Light-regulated pigment interconversion in pheophytin/chlorophyll-containing complexes formed during plant leaves greening

Abstract

Upon illumination of etiolated maize leaves the photoconversion of protochlorophyllide Pchlide 655/650 into chlorophyllide Chlide 684/676 was observed. It was shown that chlorophyllide Chlide 684/676 in the dark is transformed into pheophytin Pheo 679/675 and chlorophyll Chl 671/668 by means of two parallel reactions, occurring at room temperature: Chlide 684/676. The formed pheophytin Pheo 679/675 was unstable and in the dark was transformed into chlorophyll Chl 671/668 in a few seconds: Pheo 679/675 → Chl 671/668. The last reaction is reversed by the light: Chl/668 Pheo 679/675. Thus, on the whole in the greening etiolated leaves this process occurs according to the following scheme:The observed light-regulated interconversion of Mg-containing and Mg-free chlorophyll analogs is activated by ATP and inhibited by AMP.

Normal-phase HPLC Separation of Possible Biosynthetic Intermediates of Pheophytin a and Chlorophyll a′

“…20,21 However, the Pheo a/Chl a ratio, which they estimated from the fluorescence excitation spectra, was as high as 50%, which is far from the value obtained here (about 0.47%). Such a discrepancy might, at least partially, be due to a difference in the illumination conditions.…”

Lipid Biosynthesis and Protein Concentration Respond Uniquely to Phosphate Supply during Leaf Development in Highly Phosphorus-Efficient Hakea prostrata

“…Here, we present further evidence of this smart P-allocation strategy, which is summarized in Figure 7. In young H. prostrata leaves, pheophytin was highly abundant while chlorophylls only accumulated as the leaves matured, a situation similar to that found in maize, where pheophytin accumulates in etiolated leaves prior to light-regulated conversion into chlorophyll (Ignatov and Litvin, 1995). The chlorophyll a/b ratio was also very low in young H. prostrata leaves (Sulpice et al, 2014) and resembled ratios found in shade leaves, with 2-fold lower CO 2 assimilation rates (Lichtenthaler et al, 2007).…”