Characterization of normal and "albino" phenotypes in Erythrina crista-galli

Abstract

We present here a characterization of Erythrina crista-galli L. (syn: Erythrina lamifolia Jacq.) seedlings, obtained from a plant from the Botanical Garden of Pisa University. This plant produces seeds that, during germination, have shown two different seedling phenotypes: normal (NT, 75%) and "albino" types (AT, 25%). Albino seedlings survive only 8-9 weeks and their growth is dramatically reduced when compared with wild type seedlings. Biochemical investigations have shown that albino seedlings completely lack chlorophyll and carotenoids and also soluble sugar levels are lower than in the normal type. We have also conducted sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) experiments and silver staining analysis on different protein extracts from shoots and leaves of both phenotypes, and demonstrated strong differences in protein patterns. The almost total absence of putative small and large RuBisCo bands in albino seedlings should be emphasized. We have also microspectrophotometrically determined the DNA content of this species, as it was lacking in the literature, by means of the Feulgen method. The recorded chromosome count of the species is confirmed to be 2n = 42, a number characteristic of the genus Erythrina. No variation in Feulgen absorption and in chromosome number is detectable between NT and AT seedlings. To better characterize this species and the two phenotypes, the complete nucleotide sequences of the internal transcribed spacer regions (ITS1 and ITS2) and the 5.8S rDNA have been also reported and compared with analogous sequences of some woody Leguminosae present in the European Molecular Biology Laboratory (EMBL) database. The results of this initial report lead us to conclude that albinism, in our system, has probably occurred as a result of natural mutation, and should be connected to genetic factors rather than to environmental conditions. © 2012 Dipartimento di Biologia Evoluzionistica, Università di Firenze.