Synergistic Effects of Metabolically Related Amino Acids on the Growth of a Multicellular Plant: II. Studies of 14C-Amino Acid Incorporation 12

AUTOR(ES)
RESUMO

The synergistic inhibition of the growth of Marchantia polymorpha gemmalings by lysine and threonine and its prevention by methionine has been investigated utilizing 14C-labeled amino acids. Experiments involving the uptake of 14C-lysine or 14C-threonine in the presence or absence of methionine indicated that the synergistic growth effects were not a result of altered amino acid uptake. These data, as well as direct chemical analysis, indicated that growth inhibition was correlated with an inhibition of protein synthesis. Experiments utilizing 14C-aspartic acid revealed that the presence of lysine and threonine resulted in increased 14CO2 production and an accumulation of soluble 14C-aspartic acid and labeled ninhydrin-positive compounds. These metabolic alterations were prevented when methionine was also included in the growth media. A model depicting a sequence of events which involve the interaction of regulatory mechanisms is suggested to account for the effects of specific amino acids on plant growth.

Documentos Relacionados