Anthocyanin synthesis began in the skin of 'Olympia' (Vitis labruscana Bail
ey) grape when the berry growth reached a late stage in the second sigmoid
growth-curve. During berry development, shikimate NADP oxidoreductase (SORa
se, EC.1.1.1.25), phenylalanine ammonia-lyase (PAL, EC.4.3.1.5), and chalco
ne flavanone isomerase (CM, EC.5.5.1.6) were investigated in the skin. Thes
e enzyme activities were high during early development of the young berry,
but rapidly decreased thereafter, and were activated again when rapid antho
cyanin synthesis subsequently occurred. When PAL from the young berry was a
nalyzed by isoelectricfocusing polyacrylamide gel electrophoresis (IEF-PAGE
), it showed a single activity band with a pI value of approximately 5.4, w
hereas PAL from the ripe berry showed two activity bands with pIs of 5.4 an
d 6.5. Thus, SORase, PAL, and CHFI seem to be involved in anthocyanin accum
ulation simultaneously, and newly synthesized isozyme of PAL may play a key
role in pigment formation in 'Olympia' skin. The function of these enzyme
activities in young berry is also discussed in this text. (C) 2001 Elsevier
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