Plastid Genome Degradation in the Endangered, Mycoheterotrophic, North American Orchid Hexalectris warnockii

Document Type

Article

Publication Date

2018

College/Unit

Eberly College of Arts and Sciences

Department/Program/Center

Biology

Abstract

Heterotrophic plants provide evolutionarily independent, natural experiments in the genomic consequences of radically altered nutritional regimes. Here, we have sequenced and annotated the plastid genome of the endangered mycoheterotrophic orchid Hexalectris warnockii. This orchid bears a plastid genome that is ��80% the total length of the leafy, photosynthetic Phalaenopsis, and contains just over half the number of putatively functional genes of the latter. The plastid genome of H. warnockii bears pseudogenes and has experienced losses of genes encoding proteins directly (e.g., psa/psb, rbcL) and indirectly involved in photosynthesis (atp genes), suggesting it has progressed beyond the initial stages of plastome degradation, based on previous models of plastid genome evolution. Several dispersed and tandem repeats were detected, that are poten- tially useful as conservation genetic markers. In addition, a 29-kb inversion and a significant contraction of the inverted repeat boundaries are observed in this plastome. The Hexalectris warnockii plastid genome adds to a growing body of data useful in refining evolutionary models in parasites, and provides a resource for conservation studies in these endangered orchids.

Source Citation

Barrett, C. F., & Kennedy, A. H. (2018). Plastid genome degradation in the endangered, mycoheterotrophic, North American orchid Hexalectris warnockii. Genome Biology and Evolution. https://doi.org/10.1093/gbe/evy107

Comments

ß The Author(s) 2018. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com

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