RESUMO
Cytosine DNA methylation is a conserved epigenetic regulatory mechanism in both plants and animals. DNA methyltransferases (DNA MTases) not only initiate (de novo) but also maintain the process of DNA methylation. Here, we characterized the genome-wide expression profiles of 10 cytosine DNA MTase genes belonging to 4 subfamilies, MET1, CMT, DNMT2, and DRM, in rice. Tissue-specific gene expression analysis showed that all family members varied widely in their expression and specificities and might be involved in some basic metabolic pathways. Similarly, the expression of all rice cytosine DNA MTase genes was not regulated by plant hormones except OsDRM1a and OsDRM1b, which were downregulated by jasmonic acid. The transcription level of 10 genes in rice shoots and roots was also measured under salt and osmotic stress. Meanwhile, quantitative polymerase chain reaction data of the japonica and indica rice cultivars revealed that there is large variation in the expression activities of all genes. The results provide a foundation to further explore the roles of DNA MTases and the epigenetic regulation of abiotic stress responses in rice.
Assuntos
DNA (Citosina-5-)-Metiltransferases/genética , DNA de Plantas/genética , Epigênese Genética , Regulação da Expressão Gênica de Plantas , Oryza/genética , Proteínas de Plantas/genética , Ciclopentanos/metabolismo , DNA (Citosina-5-)-Metiltransferases/metabolismo , Metilação de DNA , DNA de Plantas/metabolismo , Isoenzimas/genética , Isoenzimas/metabolismo , Oryza/classificação , Oryza/metabolismo , Pressão Osmótica , Oxilipinas/metabolismo , Filogenia , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Brotos de Planta/genética , Brotos de Planta/metabolismo , Salinidade , Estresse FisiológicoRESUMO
AIM: To study the influences of gomisin J on lipid peroxidation and calcium paradox. METHODS: Using two in vitro models of rat liver mitochondria membrane lipid peroxidation (LPO) and cultured myocardial cells. RESULTS: Gomisin J inhibited Fe2+/ascorbic acid and ADP/NADPH-induced LPO with IC50 (95% confidence limits) 5.5 (4.5-6.7) and 4.7 (2.8-7.8) mumol.L-1, respectively, when cultured myocardial cells preincubated with Ca(2+)-free medium for 2 min were incubated with normal medium containing Ca2+, a marked increase of malondialdehyde (MDA) formation occurred and gomisin J 10 mumol.L-1 protected myocardial cells through decreasing MDA formation. CONCLUSION: Gomisin J inhibits LPO in rat liver mitochondria and protects cultured myocardial cells from being injured by calcium paradox.