A role for phytosiderophores by Poaceae to acquire phosphorus in severely phosphorus‐impoverished habitats
Abstract
Grasses (Poaceae) are ubiquitous across all continents, even in phosphorus (P)‐impoverished environments. While root carboxylate exudation is a common P‐acquisition strategy in many plants, Poaceae generally release minimal amounts of carboxylates under P deficiency. In contrast, phytosiderophores are well‐known for their role in iron (Fe) acquisition in grasses, and emerging evidence suggests they may also participate in soil P mobilisation, potentially complementing or replacing carboxylate‐based strategies under P deficiency. However, the prevalence and significance of this strategy across native Poaceae in south‐western Australia remain unknown. We examined the carboxylate and phytosiderophore exudation of native grass species under different P availability, grown both in hydroponics (eight species) and in soil (six species) in glasshouse experiments. The tested species were chosen based on their leaf manganese concentration ([Mn]) (a proxy for carboxylate‐based strategies) in 21 grass species native to south‐western Australia, collected from 18 field sites. The leaf silicon concentration ([Si]) and [Mn] of grass species grown in two soils with different P availability were also analysed. Seven of the tested eight native grass species released both carboxylates and phytosiderophores. The exudation of phytosiderophores was significantly greater than that of carboxylates in two soils with contrasting P availability (up to 93.3 vs. 16.4 nmol g −1 root FW) and varied among species. Notably, Anthosachne scabra exuded significantly more phytosiderophores in old severely P‐impoverished soil (93.3 nmol g −1 root FW) than in younger soil with greater P availability (47.1 nmol g −1 root FW), and Dichelachne crinita showed a similar trend, with 11.8 and 6.5 nmol g −1 root FW, respectively. Leaf [Si] was positively correlated with leaf [Mn], confirming previous observations on a range of other species. We found a positive correlation between phytosiderophore exudation and both leaf [Mn] and rhizosheath soil P availability. Synthesis . This study demonstrates that several native grasses employed phytosiderophores not only for Fe acquisition, but probably also to mobilise P in their natural severely P‐impoverished habitats, supported by concomitant carboxylate exudation. These findings expand our understanding of integrated P‐acquisition mechanisms in Poaceae within nutrient‐limited ecosystems.
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BibTeX
@article{kang2026role,
title = {{A role for phytosiderophores by Poaceae to acquire phosphorus in severely phosphorus‐impoverished habitats}},
author = {Haibin Kang and Ling‐ling Chen and Zhao Zhang and Zhijian Mou and Terry Macfarlane and Miroslav Nikolic and Li Yan and Dan Tang and Félix de Tombeur and Joanna Kotula and Kingsley Dixon and Patrick Finnegan and Kosala Ranathunge and Hans Lambers},
journal = {Journal of Ecology},
year = {2026},
month = aug,
doi = {10.1111/1365-2745.70430},
url = {https://hal.science/hal-05844666v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - A role for phytosiderophores by Poaceae to acquire phosphorus in severely phosphorus‐impoverished habitats
AU - Haibin Kang
AU - Ling‐ling Chen
AU - Zhao Zhang
AU - Zhijian Mou
AU - Terry Macfarlane
AU - Miroslav Nikolic
AU - Li Yan
AU - Dan Tang
AU - Félix de Tombeur
AU - Joanna Kotula
AU - Kingsley Dixon
AU - Patrick Finnegan
AU - Kosala Ranathunge
AU - Hans Lambers
PY - 2026
DA - 2026/08/25
JO - Journal of Ecology
DO - 10.1111/1365-2745.70430
UR - https://hal.science/hal-05844666v1
AB - Grasses (Poaceae) are ubiquitous across all continents, even in phosphorus (P)‐impoverished environments. While root carboxylate exudation is a common P‐acquisition strategy in many plants, Poaceae generally release minimal amounts of carboxylates under P deficiency. In contrast, phytosiderophores are well‐known for their role in iron (Fe) acquisition in grasses, and emerging evidence suggests they may also participate in soil P mobilisation, potentially complementing or replacing carboxylate‐based strategies under P deficiency. However, the prevalence and significance of this strategy across native Poaceae in south‐western Australia remain unknown. We examined the carboxylate and phytosiderophore exudation of native grass species under different P availability, grown both in hydroponics (eight species) and in soil (six species) in glasshouse experiments. The tested species were chosen based on their leaf manganese concentration ([Mn]) (a proxy for carboxylate‐based strategies) in 21 grass species native to south‐western Australia, collected from 18 field sites. The leaf silicon concentration ([Si]) and [Mn] of grass species grown in two soils with different P availability were also analysed. Seven of the tested eight native grass species released both carboxylates and phytosiderophores. The exudation of phytosiderophores was significantly greater than that of carboxylates in two soils with contrasting P availability (up to 93.3 vs. 16.4 nmol g −1 root FW) and varied among species. Notably, Anthosachne scabra exuded significantly more phytosiderophores in old severely P‐impoverished soil (93.3 nmol g −1 root FW) than in younger soil with greater P availability (47.1 nmol g −1 root FW), and Dichelachne crinita showed a similar trend, with 11.8 and 6.5 nmol g −1 root FW, respectively. Leaf [Si] was positively correlated with leaf [Mn], confirming previous observations on a range of other species. We found a positive correlation between phytosiderophore exudation and both leaf [Mn] and rhizosheath soil P availability. Synthesis . This study demonstrates that several native grasses employed phytosiderophores not only for Fe acquisition, but probably also to mobilise P in their natural severely P‐impoverished habitats, supported by concomitant carboxylate exudation. These findings expand our understanding of integrated P‐acquisition mechanisms in Poaceae within nutrient‐limited ecosystems.
SN - 0022-0477
SN - 1365-2745
ER -