The Physcomitrella genome reveals evolutionary insights into the conquest of land by plants
We report the draft genome sequence of the model moss Physcomitrella patens and compare its features with those of flowering plants, from which it is separated by more than 400 million years, and unicellular aquatic algae. This comparison reveals genomic changes concomitant with the evolutionary movement to land, including a general increase in gene family complexity; loss of genes associated with aquatic environments (e.g., flagellar arms); acquisition of genes for tolerating terrestrial stresses (e.g., variation in temperature and water availability); and the development of the auxin and abscisic acid signaling pathways for coordinating multicellular growth and dehydration response. The …
Biosystematic studies on the genus Polygonatum (Convallariaceae) IV. Molecular phylogenetic analysis based on restriction site mapping of the chloroplast gene trn K
Phylogenetic relationships of 14 species and one variety of the genus Polygonatum as well as three species of the genus Disporopsis and Heteropolygonatum roseolum were analyzed based on mapped restriction site variation in a PCR-amplified chloroplast genome region, trnK. In agreement with earlier taxonomic treatments it was found that Disporopsis and Heteropolygonatum should be distinguished from Polygonatum at generic level, and that P. sect. Polygonatum can be recognized as a monophyletic group. Earlier series concepts in P. sect. Polygonatum based on chromosome number and characteristics of staminal filaments are not supported by the molecular data. The molecular data suggest that satell…