Bisphenol A (BPA) is used in manufacturing plastics. Even though BPA is reported to produce reproductive and behavioral toxicity in experimental animals, the direct effect of BPA on the cardiovascular system is not known. The present study was therefore undertaken to evaluate the effect of BPA, on spontaneously beating rat right atrial preparations. In this study, in vitro isometric contractions of right atria were recorded. Cumulative concentration-response of BPA on atrial contractions was obtained in the absence or presence of antagonists. BPA (0.1-100 μ m) decreased the rate and the force of atrial contractions in a concentration-dependent manner. At 100 μ m, the decreases were >90%. The BPA-induced changes were not blocked by atropine (muscarinic receptor blocker). However, pretreatment with N-ω-nitro-L-arginine methyl ester (L-NAME, a nitric oxide synthase inhibitor) or methylene blue (a guanylyl cyclase inhibitor) blocked the BPA-induced changes in rate and force. Nitroglycerine, an NO-donor, decreased the rate and force of atrial contractions. Further, the BPA-induced changes were not due to the solvent (ethanol) used to dissolve it. The present study therefore indicates that BPA decreases the atrial contractility involving NO-dependent G-cyclase signaling mechanisms.

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WRKY, a plant-specific transcription factor family, has important roles in pathogen defense, abiotic cues and phytohormone signaling, yet little is known about their roles and molecular mechanism of function in response to rust diseases in wheat. We identified 100 TaWRKY sequences using wheat Expressed Sequence Tag database of which 22 WRKY sequences were novel. Identified proteins were characterized based on their zinc finger motifs and phylogenetic analysis clustered them into six clades consisting of class IIc and class III WRKY proteins. Functional annotation revealed major functions in metabolic and cellular processes in control plants; whereas response to stimuli, signaling and defense in pathogen inoculated plants, their major molecular function being binding to DNA. Tag-based expression analysis of the identified genes revealed differential expression between mock and Puccinia triticina inoculated wheat near isogenic lines. Gene expression was also performed with six rust-related microarray experiments at Gene Expression Omnibus database. TaWRKY10, 15, 17 and 56 were common in both tag-based and microarray-based differential expression analysis and could be representing rust specific WRKY genes. The obtained results will bestow insight into the functional characterization of WRKY transcription factors responsive to leaf rust pathogenesis that can be used as candidate genes in molecular breeding programs to improve biotic stress tolerance in wheat.