{"entity": "researcher", "timestamp": "2026-07-14T04:23:19.408Z", "family": "Melnyk", "given": "Charles W", "initials": "CW", "orcid": "0000-0003-3251-800X", "affiliations": ["Department of Plant Biology, Linnean Center for Plant Biology, Swedish University of Agricultural Sciences, Almas all\u00e9 5, 756 51, Uppsala, Sweden. charles.melnyk@slu.se."], "links": {"self": {"href": "https://publications.scilifelab.se/researcher/cd60bb90f97b42ca902c63ca66fbc96f.json"}, "display": {"href": "https://publications.scilifelab.se/researcher/cd60bb90f97b42ca902c63ca66fbc96f"}}, "publications": [{"entity": "publication", "iuid": "1ff33641093042958cf2612e484a087c", "links": {"self": {"href": "https://publications.scilifelab.se/publication/1ff33641093042958cf2612e484a087c.json"}, "display": {"href": "https://publications.scilifelab.se/publication/1ff33641093042958cf2612e484a087c"}}, "title": "A long-distance inhibitory system regulates haustoria numbers in parasitic plants.", "authors": [{"family": "Kokla", "given": "Anna", "initials": "A"}, {"family": "Leso", "given": "Martina", "initials": "M", "orcid": "0000-0003-4192-8027", "researcher": {"href": "https://publications.scilifelab.se/researcher/4ec4323cecc7419a8bcf1b8bd98c58e6.json"}}, {"family": "\u0160imura", "given": "Jan", "initials": "J"}, {"family": "W\u00e4rdig", "given": "Cecilia", "initials": "C"}, {"family": "Hayashi", "given": "Marina", "initials": "M"}, {"family": "Nishii", "given": "Naoshi", "initials": "N"}, {"family": "Tsuchiya", "given": "Yuichiro", "initials": "Y"}, {"family": "Ljung", "given": "Karin", "initials": "K", "orcid": "0000-0003-2901-189X", "researcher": {"href": "https://publications.scilifelab.se/researcher/f91b1e1f90c24559b915ebcd265804a4.json"}}, {"family": "Melnyk", "given": "Charles W", "initials": "CW", "orcid": "0000-0003-3251-800X", "researcher": {"href": "https://publications.scilifelab.se/researcher/cd60bb90f97b42ca902c63ca66fbc96f.json"}}], "type": "journal article", "published": "2025-02-25", "journal": {"title": "Proc. Natl. Acad. Sci. U.S.A.", "issn": "1091-6490", "volume": "122", "issue": "8", "pages": "e2424557122", "issn-l": "0027-8424"}, "abstract": "The ability of parasitic plants to withdraw nutrients from their hosts depends on the formation of an infective structure known as the haustorium. How parasites regulate their haustoria numbers is poorly understood, and here, we uncovered that existing haustoria in the facultative parasitic plants Phtheirospermum japonicum and Parentucellia viscosa suppressed the formation of new haustoria located on distant roots. Using Phtheirospermum, we found that this effect depended on the formation of mature haustoria and could be induced through the application of external nutrients. To understand the molecular basis of this root plasticity, we analyzed hormone response and found that existing infections upregulated cytokinin-responsive genes first at the haustoria and then more distantly in Phtheirospermum shoots. We observed that infections increased endogenous cytokinin levels in Phtheirospermum roots and shoots, and this increase appeared relevant since local treatments with exogenous cytokinins blocked the formation of both locally and distantly formed haustoria. In addition, local overexpression of a cytokinin-degrading enzyme in Phtheirospermum prevented this systemic interhaustoria repression and increased haustoria numbers locally. We propose that a long-distance signal produced by haustoria negatively regulates future haustoria, and in Phtheirospermum, such a signaling system is mediated by a local increase in cytokinin to regulate haustoria numbers and balance nutrient acquisition.", "doi": "10.1073/pnas.2424557122", "pmid": "39964721", "labels": {"Swedish Metabolomics Centre": "Service"}, "xrefs": [{"db": "pmc", "key": "PMC11874510"}], "notes": [], "created": "2025-11-18T12:13:53.745Z", "modified": "2025-11-18T12:13:53.824Z"}, {"entity": "publication", "iuid": "5e3de96d3dfe4cc0bd7ab308e2adbcb9", "links": {"self": {"href": "https://publications.scilifelab.se/publication/5e3de96d3dfe4cc0bd7ab308e2adbcb9.json"}, "display": {"href": "https://publications.scilifelab.se/publication/5e3de96d3dfe4cc0bd7ab308e2adbcb9"}}, "title": "A conserved graft formation process in Norway spruce and Arabidopsis identifies the PAT gene family as central regulators of wound healing.", "authors": [{"family": "Feng", "given": "Ming", "initials": "M", "orcid": "0000-0002-1690-5651", "researcher": {"href": "https://publications.scilifelab.se/researcher/8523b6aee63c4e76ac584692da4d7779.json"}}, {"family": "Zhang", "given": "Ai", "initials": "A", "orcid": "0000-0002-8308-9973", "researcher": {"href": "https://publications.scilifelab.se/researcher/a56072abd97148cf87466ad568502b83.json"}}, {"family": "Nguyen", "given": "Van", "initials": "V"}, {"family": "Bisht", "given": "Anchal", "initials": "A"}, {"family": "Almqvist", "given": "Curt", "initials": "C", "orcid": "0000-0001-5739-4854", "researcher": {"href": "https://publications.scilifelab.se/researcher/95e0d8e8446849dbbad0e7bbdcc53c06.json"}}, {"family": "De Veylder", "given": "Lieven", "initials": "L", "orcid": "0000-0003-1150-4426", "researcher": {"href": "https://publications.scilifelab.se/researcher/7e15711bd16e4c0c8b20c1c26e581d77.json"}}, {"family": "Carlsbecker", "given": "Annelie", "initials": "A", "orcid": "0000-0002-8450-3718", "researcher": {"href": "https://publications.scilifelab.se/researcher/f913d526d4ea46b5bdd3f8bce6db1220.json"}}, {"family": "Melnyk", "given": "Charles W", "initials": "CW", "orcid": "0000-0003-3251-800X", "researcher": {"href": "https://publications.scilifelab.se/researcher/cd60bb90f97b42ca902c63ca66fbc96f.json"}}], "type": "journal article", "published": "2024-01-00", "journal": {"title": "NPLANTS", "issn": "2055-0278", "volume": "10", "issue": "1", "pages": "53-65", "issn-l": "2055-0278"}, "abstract": "The widespread use of plant grafting enables eudicots and gymnosperms to join with closely related species and grow as one. Gymnosperms have dominated forests for over 200 million years, and despite their economic and ecological relevance, we know little about how they graft. Here we developed a micrografting method in conifers using young tissues that allowed efficient grafting with closely related species and between distantly related genera. Conifer graft junctions rapidly connected vasculature and differentially expressed thousands of genes including auxin and cell-wall-related genes. By comparing these genes to those induced during Arabidopsis thaliana graft formation, we found a common activation of cambium, cell division, phloem and xylem-related genes. A gene regulatory network analysis in Norway spruce (Picea abies) predicted that PHYTOCHROME A SIGNAL TRANSDUCTION 1 (PAT1) acted as a core regulator of graft healing. This gene was strongly up-regulated during both spruce and Arabidopsis grafting, and Arabidopsis mutants lacking PAT genes failed to attach tissues or successfully graft. Complementing Arabidopsis PAT mutants with the spruce PAT1 homolog rescued tissue attachment and enhanced callus formation. Together, our data show an ability for young tissues to graft with distantly related species and identifies the PAT gene family as conserved regulators of graft healing and tissue regeneration.", "doi": "10.1038/s41477-023-01568-w", "pmid": "38168607", "labels": {"Bioinformatics Support for Computational Resources": "Service"}, "xrefs": [{"db": "pmc", "key": "PMC10808061"}, {"db": "pii", "key": "10.1038/s41477-023-01568-w"}], "notes": [], "created": "2024-11-25T10:18:30.723Z", "modified": "2025-02-28T14:14:57.234Z"}, {"entity": "publication", "iuid": "7c2be66358fe4a249888dc529c7b6921", "links": {"self": {"href": "https://publications.scilifelab.se/publication/7c2be66358fe4a249888dc529c7b6921.json"}, "display": {"href": "https://publications.scilifelab.se/publication/7c2be66358fe4a249888dc529c7b6921"}}, "title": "Nitrogen represses haustoria formation through abscisic acid in the parasitic plant Phtheirospermum japonicum.", "authors": [{"family": "Kokla", "given": "Anna", "initials": "A", "orcid": "0000-0002-2185-326X", "researcher": {"href": "https://publications.scilifelab.se/researcher/ae2e3351e11842eba5ea207a59d61d9e.json"}}, {"family": "Leso", "given": "Martina", "initials": "M", "orcid": "0000-0003-4192-8027", "researcher": {"href": "https://publications.scilifelab.se/researcher/4ec4323cecc7419a8bcf1b8bd98c58e6.json"}}, {"family": "Zhang", "given": "Xiang", "initials": "X"}, {"family": "Simura", "given": "Jan", "initials": "J"}, {"family": "Serivichyaswat", "given": "Phanu T", "initials": "PT"}, {"family": "Cui", "given": "Songkui", "initials": "S", "orcid": "0000-0001-7777-6681", "researcher": {"href": "https://publications.scilifelab.se/researcher/d27f3c541a4a47cc9d2f4c4c1a5d9e3a.json"}}, {"family": "Ljung", "given": "Karin", "initials": "K", "orcid": "0000-0003-2901-189X", "researcher": {"href": "https://publications.scilifelab.se/researcher/f91b1e1f90c24559b915ebcd265804a4.json"}}, {"family": "Yoshida", "given": "Satoko", "initials": "S"}, {"family": "Melnyk", "given": "Charles W", "initials": "CW", "orcid": "0000-0003-3251-800X", "researcher": {"href": "https://publications.scilifelab.se/researcher/cd60bb90f97b42ca902c63ca66fbc96f.json"}}], "type": "journal article", "published": "2022-05-27", "journal": {"title": "Nat Commun", "issn": "2041-1723", "volume": "13", "issue": "1", "pages": "2976", "issn-l": "2041-1723"}, "abstract": "Parasitic plants are globally prevalent pathogens that withdraw nutrients from their host plants using an organ known as the haustorium. The external environment including nutrient availability affects the extent of parasitism and to understand this phenomenon, we investigated the role of nutrients and found that nitrogen is sufficient to repress haustoria formation in the root parasite Phtheirospermum japonicum. Nitrogen increases levels of abscisic acid (ABA) in P. japonicum and prevents the activation of hundreds of genes including cell cycle and xylem development genes. Blocking ABA signaling overcomes nitrogen's inhibitory effects indicating that nitrogen represses haustoria formation by increasing ABA. The effect of nitrogen appears more widespread since nitrogen also inhibits haustoria in the obligate root parasite Striga hermonthica. Together, our data show that nitrogen acts as a haustoria repressing factor and suggests a mechanism whereby parasitic plants use nitrogen availability in the external environment to regulate the extent of parasitism.", "doi": "10.1038/s41467-022-30550-x", "pmid": "35624089", "labels": {"Bioinformatics Support for Computational Resources": "Service", "Swedish Metabolomics Centre": "Service"}, "xrefs": [{"db": "pmc", "key": "PMC9142502"}, {"db": "pii", "key": "10.1038/s41467-022-30550-x"}], "notes": [], "created": "2022-11-09T15:52:04.586Z", "modified": "2025-10-17T13:03:14.993Z"}]}