Abstract Detail

Systematics Section/ASPT

Gallaher, Timothy [1], Wysocki, William [2], Attigala, Lakshmi [3], Craine, Joe [4], Duvall, Mel [5], Clark, Lynn [6].

Chlorenchyma shape variation in the grasses.

There is substantial variation in the internal anatomy of grass leaves across the family suggesting that this variation may be adaptive. In the present study, we characterize adaxial chlorenchyma and outer bundle sheath cells in three dimensions and reconstruct the evolution of these characters over a new subtribal level grass plastome phylogeny. We also investigate the link between cell shape variation and environmental factors such as drought and frost tolerance and low and high light conditions. While most monocots have chlorenchyma which is spherical or elongated into a cylinder in the adaxial-abaxial plane, grass leaf chlorenchyma is elongated and characteristically lobed in the proximal-distal plane. This appears to represent the ancestral condition in the grasses and modifications of this shape occur throughout the family. The design of grass chlorenchyma allows for a wide variety of cell arrangements both within a single leaf and between species. Surface area/volume ratios, the volume and configuration of intercellular spaces and the distribution of chloroplasts within cells are altered by changes in the number, length and orientation of lobes. The variation is an inherited character with certain shapes distinguishing clades; however, environmental factors and changes between dominant photosynthetic pathways appear to override phylogenetic inertia resulting in convergence towards alternate shape configurations.

1 - Iowa State University, EEOB, 251 Bessey Hal, Iowa State University, Ames, IA, 50010, United States
2 - Nothern Illinois University, DeKalb, IL, 60115, USA
3 - Iowa State University, EEOB, Ames, IA, 50011, United States
4 - Kansas State University, Division of Biology, Manhattan, KS, 66502, USA
5 - Northern Illinois University, Department Of Biological Sciences, 1425 W Lincoln Hwy, Dekalb, IL, 60115-2861, USA
6 - Iowa State University, Department Of Ecology, Evolution, And Organismal Biology, 251 Bessey Hall, Ames, IA, 50011-1020, USA

Keywords:
poaceae
Cell shape
cell size
Cell Biology
Grass
Photosynthesis
Chlorenchyma
Bundle Sheath
plant functional trait
functional leaf traits.

Presentation Type: Oral Paper:Papers for Sections
Session: 50
Location: Salon 10/The Shaw Conference Centre
Date: Tuesday, July 28th, 2015
Time: 4:45 PM
Number: 50013
Abstract ID:1237
Candidate for Awards:None