Age-dependent shifts in root resource allocation strategies of Pinus yunnanensis seedlings under variable light gradients
To elucidate how seedling age affects shade adaptation mechanisms in Pinus yunnanensis, we conducted a light intensity experiment with 1- and 3-year-old seedlings under five light levels (100%, 80%, 45%, 30%, and 5% of full sunlight). We evaluated the root non-structural carbohydrates (NSC), carbon:...
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Frontiers Media S.A.
2025-07-01
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| author | Yuanxi Liu Guihe Duan Junwen Wu Rui Shi |
| author_facet | Yuanxi Liu Guihe Duan Junwen Wu Rui Shi |
| author_sort | Yuanxi Liu |
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| description | To elucidate how seedling age affects shade adaptation mechanisms in Pinus yunnanensis, we conducted a light intensity experiment with 1- and 3-year-old seedlings under five light levels (100%, 80%, 45%, 30%, and 5% of full sunlight). We evaluated the root non-structural carbohydrates (NSC), carbon:nitrogen:phosphorus (C:N:P) stoichiometry, and biomass allocation using phenotypic plasticity indices and correlation analysis. Phenotypic plasticity analysis revealed distinct age-dependent strategies: 1-year-old seedlings prioritized root morphological features (biomass, surface area) and starch storage, whereas 3-year-old seedlings prioritized metabolic flexibility (soluble sugar/starch ratio, N/P balance). Correlation analyses further demonstrated age-specific resource allocation patterns; in 1-year-old seedlings, biomass was associated with the root C/P ratio and starch reserves, whereas in 3-year-old seedlings, growth was associated with soluble sugars and N metabolism. Investment in photosynthetic organs (needle biomass) was prioritized under shade in 1-year-old seedlings, which is consistent with the source-sink theory; however, the root C content of these seedlings was reduced, and their N uptake was enhanced to maintain chlorophyll synthesis. Conversely, survival was prioritized in 3-year-old seedlings by increasing the amount of structural C in roots and optimizing C:N:P stoichiometry (e.g., lower C/N ratio and higher N/P ratio), which is consistent with the C storage priority hypothesis. These findings highlight a developmental transition from growth-driven C allocation in young seedlings to survival-oriented stoichiometric adjustments in older seedlings, which provides important insights for silvicultural practices in heterogeneous light environments. |
| format | Article |
| id | doaj-art-ed3cb42ff8e44cd3b5e4f0b87d07b630 |
| institution | Kabale University |
| issn | 1664-462X |
| language | English |
| publishDate | 2025-07-01 |
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| series | Frontiers in Plant Science |
| spelling | doaj-art-ed3cb42ff8e44cd3b5e4f0b87d07b6302025-08-20T03:50:53ZengFrontiers Media S.A.Frontiers in Plant Science1664-462X2025-07-011610.3389/fpls.2025.16193861619386Age-dependent shifts in root resource allocation strategies of Pinus yunnanensis seedlings under variable light gradientsYuanxi Liu0Guihe Duan1Junwen Wu2Rui Shi3College of Forestry, Southwest Forestry University, Kunming, Yunnan, ChinaCollege of Forestry, Southwest Forestry University, Kunming, Yunnan, ChinaCollege of Forestry, Southwest Forestry University, Kunming, Yunnan, ChinaYunnan Provincial Key Laboratory for Conservation and Utilization of In-forest Resource, Southwest Forestry University, Kunming, Yunan, ChinaTo elucidate how seedling age affects shade adaptation mechanisms in Pinus yunnanensis, we conducted a light intensity experiment with 1- and 3-year-old seedlings under five light levels (100%, 80%, 45%, 30%, and 5% of full sunlight). We evaluated the root non-structural carbohydrates (NSC), carbon:nitrogen:phosphorus (C:N:P) stoichiometry, and biomass allocation using phenotypic plasticity indices and correlation analysis. Phenotypic plasticity analysis revealed distinct age-dependent strategies: 1-year-old seedlings prioritized root morphological features (biomass, surface area) and starch storage, whereas 3-year-old seedlings prioritized metabolic flexibility (soluble sugar/starch ratio, N/P balance). Correlation analyses further demonstrated age-specific resource allocation patterns; in 1-year-old seedlings, biomass was associated with the root C/P ratio and starch reserves, whereas in 3-year-old seedlings, growth was associated with soluble sugars and N metabolism. Investment in photosynthetic organs (needle biomass) was prioritized under shade in 1-year-old seedlings, which is consistent with the source-sink theory; however, the root C content of these seedlings was reduced, and their N uptake was enhanced to maintain chlorophyll synthesis. Conversely, survival was prioritized in 3-year-old seedlings by increasing the amount of structural C in roots and optimizing C:N:P stoichiometry (e.g., lower C/N ratio and higher N/P ratio), which is consistent with the C storage priority hypothesis. These findings highlight a developmental transition from growth-driven C allocation in young seedlings to survival-oriented stoichiometric adjustments in older seedlings, which provides important insights for silvicultural practices in heterogeneous light environments.https://www.frontiersin.org/articles/10.3389/fpls.2025.1619386/fullPinus yunnanensislight intensityroot nutrient acquisition and storagebiomass allocationdifferent ages |
| spellingShingle | Yuanxi Liu Guihe Duan Junwen Wu Rui Shi Age-dependent shifts in root resource allocation strategies of Pinus yunnanensis seedlings under variable light gradients Frontiers in Plant Science Pinus yunnanensis light intensity root nutrient acquisition and storage biomass allocation different ages |
| title | Age-dependent shifts in root resource allocation strategies of Pinus yunnanensis seedlings under variable light gradients |
| title_full | Age-dependent shifts in root resource allocation strategies of Pinus yunnanensis seedlings under variable light gradients |
| title_fullStr | Age-dependent shifts in root resource allocation strategies of Pinus yunnanensis seedlings under variable light gradients |
| title_full_unstemmed | Age-dependent shifts in root resource allocation strategies of Pinus yunnanensis seedlings under variable light gradients |
| title_short | Age-dependent shifts in root resource allocation strategies of Pinus yunnanensis seedlings under variable light gradients |
| title_sort | age dependent shifts in root resource allocation strategies of pinus yunnanensis seedlings under variable light gradients |
| topic | Pinus yunnanensis light intensity root nutrient acquisition and storage biomass allocation different ages |
| url | https://www.frontiersin.org/articles/10.3389/fpls.2025.1619386/full |
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