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Papers by piera bonatti

$Research paper thumbnail of Sensibilit\ue0 allo stress ossidativo indotto da ozono e meccanismi di detossificazione in due linee cellulari di Vitis vinifera in coltura$

Two wheat cultivars, Mec, sensitive and Chiarano, more tolerant, were used to evaluate the ultras... more Two wheat cultivars, Mec, sensitive and Chiarano, more tolerant, were used to evaluate the ultrastructural response to long-term, non marking exposures to low SO2 concentration (30, 60, 90 ppb). Significant chloroplast alterations, although discontinuously distribuited, occurr in Mec at all SO2 levels tested; end granal membranes swell and burst, suggesting SO2-induced acidification of the thylacoid lumen. The more tolerant Chiarano displays similar modifications only as a consequence of a 90 ppb SO2 exposure. The number but not the fine structure of affected chloroplasts varies significatively in relation to SO2 levels and leaf age. Such alterations problably modify the balance between PSII/PSI efficienc

Le piante e l'inquinamento dell'aria: aspetti biologici ed economici, 1994

Physiological and Molecular Plant Pathology, 1994

A localized but highly protective effect of rust infection towards injury induced by the air poll... more A localized but highly protective effect of rust infection towards injury induced by the air pollutants ozone and sulphur dioxide, either alone or in mixture and the herbicide paraquat was found. The effect was proportional to inoculum density, was non-translocatable, and dependent on temperature. Protection continued even after the infection was no longer active, and was induced by different strains of the fungus in cultivars of both broad bean and pea. Protection was not due to the exclusion of pollutants resulting from stomata1 closure.. Histopathological investigations indicated that the effect was present in uncolonized tissues adjacent to the site of infection. Ultrastructural studies showed normal cell structure in the green islands surrounding the infection centres, even when nearby regions had collapsed. Peroxidase activity was increased rapidly in the infected tissues both in the colonized and in the adjacent non-colonized cells. Such activity was not detectable at significant levels in non-parasitized tissues. The results are discussed in connection with the possible mechanisms involved.

Giornale botanico italiano, 1976

... germogliazione PIERA hlEDEGIINI-BONATTI e MARIA DOhlENICA RONETTA CONTE Istituto Botanic0 de... more ... germogliazione PIERA hlEDEGIINI-BONATTI e MARIA DOhlENICA RONETTA CONTE Istituto Botanic0 dell'universiti di hlodena ... magnograni. L'aspetto gcnerale & simile a quello ossewato in cellule di foglioline di Piceu excefsu nello stesso stadio. ...

Journal of Plant Research, 2006

Self-pollination conditions have been recorded frequently in local populations of the genus Epipa... more Self-pollination conditions have been recorded frequently in local populations of the genus Epipactis, and structural modifications have sometimes been reported, supporting taxonomic recognition of new species. As part of a survey of gynostemium micromorphology of Italian Epipactis populations, we studied an Apennine population of Epipactis microphylla (Ehrh.) Sw. a species listed as autogamous but with residual allogamous characters. In this population we observed the tendency to perform pre-anthesis cleistogamy. However, self-pollination was not a consequence of modification in column morphology. Cryptic pollen germination occurred in anther thecae or in the clinandrium, bypassing any contact with the receptive stigma. Pollen germination started from the distal pool of the pollinium, close to the rostellum-viscidium, suggesting that the rostellum-viscidium may have a function in promoting pollen-tube growth. Germinated pollen was exposed at the anthesis.

Journal of Plant Physiology, 1999

Plant sensitivity to owne toxicity is influenced by leaf architecture and micromorphology, tissue... more Plant sensitivity to owne toxicity is influenced by leaf architecture and micromorphology, tissue age and physiological conditions; however, it strongly depends on the efficiency of detoxifying systems operating at the cellular level.

Journal of Phytopathology, 1993

Ultrastructural observations were carried out in bean leaf tissue infiltrated with bacterial extr... more Ultrastructural observations were carried out in bean leaf tissue infiltrated with bacterial extracellular polysaccharides. These investigations revealed changes m the cell fine structure, especially related with chloroplast organization. Up to 24 h after EPS infiltration alterations consisted in irregularly running thylakoids and distortions of stacked regions. Invaginations of the plastid envelope and appearance of cytoplasm pockets inside the stroma were also noted. The most severe alterations, consisting in stroma dilations and envelope infoldings, were noted 24 h after EPS infiltration, parallehng the yellowing of the treated leaf areas; chloroplast shrinkage and collapse of thylakoid system were also sometimes observed. Chloroplast ultrastructure generally recovered 48 h after treatment; at this time local detachment of the plasma membrane and vesicle formation in the periplasmic space were observed, resembling a non specific, locahzed cellular response. The observed, permanent chlorosis and ultrastructural alterations suggest an interference of the EPS in the global metabolism of the bean mesophyll cell.

Journal of Industrial Hemp, 2005

ABSTRACT This paper reports the preliminary results of a microscopic study carried out on stem cr... more ABSTRACT This paper reports the preliminary results of a microscopic study carried out on stem cross sections of hemp. Stems were harvested from two field experiments carried out in 2001 and 2002 in the north of Italy to compare the monoecious genotype Futura 75 over four plant populations. Fibre characteristics such as cell shape, diameter, maturation and quantity of secondary fibre tended to vary with harvest time, plant density, and between and within internodes. After the end of internode elongation, fibre cells changed from oblong to round shaped and fibre maturation started and progressed to a maximum level. At various moments of the growing cycle, fibre maturity and presence of secondary fibre seemed higher at lower internodes and plant densities.

Euphytica, 2004

The composition and supramolecular structure of hemp primary bast fibres have been assessed using... more The composition and supramolecular structure of hemp primary bast fibres have been assessed using microscopy, compositional analysis, wide-angle X-ray diffractometry and CP-MAS 13 C-NMR, in order to unambiguously define some quality parameters. The main components of the fibre wall were detected by histochemical reactions and modifications occurring during the plant growth have been pointed out. Some differences in fibre lignification degree were recorded among cultivars and confirmed by means of compositional and structural analysis. As for flax and kenaf, X-ray patterns revealed semicrystalline structure of hemp cellulose. NMR spectra and their probabilistic elaboration by MaxEnt method gave further insight on the presence of paracrystalline and amorphous phases and provided an accurate evaluation of polymeric components.

Annals of microbiology, 2003

Abstract-Mitochondrial transmission to the progeny of interspecific hybrids, resulting from cross... more Abstract-Mitochondrial transmission to the progeny of interspecific hybrids, resulting from crosses between strains of Saccharomyces cerevisiae and Saccharomyces uvarum, was investigated. RFLP analysis of the entire mtDNA showed that progeny of these hybrids has mitochondria from only one of the parental strains. On the other hand, the mitochondrial proteins resulted from the recombination between the genomes of the two parental strains. It was assumed that proteins play an important role in the process of mitochondrial ...

Journal of Applied Microbiology, 2010

Aims: To study the effect of selected bacterial strains on hemp water-retting and properties of r... more Aims: To study the effect of selected bacterial strains on hemp water-retting and properties of retted fibre. Methods and Results: The trials were performed in laboratory tanks. The traditional water-retting process, without inoculum addition, was compared to a process modified by inoculating water tanks with two selected pectinolytic bacteria: the anaerobic strain Clostridium sp. L1 ⁄ 6 and the aerobic strain Bacillus sp. ROO40B. Six different incubation times were compared. Half the fibre obtained from each tank was combed. Micromorphological analyses were performed by scanning electron microscopy on uncombed and combed fibres. Moreover, organoleptic and chemical analyses of uncombed fibres were performed. Conclusions: The inoculum, besides speeding up the process, significantly improved the fibre quality. The fibre was not damaged by mechanical hackling, thanks to the good retting level obtained by the addition of selected strains, differently to what happened with the traditionally retted fibre. The best fibre quality was obtained after 3-4 days of retting with the addition of the bacterial inoculum. Significance and Impact of the Study: Retting is the major limitation to an efficient production of high-quality hemp fibres. The water-retting process and fibre quality were substantially improved by simultaneously inoculating water tanks with two selected pectinolytic strains.

With the aim to examine its potential as a renewable resource to decontaminate polluted soils, el... more With the aim to examine its potential as a renewable resource to decontaminate polluted soils, electron microscopy combined with X-ray microanalysis was used to investigate the localization of copper in Cannabis sativa grown in hydroponic copper-rich culture. Cu was found to accumulate preferentially in the upper leaf epidermal cells; it was also detected in spiculae and in abaxial trichomes too. Primary bast fibres seem to be not involved in copper accumulation.