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 für th. ose w. orking directly. on the mechanism. of phyt. ochr. ome acti. on t. o get t. ogether für 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 prüvide maj. or new insights int. o the phyt. ochrüme system and the integratiün üf m. olecular, genetic and bi. ochemica1 infürmati. on t.