3 research outputs found
Spirabat paululum iam. Una nuova congettura per un noto locus desperatus agostiniano
No full textThis short article is intended to contribute to the solution of a known locus desperatus of the Augustinian Confessions. The Author proposes that 8, 2, 3 should be read spirabat paululum iam instead of spirabat † popilios iam †. The conjecture is reminiscent of Catil. 61, 4 paululum etian spirans concerning Catilina’s death (Augustine remembers this famous Sallustian locus when he writes civ. 3, 27 vix paululum respirante civitate). Catilina’s death is a metaphor for the fall of Roman paganism, and for Marius Victorinus’s and Augustine's personal lives as well as their conversions. Ruggiero adds further evidence to Manlio Simonetti’s arguments as shown in the «Nota al Testo» (vol. I, 1992, pp. CLXIIICLXVIII) preceding his edition of Confessiones for the Italian collection “Lorenzo Valla”: common mistakes such as popilios iam were already in the edition’s manuscript.</jats:p
AtHD2D gene plays a role in plant growth, development and response to abiotic stresses in Arabidopsis thaliana
No full textAbstracts: The histone deacetylases play important roles in the regulation of gene expression and the subsequent control of a number of important biological processes, including those involved in the response to environmental stress. A specific group of histone deacetylase genes, HD2, is present in plants. In Arabidopsis, HD2s include HD2A, HD2B, HD2C and HD2D. Previous research showed that HD2A, HD2B and HD2C are more related in terms of expression and function, but not HD2D. In this report, we studied different aspects of AtHD2D in Arabidopsis with respect to plant response to drought and other abiotic stresses. Bioinformatics analysis indicates that HD2D is distantly related to other HD2 genes. Transient expression in Nicotiana benthamiana and stable expression in Arabidopsis of AtHD2D fused with gfp showed that AtHD2D was expressed in the nucleus. Overexpression of AtHD2D resulted in developmental changes including fewer main roots, more lateral roots, and a higher root:shoot ratio. Seed germination and plant flowering time were delayed in transgenic plants expressing AtHD2D, but these plants exhibited higher degrees of tolerance to abiotic stresses, including drought, salt and cold stresses. Physiological studies indicated that the malondialdehyde (MDA) content was high in wild-type plants but in plants overexpressing HD2D the MDA level increased slowly in response to stress conditions of drought, cold, and salt stress. Furthermore, electrolyte leakage in leaf cells of wild type plants increased but remained stable in transgenic plants. Our results indicate that AtHD2D is unique among HD2 genes and it plays a role in plant growth and development regulation and these changes can modulate plant stress responses
Expression and Functional Analysis of the Plant-Specific Histone Deacetylase HDT701 in Rice
No full textReversible histone acetylation and deacetylation at the N-terminus of histone tails play a crucial role in regulating eukaryotic gene activity. Acetylation of core histones is associated with gene activation, whereas deacetylation of histone is often correlated with gene repression. The level of histone acetylation is antagonistically catalyzed by histone acetyltransferases (HATs) and histone deacetylases (HDACs). In this work, we examined the subcellular localization, expression pattern and function of HDT701, a member of the plant-specific HD2-type histone deacetylase in rice. HDT701 is localized at the subcellular level in the nucleus. Histochemical GUS-staining analysis revealed that HDT701 is constitutively expressed throughout the life cycle of rice. Overexpression of HDT701 in rice decreases ABA, salt and osmotic stress resistance during seed germination. Delayed seed germination of HDT701 overexpression lines is associated with decreased histone H4 acetylation and down-regulated expression of GA biosynthetic genes. Moreover, overexpression of HDT701 in rice enhances salt and osmotic stress resistance during the seedling stage. Taken together, our findings suggested that HDT701 may play an important role in regulating seed germination in response to abiotic stresses in rice
