CHLOROPHYLL SYNTHETASE-ACTIVITY IS RELOCATED FROM TRANSFORMING PROLAMELLAR BODIES TO DEVELOPING THYLAKOIDS DURING IRRADIATION OF DARK-GROWNWHEAT

Analyses of the esterification of newly formed chlorophyllide in irrad iated dark-grown leaves of wheat (Triticum aestivum L. cv. Kosack) sug gest a translocation of chlorophyll synthetase activity from transform ing prolamellar bodies to developing thylakoids. We have fractionated plastid inner membranes from dark-grown leaves and from leaves irradia ted for 5, 10, or 20 min and compared the in vitro esterification of c hlorophyllide in two fractions, corresponding (in density) to the prol amellar body and the prothylakoid fraction of dark-grown leaves. The r elative amounts of chlorophyllide, and total protein, as well as the s pecific esterification activity, increased with irradiation time in th e prothylakoid fraction. The esterification of chlorophyllide seems to depend on a transformation of the prolamellar body structure. The res ults are discussed also in relation to other events initiated by irrad iation, such as the Shibata-shift and the altered distribution of NADP H-protochlorophyllide oxidoreductase (EC 1.3.1.33).