
%0 Journal Article
%A Theodorides, TN 
%A Pearson, CJ 
%T Effect of Temperature on Total Nitrogen Distribution in <I>Pennisetum Americanum</I>
%J Functional Plant Biology
%D 1981/04/01
%V 8
%N 2
%P 201-210
%K 
%R https://doi.org/10.1071/PP9810201
%U https://www.publish.csiro.au/paper/PP9810201 
%X Total N uptake and distribution and relative accumulation of N and dry matter were studied from 26 days after sowing until 50% anthesis in two genotypes of Pennisetum americanum growing at day/night temperatures ranging from 18/13 to 30/25&#176;C. Nitrogen was taken up throughout growth and there was no indication of a net loss of N from the whole plant or from individual organs. Rate of N uptake was closely correlated with dry weight increments until stem elongation: there was a single relationship between uptake and dry weight increment over the three temperatures and two genotypes (41 mg N per g whole-plant dry weight increment). Relative rates of N accumulation and dry weight increment were higher at high temperature and again a single equation related relative accumulation of N to dry weight over all treatments. However, in contrast to the constancy of N uptake per unit dry weight, N distribution within the plant was affected by temperature. Low temperatures resulted in high root N concentrations and relatively high NO3 concentrations in root and stem apices. Temperature did not affect the proportional distribution of N between organs of the top.    The results are interpreted as showing that activity of components of the nitrogen pathway are adjusted to maintain a constant rate of N uptake per unit dry weight increment in vegetative growth, but that N distribution within pearl millet is sensitive to temperature. 
