# A perspective: some relationships between the biochemistry of photosynthesis and the gas exchange of leaves (Planta 153, 376–387)

## TL;DR

This paper explains how leaf gas exchange measurements can reveal key photosynthesis processes like Rubisco activity and electron transport.

## Contribution

The paper introduced A/Ci curves and equations for Ci calculation using a ternary diffusion model, now widely used in gas exchange systems.

## Key findings

- A/Ci curves effectively capture photosynthetic biochemistry and quantify Rubisco activity and electron transport in vivo.
- Equations derived for Ci calculation using a ternary diffusion model are now standard in portable gas exchange systems.
- The findings have had lasting influence on photosynthesis research and measurement techniques.

## Abstract

The Planta paper “Some relationships between the biochemistry of photosynthesis and the gas exchange of leaves” explored the relationship between gas exchange measurements of CO2 assimilation rate and the in vitro activity of Rubisco and chloroplast electron transport capacity. It showed that A/Ci curves, the response of CO2 assimilation rate, A, to intercellular CO2 partial pressure, Ci, were an ideal tool to capture the underlying photosynthetic biochemistry and could be used to quantify maximum Rubisco activity and electron transport capacity in vivo. We also derived the equations required to calculate Ci using a ternary diffusion model which are now used world-wide in portable gas exchange systems. Below we highlight the major findings reported in this paper and how they continue to influence current research.