TY - JOUR

T1 - Developmental plasticity of Brachypodium distachyon in response to P deficiency

T2 - Modulation by inoculation with phosphate-solubilizing bacteria

AU - Baudson, Caroline

AU - Delory, Benjamin M.

AU - Spaepen, Stijn

AU - du Jardin, Patrick

AU - Delaplace, Pierre

N1 - Publisher Copyright: © 2021 The Authors. Plant Direct published by American Society of Plant Biologists, Society for Experimental Biology and John Wiley & Sons Ltd.

PY - 2021/1/1

Y1 - 2021/1/1

N2 - Background: Mineral phosphorus (P) fertilizers must be used wisely in order to preserve rock phosphate, a limited and non-renewable resource. The use of bio-inoculants to improve soil nutrient availability and trigger an efficient plant response to nutrient deficiency is one potential strategy in the attempt to decrease P inputs in agriculture. Method: An in vitro co-cultivation system was used to study the response of Brachypodium distachyon to contrasted P supplies (soluble and poorly soluble forms of P) and inoculation with P solubilizing bacteria. Brachypodium's responses to P conditions and inoculation with bacteria were studied in terms of developmental plasticity and P use efficiency. Results: Brachypodium showed plasticity in its biomass allocation pattern in response to variable P conditions, specifically by prioritizing root development over shoot productivity under poorly soluble P conditions. Despite the ability of the bacteria to solubilize P, shoot productivity was depressed in plants inoculated with bacteria, although the root system development was maintained. The negative impact of bacteria on biomass production in Brachypodium might be attributed to inadequate C supply to bacteria, an increased competition for P between both organisms under P-limiting conditions, or an accumulation of toxic bacterial metabolites in our cultivation system. Both P and inoculation treatments impacted root system morphology. The modulation of Brachypodium's developmental response to P supplies by P solubilizing bacteria did not lead to improved P use efficiency. Conclusion: Our results support the hypothesis that plastic responses of Brachypodium cultivated under P-limited conditions are modulated by P solubilizing bacteria. The considered experimental context impacts plant–bacteria interactions. Choosing experimental conditions as close as possible to real ones is important in the selection of P solubilizing bacteria. Both persistent homology and allometric analyses proved to be useful tools that should be considered when studying the impact of bio-inoculants on plant development in response to varying nutritional context.

AB - Background: Mineral phosphorus (P) fertilizers must be used wisely in order to preserve rock phosphate, a limited and non-renewable resource. The use of bio-inoculants to improve soil nutrient availability and trigger an efficient plant response to nutrient deficiency is one potential strategy in the attempt to decrease P inputs in agriculture. Method: An in vitro co-cultivation system was used to study the response of Brachypodium distachyon to contrasted P supplies (soluble and poorly soluble forms of P) and inoculation with P solubilizing bacteria. Brachypodium's responses to P conditions and inoculation with bacteria were studied in terms of developmental plasticity and P use efficiency. Results: Brachypodium showed plasticity in its biomass allocation pattern in response to variable P conditions, specifically by prioritizing root development over shoot productivity under poorly soluble P conditions. Despite the ability of the bacteria to solubilize P, shoot productivity was depressed in plants inoculated with bacteria, although the root system development was maintained. The negative impact of bacteria on biomass production in Brachypodium might be attributed to inadequate C supply to bacteria, an increased competition for P between both organisms under P-limiting conditions, or an accumulation of toxic bacterial metabolites in our cultivation system. Both P and inoculation treatments impacted root system morphology. The modulation of Brachypodium's developmental response to P supplies by P solubilizing bacteria did not lead to improved P use efficiency. Conclusion: Our results support the hypothesis that plastic responses of Brachypodium cultivated under P-limited conditions are modulated by P solubilizing bacteria. The considered experimental context impacts plant–bacteria interactions. Choosing experimental conditions as close as possible to real ones is important in the selection of P solubilizing bacteria. Both persistent homology and allometric analyses proved to be useful tools that should be considered when studying the impact of bio-inoculants on plant development in response to varying nutritional context.

KW - bio-inoculants

KW - biomass allocation

KW - P solubilizing bacteria

KW - P use efficiency

KW - root system morphology

KW - Ecosystems Research

UR - http://www.scopus.com/inward/record.url?scp=85100256399&partnerID=8YFLogxK

U2 - 10.1002/pld3.296

DO - 10.1002/pld3.296

M3 - Journal articles

C2 - 33532689

AN - SCOPUS:85100256399

VL - 5

JO - Plant Direct

JF - Plant Direct

SN - 2475-4455

IS - 1

M1 - e00296

ER -