Soundararajan, Madhavan , Nemecek, Branden , Sarath, Gautam .
13C labeling studies to trace carbon partitioning into cell wall structural carbohydrates in Switchgrass.
Much current research effort in the area of renewable energy production is focused on switchgrass (Panicum virgatum L.). In a previous study, in vitro dry matter digestibility (IVDMD) has been used as a selection criterion to improve its forage quality. Results from this study showed that the stem and sheath cell wall concentration did differ but stem hemicellulose and cellulose concentrations did not differ in their low IVDMD (C-1) and high IVDMD (C1,C2,C3) switchgrass populations. The lignin concentrations in the cell wall of the high IVDMD populations were however, significantly lower than the low IVDMD population. These observations tend to suggest that there is a differential carbon partitioning between the structural and non-structural carbohydrates in these low and high IVDMD populations as well. The purpose of this study is to follow the partitioning of carbon into the cell wall structural carbohydrates of Switchgrass plants at various stages of their growing period, using carbon isotope ratio mass spectrometry. Preliminary results from 13CO2 pulse labeling of greenhouse grown Switchgrass plants indicated an active partitioning of carbon in their stem (stover) tissue over a period of 6 weeks than either in the leaf or root tissue during the same growth period. Preliminary results stemming from the analyses of different cell wall fractions of both the lowland and upland varieties of switchgrass populations also indicated that carbon isotope ratio mass spectrometric procedures could provide a quantitative tool to assess partitioning of carbon into these fractions. Results from further analyses of carbon partitioning into hemicelluloses, celluloses and lignins from the stem tissues of plants exposed to labeled 13CO2 will be presented.
Log in to add this item to your schedule
1 - University of Nebraska, Biochemistry, N 253 Beadle Center, Lincoln, Nebraska, 68588-0664, USA
2 - Univgersity of Nebraska, Biochemistry
3 - University of Nebraska, USDA-ARS
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM