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The efficiency of Arabidopsis thaliana (Brassicaceae) root hairs in phosphorus acquisition
Author(s) -
Bates Terence R.,
Lynch Jonathan P.
Publication year - 2000
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.2307/2656995
Subject(s) - phosphorus , root hair , biology , arabidopsis thaliana , phosphorus deficiency , shoot , arabidopsis , botany , agronomy , horticulture , nutrient , mutant , chemistry , ecology , biochemistry , gene , organic chemistry
Arabidopsis thaliana root hairs grow longer and denser in response to low‐phosphorus availability. In addition, plants with the root hair response acquire more phosphorus than mutants that have root hairs that do not respond to phosphorus limiting conditions. The purpose of this experiment was to determine the efficiency of root hairs in phosphorus acquisition at high‐ and low‐phosphorus availability. Root hair growth, root growth, root respiration, plant phosphorus uptake, and plant phosphorus content of 3‐wk‐old wild‐type Arabidopsis (WS) were compared to two root hair mutants ( rhd6 and rhd2 ) under high (54 mmol/m 3 ) and low (0.4 mmol/m 3 ) phosphorus availability. A cost‐benefit analysis was constructed from the measurements to determine root hair efficiency. Under high‐phosphorus availability, root hairs did not have an effect on any of the parameters measured. Under low‐phosphorus availability, wild‐type Arabidopsis had greater total root surface area, shoot biomass, phosphorus per root length, and specific phosphorus uptake. The cost‐benefit analysis shows that under low phosphorus, wild‐type roots acquire more phosphorus for every unit of carbon respired or unit of phosphorus invested into the roots than the mutants. We conclude that the response of root hairs to low‐phosphorus availability is an efficient strategy for phosphorus acquisition.