Mechanistic modelling of carbon partitioning

Abstract

Carbon partitioning between alternative sinks is the weak point of all plant growth models, being done using empirically based algorithms. While this approach is effective for simulations, it is unreliable for extrapolation to new conditions, and cannot provide mechanistic understanding of the processes involved. All long-distance carbohydrate transport and partitioning involves the phloem, hence partitioning must be a property of phloem physiology. However, no growth model utilizes the known phloem physiology. Relevant aspects of phloem physiology are discussed and used to produce a minimalist Münch-based flow model. This model provides a theoretical basis for an unambiguous definition of sink strength, with sink priority being an emergent property of the model. A method to extend this minimalist model is discussed.