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Oota M, Toyoda S, Kotake T, Wada N, Hashiguchi M, Akashi R, Ishikawa H, Favery B, Tsai AYL, Sawa S. Rhamnogalacturonan-I as a nematode chemoattractant from Lotus corniculatus L. super-growing root culture. FRONTIERS IN PLANT SCIENCE 2023; 13:1008725. [PMID: 36777533 PMCID: PMC9908596 DOI: 10.3389/fpls.2022.1008725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 12/29/2022] [Indexed: 06/18/2023]
Abstract
INTRODUCTION The soil houses a tremendous amount of micro-organisms, many of which are plant parasites and pathogens by feeding off plant roots for sustenance. Such root pathogens and parasites often rely on plant-secreted signaling molecules in the rhizosphere as host guidance cues. Here we describe the isolation and characterization of a chemoattractant of plant-parasitic root-knot nematodes (Meloidogyne incognita, RKN). METHODS The Super-growing Root (SR) culture, consisting of excised roots from the legume species Lotus corniculatus L., was found to strongly attract infective RKN juveniles and actively secrete chemoattractants into the liquid culture media. The chemo-attractant in the culture media supernatant was purified using hydrophobicity and anion exchange chromatography, and found to be enriched in carbohydrates. RESULTS Monosaccharide analyses suggest the chemo-attractant contains a wide array of sugars, but is enriched in arabinose, galactose and galacturonic acid. This purified chemoattractant was shown to contain pectin, specifically anti-rhamnogalacturonan-I and anti-arabinogalactan protein epitopes but not anti-homogalacturonan epitopes. More importantly, the arabinose and galactose sidechain groups were found to be essential for RKN-attracting activities. This chemo-attractant appears to be specific to M. incognita, as it wasn't effective in attracting other Meloidogyne species nor Caenorhabditis elegans. DISCUSSION This is the first report to identify the nematode attractant purified from root exudate of L corniculatus L. Our findings re-enforce pectic carbohydrates as important chemicals mediating micro-organism chemotaxis in the soil, and also highlight the unexpected utilities of the SR culture system in root pathogen research.
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Affiliation(s)
- Morihiro Oota
- Faculty of Advanced Science and Technology, Kumamoto University, Kumamoto, Japan
| | - Syuuto Toyoda
- Faculty of Advanced Science and Technology, Kumamoto University, Kumamoto, Japan
| | - Toshihisa Kotake
- Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama, Japan
| | - Naoki Wada
- Faculty of Advanced Science and Technology, Kumamoto University, Kumamoto, Japan
| | | | - Ryo Akashi
- Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan
| | - Hayato Ishikawa
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba, Japan
| | - Bruno Favery
- Institut national de recherche pour l'agriculture, l'alimentation et l’environnement (INRAE), Université Côte d’Azur, CNRS, UMR 1355-7254 Institut Sophia Agrobiotech, Sophia Antipolis, France
- International Research Organization for Advanced Science and Technology, Kumamoto University, Kumamoto, Japan
| | - Allen Yi-Lun Tsai
- Faculty of Advanced Science and Technology, Kumamoto University, Kumamoto, Japan
- International Research Center for Agricultural and Environmental Biology, Kumamoto University, Kumamoto, Japan
| | - Shinichiro Sawa
- Faculty of Advanced Science and Technology, Kumamoto University, Kumamoto, Japan
- International Research Center for Agricultural and Environmental Biology, Kumamoto University, Kumamoto, Japan
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Tsai AYL, Iwamoto Y, Tsumuraya Y, Oota M, Konishi T, Ito S, Kotake T, Ishikawa H, Sawa S. Root-knot nematode chemotaxis is positively regulated by l-galactose sidechains of mucilage carbohydrate rhamnogalacturonan-I. SCIENCE ADVANCES 2021; 7:eabh4182. [PMID: 34215589 PMCID: PMC11060035 DOI: 10.1126/sciadv.abh4182] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 05/18/2021] [Indexed: 06/13/2023]
Abstract
Root-knot nematodes (RKNs) are plant parasites and major agricultural pests. RKNs are thought to locate hosts through chemotaxis by sensing host-secreted chemoattractants; however, the structures and properties of these attractants are not well understood. Here, we describe a previously unknown RKN attractant from flaxseed mucilage that enhances infection of Arabidopsis and tomato, which resembles the pectic polysaccharide rhamnogalacturonan-I (RG-I). Fucose and galactose sidechains of the purified attractant were found to be required for attractant activity. Furthermore, the disaccharide α-l-galactosyl-1,3-l-rhamnose, which forms the linkage between the RG-I backbone and galactose sidechains of the purified attractant, was sufficient to attract RKN. These results show that the α-l-galactosyl-1,3-l-rhamnose linkage in the purified attractant from flaxseed mucilage is essential for RKN attraction. The present work also suggests that nematodes can detect environmental chemicals with high specificity, such as the presence of chiral centers and hydroxyl groups.
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Affiliation(s)
- Allen Yi-Lun Tsai
- Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan
- International Research Center for Agricultural and Environmental Biology, Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan
| | - Yuka Iwamoto
- Department of Chemistry, Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan
| | - Yoichi Tsumuraya
- Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
| | - Morihiro Oota
- Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan
| | - Teruko Konishi
- Department of Bioscience and Biotechnology, Faculty of Agriculture, University of the Ryukyus, Okinawa 903-0213, Japan
| | - Shinsaku Ito
- Department of Bioscience, Faculty of Life Sciences, Tokyo University of Agriculture, Tokyo 156-8502, Japan
| | - Toshihisa Kotake
- Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
| | - Hayato Ishikawa
- Department of Chemistry, Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan
| | - Shinichiro Sawa
- Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan.
- International Research Center for Agricultural and Environmental Biology, Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan
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Small flexible automated system for monitoring Caenorhabditis elegans lifespan based on active vision and image processing techniques. Sci Rep 2021; 11:12289. [PMID: 34112931 PMCID: PMC8192789 DOI: 10.1038/s41598-021-91898-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 06/02/2021] [Indexed: 11/29/2022] Open
Abstract
Traditionally Caenorhabditis elegans lifespan assays are performed by manually inspecting nematodes with a dissection microscope, which involves daily counting of live/dead worms cultured in Petri plates for 21–25 days. This manual inspection requires the screening of hundreds of worms to ensure statistical robustness, and is therefore a time-consuming approach. In recent years, various automated artificial vision systems have been reported to increase the throughput, however they usually provide less accurate results than manual assays. The main problems identified when using these vision systems are the false positives and false negatives, which occur due to culture media changes, occluded zones, dirtiness or condensation of the Petri plates. In this work, we developed and described a new C. elegans monitoring machine, SiViS, which consists of a flexible and compact platform design to analyse C. elegans cultures using the standard Petri plates seeded with E. coli. Our system uses an active vision illumination technique and different image-processing pipelines for motion detection, both previously reported, providing a fully automated image processing pipeline. In addition, this study validated both these methods and the feasibility of the SiViS machine for lifespan experiments by comparing them with manual lifespan assays. Results demonstrated that the automated system yields consistent replicates (p-value log rank test 0.699), and there are no significant differences between automated system assays and traditionally manual assays (p-value 0.637). Finally, although we have focused on the use of SiViS in longevity assays, the system configuration is flexible and can, thus, be adapted to other C. elegans studies such as toxicity, mobility and behaviour.
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Abstract
For the first 25 years after the landmark 1974 paper that launched the field, most C. elegans biologists were content to think of their subjects as solitary creatures. C. elegans presented no shortage of fascinating biological problems, but some of the features that led Brenner to settle on this species-in particular, its free-living, self-fertilizing lifestyle-also seemed to reduce its potential for interesting social behavior. That perspective soon changed, with the last two decades bringing remarkable progress in identifying and understanding the complex interactions between worms. The growing appreciation that C. elegans behavior can only be meaningfully understood in the context of its ecology and evolution ensures that the coming years will see similarly exciting progress.
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Affiliation(s)
- Douglas S Portman
- Departments of Biomedical Genetics, Neuroscience, and Biology, Del Monte Institute for Neuroscience, University of Rochester, Rochester, NY, USA
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Shimizu K, Ashida K, Hotta K, Oka K. Food deprivation changes chemotaxis behavior in Caenorhabditis elegans. Biophys Physicobiol 2020; 16:167-172. [PMID: 31984168 PMCID: PMC6975978 DOI: 10.2142/biophysico.16.0_167] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 10/19/2019] [Indexed: 12/01/2022] Open
Abstract
Exploring for food is important in food-deprived condition. Chemotaxis is one of the important behaviors to search food. Although chemotactic strategies in C. elegans have been well investigated: the pirouette and the weathervane strategies, the change of the chemotactic strategy by food deprivation is largely unclear. Here, we show the change of chemotactic strategy by food deprivation, especially for isoamyl alcohol. To compare chemotaxis under different food-deprivation period, we showed that worms change their chemotactic behaviors by food deprivation. The worms with 1-h food-deprivation change the weathervane strategy. On the other hand, 6-h food deprived animals change the pirouette strategy. These results demonstrate that worms change chemotactic strategy different way depend on period of food deprivation.
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Affiliation(s)
- Kei Shimizu
- Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, Yokohama, Kanagawa 223-8522, Japan
| | - Keita Ashida
- Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, Yokohama, Kanagawa 223-8522, Japan
| | - Kohji Hotta
- Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, Yokohama, Kanagawa 223-8522, Japan
| | - Kotaro Oka
- Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, Yokohama, Kanagawa 223-8522, Japan.,Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung City 80708, Taiwan.,Waseda Research Institute for Science and Engineering, Waseda University, Shinjuku-ku, Tokyo 162-8480, Japan
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Serotonin modulates behavior-related neural activity of RID interneuron in Caenorhabditis elegans. PLoS One 2019; 14:e0226044. [PMID: 31800640 PMCID: PMC6892467 DOI: 10.1371/journal.pone.0226044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 11/17/2019] [Indexed: 11/29/2022] Open
Abstract
Animals change their behaviors in response to external stimuli, and numerous neurotransmitters are involved in these behavioral changes. In Caenorhabditis elegans, serotonin (5-HT) affects various behaviors such as inhibition of locomotion, stimulation of egg laying, and pharyngeal pumping. Previous research has shown that the neural activity of the RID interneuron increases when the worm moves forward, and the RID is necessary for sustaining forward locomotion. However, the relationship between 5-HT and neural activity of RID, and how it modulates the behavior of the worm has not been investigated. In this article, we reveal the relationship among 5-HT, RID activity, and the behavior of worms using a custom-made tracking and imaging system. We simultaneously measured the neural activity of the RID and behavior in worms with three conditions: mock animals, animals pre-exposed to 5-HT, and 5-HT receptor mod-1 mutants. As shown in previous research, the neural activity of the RID increased during the transition from backward to forward, whereas it decreased during the transition from forward to backward in mock animals. These changes in neural activity were not observed in animals pre-exposed to 5-HT and mod-1 mutants. Moreover, RID activity was correlated with the velocity of the worm in mock animals. However, this correlation was not observed in animals pre-exposed to 5-HT and mod-1 mutants. Our results demonstrate that 5-HT modulates the activity of the RID interneuron, and we infer that the RID plays a role in modulating forward locomotion by changing its activity through 5-HT.
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Ashida K, Kato T, Hotta K, Oka K. Multiple tracking and machine learning reveal dopamine modulation for area-restricted foraging behaviors via velocity change in Caenorhabditis elegans. Neurosci Lett 2019; 706:68-74. [PMID: 31082452 DOI: 10.1016/j.neulet.2019.05.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 05/08/2019] [Accepted: 05/09/2019] [Indexed: 11/26/2022]
Abstract
Food exploration is an essential survival behavior in organisms. To find food efficiently, many organisms use a foraging strategy called area-restricted search (ARS) wherein individuals first turn more frequently, restricting their search to one area, then turn less frequently, moving along a straight path to widen the search area. Previous research suggests that the nematode Caenorhabditis elegans shows ARS behavior by changing turn frequency, and that dopamine is a crucial determinant. However, the effects of dopamine on multiple behavioral parameters have remained unknown. Here, we evaluated turn (pirouette) frequency, moving velocity, and specific area occupancy (cell occupancy) over time by using a multiple-worms tracking system. In the control (mock) experiments, all parameters changed over time, but no changes were observed in experiments with dopamine pre-exposed and dopamine-deficient animals. In inverse reinforcement learning analysis, the value function for specific velocity was found to modulate over time in mock animals only. These results demonstrate that dopamine regulates ARS via changes not only to pirouette frequency change but also to velocity.
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Affiliation(s)
- Keita Ashida
- Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, Yokohama 223-8522, Japan
| | - Taiki Kato
- Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, Yokohama 223-8522, Japan
| | - Kohji Hotta
- Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, Yokohama 223-8522, Japan
| | - Kotaro Oka
- Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, Yokohama 223-8522, Japan; Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung City, 80708, Taiwan; Waseda Research Institute for Science and Engineering, Waseda University, 2-2 Wakamatsucho, Shinjuku, Tokyo 162-8480, Japan.
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