[Construction of an alr3504 defected mutant and its phenotype analysis in anabaena PCC7120]

C-di-GMP [Bis-(3',5')-cyclic dimeric guanosine monophosphate] is a novel global second messenger in bacteria. The diguanylate cyclase and phosphodiesterase involve in c-di-GMP synthesis and degradation, respectively. alr3504 in Anabaena PCC7120 possibly encodes diguanylate cyclase with a coserved GGDEF domain. [Objective] For functional characterization, [Methods] the deletion mutant of alr3504 was constructed by using marker exchange method. [Results]No significant differences were found in the cell morphology, growth rate or heterocyst development between the deletion mutant and the wild type strain. But the mutant was more sensitive to Na'-salt under salt-stress. [Conclusion] The results show that alr3504 did not affect heterocyst development directly, but involved in other signaling pathway, which lay a foundation for exploring the abundant and complex signal transduction of cyanobacteria.