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Tradeoffs among root morphology, exudation and mycorrhizal symbioses for phosphorus‐acquisition strategies of 16 crop species
Author(s) -
Wen Zhihui,
Li Hongbo,
Shen Qi,
Tang Xiaomei,
Xiong Chuanyong,
Li Haigang,
Pang Jiayin,
Ryan Megan H.,
Lambers Hans,
Shen Jianbo
Publication year - 2019
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.15833
Subject(s) - biology , symbiosis , interspecific competition , root system , botany , colonization , limiting , rhizosphere , herbaceous plant , phosphorus , agronomy , ecology , chemistry , bacteria , mechanical engineering , genetics , organic chemistry , engineering
Summary Plant roots exhibit diverse root functional traits to enable soil phosphorus (P) acquisition, including changes in root morphology, root exudation and mycorrhizal symbioses. Yet, whether these traits are differently coordinated among crop species to enhance P acquisition is unclear. Here, eight root functional traits for P acquisition were characterized in 16 major herbaceous crop species grown in a glasshouse under limiting and adequate soil P availability. We found substantial interspecific variation in root functional traits among species. Those with thinner roots showed more root branching and less first‐order root length, and had consistently lower colonization by arbuscular mycorrhizal fungi (AMF), fewer rhizosheath carboxylates and reduced acid phosphatase activity. In response to limiting soil P, species with thinner roots showed a stronger response in root branching, first‐order root length and specific root length of the whole root system, Conversely, species with thicker roots exhibited higher colonization by AMF and/or more P‐mobilizing exudates in the rhizosheath. We conclude that, at the species level, tradeoffs occur among the three groups of root functional traits we examined. Root diameter is a good predictor of the relative expression of these traits and how they change when P is limiting.