Introduction to the themed issue on tetrapyrrole photoreceptors

This issue is a collection of papers presented at the “7th International Conference on Tetrapyrrole Photoreceptors in Photosynthetic Organisms” held in Kyoto from 9–14 December 2007. This was a continuation of the previous successful conference held in Lucerne, Switzerland, 2005, and was an extension of the scientific research on tetrapyrroles. In Kyoto, we discussed the basic processes of chlorophyll metabolism and bilin metabolism, primary processes of photosynthesis, and photodynamic therapy as an application of tetrapyrrole pigments to medicine. Many interesting topics were presented, and new areas for this field were identified.

Tetrapyrroles are key pigments for the global primary production of plant material with chlorophylls as the main pigments employed. Furthermore one of the open tetrapyrroles, phycobilin, is a light-energy acceptor of cyanobacteria, red algae and cryptophytes. Other open tetrapyrroles, such as phytochrome and other light-sensors, work in algae and plants as regulators of metabolic pathways, development of individuals, and adaptation to various light conditions. Research on these points are closely related to global primary production and may give fair and sound solutions to current global problems relating to food, energy, and the environment. Kyoto is the birthplace of the “Kyoto protocol” that is designed to prevent climate change and it was not a coincidence that this conference was held in this city.

Six authors were invited to submit review papers on the primary processes of photosynthesis, chlorophyll metabolism, bilin metabolism and processes in cyanobacteria. These perspectives described the current status of these scientific fields and it is hoped they will attract the interest of scientists both inside and outside this area of science.

I hope that many scientists in the field of photochemistry and photobiology enjoy all the papers in this themed issue.

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