Abstract Detail

Systematics Section/ASPT

Cox, Monica [1], Washburn , Jacob D [2], Gallaher, Timothy [1], Clark, Lynn G. [1].

Out of the Forest and into the Light: A 3D Reconstruction of Leaf Anatomy related to C4 Evolution and Habitat Transitions within the Boivinellinae (Paniceae – Poaceae).

Boivinellinae (14 genera, ca. 135 species – Paniceae, Poaceae) is known as the “forest shade” clade as many of its members occupy interior forest habitat and have evolved gross leaf morphology consistent with shade tolerance. Yet some species of this clade have emerged from the forest and others have found an intermediate placement on the forest edge. In addition, there are potentially two independent origins of C4 photosynthesis within the C3 clade, in Alloteropsis and Echinochloa. The phylogenetic position of Alloteropsis within Boivinellinae has been supported by molecular data. Alloteropsis, which includes C3 species and species with PEP CK, NAD ME and NADP ME C4 subtypes, represents an independent transition from C3 to C4 and includes the only putative reversal to C3. On the other hand, the placement of Echinochloa has been called into question due to conflicts between the chloroplast and nuclear genomes. Anatomical studies will enable us to more fully understand these transitions to C4 and the reversal from C4 to C3, as well as the relationship of anatomy to habitat. While some anatomical information is available for the Boivinellinae clade, it largely consists of transverse (cross) sections. In the present study, we have combined longitudinal, paradermal, and transverse sections to model 3D images of cell shapes within seven of the 14 genera of the Boivinellinae. A three dimensional analysis provides additional informative characters for the reconstruction of transitions in photosynthetic pathways and habitat. Given the presence of palisade parenchyma in Oplismenus, we are also testing whether this is a general feature of the shade tolerant members of the subtribe. 

1 - Iowa State University, Department Of Ecology, Evolution, And Organismal Biology, 251 Bessey Hall, Ames, IA, 50011-1020, USA
2 - University Of Missouri, Biological Sciences, 311 Bond Life Sciences Center, Columbia, MO, 65211, USA

Keywords:
Poaceae
Grass
leaf anatomy
C4 photosynthesis
3D reconstruction.

Presentation Type: Oral Paper:Papers for Sections
Session: 13
Location: Pines South/Boise Centre
Date: Monday, July 28th, 2014
Time: 4:15 PM
Number: 13011
Abstract ID:630
Candidate for Awards:None