Senescence in Detached Oat Leaves I. : Changes in Free Amino Acid Levels

概要

論文の詳細を見る
Changes in the levels of free amino acids have been measured during light and dark senescence of oat leaf segments. Leaves were aged either on water, 5 ppm kinetin or 30 ppm abscisic acid. The patterns with which levels of individual amino acids change differ a great deal in leaves senescing either in dark or light, signifying that different mechanisms may regulate oat leaf senescence in light and dark. Levels of serine and most of the other amino acids that increase substantially during dark senescence of oat leaves change parallel to mitochondrial respiration. Kinetin depresses the rise in amino acids just as it does with respiration in the dark. The synthesis of serine proteases does not seem to be limited by the availability of endogenous serine. The levels of glutamine increase dramatically in leaves kept in light (ca. 2,200% of initial value within 7 days) but only a little in the dark, which may reflect a possible role of photorespiration during the senescence of oat leaves in the light. Abscisic acid enhances the release of amino acids more strongly in the light than dark. The senescence promoting effect of abscisic acid in the light seems to bring about changes in amino acid levels similar to those that appear in leaves senescing on water in the dark.
日本植物生理学会の論文