Roots navigate around decay regions by sensing local pH gradients.
Saved in:
| Title: | Roots navigate around decay regions by sensing local pH gradients. |
|---|---|
| Authors: | Bao, Zhulatai (AUTHOR), Wang, Huihui (AUTHOR), Zhang, Ai (AUTHOR), Gao, Ruxi (AUTHOR), Gu, Wen (AUTHOR), Fan, Ni (AUTHOR), Friml, Jiří (AUTHOR), Zhang, Yuzhou (AUTHOR) |
| Source: | Science. 7/9/2026, Vol. 393 Issue 6807, p1-13. 13p. |
| Subjects: | Saprophytes, Abscisic acid, Wood-decaying fungi, Soil acidity, Plant cells & tissues, Root growth, Biodegradation |
| Abstract: | Plant tropisms enable roots to navigate complex soils by responding to directional environmental cues. Biological decay, although central to nutrient cycling, also creates microbially active and potentially hostile niches. In this work, we identified "saprotropism," a previously unrecognized growth response that enables roots to actively bend away from decaying plant-derived matter. Fungal-driven microbial decomposition released organic acids and formed stable pH gradients in surrounding soil, allowing roots to pinpoint decay without direct contact. Root epidermal cells sensed this acidic gradient through the root meristem growth factor peptide-receptor module, converting external pH asymmetry into asymmetric abscisic acid (ABA) distribution. ABA asymmetry drove microtubule reorganization, which was decoded into decay-avoidant root bending. Together, these findings establish microbial decay–derived chemical gradients as an instructive signal for root navigation and expand the framework of microbe-soil-plant communication. Editor's summary: Biological decay is widespread in soil and is important for nutrient recycling. However, it can also harbor pathogenic and spoilage microbes. Whether plants can sense and evade decaying matter has not been well understood. Bao et al. found that plant roots can sense the acidic environment resulting from decomposition. Root bending in response to the decay, which the authors refer to as "saprotropism," is a specific response to plant-derived organic matter being broken down primarily by fungi. The decay-induced acidic pH cue is converted into an asymmetric distribution of the phytohormone abscisic acid, leading to microtubule reorganization and root bending. —Unnati Sonawala and Madeleine Seale INTRODUCTION: Plants grow in complex and heterogeneous soil environments, where roots must anchor the plant, acquire water and nutrients, and cope with environmental stresses. To navigate such environments, plants have evolved tropisms, directional growth responses to environmental stimuli. Classical tropisms described since Darwin's time are primarily driven by abiotic cues, such as gravity, light, water, and salinity. However, soil is also a biologically dynamic ecosystem shaped by shifting microbial communities. Microbial decay of dead plant material is ubiquitous in soils and drives decomposition and nutrient recycling, creating localized decay zones with intense microbial activity. Whether and how living roots can sense and actively avoid these underground decay zones to reduce the risk of infection by spoilage microbes remains unknown. RATIONALE: To address these questions, we first tested whether decaying plant material constituted a hostile environment for root growth. We then established localized decay zones adjacent to roots in both natural soil and split agar systems to observe root growth responses. Roots exhibited robust, directional bending away from the places of decay, which we termed "saprotropism." To identify the decay-generated chemical signals recognized by roots for navigation and the microbes colonizing on plant-derived matter responsible for producing these chemicals, we performed multiomics analysis (microbiomics, metabolomics, and transcriptomics) and microbial isolation for experimental validation. Using confocal imaging and genetic screening, we investigated the root sensory cells and molecular sensor involved in perceiving decay-induced chemical cues. Lastly, we explored how roots translate these external chemical signals into cell growth behavior that drove saprotropic bending. RESULTS: We showed that decaying plant material formed a niche of hostile microbes that inhibited root growth and reduced plant fitness upon direct contact. When roots were placed near, but not touching, decaying plant material, they consistently bent away from the decay source, a directional avoidance response that we termed saprotropism. We further found that fungi colonizing decaying plant material, rather than bacteria, produced acidic metabolites, including organic and phenolic acids, during decomposition. These acids diffused into the surrounding soil and established stable acidic pH gradients that served as directional cues for root navigation. Root epidermal cells sensed this acidic microenvironment through the root meristem growth factor (RGF)–RGF receptor (RGFR) peptide-receptor pH sensor module, which converted pH asymmetry into asymmetric abscisic acid (ABA) distribution across the root. ABA asymmetry the drove microtubule reorganization and anisotropic epidermal cell expansion, generating handed root twisting that directs root bending away from decay. CONCLUSION: This study identified saprotropism as a previously unrecognized plant bending response that enables roots to actively evade decay zones. Fungi-driven decomposition of plant-derived material generated acidic chemical gradients that served as environmental guidance cues for root navigation, and we delineated the molecular and cellular mechanisms by which this microbial decay–generated chemical landscape reprogrammed root growth decisions. Our findings not only expand the current framework of plant tropisms but also reveal a previously unrecognized form of microbe-soil-plant communication, providing new insights into how plant roots navigate complex underground environments to avoid harmful microbial niches. A molecular framework for root saprotropism guiding navigation around microbial decay.: Microbial decay establishes a soil microenvironment characterized by stable acidic pH gradients. This pH asymmetry is sensed by the epidermal pH sensor, RGF-RGFR peptide-receptor module, which converts it into asymmetric ABA distribution. ABA asymmetry drives microtubule-dependent anisotropic cell expansion and handed root twisting, ultimately steering roots away from hostile decay zones. [ABSTRACT FROM AUTHOR] |
| Copyright of Science is the property of American Association for the Advancement of Science and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Psychology and Behavioral Sciences Collection |
|
Full text is not displayed to guests.
Login for full access.
|
|
| FullText | Links: – Type: pdflink Text: Availability: 1 |
|---|---|
| Header | DbId: pbh DbLabel: Psychology and Behavioral Sciences Collection An: 195271071 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
| IllustrationInfo | |
| Items | – Name: Title Label: Title Group: Ti Data: Roots navigate around decay regions by sensing local pH gradients. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Bao%2C+Zhulatai%22">Bao, Zhulatai</searchLink> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Wang%2C+Huihui%22">Wang, Huihui</searchLink> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Zhang%2C+Ai%22">Zhang, Ai</searchLink> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Gao%2C+Ruxi%22">Gao, Ruxi</searchLink> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Gu%2C+Wen%22">Gu, Wen</searchLink> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Fan%2C+Ni%22">Fan, Ni</searchLink> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Friml%2C+Jiří%22">Friml, Jiří</searchLink> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Zhang%2C+Yuzhou%22">Zhang, Yuzhou</searchLink> (AUTHOR) – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Science%22">Science</searchLink>. 7/9/2026, Vol. 393 Issue 6807, p1-13. 13p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Saprophytes%22">Saprophytes</searchLink><br /><searchLink fieldCode="DE" term="%22Abscisic+acid%22">Abscisic acid</searchLink><br /><searchLink fieldCode="DE" term="%22Wood-decaying+fungi%22">Wood-decaying fungi</searchLink><br /><searchLink fieldCode="DE" term="%22Soil+acidity%22">Soil acidity</searchLink><br /><searchLink fieldCode="DE" term="%22Plant+cells+%26+tissues%22">Plant cells & tissues</searchLink><br /><searchLink fieldCode="DE" term="%22Root+growth%22">Root growth</searchLink><br /><searchLink fieldCode="DE" term="%22Biodegradation%22">Biodegradation</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Plant tropisms enable roots to navigate complex soils by responding to directional environmental cues. Biological decay, although central to nutrient cycling, also creates microbially active and potentially hostile niches. In this work, we identified "saprotropism," a previously unrecognized growth response that enables roots to actively bend away from decaying plant-derived matter. Fungal-driven microbial decomposition released organic acids and formed stable pH gradients in surrounding soil, allowing roots to pinpoint decay without direct contact. Root epidermal cells sensed this acidic gradient through the root meristem growth factor peptide-receptor module, converting external pH asymmetry into asymmetric abscisic acid (ABA) distribution. ABA asymmetry drove microtubule reorganization, which was decoded into decay-avoidant root bending. Together, these findings establish microbial decay–derived chemical gradients as an instructive signal for root navigation and expand the framework of microbe-soil-plant communication. Editor's summary: Biological decay is widespread in soil and is important for nutrient recycling. However, it can also harbor pathogenic and spoilage microbes. Whether plants can sense and evade decaying matter has not been well understood. Bao et al. found that plant roots can sense the acidic environment resulting from decomposition. Root bending in response to the decay, which the authors refer to as "saprotropism," is a specific response to plant-derived organic matter being broken down primarily by fungi. The decay-induced acidic pH cue is converted into an asymmetric distribution of the phytohormone abscisic acid, leading to microtubule reorganization and root bending. —Unnati Sonawala and Madeleine Seale INTRODUCTION: Plants grow in complex and heterogeneous soil environments, where roots must anchor the plant, acquire water and nutrients, and cope with environmental stresses. To navigate such environments, plants have evolved tropisms, directional growth responses to environmental stimuli. Classical tropisms described since Darwin's time are primarily driven by abiotic cues, such as gravity, light, water, and salinity. However, soil is also a biologically dynamic ecosystem shaped by shifting microbial communities. Microbial decay of dead plant material is ubiquitous in soils and drives decomposition and nutrient recycling, creating localized decay zones with intense microbial activity. Whether and how living roots can sense and actively avoid these underground decay zones to reduce the risk of infection by spoilage microbes remains unknown. RATIONALE: To address these questions, we first tested whether decaying plant material constituted a hostile environment for root growth. We then established localized decay zones adjacent to roots in both natural soil and split agar systems to observe root growth responses. Roots exhibited robust, directional bending away from the places of decay, which we termed "saprotropism." To identify the decay-generated chemical signals recognized by roots for navigation and the microbes colonizing on plant-derived matter responsible for producing these chemicals, we performed multiomics analysis (microbiomics, metabolomics, and transcriptomics) and microbial isolation for experimental validation. Using confocal imaging and genetic screening, we investigated the root sensory cells and molecular sensor involved in perceiving decay-induced chemical cues. Lastly, we explored how roots translate these external chemical signals into cell growth behavior that drove saprotropic bending. RESULTS: We showed that decaying plant material formed a niche of hostile microbes that inhibited root growth and reduced plant fitness upon direct contact. When roots were placed near, but not touching, decaying plant material, they consistently bent away from the decay source, a directional avoidance response that we termed saprotropism. We further found that fungi colonizing decaying plant material, rather than bacteria, produced acidic metabolites, including organic and phenolic acids, during decomposition. These acids diffused into the surrounding soil and established stable acidic pH gradients that served as directional cues for root navigation. Root epidermal cells sensed this acidic microenvironment through the root meristem growth factor (RGF)–RGF receptor (RGFR) peptide-receptor pH sensor module, which converted pH asymmetry into asymmetric abscisic acid (ABA) distribution across the root. ABA asymmetry the drove microtubule reorganization and anisotropic epidermal cell expansion, generating handed root twisting that directs root bending away from decay. CONCLUSION: This study identified saprotropism as a previously unrecognized plant bending response that enables roots to actively evade decay zones. Fungi-driven decomposition of plant-derived material generated acidic chemical gradients that served as environmental guidance cues for root navigation, and we delineated the molecular and cellular mechanisms by which this microbial decay–generated chemical landscape reprogrammed root growth decisions. Our findings not only expand the current framework of plant tropisms but also reveal a previously unrecognized form of microbe-soil-plant communication, providing new insights into how plant roots navigate complex underground environments to avoid harmful microbial niches. A molecular framework for root saprotropism guiding navigation around microbial decay.: Microbial decay establishes a soil microenvironment characterized by stable acidic pH gradients. This pH asymmetry is sensed by the epidermal pH sensor, RGF-RGFR peptide-receptor module, which converts it into asymmetric ABA distribution. ABA asymmetry drives microtubule-dependent anisotropic cell expansion and handed root twisting, ultimately steering roots away from hostile decay zones. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Science is the property of American Association for the Advancement of Science and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
| PLink | https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=pbh&AN=195271071 |
| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1126/science.adw6568 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 13 StartPage: 1 Subjects: – SubjectFull: Saprophytes Type: general – SubjectFull: Abscisic acid Type: general – SubjectFull: Wood-decaying fungi Type: general – SubjectFull: Soil acidity Type: general – SubjectFull: Plant cells & tissues Type: general – SubjectFull: Root growth Type: general – SubjectFull: Biodegradation Type: general Titles: – TitleFull: Roots navigate around decay regions by sensing local pH gradients. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Bao, Zhulatai – PersonEntity: Name: NameFull: Wang, Huihui – PersonEntity: Name: NameFull: Zhang, Ai – PersonEntity: Name: NameFull: Gao, Ruxi – PersonEntity: Name: NameFull: Gu, Wen – PersonEntity: Name: NameFull: Fan, Ni – PersonEntity: Name: NameFull: Friml, Jiří – PersonEntity: Name: NameFull: Zhang, Yuzhou IsPartOfRelationships: – BibEntity: Dates: – D: 09 M: 07 Text: 7/9/2026 Type: published Y: 2026 Identifiers: – Type: issn-print Value: 00368075 Numbering: – Type: volume Value: 393 – Type: issue Value: 6807 Titles: – TitleFull: Science Type: main |
| ResultId | 1 |
