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Metabolism and translocation of nitrogen in two Lolium perenne populations with contrasting rates of mature leaf respiration and yield
Author(s) -
Barneix Atilio J.,
Cooper H. David,
Stulen Ineke,
Lambers Hans
Publication year - 1988
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1988.tb09174.x
Subject(s) - lolium perenne , respiration , glutamine synthetase , biology , nitrate reductase , respiration rate , glutamate dehydrogenase , glutamate synthase , nitrogen cycle , shoot , metabolism , glutamine , lolium , botany , nitrogen , poaceae , nitrate , biochemistry , chemistry , amino acid , ecology , glutamate receptor , receptor , organic chemistry
Barneix, A. J., Cooper, H. D., Stulen, I. and Lambers, H. 1988. Metabolism and translocation of nitrogen in two Lolium perenne populations with contrasting rates of mature leaf respiration and yield. ‐ Physiol. Plant. 72: 631–636. Several aspects of nitrogen metabolism and transport were investigated to determine whether these processes could account for the observed differences in the dark respiration rate of mature leaves between two populations of Lolium perenne L. cv. S23: GL72 ‐ a slow respiring, high growth rate line, and cv. GL66 ‐ a fast respiring, low growth rate line. No differences were found in total nitrogen or soluble protein concentrations between the populations, but GL72 showed a higher concentration of soluble amino acids, accounted for mainly by increases in the amounts of asparagine and glutamine. There were no differences in the glutamine synthetase (EC 6.3.1.2) or nitrate reductase (EC 1.6.6.1) activities between populations, but the fast respiring GL66 line showed higher glutamate dehydrogenase (EC 1.4.1.3) and peroxidase (EC 1.11.1.7) activities than GL72. The protein turnover rate, determined from 3 H disappearance from leaves labelled with [ 3 H]‐acetic anhydride, appeared to be larger in GL66, but the difference was not significant and could not account for the differences in respiration rate. The apparent extent of 15 N cycling between roots and shoots was low in Lolium compared to other grass species, and there were no differences between the two populations. It is concluded that the differences in dark respiration rate are not due to differences in demand for ATP by nitrogen assimilatory processes, but may be related to faster leaf senescence in the GL66 population.