1,721,279 research outputs found
Disturbi della fotosintesi e della conduttanza stomatica in piante di grano cresciute in presenza di SO2
No full textEffetti fisiologici dell’esposizione delle piante ad aerosol salini addizionati di tensioattivi
No full textOzone effects on high light-induced photoinhibition in Phaseolus vulgaris
No full textIn this study the response to photoinhibition of photosynthesis and subsequent recovery was examined
in plants of Phaseolus vulgaris L. cultivar ‘Pinto’ exposed to charcoal-filtered air or to ozone (O3) at
150 nL L1 either for 3 h, or for 5 h. The responses were analysed using chlorophyll fluorescence imaging
and by conventional fluorometry. Compared to control plants maintained in charcoal-filtered air, in
plants exposed for 3 h to O3 and then subjected to high light treatment, the results show an increased
tolerance to photoinhibition. Plants exposed to the same O3 concentration but for the longer 5-h period,
were not tolerant to the photoinhibition treatment and, instead showed visible symptoms of damage
(chlorosis and necrosis) clearly attributable to the longer O3 exposure. Here the detrimental effects of O3
aggravated the effects of the high light photoinhibitory treatment. The leaves exposed to the shorter O3
treatment (150 nL L1 for 3 h) developed an ability to counteract the negative effects of a high light
exposure probably because the O3 had activated an antioxidant system able to protect the photosynthetic
machinery
I colori della salute
No full textGli Antociani sono sostanze che determinano la colorazione dal rosso al blu di fiori, frutti e foglie,
e possono contribuire alla prevenzione di malattie cronico-degenerativ
Labiateae species in Mediterranean environment: unrivaled sources of secondary metabolites
No full textThe Mediterranean basin represents a harsh environment
for plant species to inhabit due to the occurrence
of many environmental constrains including
high level of solar radiation, temperature, drought,
and salinity. In many instances these factors occur
simultaneously. Seasonal or even daily variation of
climatic conditions can also seriously threaten plant
survival. Under this combination of environmental
cues, plants have evolved a wide range of secondary
metabolites to contrast/counteract the detrimental
effects of these factors on plant’s physiological processes.
Besides their adaptative meaning in plants,
these compounds can also be useful for human applications
such as: antibiotics, antimycotic, animal nutrition,
cosmetics, food additives, biorepellents and
many others. In the last few years there has been a
substantial increment in the use of aromatic herbs and
their essential oils, hence increasing the prospective
for a profitable cultivation of these species. The
growing interest for aromatic species is mainly attributable
to the increasing body of scientific evidence,
which confirms the potentiality of their metabolites,
and supports the empiric uses that in the past was
made by folk medicine. Despite most of the herbs are
still collected from the wild, especially in developing
countries, many reports suggest that most of them can
be successfully cultivated as powerful biofarm species.
Aromatic species are particularly attractive
because they require low agronomical inputs and are
grown under sub-optimal environmental conditions,
since most secondary metabolites are usually synthetized
in response to stress factors. The knowledge of
the factors leading to maximize and standardize the
production of desired compounds is of crucial importance.
Indeed, albeit the progresses that have been
made on the chemical synthesis of organic compounds,
for some of them the extraction from plant
tissues is actually cheaper than their chemical synthesis,
and for other secondary metabolites the extraction
from plants is the only way to obtain the moiety,
being impossible (or still unknown) their chemical
synthesis. This article reviews the literature on the
effect of environmental as well as agronomical practice
that can affect the biosynthesis of secondary metabolites
in Labiateae members. This family is one of
the most representatives in Mediterranean area,
encompassing many herbs including lavender, mint,
oregano, rosemary, sage, summer savory, sweet basil,
and sweet marjorana. The review also includes the
potentiality of extracts, essential oils and other secondary
metabolites isolated from the aforementioned
Labiateae species. Further work is necessary to identify
the best agronomical techniques and the pedo-climatic
conditions that could increase the yield of
nutraceutical compounds, especially in this family of
plant that represents an urivaled source of secondary
metabolites
Non-invasive tools to estimate stress-induced changes in photosynthetic performance in plants inhabiting Mediterranean areas
No full textIn Mediterranean areas, plants are concomitantly exposed to various abiotic stresses such as light intensity, water deficit, extremes in air temperature, air pollutants, etc. These environmental pressures adversely affect plant development. Changes in photosystem activity are an early response of plants to abiotic stresses. Therefore, chlorophyll (Chl) fluorescence and gas exchange, two non-invasive, rapid and inexpensive techniques for measuring photosynthesis in leaves, have been widely used by plant ecophysiologists to analyse plant responses to stressful conditions. Chl a fluorescence and gas exchange parameters can be indeed used to evaluate changes in photochemical and non-photochemical processes in photosystems associated with electron transport, CO2 fixation, and heat dissipation.In this review, we focus our analysis on the effects of different abiotic stresses on the photochemistry of Mediterranean plants using Chl a fluorescence and gas exchange measurements. Since changes in photosynthetic parameters are observed in the absence of visual injuries, these methodologies constitute fundamental tools to predict and evaluate the extent to which abiotic stresses damage photosynthesis
Una fetta di benessere
No full textIl suo nome cambia nelle varie zone d’Italia (al centro Cocomero, Mellone d’acqua al sud e Anguria al nord), tuttavia non cambiano invece le sue incredibili proprietà, soprattutto antiossidanti, che lo
rendono uno dei frutti più salutari per il periodo estivo. Nell'articolo vengono riportati contenuti dei principi nutritivi e delle molecole chiave che fanno questo frutto un'enorme fonte di benessere
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