STUDIES ON THE DIURNAL COURSES OF THE CONTENTS OF ABSCISIC-ACID, 1-AMINOCYCLOPROPANE CARBOXYLIC-ACID AND ITS MALONYL CONJUGATE IN NEEDLES OF DAMAGED AND UNDAMAGED SPRUCE TREES

The diurnal courses of the contents of 1-aminocyclopropane carboxylic acid (ACC), its malonyl conjugate (MACC) and abscisic acid (ABA) in th e two-year-old needles of damaged and undamaged spruce trees (Picea ab ies L.) were investigated. The contents of ACC and MACC were significa ntly higher in the needles of the damaged trees as compared with the u ndamaged ones. In the needles of the damaged spruce trees, the ACC and MACC contents, and ABA contents as well, fluctuated to a greater exte nt than those in the undamaged spruce trees during the day. The relati onships between ACC-ABA and MACC-ACC contents as well are also discuss ed.