THE INHIBITION OF BRUSSELS SPROUT LEAF SENESCENCE BY KININS

Abstract

The senescence of leaf discs cut from mature Brussels sprout leaves is retarded by a number of kinins. Other plant growth regulators are without effect. When young expanding leaves are treated with kinins the senescence processes appear to be accelerated. The effect of N-6-benzyladenine on the structure of the cell organelles in young and old leaves has been studied by electron microscopy. It has been found that in mature leaves the chloroplast is the organelle which senesces first and the breakdown is retarded by N-6-benzyladenine. The mitochondria are very stable. In young leaves N-6-benzyladenine appears to over-stimulate the chloroplast, causing enlargement and excessive membrane synthesis.