Nitrogen status and heat-stress-dependent differential expression of the cpn60 chaperonin gene influences thermotolerance in the cyanobacterium Anabaena

摘要: Heat stress caused rapid and severe inhibition of photosynthesis nitrate reduction in nitrate-supplemented cultures the cyanobacterium Anabaena sp. strain L-31, compared to nitrogen-fixing cultures. strains harbour two hsp60 family genes, groEL cpn60, respectively encoding 59 kDa GroEL 61 Cpn60 chaperonin proteins. Of these Hsp60 chaperonins, was strongly induced during heat stress, irrespective nitrogen status cultures, but rapidly repressed degraded heat-stressed or ammonium-supplemented The recovery photosynthesis, assimilation growth heat-stressed, were preceded by resynthesis restoration cellular levels. Glutamine synthetase activity, although adversely affected prolonged not dependent on either levels stress. Overexpression protein closely related PCC7120 conferred significant protection from growth, recombinant strain. data favour a role for carbon Anabaena.