Prof. Craig Barrett (West Virginia University)
in: 'Frontiers in Ecology and Evolution': "Genome evolution in mycoheterotrophic orchids"
by Prof. Craig Barrett (West Virginia University)
The heterotrophic lifestyle has evolved numerous times independently within the orchids, likely due to their mode of parasitizing mycorrhizal fungi at the initial stages of their development. Thus, the orchids are an ideal group in which to study the genomic and physiological consequences of shifting from autotrophy to obligate heterotrophy. In this seminar I will discuss: 1) the basic biology or orchids and the evolution of heterotrophy, 2) the now extensive findings on plastid genome evolution in heterotrophic orchids, and 3) the far less extensive findings on evolution of the mitochondrial and nuclear genomes in these plants. I will use two well-sampled case studies, the North American orchid genera Corallorhiza and Hexalectris, and place these in the broader context of the evolution of heterotrophy in plants.