Host-Specific and Environment-Dependent Effects of Endophyte <i>Alternaria oxytropis</i> on Three Locoweed <i>Oxytropis</i> Species in China
Plant–endophyte symbioses are widespread in grasslands. While symbiotic interactions often provide hosts with major fitness enhancements, the role of the endophyte <i>Alternaria oxytropis</i>, which produces swainsonine in locoweeds (<i>Oxytropis</i> and <i>Astragalus&l...
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-07-01
|
| Series: | Journal of Fungi |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2309-608X/11/7/516 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849732986764787712 |
|---|---|
| author | Yue-Yang Zhang Yan-Zhong Li Zun-Ji Shi |
| author_facet | Yue-Yang Zhang Yan-Zhong Li Zun-Ji Shi |
| author_sort | Yue-Yang Zhang |
| collection | DOAJ |
| description | Plant–endophyte symbioses are widespread in grasslands. While symbiotic interactions often provide hosts with major fitness enhancements, the role of the endophyte <i>Alternaria oxytropis</i>, which produces swainsonine in locoweeds (<i>Oxytropis</i> and <i>Astragalus</i> spp.), remains enigmatic. We compared endophyte-infected (E+) and endophyte-free (E−) plants of three main Chinese locoweed species (<i>O. kansuensis</i>, <i>O. glabra</i>, and <i>O. ochrocephala</i>) under controlled conditions, and analyzed environmental factors at locoweed poisoning hotspots for herbivores. The results demonstrated significant species-specific effects: E+ plants of <i>O. glabra</i> and <i>O. ochrocephala</i> exhibited 26–39% reductions in biomass, net photosynthetic rate, and stomatal conductance, with elevated CO<sub>2</sub> levels, while <i>O. kansuensis</i> showed no measurable impacts. Swainsonine concentrations were 16–20 times higher in E+ plants (122.6–151.7 mg/kg) than in E− plants. Geospatial analysis revealed that poisoning hotspots for herbivores consistently occurred in regions with extreme winter conditions (minimum temperatures ≤ −17 °C and precipitation ≤ 1 mm during the driest month), suggesting context-dependent benefits under abiotic stress. These findings suggest that the ecological role of <i>A. oxytropis</i> may vary depending on both host species and environmental context, highlighting a trade-off between growth costs and potential stress tolerance conferred by <i>A. oxytropis</i>. The study underscores the need for field validation to elucidate the adaptive mechanisms maintaining this symbiosis in harsh environments. |
| format | Article |
| id | doaj-art-9fe32ece64d642eda6cdb2e7731a92ae |
| institution | DOAJ |
| issn | 2309-608X |
| language | English |
| publishDate | 2025-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Journal of Fungi |
| spelling | doaj-art-9fe32ece64d642eda6cdb2e7731a92ae2025-08-20T03:08:09ZengMDPI AGJournal of Fungi2309-608X2025-07-0111751610.3390/jof11070516Host-Specific and Environment-Dependent Effects of Endophyte <i>Alternaria oxytropis</i> on Three Locoweed <i>Oxytropis</i> Species in ChinaYue-Yang Zhang0Yan-Zhong Li1Zun-Ji Shi2State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Pastoral Agriculture Science and Technology, Center for Grassland Microbiome, Engineering Research Center of Grassland Industry, Ministry of Education, Lanzhou University, Lanzhou 730020, ChinaState Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Pastoral Agriculture Science and Technology, Center for Grassland Microbiome, Engineering Research Center of Grassland Industry, Ministry of Education, Lanzhou University, Lanzhou 730020, ChinaState Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Pastoral Agriculture Science and Technology, Center for Grassland Microbiome, Engineering Research Center of Grassland Industry, Ministry of Education, Lanzhou University, Lanzhou 730020, ChinaPlant–endophyte symbioses are widespread in grasslands. While symbiotic interactions often provide hosts with major fitness enhancements, the role of the endophyte <i>Alternaria oxytropis</i>, which produces swainsonine in locoweeds (<i>Oxytropis</i> and <i>Astragalus</i> spp.), remains enigmatic. We compared endophyte-infected (E+) and endophyte-free (E−) plants of three main Chinese locoweed species (<i>O. kansuensis</i>, <i>O. glabra</i>, and <i>O. ochrocephala</i>) under controlled conditions, and analyzed environmental factors at locoweed poisoning hotspots for herbivores. The results demonstrated significant species-specific effects: E+ plants of <i>O. glabra</i> and <i>O. ochrocephala</i> exhibited 26–39% reductions in biomass, net photosynthetic rate, and stomatal conductance, with elevated CO<sub>2</sub> levels, while <i>O. kansuensis</i> showed no measurable impacts. Swainsonine concentrations were 16–20 times higher in E+ plants (122.6–151.7 mg/kg) than in E− plants. Geospatial analysis revealed that poisoning hotspots for herbivores consistently occurred in regions with extreme winter conditions (minimum temperatures ≤ −17 °C and precipitation ≤ 1 mm during the driest month), suggesting context-dependent benefits under abiotic stress. These findings suggest that the ecological role of <i>A. oxytropis</i> may vary depending on both host species and environmental context, highlighting a trade-off between growth costs and potential stress tolerance conferred by <i>A. oxytropis</i>. The study underscores the need for field validation to elucidate the adaptive mechanisms maintaining this symbiosis in harsh environments.https://www.mdpi.com/2309-608X/11/7/516endosymbiontphotosynthesisswainsoninelocoweedabiotic stress |
| spellingShingle | Yue-Yang Zhang Yan-Zhong Li Zun-Ji Shi Host-Specific and Environment-Dependent Effects of Endophyte <i>Alternaria oxytropis</i> on Three Locoweed <i>Oxytropis</i> Species in China Journal of Fungi endosymbiont photosynthesis swainsonine locoweed abiotic stress |
| title | Host-Specific and Environment-Dependent Effects of Endophyte <i>Alternaria oxytropis</i> on Three Locoweed <i>Oxytropis</i> Species in China |
| title_full | Host-Specific and Environment-Dependent Effects of Endophyte <i>Alternaria oxytropis</i> on Three Locoweed <i>Oxytropis</i> Species in China |
| title_fullStr | Host-Specific and Environment-Dependent Effects of Endophyte <i>Alternaria oxytropis</i> on Three Locoweed <i>Oxytropis</i> Species in China |
| title_full_unstemmed | Host-Specific and Environment-Dependent Effects of Endophyte <i>Alternaria oxytropis</i> on Three Locoweed <i>Oxytropis</i> Species in China |
| title_short | Host-Specific and Environment-Dependent Effects of Endophyte <i>Alternaria oxytropis</i> on Three Locoweed <i>Oxytropis</i> Species in China |
| title_sort | host specific and environment dependent effects of endophyte i alternaria oxytropis i on three locoweed i oxytropis i species in china |
| topic | endosymbiont photosynthesis swainsonine locoweed abiotic stress |
| url | https://www.mdpi.com/2309-608X/11/7/516 |
| work_keys_str_mv | AT yueyangzhang hostspecificandenvironmentdependenteffectsofendophyteialternariaoxytropisionthreelocoweedioxytropisispeciesinchina AT yanzhongli hostspecificandenvironmentdependenteffectsofendophyteialternariaoxytropisionthreelocoweedioxytropisispeciesinchina AT zunjishi hostspecificandenvironmentdependenteffectsofendophyteialternariaoxytropisionthreelocoweedioxytropisispeciesinchina |