Can psilotum and/or gnetum synthesise chlorophyll in darkness?

摘要

Most plants including angiosperms can synthesise chlorophyll (Chl) in darkness as well as in light albeit at a lower rate. For this, they require a light-independent reductase to catalyse the conversion of protochlorophyllide (Pchl(ide)) to chlorophyllide (Chl(ide)). Genes coding for individual sub-units of a such an enzyme have been identified in purple bacteria (bch L,bch N and bch B) and a wide variety of oxygenic photosynthetic organisms ranging from cyanobacteria to gymnosperms (chl L, chl N and chl B). However they have not been found in angiosperms. This could be a consequence of sequence divergence following gene transfer from the chloroplast to the nucleus. Alternatively, it might reflect gene deletion during evolution.