Contrasting responses of root morphology and root-exuded organic acids to low phosphorus availability in three important food crops with divergent root traits.
Phosphorus (P) is an important element for crop productivity and is widely applied in fertilizers. Most P fertilizers applied to land are sorbed onto soil particles, so research on improving plant uptake of less easily available P is important. In the current study, we investigated the responses in root morphology and root-exuded organic acids (OAs) to low available P (1 μM P) and sufficient P (50 μM P) in barley, canola and micropropagated seedlings of potato-three important food crops with divergent root traits, using a hydroponic plant growth system. We hypothesized that the dicots canola and tuber-producing potato and the monocot barley would respond differently under various P availabilities. WinRHIZO and liquid chromatography triple quadrupole mass spectrometry results suggested that under low P availability, canola developed longer roots and exhibited the fastest root exudation rate for citric acid. Barley showed a reduction in root length and root surface area and an increase in root-exuded malic acid under low-P conditions. Potato exuded relatively small amounts of OAs under low P, while there was a marked increase in root tips. Based on the results, we conclude that different crops show divergent morphological and physiological responses to low P availability, having evolved specific traits of root morphology and root exudation that enhance their P-uptake capacity under low-P conditions. These results could underpin future efforts to improve P uptake of the three crops that are of importance for future sustainable crop production.
Norwegian Institute of Bioeconomy Research (NIBIO), PO Box 115, N-1431 Ås, Norway Department of Environmental Sciences, Norwegian University of Life Sciences, PO Box 5003, N-1432 Ås, Norway.
Yan-Liang
YL
Wang
Norwegian Institute of Bioeconomy Research (NIBIO), PO Box 115, N-1431 Ås, Norway.
Marit
M
Almvik
Norwegian Institute of Bioeconomy Research (NIBIO), PO Box 115, N-1431 Ås, Norway.
Nicholas
N
Clarke
Department of Environmental Sciences, Norwegian University of Life Sciences, PO Box 5003, N-1432 Ås, Norway.
Susanne
S
Eich-Greatorex
Norwegian Institute of Bioeconomy Research (NIBIO), PO Box 115, N-1431 Ås, Norway.
Anne Falk
AF
Øgaard
Department of Environmental Sciences, Norwegian University of Life Sciences, PO Box 5003, N-1432 Ås, Norway.
Tore
T
Krogstad
School of Plant Biology and Institute of Agriculture, University of Western Australia, Crawley (Perth), WA 6009, Australia hans.lambers@uwa.edu.au jihong.liu-clarke@nibio.no.
Hans
H
Lambers
Norwegian Institute of Bioeconomy Research (NIBIO), PO Box 115, N-1431 Ås, Norway hans.lambers@uwa.edu.au jihong.liu-clarke@nibio.no.
Jihong Liu
JL
Clarke
Crops; hydroponic culture; phosphorus; root exudates; root morphology