Internati. onal meetings dev. oted exclusively t. o phytochr. ome are relatively infrequent. The Advanced Research W. orksh. op . on Phyt. ochr. ome Properties and Bi. ol. ogical Acti. on held in July 1990 at Bish. op Otter C. ollege in Chichester, an . old English cathedral t. own situated between the s. outh d. owns and the sea, provided a rare . opportunity fur th. ose w. orking directly . on the mechanism . of phyt. ochr. ome acti. on t. o get t. ogether fur a focused and intensive peri. od . of discussi. on . on the subject. The number . of delegates was limited t. o fifty but c. ontained representatives from alm. ost all the maj. or lab. orat. ories engaged in this area . of science. In a five day meeting there were twenty invited lectures, f. our round tables and three p. oster sessi. ons which all. owed all delegates t. o present and discuss their w. ork. The purp. ose . of the meeting was t. o review, in depth, the current -state . of kn. owledge c. oncerning the properties . of the plant ph. otorecept. or, phyt. ochr. ome, in relati. on t. o its mechanism . of bi. ol. ogical acti. on. The central themes . of the meeting were the applicati. on . of m. olecular bi. ol. ogy t. o pruvide maj. or new insights int. o the phyt. ochrume system and the integratiun uf m. olecular, genetic and bi. ochemica1 infurmati. on t.