{
  "abstract": "Auxin, primarily indole‐3‐acetic acid (IAA), is a central regulator of growth and development in land plants, but its physiological role in chlorophyte algae remains unclear. Here, we show that exogenous IAA modulates growth in Chlorella sorokiniana, Chlorella variabilis, and Chlamydomonas reinhardtii in a concentration‐dependent manner. Low IAA concentrations promoted growth by accelerating the onset of cell division without affecting cell size, whereas higher concentrations inhibited proliferation. Radiotracer assays showed that all three species take up and release IAA across the plasma membrane through a combination of passive diffusion and energy‐dependent, saturable processes. Competition by excess unlabeled natural and synthetic auxins further supported the presence of carrier‐mediated transport with broad substrate recognition. Phylogenetic analyses identified potential PIN‐like auxin exporters in chlorophytes and other non‐plant eukaryotes, and structural modeling supported conservation of the overall PIN fold and predicted auxin‐binding residues. However, functional assays in Xenopus laevis oocytes, tobacco BY‐2 cultured cells, and Arabidopsis thaliana did not support a role for these proteins in directional auxin export. Instead, non‐plant PIN homologs localized predominantly to the endoplasmic reticulum and showed limited or no transport activity in heterologous systems. Together, these findings indicate that auxin responsiveness and basic cellular auxin transport predate canonical PIN‐mediated directional auxin export, which appears to be a later innovation of the streptophyte lineage.",
  "abstract_shown": true,
  "affiliations": [
    "Institute of Science and Technology Austria (ISTA) Klosterneuburg 3400 Austria",
    "School of Life Sciences Weihenstephan, Plant Systems Biology Technical University of Munich Freising 85354 Germany",
    "Institute of Experimental Botany Czech Academy of Sciences Prague 165 00 Czech Republic",
    "State Key Laboratory for Crop Stress Resistance and High‐Efficiency Production, College of Life Sciences Northwest A&F University Yangling 712100 China",
    "Institute of Future Agriculture Northwest A&F University Yangling 712100 China",
    "Department of Experimental Plant Biology, Faculty of Science Charles University Prague 128 44 Czech Republic"
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 12,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Adrijana Smoljan",
      "orcid": "0009-0008-0730-3617"
    },
    {
      "affs": [
        1
      ],
      "name": "Sarah Koutnik‐Abele",
      "orcid": "0009-0006-7266-0704"
    },
    {
      "affs": [
        0
      ],
      "name": "Dmitrii Vladimirtsev"
    },
    {
      "affs": [
        2
      ],
      "name": "Petr Klíma",
      "orcid": "0000-0001-5678-2919"
    },
    {
      "affs": [
        2
      ],
      "name": "Anita Bírošíková",
      "orcid": "0009-0004-3549-2954"
    },
    {
      "affs": [
        0,
        3,
        4
      ],
      "name": "Yuzhou Zhang",
      "orcid": "0000-0003-2627-6956"
    },
    {
      "affs": [
        0
      ],
      "name": "Jack Merrin",
      "orcid": "0000-0001-5145-4609"
    },
    {
      "affs": [
        0
      ],
      "name": "Maximilian Schuster",
      "orcid": "0009-0001-8800-756X"
    },
    {
      "affs": [
        5
      ],
      "name": "Katarina Kurtović",
      "orcid": "0000-0003-4047-545X"
    },
    {
      "affs": [
        1
      ],
      "name": "Ulrich Z. Hammes",
      "orcid": "0000-0002-3663-4908"
    },
    {
      "affs": [
        2
      ],
      "name": "Jan Petrášek",
      "orcid": "0000-0002-6719-2735"
    },
    {
      "affs": [
        0
      ],
      "name": "Jiří Friml",
      "orcid": "0000-0002-8302-7596"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/f9jxra5q4wppz.bib",
  "cited_by": 0,
  "doi": "10.1111/jipb.70309",
  "fulltext_url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC13725606/",
  "id": "f9jxra5q4wppz",
  "issns": [
    "1672-9072",
    "1744-7909"
  ],
  "landing_url": "https://doi.org/10.1111/jipb.70309",
  "language": "en",
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "Cell and Developmental Biology"
    ],
    [
      "heading",
      "Research Article"
    ],
    [
      "openalex",
      "1110|Plant Molecular Biology Research"
    ]
  ],
  "openalex": "W7164312931",
  "pdf_url": null,
  "pmcid": "PMC13725606",
  "pmid": "42271607",
  "published": "2026-06-10",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/f9jxra5q4wppz.ris",
  "sources": [
    {
      "first_seen": "2026-11-04T12:23:57Z",
      "native_id": "PMC13725606",
      "source": "pmc",
      "url": "https://doi.org/10.1111/jipb.70309"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "openalex:1110|Plant Molecular Biology Research",
      "subfield": "plant-biology"
    }
  ],
  "title": "Auxin response and PIN‐mediated transport in chlorophyte algae",
  "title_text": "Auxin response and PIN‐mediated transport in chlorophyte algae",
  "type": "peer-reviewed",
  "updated_at": "2026-11-06T12:21:48Z",
  "url": "https://research.draconitic.com/paper/f9jxra5q4wppz",
  "venue": "Journal of Integrative Plant Biology",
  "versions": []
}