Abstract
In terrestrial cyanobacteria, the cyanobacteria with very strong drought-tolerant ability exists. It is considered that there are three phases in the drought-tolerant mechanism. The first is the drying phase which initiates from outside of cells. The second is the desiccation phase which makes inside of the cells dry. The third is the recovery phase of cells when water comes again.
Comparison analysis of the gene expression of sigma factors in drying phase was carried out using an aquatic cyanobacterium, Anabaena PCC 7120 and a terrestrial cyanobacterium, Nostoc HK-01, a related species to Anabaena PCC 7120.
Anabaena PCC 7120 has putative 12 sigma factors in the genome sequence. Nostoc punctiforme and Anabaena variabilis also have these sigma factors mostly in common. Then, using the conserved regions in the ORFs of sigma factors of these cyanobacteria as primers, Reverse transcription-PCR was carried out in both Anabaena PCC 7120 and Nostoc HK-01.
