Compensatory Aspects of the Biosynthesis of Spermidine in Tobacco Cells in Suspension Culture

概要

論文の詳細を見る
The relationship between the biosynthesis of polyamines and ethylene was examined in suspension cultures of Nicotiana tabacum L. cells. Aminooxyacetic acid (AOA), an inhibitor of l-aminocyclopropane-l-carboxylic acid synthase, inhibited the production of ethylene and raised levels of spermidine by increasing the availability of S-adenosylmethionine (SAM) for the synthesis of polyamines. In contrast, methylglyoxal bis (guanylhydrazone) (MGBG), an inhibitor of S-adenosylmethionine decarboxylase (SAMDC), an enzyme involved in the biosynthesis of Polyamine, caused a slight increase in the rate of biosynthesis of ethylene. However MGBG did not decrease the rate of biosynthesis of polyamines in 10-day-old senescing cells. Although MGBG inhibited the conversion of L-[U-<14>^C]methionine into labeled spermidine via SAM both in 4-day-and in 10-day-cultured cells, it stimulated the conversion of L-[U-<14>^C]aspartic acid into labeled spermidine in 10-day-cultured cells. In actively dividing 4-day-cultured cells, L-[U-<14>^C]homoserine was also converted into polyamines. In senescing cells, which produce large amounts of ethylene, the biosynthesis of spermidine from aspartic acid coincided with that from methionine. In actively growing cells, which produce large amounts of polyamines, the biosynthesis of spermidine from homoserine coincided with that from methionine. These results indicate that homoserine and aspartic acid can be both used as precursors in the biosynthesis of polyamines and help to maintain appropriate titers of polyamines, when SAMDC is inhibited and the level of decarboxylated SAM becomes limiting.
日本植物生理学会の論文

Compensatory Aspects of the Biosynthesis of Spermidine in Tobacco Cells in Suspension Culture

スポンサーリンク

概要

著者

関連論文

スポンサーリンク