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Influence of nitrate and ammonium on the growth and 2,4‐diaminobutyric acid composition of flatpea ( Lathyrus sylvestris L.)
Author(s) -
SHEN L.,
FOSTER J. G.,
ORCUTT D. M.
Publication year - 1990
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/j.1365-3040.1990.tb01100.x
Subject(s) - amino acid , ammonium , asparagine , shoot , composition (language) , chemistry , glutamine , ammonia , lathyrus , nutrient , nitrate , botany , food science , biochemistry , biology , organic chemistry , linguistics , philosophy
Abstract. Presence of 2.4‐diaminobutyric acid (A 2 bu), a neurotoxin, in tissues of flatpea ( Lathyrus sylvestris L.) necessitates a thorough understanding of the regulation of this nonprotein amino acid before the species can be recommended to livestock producers for forage applications. To determine how different concentrations and ratios of NO 3 and NH + 4 in growth media influence the levels of A 2 bu and other free amino acids in the ‘Lathco’flatpea cultivar, plants were grown hydroponically in controlled environments. The concentration of A 2 bu was highest in tissues when the NO 3 to NH + 4 ratio in the nutrient solution was low. Responses of amides and other nonprotein amino acids, especially in the roots, followed a similar trend. Free protein amino acids in leaves and stems were generally unaffected by changes in NO 3 to NH + 4 ratios. In roots, protein amino acids increased as the NO 3 to NH + 4 ratio in the growth medium increased. Ammonium inhibited shoot and root growth; NO 3 alleviated the toxic effects of NH + 4 . Soluble protein concentrations were higher in the shoots of NO 3 ‐fed plants and in the roots of plants supplied with NH + 4 . These results suggest that accumulation of A 2 bu and other nonprotein amino acids, as well as asparagine and glutamine, plays a role in detoxification of NH + 4 and storage of N.