Monday, November 5, 2007 - 3:20 PM
62-5
Resource Allocation and Grass Leaf Growth.
Fernando Lattanzi, Melanie Wild, Christoph Lehmeier, Rudi Schäufele, and Hans Schnyder. Lehrstuhl für Grünlandlehre, Technische Universität München, D-85350 Freising-Weihenstephan, Germany
The growth zone of grass leaves is heterotrophic, and is therefore dependent on the import of assimilate from other plant parts. Assimilation of carbon (C) and nitrogen (N) is discontinuous and dynamic, whereas the demand of growth zones is much more continuous. It is thought that the imbalance between current assimilate production and consumption is buffered by (short- and long-term) storage pools, but the actual quantitative role of stores and their kinetic properties are not well known. Here we present results from experiments with Lolium perenne in which we have used steady state labelling with 13C and 15N, determination of the tracer kinetics in the C and N substrate imported into leaf growth zones, and compartmental modelling to assess the size, turnover and importance of different carbohydrate- and amino-C pools feeding leaf growth.