Plant growth responses to elevated atmospheric CO₂ are increased by phosphorus sufficiency but not by arbuscular mycorrhizas

TY - JOUR

T1 - Plant growth responses to elevated atmospheric CO2 are increased by phosphorus sufficiency but not by arbuscular mycorrhizas

AU - Jakobsen, Iver

AU - Smith, Sally E

AU - Smith, F. Andrew

AU - Watts-Williams, Stephanie J.

AU - Clausen, Signe Sandbech

AU - Grønlund, Mette

N1 - © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

PY - 2016/11/1

Y1 - 2016/11/1

N2 - Capturing the full growth potential in crops under future elevated CO2 (eCO2) concentrations would be facilitated by improved understanding of eCO2 effects on uptake and use of mineral nutrients. This study investigates interactions of eCO2, soil phosphorus (P), and arbuscular mycorrhizal (AM) symbiosis in Medicago truncatula and Brachypodium distachyon grown under the same conditions. The focus was on eCO2 effects on vegetative growth, efficiency in acquisition and use of P, and expression of phosphate transporter (PT) genes. Growth responses to eCO2 were positive at P sufficiency, but under low-P conditions they ranged from non-significant in M. truncatula to highly significant in B. distachyon Growth of M. truncatula was increased by AM at low P conditions at both CO2 levels and eCO2×AM interactions were sparse. Elevated CO2 had small effects on P acquisition, but enhanced conversion of tissue P into biomass. Expression of PT genes was influenced by eCO2, but effects were inconsistent across genes and species. The ability of eCO2 to partly mitigate P limitation-induced growth reductions in B. distachyon was associated with enhanced P use efficiency, and requirements for P fertilizers may not increase in such species in future CO2-rich climates.

AB - Capturing the full growth potential in crops under future elevated CO2 (eCO2) concentrations would be facilitated by improved understanding of eCO2 effects on uptake and use of mineral nutrients. This study investigates interactions of eCO2, soil phosphorus (P), and arbuscular mycorrhizal (AM) symbiosis in Medicago truncatula and Brachypodium distachyon grown under the same conditions. The focus was on eCO2 effects on vegetative growth, efficiency in acquisition and use of P, and expression of phosphate transporter (PT) genes. Growth responses to eCO2 were positive at P sufficiency, but under low-P conditions they ranged from non-significant in M. truncatula to highly significant in B. distachyon Growth of M. truncatula was increased by AM at low P conditions at both CO2 levels and eCO2×AM interactions were sparse. Elevated CO2 had small effects on P acquisition, but enhanced conversion of tissue P into biomass. Expression of PT genes was influenced by eCO2, but effects were inconsistent across genes and species. The ability of eCO2 to partly mitigate P limitation-induced growth reductions in B. distachyon was associated with enhanced P use efficiency, and requirements for P fertilizers may not increase in such species in future CO2-rich climates.

U2 - 10.1093/jxb/erw383

DO - 10.1093/jxb/erw383

M3 - Journal article

C2 - 27811084

SN - 0022-0957

VL - 67

SP - 6173

EP - 6186

JO - Journal of Experimental Botany

JF - Journal of Experimental Botany

IS - 21

ER -