L'angolo dell’intervista: uno spazio per testimonianze di sofferenza, di speranza e di solidarietà

In questo numero, Luca Guglielminetti intervista Antonio Iosa a proposito de Il libro dell’incontro. Vittime e responsabili della lotta armata a confronto, curato da Guido Bertagna, Adolfo Ceretti e Claudia Mazzucato, pubblicato presso Il Saggiatore nel 2015

Physiological responses of C4 grasses to prolonged heat stress

C4 grasses are best adapted to the transition, warm-arid, and warm-humid climatic zones and have the ability to acquire thermotolerance by exposure to acute heat stress. Exposure to sub-lethal temperatures results in changes in physiological, biochemical, metabolic, and molecular processes. The response of two warm-season grasses to prolonged heat stress was investigated. Plants of hybrid bermudagrass (Cynodon dactylon × C. transvaalensis ‘Tifway’) and Japanese lawn grass (Zoysia japonica Steud. ‘Meyer’) were exposed for 168 h to supraoptimal temperature conditions (47°C) in controlled-environment chamber. Compared with zoysiagrass, bermudagrass showed greater damage. Metabolite profi les were affected by prolonged heat exposure, with signifi cant differences between these species. Consistent differences were found in total soluble sugars accumulation over the study period and severity of plant organ senescence. Bermudagrass roots were more affected, as compared to leaves. Leaf proteins expression determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis showed an early degradation in zoysiagrass, as thermal exposure proceeded. A signifi - cant net decline in protein content was observed after 48 h of exposure, while in bermudagrass an analogous decline was not detected until 96 h of treatment. Although heat stress is not considered a detrimental factor to C4 grass species, the two species showed signifi cant differences in their physiological response to continuous high temperatures

Fructan metabolism in tall fescue calli under different environmental condition

Several grasses usually accumulate high levels of fructans at low temperature or in the presence of high sugar supply. Fructans enhance plant resistance in adverse environmental conditions thanks to their vacuolar  localization which allow osmotic adjustments. Tall fescue calli do not show mature vacuoles due to its  anatomic characteristics, and these in vitro cultures can provide more knowledge about the fructan rule in  unspecialized tissues especially during stress conditions. The aim of this study was to evaluate the sugar  metabolism in embryogenic calli of tall fescue fed with different sucrose concentrations (0, 50 or 100 mM)  during growth culture, kept at “control” or “cold” temperatures (23 or 4°C, respectively). In the presence of  sucrose (50 or 100 mM), embryogenic calli accumulated fructans under control conditions. On the other hand,  the accumulation is inhibited by the simultaneously sugar supply and cold treatment while invertase activity  increased. From our data, cold temperature and high sucrose concentration seemed to be negatively  correlated in the fructans biosynthetic pathway in tall fescue in vitro cultures.Key words: Cold, Festuca arundinacea, invertase, sucrose:sucrose fructosyltransferase (SST), sugars

Almas (fragmento de 'Le vergini folli')

Amalia Guglielminetti was born in Turin in 1881. He had a religious school education, conditioned by the presence of his grandfather, who assumed the role of pater familias after the death of Amalia's father. His first book of poems was published in 1901, but it was considered too childish and simple. With the second, however, Le vergini folli (of which we have translated the first section, dedicated to souls), he achieved success and his verses, well structured and of great technical perfection, earned him the praise of her teacher, Arturo Graf, of the critic Dino Mantovani and of the poet Guido Gozzano, especially because of their spontaneity. However, she considered that she had barely touched the essence of art and considered that she should continue working to reach that state. Amalia Guglielminetti was a very prolific writer who dedicated herself not only to poetry, but also to theater (both comedy and tragedy) and narrative. After an attempt to become a journalist in Rome, he returned to Turin, where he died in 1941 because of an injury done when he was going down to an air raid shelter