Movie 2

Movie 2. Screening for state transition mutants.

Leaves of the thale cress (Arabidopsis thaliana) were imaged by a camera that detects chlorophyll fluorescence. Fluorescence is initially high (seen as the red color), and falls after 6 min in the light (the movie is 10 times normal speed), as LHC II becomes phosphorylated and the chloroplasts undergo the transition to state 2. A far-red is then switched on, and fluorescence falls further, to rise slightly after a further 2 min, as the phosphate group is removed from phospho-LHC II, resulting in the transition to state 1. One plant, whose two leaves are seen near the center, behaves differently, and its fluorescence stays high.

Citation: J. F. Allen, H. L. Race, Will the real LHC II kinase please step forward? Science's STKE (2002),;2002/155/pe43.

This movie is viewable using QuickTime, which can be downloaded from Apple's QuickTime Site.