Evolution of notions about relationships between photosynthesis and plant productivity

The concepts of photosynthesis role in the production process underwent evolution from the initial assumption of complete identity of these terms to the notion that photosynthesis is only a supplier of assimilates for sink organs. The following issues are discussed as individual stages of problem resolution: whether or not photosynthesis restricts productivity; what is the contribution of chlorophyll-containing non-leaf organs to the production process; what are the roles of photooxidation processes and source-sink relations between photosynthesizing organs and assimilate consumers; how the apoplast is involved in regulation of photosynthetic function of the whole plant; and what is the role of nitrate in control of photosynthesis and assimilate export from the leaf. Finally, the distribution of assimilates among the sink organs and the role of competition among the organs in regulation of photosynthesis and yield formation are considered.