title: Major Crop Species Show Differential Balance between Root Morphological and Physiological Responses to Variable Phosphorus Supply.
abstract: The relationship between root morphological and physiological responses to variable P supply in different plant species is poorly understood. We compared root morphological and physiological responses to P supply in seven crop species (Zea mays,Triticum aestivum,Brassica napus,Lupinus albus, Glycine max, Vicia faba,Cicer arietinum) treated with or without 100 mg P kg-1in two soils (acidic and calcareous). Phosphorus deficiency decreased root length more in fibrous root species (Zea mays, Triticum aestivum, Brassica napus) than legumes.Zea maysandTriticum aestivumhad higher root/shoot biomass ratio andBrassica napushad higher specific root length compared to legumes, whereas legumes (except soybean) had higher carboxylate exudation than fibrous root species.Lupinus albusexhibited the highest P-acquisition efficiency due to high exudation of carboxylates and acid phosphatases.Lupinus albusandCicer arietinumdepended mostly on root exudation (i.e., physiological response) to enhance P acquisition, whereasZea mays, Triticum aestivum and Brassica napushad higher root morphology dependence, withGlycine maxandVicia fabain between. Principal component analysis using six morphological and six physiological responses identified root size and diameter as the most important morphological traits, whereas important physiological responses included carboxylate exudation, and P-acquisition and P-utilization efficiency followed by rhizosphere soil pH and acid phosphatase activity. In conclusion, plant species can be grouped on the basis of their response to soil P being primarily via root architectural or exudation plasticity, suggesting a potential benefit of crop-specific root-trait-based management to cope with variable soil P supply in sustainable grain production.
authors.affiliation: Centre for Resources, Environment and Food Security, Department of Plant Nutrition, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University Beijing, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Lyu
authors.affiliation: Centre for Resources, Environment and Food Security, Department of Plant Nutrition, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural UniversityBeijing, China; College of Life Science, Hebei UniversityBaoding, China.
authors.forename: Hongliang
authors.initials: H
authors.lastname: Tang
authors.affiliation: Centre for Resources, Environment and Food Security, Department of Plant Nutrition, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University Beijing, China.
authors.forename: Haigang
authors.initials: H
authors.lastname: Li
authors.affiliation: Centre for Resources, Environment and Food Security, Department of Plant Nutrition, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University Beijing, China.
authors.forename: Fusuo
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Soil Science and Plant Nutrition, School of Earth and Environment, The UWA Institute of Agriculture, The University of Western Australia, Crawley WA, Australia.
authors.forename: Zed
authors.initials: Z
authors.lastname: Rengel
authors.affiliation: Rothamsted Research Harpenden, UK.
authors.forename: William R
authors.initials: WR
authors.lastname: Whalley
authors.affiliation: Centre for Resources, Environment and Food Security, Department of Plant Nutrition, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University Beijing, China.
authors.forename: Jianbo
authors.initials: J
authors.lastname: Shen
keywords: fibrous root species; legume species; phosphorus supply; phosphorus uptake; root exudation; root morphological traits