Abstract Detail



Ecology

Das, Aayudh [1], Preston, Jill [2].

Understanding how Pooideae stress adaptations explain climatic distributions.

Future climate projections predict increased aridity (drought) and seasonal temperature extremes that will likely affect the distribution of plants. Like grasses in general, members of subfamily Pooideae – containing important crops such as wheat, oats, and barley – can be found across a range of aridity zones as well in areas where they are regularly exposed to cold, subzero temperatures. Phylogenetic history indicates that like aridification, the major cooling event that gave rise to the expansion of the modern temperate-continental-boreal zones, occurred at the Eocene-Oligocene boundary approximately 34 million years ago (mya), around the time when the major Pooideae tribes were diversifying. We hypothesized that that cold adaptation may have predated drought adaptation because ancestors of all major lineages of Pooideae have originated in a temperate microniche. To test my hypothesis, we included Pooideae tribes (Meliceae, Stipeae,  and Brachypodieae) that span in the period of time where this aridification and cooling was occurring and analyzed different types of physiological traits and fitness traits to measure stress resistance. Our analysis shows an overlap between the tribes for cold stress and unique response between the tribes for drought which justifies. This indicates that it is possible that cold might have evolved much earlier in the pooideae ancestors even before the E-O boundary with aridification and global cooling. We further tested whether all these physiological traits drive the same pattern and found that various key traits drive the distribution with some exceptions. Moreover, we tested whether climate distributions are driven by stress resistance and found that grasses from highly arid areas are capable to tolerate drought better and grasses from coldest climate space are capable to adapt with cold stress.


1 - University Of Veromnt, Plant Biology, 63 Carrigan Drive, 111 Jeffords Hall, Burlington, VT, 05405, United States
2 - University Of Vermont, Department Of Plant Biology, 111 Jeffords Hall, 63 Carrigan Drive, Burlington, VT, 05405, United States

Keywords:
Grasses
drought tolerance
Abiotic stress.

Presentation Type: Oral Paper
Number: ECO2002
Abstract ID:824
Candidate for Awards:Ecological Section Best Graduate Student Paper


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