|Mcgrath, Justin - UNIVERSITY OF ILLINOIS|
|Marshak, David - CORNELL UNIVERSITY|
Submitted to: American Society of Plant Biologists
Publication Type: Abstract Only
Publication Acceptance Date: April 1, 2006
Publication Date: August 5, 2006
Citation: Mcgrath, J.M., Marshak, D., Ainsworth, E.A. 2006. Temporal analysis of leaf growth under climate change scenarios [abstract]. American Society of Plant Biologists. Paper No. P02010. Technical Abstract: Many of the cellular and molecular mechanisms that control leaf growth and expansion have yet to be examined, even though this information would be valuable for predicting leaf area throughout growth and could potentially be used to maximize leaf area index, which could increase canopy productivity and increase carbon gain in ecosystems. Furthermore, the molecular interactions that control leaf growth responses have not been examined in predicted elevated [CO2] and [O3] environments. SoyFACE is a Free Air Concentration Enrichment facility which examines the impacts of these two rising greenhouse gases on soybeans. It offers a unique opportunity to analyze leaf growth data and to examine how mechanisms of leaf growth are altered by elevated [CO2] and [O3]. To assess how these gases affect leaf growth, during the 2005 growing season at SoyFACE, we measured final leaf area (FLA) of trifoliates 1 through 10 and the top (youngest) trifoliate as of August 1. We also measured the leaf area of trifoliates 2, 6, 9 and the top trifoliate from unfolding until full expansion. Treatments did not affect FLA of early trifoliates, but did affect later ones. CO2 and CO2 x O3 treatments increased FLA, whereas O3 decreased FLA. During early expansion in the 9th and top trifoliates, treatments had no effect, but did affect later stages. Interestingly, relative growth rates were not different between treatments. Treatments may cause differences in leaf primordia cell size and number, or may alter duration of growth, both of which may result in changes in FLA. Further experiments will investigate changes in cell kinematics, as well as correlate biotic and abiotic factors such as gene expression and diurnal entrainment in order to determine mechanisms which control leaf growth.