Comparative study on the turnover of quinic- and shikimic acid and of its derivatives in needles of Norway spruce, Picea abies (L.) Karst., affected by 'Waldsterben' syndrome

A comparative study on the incorporation of 14C into quinic- and shikimic acid in spruce needles was carried out with four different syndroms of Picea abies (L.) Karst: a tree from high altitudes of the Bayerischer Wald with the syndrom of 'acute yellowing', a light-sensitive mutant with yellowish needles (Picea abies Karst. finedonensis), a tree exhibiting 'Lametta' syndrome with a translucent crown and twigs hanging down like tinsel, and a healthy tree for control. The needles of these trees were labelled via photosynthetic fixation of 14CO2 in June, and the fate of labelled compounds was monitored over 125 days. In the youngest needles incorporation rates of quinic and shikimic acid reached a dominating level of about 60% of the label of soluble metabolites, which underlines the decisive role of both acids during needle development. The yellow mutant 'finedonensis' and the tree with 'Lametta' syndrome, which exhibit rather identical turnover kinetics of quinate and shikimate, show lower rates and reach, in particular in one- and two-year-old needles, only about 50% of the incorporation rates of the control spruce. The tree with the syndrome of 'acute yellowing' exhibits a significant reduction of incorporation already in the youngest needles; the older needles of this tree virtually suspend metabolism of both acids all together, though apparently high but dormant pools of shikimate and quinate are present. The degree of label incorporation into shikimate and quinate may possibly serve as a measure of needle damage. Exclusively in the yellow mutant a novel spruce constituent, 3-0-p-coumaroylquinic acid, could be detected; a related compound, 3-0-p-caffeoylshikimic acid was identified in the needles of the 'acute yellowing' tree. (orig./MG)