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Modelling postsilking nitrogen fluxes in maize ( Zea mays ) using 15 N‐labelling field experiments
Author(s) -
Gallais André,
Coque Marie,
Quilléré Isabelle,
Prioul JeanLouis,
Hirel Bertrand
Publication year - 2006
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.1469-8137.2006.01890.x
Subject(s) - stover , agronomy , nitrogen , corn stover , zea mays , poaceae , field experiment , nitrogen balance , labelling , chemistry , hydrolysis , biology , biochemistry , organic chemistry
Summary• In maize ( Zea mays ), nitrogen (N) remobilization and postflowering N uptake are two processes that provide amino acids for grain protein synthesis. • To study the way in which N is allocated to the grain and to the stover, two different 15 N‐labelling techniques were developed. 15 NO 3 − was provided to the soil either at the beginning of stem elongation or after silking. The distribution of 15 N in the stover and in the grain was monitored by calculating relative 15 N‐specific allocation (RSA). • A nearly linear relationship between the RSA of the kernels and the RSA of the stover was found as a result of two simultaneous N fluxes: N remobilization from the stover to the grain, and N allocation to the stover and to the grain originating from N uptake. • By modelling the 15 N fluxes, it was possible to demonstrate that, as a consequence of protein turnover, a large proportion of the amino acids synthesized from the N taken up after silking were integrated into the proteins of the stover, and these proteins were further hydrolysed to provide N to the grain.