The Chl a Carboxylic Biosynthetic Routes: (Photo) Conversion of Protochlorophyllides (Pchlides) a to Chlorophyllide (Chlide) a - Chlorophyll Biosynthesis and Technological Applications - page 238

Fig. 9.2 Photoconversion of DV Pchlide a to DV Chlide a in DDDV-LDV-LDDV plants via
routes 1 and 8 (Adapted from Fig. 6.3 of Chap. 6 )

environments via routes 1 and 8 as suggested by multiple resonance energy transfer
from DV Pchlide a to various Chl a -Protein complexes (Table 6.1 ,Chap. 6 )and
(Kolossov et al. 2003 ), as well as further conversions to Chlide a and Chls as will be
discussed later. It is unclear at this stage whether the spatial biosynthetic heterogene-
ity of DV Chlide a is accompanied by chemical biosynthetic heterogeneity or not. In
other words, it is unclear whether the proposed biosynthesis of DV Chlide a from DV
Pchlide a via routes 1, and 8 is catalyzed by identical POR A photoenzymes or by
different POR A isozymes. These biosynthetic routes will be discussed further below.

9.4.1.1 Photoconversion of DV Pchlide a to DV Chlorophyllide

a in DDDV-LDV-LDDV Plants via Route 1

Photoconversion of DV Pchlide a to DV Chlide a via biosynthetic route 1 (Fig. 9.2 )
in etiolated DDV-LDV-LDDV plants was demonstrated in vivo and in organello by
conversion of DV Pchlide a to DV Chlide a (Duggan and Rebeiz 1982a , b ).
Biosynthetic route 1 is also probably active in greening DDV-LDV-LDDV plants
during the first few dark phases of the photoperiod when DV Pchlide a accumula-
tion is substantial (Cohen et al. 1977 ; Cohen and Rebeiz 1978 ).