases. We then compiled a list of numerous genes according to the mRNA levels that were altered after cyst nematode infection. Our SAGE results showed significant changes in expression of many unreported genes involved in nematode infection. Of these, for discussion we selected five SAGE tags of RSI-1, BURP domain-containing protein, hexose transporter, P-rich protein, and PHAP2A that were activated by cyst nematode infection. Over 20% of the tags that were upregulated in the infected root have unknown functions (non-annotated), suggesting that we can obtain information on previously unreported and uncharacterized genes by SAGE. We can also obtain information on previously reported genes involved in nematode infection (e.g., multicystatin, peroxidase, catalase, pectin esterase, and S-adenosylmethionine transferase). To evaluate the validity of our SAGE results, seven genes were further analyzed by semiquantitative reverse transcriptase-polymerase chain reaction and Northern blot hybridization; the results agreed well with the SAGE data.
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Affiliation(s)
- Taketo Uehara
- National Agricultural Research Center for Hokkaido Region, 1 Hitsujigaoka, Toyohira-ku, Sapporo, 062-8555, Japan.
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Hammes UZ, Nielsen E, Honaas LA, Taylor CG, Schachtman DP. AtCAT6, a sink-tissue-localized transporter for essential amino acids in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2006; 48:414-26. [PMID: 17052324 DOI: 10.1111/j.1365-313x.2006.02880.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Amino acids represent the major form of reduced nitrogen that is transported in plants. Amino acid transporters in plants often show tissue-specific expression patterns and are used by plants to transport these metabolites from source to sink during development and under changing environmental conditions. We identified one amino acid transporter, AtCAT6, which is expressed in sink tissues such as lateral root primordia, flowers and seeds. Additionally AtCAT6 was induced during infestation of roots by the plant-parasitic root-knot nematode, Meloidogyne incognita. Quantitative reverse-transcriptase PCR revealed nematode inducibility throughout the duration of nematode infestation and in nematode-induced feeding sites. Promoter analyses confirmed expression in endogenous sink tissues and nematode-induced feeding sites. In Xenopus oocytes, AtCAT6 mediated electrogenic transport of proteinogenic as well as non-proteinogenic amino acids with moderate affinity. AtCAT6 transported large, neutral and cationic amino acids in preference to other amino acids. Knockout mutants of this transporter failed to grow on medium containing l-glutamine as the sole nitrogen source. Our data suggest that AtCAT6 plays a role in supplying amino acids to sink tissues of plants and nematode-induced feeding structures.
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Affiliation(s)
- Ulrich Z Hammes
- Donald Danforth Plant Science Center, 975 North Warson Road, St Louis, MO 63122, USA.
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Sukno S, Shimerling O, McCuiston J, Tsabary G, Shani Z, Shoseyov O, Davis EL. Expression and Regulation of the Arabidopsis thaliana Cel1 Endo 1,4 beta Glucanase Gene During Compatible Plant-Nematode Interactions. J Nematol 2006; 38:354-361. [PMID: 19259541 PMCID: PMC2586709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2006] [Indexed: 05/27/2023] Open
Abstract
The root-knot nematode Meloidogyne incognita is an obligate endoparasite of plant roots and stimulates elaborate modifications of selected root vascular cells to form giant cells for feeding. An Arabidopsis thaliana endoglucanase (Atcel1) promoter is activated in giant cells that were formed in Atcel1::UidA transgenic tobacco and Arabidopsis plants. Activity of the full-length Atcel1 promoter was detected in root and shoot elongation zones and in the lateral root primordia. Different 5' and internal deletions of regions of the 1,673 bp Atcel1 promoter were each fused to the UidA reporter gene and transformed in tobacco, and roots of the transformants were inoculated with M. incognita to assay for GUS expression in giant cells and noninfected plant tissues. Comparison of the Atcel1 promoter deletion constructs showed that the region between -1,673 and -1,171 (fragment 1) was essential for Atcel1 promoter activity in giant cells and roots. Fragment 1 alone, however, was not sufficient for Atcel1 expression in giant cells or roots, suggesting that cis-acting elements in fragment 1 may function in consort with other elements within the Atcel1 promoter. Root-knot nematodes and giant cells developed normally within roots of Arabidopsis that expressed a functional antisense construct to Atcel1, suggesting that a functional redundancy in endoglucanase activity may represent another level of regulatory control of cell wall-modifying activity within nematode feeding cells.
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Affiliation(s)
- Serenella Sukno
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77845; The Institute of Plant Sciences and Genetics in Agriculture and The Otto Warburg Minerva Center for Agricultural Biotechnology Faculty of Agricultural, Food and Environmental Quality Sciences The Hebrew University of Jerusalem, Rehovot 76100, Israel; Department of Plant Pathology, NC State University, Raleigh, NC 27695- 7616
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Norholm MHH, Nour-Eldin HH, Brodersen P, Mundy J, Halkier BA. Expression of the Arabidopsis high-affinity hexose transporter STP13 correlates with programmed cell death. FEBS Lett 2006; 580:2381-7. [PMID: 16616142 DOI: 10.1016/j.febslet.2006.03.064] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2005] [Revised: 03/07/2006] [Accepted: 03/21/2006] [Indexed: 11/17/2022]
Abstract
We report the biochemical characterization in Xenopus oocytes of the Arabidopsis thaliana membrane protein, STP13, as a high affinity, hexose-specific H(+)-symporter. Studies with kinase activators suggest that it is negatively regulated by phosphorylation. STP13 promoter GFP reporter lines show GFP expression only in the vascular tissue in emerging petals under non-stressed conditions. Quantitative PCR and the pSTP13-GFP plants show induction of STP13 in programmed cell death (PCD) obtained by treatments with the fungal toxin fumonisin B1 and the pathogen Pseudomonas syringae. A role for STP13 in PCD is supported by microarray data from e.g. plants undergoing senescence and a strong correlation between STP13 transcripts and the PCD phenotype in different accelerated cell death (acd11) mutants.
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Affiliation(s)
- Morten H H Norholm
- Plant Biochemistry Laboratory, center for Molecular Plant Physiology, the royal Veterinary and Agricultural University, Fredericksberg C, Denmark
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Hofmann J, Grundler FMW. Females and males of root-parasitic cyst nematodes induce different symplasmic connections between their syncytial feeding cells and the phloem in Arabidopsis thaliana. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2006; 44:430-3. [PMID: 16889976 DOI: 10.1016/j.plaphy.2006.06.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2005] [Indexed: 05/11/2023]
Abstract
Root syncytia induced by the beet cyst nematode Heterodera schachtii were thought to be symplasmically isolated. A recent study with mobile and immobile GFP constructs expressed in transgenic Arabidopsis plants under the control of pAtSUC2 showed that only mobile GFP could be detected in syncytia and suggested the existence of plasmodesmata between syncytia and the phloem. In the present study the existence of plasmodesmata between syncytia and the phloem is proven by grafting experiments. This technique rules out the possibility that GFP accumulation in syncytia is due to GFP expression in syncytia. Mobile GFP could be followed from transgenic scions carrying a pAtSUC2-gfp fusion construct via wild-type rootstocks into nematode-induced syncytia. While GFP could be detected in all syncytia associated to female nematodes, it was never observed in syncytia of male juveniles. As no GFP-mRNA could be detected in the rootstock we postulate that GFP as protein entered syncytia of females via plasmodesmata, while the protein was excluded from syncytia of male juveniles by plasmodesmata with a lower size exclusion limit.
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Affiliation(s)
- Julia Hofmann
- Department of Applied Plant Sciences and Plant Biotechnology, Institute of Plant Protection, University of Natural Resources and Applied Life Sciences-Vienna, Peter-Jordan Strasse 82, 1190 Vienna, Austria
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42
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Hammes UZ, Schachtman DP, Berg RH, Nielsen E, Koch W, McIntyre LM, Taylor CG. Nematode-induced changes of transporter gene expression in Arabidopsis roots. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2005; 18:1247-57. [PMID: 16478044 DOI: 10.1094/mpmi-18-1247] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Root-knot plant-parasitic nematodes (Meloidogyne spp.) account for much of the damage inflicted to plants by nematodes. The feeding sites of these nematodes consist of "giant" cells, which have characteristics of transfer cells found in other parts of plants. Increased transport activity across the plasma membrane is a hallmark of transfer cells, and giant cells provide nutrition for nematodes; therefore, we initiated a study to identify the transport processes that contribute to the development and function of nematode-induced feeding sites. The study was conducted over a 4-week period, during which time the large changes in the development of giant cells were documented. The Arabidopsis ATH1 GeneChip was used to identify the many transporter genes that were regulated by nematode infestation. Expression of 50 transporter genes from 18 different gene families was significantly changed upon nematode infestation. Sixteen transporter genes were studied in more detail using real-time reverse-transcriptase polymerase chain reaction to determine transcript abundance in nematode-induced galls that contain giant cells and uninfested regions of the root. Certain genes were expressed primarily in galls whereas others were expressed primarily in the uninfested regions of the root, and a third group was expressed evenly throughout the root. Multiple transport processes are regulated and these may play important roles in nematode feeding-site establishment and maintenance.
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Affiliation(s)
- Ulrich Z Hammes
- Donald Danforth Plant Science Center, 975 N. Warson Rd., St. Louis, MO 63132, USA
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43
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Baud S, Wuillème S, Lemoine R, Kronenberger J, Caboche M, Lepiniec L, Rochat C. The AtSUC5 sucrose transporter specifically expressed in the endosperm is involved in early seed development in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2005; 43:824-36. [PMID: 16146522 DOI: 10.1111/j.1365-313x.2005.02496.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The sucrose transporter gene AtSUC5 was studied as part of a programme aimed at identifying and studying the genes involved in seed maturation in Arabidopsis. Expression profiling of AtSUC5 using the technique of real-time quantitative reverse transcriptase polymerase chain reaction (RT-PCR) showed that the gene was specifically and highly induced during seed development between 4 and 9 days after flowering (DAF). Analysis of the activity of the AtSUC5 promoter in planta was consistent with this timing, and suggested that AtSUC5 expression is endosperm specific, spreading from the micropylar to the chalazal pole of the filial tissue. To demonstrate the function of AtSUC5, the corresponding cDNA was used to complement a sucrose uptake-deficient yeast mutant, thus confirming its sucrose transport capacity. To investigate the function in planta, three allelic mutants disrupted in the AtSUC5 gene were isolated and characterized. A strong but transient reduction in fatty acid concentration was observed in mutant seeds 8 DAF. This biochemical phenotype was associated with a slight delay in embryo development. Taken together, these data demonstrated the role of the AtSUC5 carrier in the nutrition of the filial tissues during early seed development. However, additional sugar uptake systems, which remain to be characterized, must be functional in developing seeds, especially during maturation of the embryo.
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Affiliation(s)
- Sébastien Baud
- Unité de Biologie des Semences, UMR 204 INA P-G/INRA, RD10, 78026 Versailles Cedex, France
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de Almeida Engler J, Favery B, Engler G, Abad P. Loss of susceptibility as an alternative for nematode resistance. Curr Opin Biotechnol 2005; 16:112-7. [PMID: 15831374 DOI: 10.1016/j.copbio.2005.01.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Among plant pathogens, sedentary endoparasitic nematodes are one of the most damaging pests in global agriculture. These obligate parasites interact with their hosts in a quite unique and intriguing way. They induce the redifferentiation of root cells into specialized feeding cells essential for nematode growth and reproduction; thus, nematodes have evolved the ability to exploit plant genes and hijack host functions for their own requirements. Various approaches to engineer plants with resistance to parasitic nematodes have been pursued, most focusing on the introduction of resistance genes. An alternative strategy to achieve resistance is to exploit the susceptibility of plant disease. Better knowledge of the plant response during the compatible interaction should allow the identification of targets to engineer resistance to parasitic nematodes in crop species.
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Affiliation(s)
- Janice de Almeida Engler
- INRA, UMR Interactions Plantes-Microorganismes et Santé Végétale, 400 Route des Chappes, 06903 Sophia-Antipolis, France.
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45
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Hoth S, Schneidereit A, Lauterbach C, Scholz-Starke J, Sauer N. Nematode infection triggers the de novo formation of unloading phloem that allows macromolecular trafficking of green fluorescent protein into syncytia. PLANT PHYSIOLOGY 2005; 138:383-92. [PMID: 15849304 PMCID: PMC1104191 DOI: 10.1104/pp.104.058800] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2004] [Revised: 02/11/2005] [Accepted: 02/11/2005] [Indexed: 05/18/2023]
Abstract
Syncytial feeding complexes induced by the cyst nematode Heterodera schachtii represent strong metabolic sinks for photoassimilates. These newly formed structures were described to be symplastically isolated from the surrounding root tissue and their mechanism of carbohydrate import has repeatedly been under investigation. Here, we present analyses of the symplastic connectivity between the root phloem and these syncytia in nematode-infected Arabidopsis (Arabidopsis thaliana) plants expressing the gene of the green fluorescent protein (GFP) or of different GFP fusions under the control of the companion cell (CC)-specific AtSUC2 promoter. In the same plants, phloem differentiation during syncytium formation was monitored using cell-specific antibodies for CCs or sieve elements (SEs). Our results demonstrate that free, CC-derived GFP moved freely from the phloem into the syncytial domain. No or only marginal cell-to-cell passage of GFP was observed into other root cells adjacent to these syncytia. In contrast, membrane-anchored GFP variants as well as soluble GFP fusions with increased molecular masses were restricted to the SE-CC complex. The presented data also show that nematode infection triggers the de novo formation of phloem containing an approximately 3-fold excess of SEs over CCs. This newly formed phloem exhibits typical properties of unloading phloem previously described in other sink tissues. Our results reveal the existence of a symplastic pathway between phloem CCs and nematode-induced syncytia. The plasmodesmata responsible for this symplastic connectivity allow the cell-to-cell movement of macromolecules up to 30 kD and are likely to represent the major or exclusive path for the supply of assimilates from the phloem into the syncytial complex.
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Affiliation(s)
- Stefan Hoth
- Molekulare Pflanzenphysiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91058 Erlangen, Germany
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Mazarei M, Lennon KA, Puthoff DP, Rodermel SR, Baum TJ. Homologous soybean and Arabidopsis genes share responsiveness to cyst nematode infection. MOLECULAR PLANT PATHOLOGY 2004; 5:409-423. [PMID: 20565617 DOI: 10.1111/j.1364-3703.2004.00241.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
SUMMARY We previously isolated a partial soybean cDNA clone (D17.1) whose corresponding transcript increases in susceptible roots 1 day post inoculation (dpi) with the soybean cyst nematode, Heterodera glycines. Here we isolated the corresponding full-length cDNA from a soybean cDNA library and designated this gene of unknown function Gm17.1. Time course RNA gel blot analyses revealed that Gm17.1 mRNA steady-state levels were elevated in soybean roots following H. glycines infection up to at least 6 dpi. For further in-depth study we identified a homologous Arabidopsis thaliana gene and designated this gene At17.1. Arabidopsis is successfully infected by the sugar beet cyst nematode (H. schachtii), a close relative of H. glycines. We isolated the At17.1 promoter, fused it to the beta-glucuronidase (GUS) reporter gene, and transformed this construct into Arabidopsis plants as well as soybean hairy roots. Histochemical analysis of plant materials containing the At17.1::GUS construct revealed that the At17.1 promoter is functional in Arabidopsis as well as in soybean and that during normal plant development the At17.1 promoter directs GUS expression predominantly to the vascular tissues and root tips of both plant species. When At17.1::GUS Arabidopsis plants and soybean hairy roots were inoculated with cyst nematodes, strong GUS activity was detected within the cyst nematode-induced feeding structures. Further tests of At17.1 promoter activity in Arabidopsis revealed that this promoter was induced by auxin, jasmonic acid, mannitol and dehydration. Quantitative real-time reverse transcription-polymerase chain reaction assays of At17.1 expression confirmed the observed promoter characteristics. Based on our expression data and the observation that both the soybean and the Arabidopsis homologues behaved in a similar fashion following cyst nematode infection, it is likely that these genes are closely associated with cyst nematode parasitism of plants, potentially with hormone and osmotic changes occurring in the developing nematode feeding cells. Furthermore, these data provide additional insights into the strengths of the Arabidopsis-H. schachtii pathosystem to study cyst nematode-plant interactions in lieu of less tractable pathosystems. This finding is supported by the fact that the Arabidopsis promoter tested here produced similar results in Arabidopsis and soybean.
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Affiliation(s)
- Mitra Mazarei
- Department of Plant Pathology, Iowa State University, Bessey Hall, Ames, IA 50011, USA
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Vaghchhipawala ZE, Schlueter JA, Shoemaker RC, Mackenzie SA. Soybean FGAM synthase promoters direct ectopic nematode feeding site activity. Genome 2004; 47:404-13. [PMID: 15060594 DOI: 10.1139/g03-110] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Soybean cyst nematode (SCN) resistance in soybean is a complex oligogenic trait. One of the most important nematode resistance genes, rhg1, has been mapped to a distal region of molecular linkage group G in soybean. A simplified genetic system to identify soybean genes with modified expression in response to SCN led to the identification of several genes within the nematode feeding sites. The genes were mapped to reveal their linkage relationship to known QTLs associated with soybean cyst nematode (SCN) resistance. One candidate, a phosphoribosyl formyl glycinamidine (FGAM) synthase (EC 6.3.5.3) gene, mapped to the same genomic interval as the major SCN resistance gene rhg1 within linkage group G. Isolation of FGAM synthase from a soybean bacterial artificial chromosome (BAC) library revealed two highly homologous paralogs. The genes appeared to be well conserved between bacteria and humans. Promoter analysis of the two soybean homologs was carried out with the Arabidopsis thaliana - Heterodera schachtii system to investigate gene response to nematode feeding. The two promoters and their derived deletion constructions effected green fluorescent protein (GFP) expression within nematode feeding sites. The 1.0-kb promoter sequence immediately adjacent to the translation start site was sufficient to direct expression of GFP within syncytia. A wound-inducible element and a floral organ expression sequence were also identified within these promoters. Although a nematode-responsive element could not be identified, the observed expression of GFP within feeding sites supports the hypothesis that plant gene expression is redirected within feeding sites to benefit the parasite.
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48
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Mazarei M, Lennon KA, Puthoff DP, Rodermel SR, Baum TJ. Expression of an Arabidopsis phosphoglycerate mutase homologue is localized to apical meristems, regulated by hormones, and induced by sedentary plant-parasitic nematodes. PLANT MOLECULAR BIOLOGY 2003; 53:513-30. [PMID: 15010616 DOI: 10.1023/b:plan.0000019062.80459.80] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We previously isolated a partial soybean cDNA clone whose transcript abundance is increased upon infection by the sedentary, endoparasitic soybean cyst nematode Heterodera glycines. We now isolated the corresponding full-length cDNA and determined that the predicted gene product was similar to the group of cofactor-dependent phosphoglycerate mutase/bisphosphoglycerate mutase enzymes (PGM/bPGM; EC 5.4.2.1/5.4.2.4). We designated the corresponding soybean gene GmPGM. PGM and bPGM are key catalysts of glycolysis that have been well characterized in animals but not plants. Using the GmPGM cDNA sequence, we identified a homologous Arabidopsis thaliana gene, which we designated AtPGM. Histochemical GUS analyses of transgenic Arabidopsis plants containing the AtPGM promoter ::GUS construct revealed that the AtPGM promoter directs GUS expression in uninfected plants only to the shoot and root apical meristems. In infected plants, GUS staining also is evident in the nematode feeding structures induced by the cyst nematode Heterodera schachtii and by the root-knot nematode Meloidogyne incognita. Furthermore, we discovered that the AtPGM promoter was down-regulated by abscisic acid and hydroxyurea, whereas it was induced by sucrose, oryzalin, and auxin, thereby revealing expression characteristics typical of genes with roles in meristematic cells. Assessment of the auxin-inducible AUX1 gene promoter (a gene coding for a polar auxin transport protein) similarly revealed feeding cell and meristem expression, suggesting that auxin may be responsible for the observed tissue specificity of the AtPGM promoter. These results provide first insight into the possible roles of PGM/bPGM in plant physiology and in plant-pathogen interactions.
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Affiliation(s)
- Mitra Mazarei
- Department of Plant Pathology, Iowa State University, Bessey Hall, Ames, IA 50011, USA
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49
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Mazarei M, Lennon KA, Puthoff DP, Rodermel SR, Baum TJ. Expression of an Arabidopsis phosphoglycerate mutase homologue is localized to apical meristems, regulated by hormones, and induced by sedentary plant-parasitic nematodes. PLANT MOLECULAR BIOLOGY 2003; 53:513-530. [PMID: 15010616 DOI: 10.1023/b:plan.000] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We previously isolated a partial soybean cDNA clone whose transcript abundance is increased upon infection by the sedentary, endoparasitic soybean cyst nematode Heterodera glycines. We now isolated the corresponding full-length cDNA and determined that the predicted gene product was similar to the group of cofactor-dependent phosphoglycerate mutase/bisphosphoglycerate mutase enzymes (PGM/bPGM; EC 5.4.2.1/5.4.2.4). We designated the corresponding soybean gene GmPGM. PGM and bPGM are key catalysts of glycolysis that have been well characterized in animals but not plants. Using the GmPGM cDNA sequence, we identified a homologous Arabidopsis thaliana gene, which we designated AtPGM. Histochemical GUS analyses of transgenic Arabidopsis plants containing the AtPGM promoter ::GUS construct revealed that the AtPGM promoter directs GUS expression in uninfected plants only to the shoot and root apical meristems. In infected plants, GUS staining also is evident in the nematode feeding structures induced by the cyst nematode Heterodera schachtii and by the root-knot nematode Meloidogyne incognita. Furthermore, we discovered that the AtPGM promoter was down-regulated by abscisic acid and hydroxyurea, whereas it was induced by sucrose, oryzalin, and auxin, thereby revealing expression characteristics typical of genes with roles in meristematic cells. Assessment of the auxin-inducible AUX1 gene promoter (a gene coding for a polar auxin transport protein) similarly revealed feeding cell and meristem expression, suggesting that auxin may be responsible for the observed tissue specificity of the AtPGM promoter. These results provide first insight into the possible roles of PGM/bPGM in plant physiology and in plant-pathogen interactions.
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Affiliation(s)
- Mitra Mazarei
- Department of Plant Pathology, Iowa State University, Bessey Hall, Ames, IA 50011, USA
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50
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Abstract
Root-knot nematodes and cyst nematodes are obligate, biotrophic pathogens of numerous plant species. These organisms cause dramatic changes in the morphology and physiology of their hosts. The molecular characterization of induced plant genes has provided insight into the plant processes that are usurped by nematodes as they establish their specialized feeding cells. Recently, several gene products have been identified that are secreted by the nematode during parasitism. The corresponding genes have strong similarity to microbial genes or to genes that are found in nematodes that parasitize animals. New information on host resistance genes and nematode virulence genes provides additional insight into this complex interaction.
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Affiliation(s)
- Valerie M Williamson
- Department of Nematology, One Shields Avenue, University of California, 95616, Davis, California, USA.
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