A model of metabolizing sinks in plants

Abstract

The basic objectives of this study was to build a model that describes the physiology of sinks. This also includes the process of unloading assimilates from the phloem. The metabolic steps necessary to describe a typical sink were obtained from the literature. Several methods to mathematically describe these metabolic steps were found, but they were all either too slow or too simple. This necessitated the development of a new method to describe multiple enzyme systems. This method was developed and described using three Hypothetical enzyme systems. It was then applied to the metabolic steps of a sink to produce a generalized sink model. Detailed parametric analyses were run on each of the three hypothetical enzyme systems as well as the generalized sink model. Some general rules for enzyme kinetic behavior were formulated from the analysis of the hypothetical enzyme systems. These rules were found to hold for the generalized sink model. Estimates of the constants of the sink model were obtained from the literature. With these values, the model was applied to three different types of sinks: a growing root tip, a filling grain during milk stage and a filling grain during hard dough stage. With minor changes in the enzyme concentrations, the model amply described each of these types of sinks..