What is the fine-grained topic of the following text: The induction of the isiA (CP43') protein in iron-stressed cyanobacteriais accompanied by the formation of a ring of 18 CP43' proteinsaround the photosystem I (PSI) trimer and is thought to increasethe absorption cross section of PSI within the CP43'-PSI supercomplex.In contrast to these in vitro studies, our in vivo measurementsfailed to demonstrate any increase of the PSI absorption crosssection in two strains (Synechococcus sp. Only return the topic.
The effect of isiA (CP43') protein induction on photosystem I absorption in iron-stressed cyanobacteria.