[Effect of red light on activity of cAMP phosphodiesterases in photoperiodically different cereals and vernalized winter wheat].

Red light illumination of seedlings of photoperiodically different cereals had a different effect on the activity of multiple cyclic adenosine monophosphate phosphodiesterases. The response of all phosphodiesterase forms was reversed in fully vernalized winter wheat Triticum aestivum L.

[Effect of vernalization and red light illumination of seedlings of bread wheat (Triticum aestivum L.) on the temperature profile of the cAMP phosphodiesterase activity]. / Vliianie iarovizatsii i osveshcheniia prorostkov miagkoi pshenitsy Triticum aestivum L. krasnym svetom na khod temperaturnoi krivoi fosfodiésterazy tsAMF.

Phenotypic manifestations of Vrn (vernalization) and Ppd (photoperiodism) genes responsible for transition of bread wheat Triticum aestivum L. to generative growth (flowering) are mutually related. Since the mechanism of phytochrome-induced photoperiodism involves the enzymes of cyclic adenosine monophosphate metabolism and phosphodiesterase in particular, we tested involvement of phosphodiesterase in the process of winter wheat vernalization and formation of flowering competence in alternate wheat requiring a long day but no vernalization for the transition to flowering. We studied temperature dependence of phosphodiesterase activity in vernalized and unvernalized winter wheat on the one hand and in etiolated and red light illuminated seedlings of alternate wheat on the other hand. Short-term experiments demonstrated that vernalization and red light illumination are similar to long day by the effect on the long-day plants. Both influences induced a pronounced inversion of the temperature profile of phosphodiesterase activity in the 28-45 degrees C range. We propose that phosphodiesterase is involved in vernalization processes and can serve as a sensor of low temperature in winter wheat. Changed temperature profile is a radical control mechanism of phosphodiesterase activity in response to the influences (red light and vernalizing temperatures) responsible for competence of various bread wheat forms for generative growth.

[Plasmids of the cyanobacterium Synechocystis sp. 6803]. / Plazmidy tsianobakterii Synechocystis sp. 6803.

Three cryptic plasmids have been isolated from cyanobacterium Synechocystis sp. 6803::pSS2 (1.4 Md), pSS3 (36 Md), pSS4 (60 Md). Plasmid DNA was isolated in Cs-Cl-EB density gradient and analyzed by gel electrophoresis and electron microscopy by gel electrophoresis and electron microscopy techniques. The restriction map is constructed for plasmid pSS2 having the cleavage sites for Sau3a, HincII, HindIII, MspI restriction endonucleases. The plasmid may be used to construct the recombinant vector DNAs capable of autonomous replication in cyanobacterium Synechocystis sp. 6803. cells.