biologia plantarum

International journal on Plant Life established by Bohumil Němec in 1959

Biologia plantarum 70:18-26, 2026 | DOI: 10.32615/bp.2026.003

Composition of organic acids secreted by alpine shrub roots and its influencing factors

Chen-Kang XI1, 2, Ling ZHU3, Naveed AHMED4, Yong-Heng GAO1, *
1 Chengdu Institute of Biology, Chinese Academy of Science, Chengdu 610213, P.R. China
2 College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, P.R. China
3 Institute of Mountain in Hazards and Environment, Chinese Academy of Sciences, Chengdu 610213, P.R. China
4 The National Key Laboratory of Water Disaster Prevention, College of Hydrology and Water Resources, Hohai University, Nanjing 210098, P.R. China

Background and aims: There appears to be a strong correlation between the rapid proliferation of shrubs in the alpine grassland of the Qinghai-Tibet Plateau and the root exudates of these plants. The dynamics of root exudates during shrub development, however, have been the subject of few investigations.

Methods: This work examined Lonicera thibetica, a plant found on the eastern edge of the Qinghai-Tibet Plateau. It focused on the root systems of 5-, 10-, 15-, and 20-year-old L. thibetica plants and how their primary organic acid components changed with the seasons and other circumstances.

Results: The findings revealed that the primary components of acid secretion in the roots of L. thibetica were oxalic acid, lactic acid, and tartaric acid; of these, oxalic acid made up over 50% of the total organic acid content. The levels of these organic acids often dropped as shrubs got older, and their seasonal dynamics exhibited a parabolic shift pattern, typically peaking during the robust development stage. According to regression analysis, soil moisture was the primary determinant of the concentration of organic acids produced by alpine shrub roots, suggesting that soil moisture played a crucial role in the secretion process.

Conclusions: The physiological dynamics of roots and the mechanisms that regulate them throughout the expansion of alpine shrubs can be better understood thanks to this work.

Keywords: organic acid, seasonal dynamics, shrubification, soil moisture.

Received: July 1, 2025; Revised: December 2, 2025; Accepted: February 5, 2026; Published online: March 2, 2026  Show citation

ACS AIP APA ASA Harvard Chicago Chicago Notes IEEE ISO690 MLA NLM Turabian Vancouver
Chen-Kang, X., ZHU, L., AHMED, N., & GAO, Y. (2026). Composition of organic acids secreted by alpine shrub roots and its influencing factors. Biologia plantarum, 70, Article 18-26. https://doi.org/10.32615/bp.2026.003
Share...
Download citation
  • BibTeX (.bib)
  • Bookends (.ris)
  • EasyBib (.ris)
  • EndNote (.enw)
  • EndNote 8 (.xml)
  • ISI WoS (.isi)
  • Medlars (.medlars)
  • Mendeley (.ris)
  • MODS (.xml)
  • Papers (.ris)
  • RefWorks (.txt)
  • RefManager (.ris)
  • RIS (.ris)
  • MS Word (.xml)
  • Zotero (.ris)
    • Open full article

    References

    1. Acosta-Martínez, V., Cruz, L., Sotomayor-Ramírez, D. & Pérez-Alegría, L. (2007) Enzyme activities as affected by soil properties and land use in a tropical watershed. Applied Soil Ecology, 35, 35-45.
    2. Adeleke, R., Nwangburuka, C. & Oboirien, B. (2017) Origins, roles and fate of organic acids in soils: A review. South African Journal of Botany, 108, 393-406.
    3. Cai, Y., Yu, X., Zou, Y., Ding, S. & Min, Y. (2024) Shrubification of herbaceous peatlands modulates root exudates, increasing rhizosphere soil CO2 emissions while decreasing CH4 emissions. Catena, 245, 108282.
    4. Cao, Q., Hu, J., Chen, X. et al. (2022) [Effects of vegetation restoration on soil carbon, nitrogen, phosphorus and ecological stoichiometry in sandy land of Northwestern Sichuan.] Acta Agrestia Sinica, 30, 523-531. [In Chinese]
    5. Chen, M., Yao, X., Cheng, H. et al. (2023) Changes in Chinese fir plantations root exudation strategies seasonally and as tree age. Forest Ecology and Management, 545, 121239.
    6. Dijkstra, F.A. & Cheng, W. (2007) Moisture modulates rhizosphere effects on C decomposition in two different soil types. Soil Biology and Biochemistry, 39, 2264-2274.
    7. Fujii, Y., Dohmae, N., Takio, K. et al. (2012) A lectin from the mussel Mytilus galloprovincialis has a highly novel primary structure and induces glycan-mediated cytotoxicity of globotriaosylceramide-expressing lymphoma cells. Journal of Biological Chemistry, 287, 44772-44783.
    8. Gao, X. & Jia, Y. (2020) [Analysis of organic acids in root exudates of desert steppe plants and their ecological effects.] Journal of Ecology and Environment, 29, 1927-1934. [In Chinese]
    9. Gao, Y., Wang, H., Yang, F. et al. (2024) Relationships between root exudation and root morphological and architectural traits vary with growing season. Tree Physiology, 44, tpad118.
    10. Gargallo-Garriga, A., Preece, C., Sardans, J., Oravec, M., Urban, O. & Peñuelas, J. (2018) Root exudate metabolomes change under drought and show limited capacity for recovery. Scientific Reports, 8, 12696.
    11. Giesler, R., Högberg, M.N., Strobel, B.W., Richter, A., Nordgren, A. & Högberg, P. (2007) Production of dissolved organic carbon and low-molecular weight organic acids in soil solution driven by recent tree photosynthate. Biogeochemistry, 84, 1-12.
    12. Gómez-Romero, M., Lindig-Cisneros, R., Cruzado-Vargas, A.N. & del-Val, E. (2024) Effects of organic acid application and ectomycorrhizal symbiosis on growth and morphological parameters of Pinus pseudostrobus. Botanical Sciences, 102, 843-853.
    13. He, W., Yang, X., Xiao, J. et al. (2017) [Effects of nitrogen enrichment on root exudative carbon inputs in Sibiraea angustata shrubbery at the eastern fringe of Qinghai-Xizang Plateau.] Chinese Journal of Plant Ecology, 41, 610-621. [In Chinese]
    14. Jakoby, G., Rog, I., Megidish, S. & Klein, T. (2020) Enhanced root exudation of mature broadleaf and conifer trees in a Mediterranean forest during the dry season. Tree Physiology, 40, 1595-1605.
    15. Jiang, Z., Thakur, M.P., Liu, R. et al. (2022) Soil P availability and mycorrhizal type determine root exudation in sub-tropical forests. Soil Biology and Biochemistry, 171, 108722.
    16. Jones, D.L. (1998) Organic acids in the rhizosphere - a critical review. Plant and Soil, 205, 25-44.
    17. Li, J., Jiang, X., Yin, H., Yin, C., Wei, Y. & Liu, Q. (2014) [Root exudates and soil microbes in three Picea asperata plantations with different stand ages.] Journal of Applied Ecology, 25, 325-332. [In Chinese]
    18. Li, X., Yang, Z. & Li, Y. (2009) [Composition and dynamic changes of organic acids in root exudates of blueberry.] Journal of Jilin Agricultural University, 31, 578-580. [In Chinese]
    19. Lian, J., Li, G., Zhang, J. & Massart, S. (2024) Nitrogen fertilization affected microbial carbon use efficiency and microbial resource limitations via root exudates. Science of the Total Environment, 950, 174933.
    20. Macias-Benitez, S., Garcia-Martinez, A.M., Caballero Jimenez, P., Gonzalez, J.M., Tejada Moral, T. & Parrado Rubio, J. (2020) Rhizospheric organic acids as biostimulants: monitoring feedbacks on soil microorganisms and biochemical properties. Frontiers in Plant Science, 11, 633.
    21. Mao, M. & Zhu, F. (2021) [Research progress and prospect of root exudate-mediated plant stress resistance.] Chinese Journal of Ecological Agriculture, 29, 1649-1657. [In Chinese]
    22. Meier, I.C., Avis, P.G. & Phillips, R.P. (2013) Fungal communities influence root exudation rates in pine seedlings. FEMS Microbiology Ecology, 83, 585-595.
    23. Meier, I.C., Tückmantel, T., Heitkötter, J. et al. (2020) Root exudation of mature beech forests across a nutrient availability gradient: the role of root morphology and fungal activity. New Phytologist, 226, 583-594.
    24. Pan, K., Xu, L., Wu, F., Han, Z., Chu, L.R. & Qiu, C.F. (2013) Fungicidal effects of wheat root exudates on Fusarium oxysporum f. sp. niveum. Allelopathy Journal, 32, 257-266.
    25. Pausch, J. & Kuzyakov, Y. (2018) Carbon input by roots into the soil: Quantification of rhizodeposition from root to ecosystem scale. Global Change Biology, 24, 1-12.
    26. Shahzad, T., Chenu, C., Genet, P. et al. (2015) Contribution of exudates, arbuscular mycorrhizal fungi and litter depositions to the rhizosphere priming effect induced by grassland species. Soil Biology and Biochemistry, 80, 146-155.
    27. Van Hees, P.A.W. & Lundström, U.S. (2000) Equilibrium models of aluminium and iron complexation with different organic acids in soil solution. Geoderma, 94, 201-221.
    28. Wang, C., Gao, Q. & Yu, M. (2019) Quantifying trends of land change in Qinghai-Tibet Plateau during 2001-2015. Remote Sensing, 11, 2435.
    29. Wang, Q., Chen, L., Xu, H. et al. (2021) The effects of warming on root exudation and associated soil N transformation depend on soil nutrient availability. Rhizosphere, 17, 100263.
    30. Wang, Y., Chen, X., Lou, S. et al. (2018) [Invasion of grassland scrub: process, mechanism and effect.] Acta Prataculturae Sinica, 27, 219-227. [In Chinese]
    31. Wang, Y., Feng, F., Ge, J., Li, Y. & Yu, X. (2022) [Effects and mechanisms of plant root exudates on soil remediation.] Acta Ecologica Sinica, 42, 829-842. [In Chinese]
    32. Wasyliw, J. & Karst, J. (2020) Shifts in ectomycorrhizal exploration types parallel leaf and fine root area with forest age. Journal of Ecology, 108, 2270-2282.
    33. Weinhold, A., Döll, S., Liu, M. et al. (2022) Tree species richness differentially affects the chemical composition of leaves, roots and root exudates in four subtropical tree species. Journal of Ecology, 110, 97-116.
    34. Wu, H., Xiang, W., Ouyang, S. et al. (2020) Tree growth rate and soil nutrient status determine the shift in nutrient-use strategy of Chinese fir plantations along a chronosequence. Forest Ecology and Management, 460, 117896.
    35. Wu, L., Lin, X., Lin, W. (2014) [Advances and perspective in research on plant-soil-microbe interactions mediated by root exudates.] Chinese Journal of Plant Ecology, 38, 298-310. [In Chinese]
    36. Xie, M., Yan, C., Ye, J. & Wei, L. (2009) Impact of phenanthrene on organic acids secretion and accumulation by perennial ryegrass, Lolium perenne L., root. Bulletin of Environmental Contamination and Toxicology, 83, 75-80.
    37. Xie, Q. & Gao, Y. (2015) [Effects of freeze-thaw on soil carbon, nitrogen and phosphorus availability in alpine meadow of Qinghai-Tibet Plateau.] Journal of Soil and Water Conservation, 29, 137-142. [In Chinese]
    38. Xiong, D., Huang, J., Yang, Z. et al. (2020) The effects of warming and nitrogen addition on fine root exudation rates in a young Chinese-fir stand. Forest Ecology and Management, 458, 117793.
    39. Xu, W., Wu, F., Chang, C., Liu, S. & Zhou, Y. (2013) Effects of wheat as companion cropping on growth, soil enzymes and disease resistance of watermelon. Allelopathy Journal, 32, 267-278.
    40. Yang, Z., Meng, L., Liu, Z. et al. (2024) Warming enhances the negative effects of shrub removal on phosphorus mineralization potential. Science of the Total Environment, 924, 171517.
    41. Yu, C., Mawodza, T., Atkinson, B.S. et al. (2024) The effects of soil compaction on wheat seedling root growth are specific to soil texture and soil moisture status. Rhizosphere, 29, 100838.
    42. Zahraeni, N.A. & Uygur, V. (2024) Effect of low molecular weight organic acids and liming on phosphorus adsorption in acidic tea soils in the Black Sea Region, Türkiye. Communications in Soil Science and Plant Analysis, 55, 3161-3178.
    43. Zhalnina, K., Louie, K.B., Hao, Z. et al. (2018) Dynamic root exudate chemistry and microbial substrate preferences drive patterns in rhizosphere microbial community assembly. Nature Microbiology, 3, 470-480.
    44. Zhang, X., Yan, J., Rahman, M.K.U. & Wu, F. (2022) The impact of root exudates, volatile organic compounds, and common mycorrhizal networks on root system architecture in root-root interactions. Journal of Plant Interactions, 17, 685-694.
    45. Zhang, X., Bilyera, N., Fan, L. et al. (2023) The spatial distribution of rhizosphere microbial activities under drought: water availability is more important than root-hair-controlled exudation. New Phytologist, 237, 780-792.
    46. Zhao, D., Zhu, Y., Wu, S. & Zheng, D. (2021) Projection of vegetation distribution to 1.5°C and 2°C of global warming on the Tibetan Plateau. Global and Planetary Change, 202, 103525.
    47. Zhao, K., Zhou, B., Ma, W. & Yang, L. (2016) [Research progress on the effects of different environmental stresses on the secretion of organic acids by roots.] Soil, 48, 235-240. [In Chinese]

    Return to the content