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Rapid decline in nitrate uptake and respiration with age in fine lateral roots of grape: implications for root efficiency and competitive effectiveness
Author(s) -
Volder Astrid,
Smart David R.,
Bloom Arnold J.,
Eissenstat David M.
Publication year - 2005
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2004.01222.x
Subject(s) - nitrate , respiration , nutrient , nitrogen , root system , biology , botany , horticulture , agronomy , chemistry , ecology , organic chemistry
Summary• Changes in function as an individual root ages has important implications for understanding resource acquisition, competitive ability and optimal lifespan. • Both nitrate uptake and respiration rates of differently aged fine roots of grape ( Vitis rupestris × V. riparia cv. 3309 C) were measured. The resulting data were then used to simulate nitrate uptake efficiency and nutrient depletion as a function of root age. • Both nitrate uptake and root respiration declined remarkably quickly with increasing root age. The decline in both N uptake and root respiration corresponded with a strong decline in root N concentration, suggesting translocation of nitrogen out of the roots. • For simulations where no nutrient depletion occurs at the root surface, daily uptake efficiency was maximal at root birth and lifetime nitrate uptake efficiency slowly increased as the roots aged. Simulations of growth of roots into unoccupied soil using a solute transport model indicated the advantage of high uptake capacity in new roots under competitive conditions where nitrate availability is very transitory.