In higher plants, in general, phytochromes together with other signaling molecules like, G- proteins, kinases, phosphatases, phosphatidyl inositol, cAMP, Ca2+ ions, 14-3-3 proteins constitute the local and long-range signal transduction pathways that regulate physiological and developmental processes.It has also been well established that, that in higher plants, inorganic nitrogen has crucial effects on growth and development, providing cellular components and modulating gene expression. Not only the nitrogen assimilatory genes but also substantial numbers of genes with other functions have been shown to be selectively regulated by the availability of nitrogen. Accumulating evidence suggests that nitrogen (nitrate) itself is the primary signal molecule triggering the activation of transcription of nitrate assimilation and related genes.
Although cyanobacteria constitute a significant part of our flora inhabiting vast stretches of oceans, rivers, ponds and lakes, little is known about how they are able to respond and environmental fluctuations. What are the mechanisms for perceiving the environmental and nutritional signals? Questions to be addressed in this project include, what are the signaling pathways/ signaling molecules involved in regulating cyanobacterial nitrogen/ carbon metabolism? Are there common/ similar signaling molecules involved in higher plants and cyanobacteria?