Search

Carotenoids and phenylpropanoids play a dual role of limiting and countering photooxidative stress. We hypothesize that their "antioxidant" function is prominent in plants exposed to summer drought, when climatic conditions exacerbate the light stress. To test this, we conducted a field study on Phillyrea latifolia, a Mediterranean evergreen shrub, carrying out daily physiological and biochemical analyses in spring and summer. We also investigated the functional role of the major phenylpropanoids in different leaf tissues. Summer leaves underwent the most severe drought stress concomitantly with a reduction in radiation use efficiency upon being exposed to intense photooxidative stress, particularly during the central hours of the day. In parallel, a significant daily variation in both carotenoids and phenylpropanoids was observed. Our data suggest that the morning-to-midday increase in zeaxanthin derived from the hydroxylation of ß-carotene to sustain non-photochemical quenching and limit lipid peroxidation in thylakoid membranes. We observed substantial spring-to-summer and morning-to-midday increases in quercetin and luteolin derivatives, mostly in the leaf mesophyll. These findings highlight their importance as antioxidants, countering the drought-induced photooxidative stress. We concluded that seasonal and daily changes in photosynthetic and non-photosynthetic pigments may allow P. latifolia leaves to avoid irreversible photodamage and to cope successfully with the Mediterranean harsh climate.

Genetic structure may be highly variable across seabird species, and particularly among those that are distributed over large geographical areas. The Adélie penguin (Pygoscelis adeliae) is a numerically dominant Antarctic seabird that is considered to be a key species in coastal ecosystems. Since the Last Glacial Maximum, penguin colonization of the Antarctic coastline occurred at varying geographical and temporal scales, contributing to an incomplete understanding of how modern colonies relate to each other at local or regional scales. We assessed the population genetic structure of Adélie penguins (n = 86 individuals) from three adjacent colonies along the Victoria Land coast using molecular genetic markers (i.e. seven microsatellite loci isolated through next-generation sequencing). Our results indicate meta-population dynamics and possibly relationships with habitat quality. A generally low genetic diversity (Nei's index: 0.322-0.667) was observed within each colony, in contrast to significant genetic heterogeneity among colonies (pairwise FST = 0.071-0.148), indicating that populations were genetically structured. Accordingly, an assignment test correctly placed individuals within the respective colonies from which they were sampled. The presence of intercolony genetic differentiation contrasts with previous studies on this species that showed a lack of genetic structure, possibly due to higher juvenile or adult dispersal. Our sampled colonies were not panmictic and suggest a lower migration rate, which may reflect relatively stable environmental conditions in the Ross Sea compared to other regions of Antarctica, where the ocean climate is warming.

Agricultural sustainability is an increasing need considering the challenges posed by climate change and rapid human population growth. The use of plant growth-promoting rhizobacteria (PGPR) may represent an excellent, new agriculture practice to improve soil quality while promoting growth and yield of important crop species subjected to water stress conditions. In this study, two PGPR strains with 1-Aminocyclopropane-1-Carboxylate (ACC) deaminase activity were co-inoculated in velvet bean plants to verify the physiological, biochemical and molecular responses to progressive water stress. The results of our study show that the total biomass and the water use efficiency of inoculated plants were higher than uninoculated plants at the end of the water stress period. These positive effects may be derived from a lower root ACC content (? 45 %) in water-stressed inoculated plants than in uninoculated ones resulting in lower root ethylene emission. Furthermore, the ability of inoculated plants to maintain higher levels of both isoprene emission, a priming compound that may help to protect leaves from oxidative damage, and carbon assimilation during water stress progression may indicate the underlining metabolic processes conferring water stress tolerance. Overall, the experimental results show that coinoculation with ACC deaminase PGPR positively affects tolerance to water deficit, confirming the potential for biotechnological applications in water-stressed agricultural areas.

Arbuscular mycorrhizal (AM) fungi are root symbionts that provide mineral nutrients to the host plant in exchange for carbon compounds. AM fungi positively affect several aspects of plant life, improving nutrition and leading to a better growth, stress tolerance, and disease resistance and they interact with most crop plants such as cereals, horticultural species, and fruit trees. For this reason, they receive expanding attention for the potential use in sustainable and climate-smart agriculture context. Although several positive effects have been reported on photosynthetic traits in host plants, showing improved performances under abiotic stresses such as drought, salinity and extreme temperature, the involved mechanisms are still to be fully discovered. In this review, some controversy aspects related to AM symbiosis and photosynthesis performances will be discussed, with a specific focus on nitrogen acquisition-mediated by AM fungi.

The demand for pomegranate (Punica granatum L.) juices is increasing worldwide due to its documented healthpromoting effects which likely derive from phenolic compounds. This study reports the phenolic composition of the juices obtained from eight wildgrowing pomegranate accessions collected in eight areas of Azerbaijan, characterized by different climate and soil composition. The anthocyanins found in all the accessions were cyaniding derivatives and pelargonidin derivatives, while only two accessions contained also delphinidin3,5Odiglucoside. The main hydrolysable tannins contained in the juices were punicalagin and ellagic acid derivatives. These bioactive metabolites found in the juices varied qualitatively and quantitatively among the eight accessions, thus constituting specific traits for selecting promising accessions that can be used as a nutritious food source. The different phenolic profiles might be determined both by genotype and the growing environmental conditions, or by their interaction. Our results suggest that some of the studied wildgrowing pomegranate accessions might have a commercial value because of their richness in bioactive metabolites and might constitute a suitable source of genes for breeding programs.

Maquis species play a central role in the maintenance of coastal ecosystems thanks to anatomical, physiological and biochemical features evolved to cope with severe stress conditions. Because the seasonal and daily dynamics of physiological and biochemical traits of maquis species are not fully addressed, we performed a field study on three coexisting Mediterranean shrubs (Pistacia lentiscus L. and Phillyrea latifolia L., evergreen schlerophylls, and Cistus incanus L., semi-deciduous) aiming at detecting the main adaptive differences, on a seasonal and daily basis, in primary and secondary metabolism along with the principal climatic determinants. These species differed in their physiological and biochemical responses especially on a seasonal level. In P. latifolia, a great investment in antioxidant phenylpropanoids contributed to maintain high photosynthetic rates throughout the whole growing season. In C. incanus, high carotenoid content associated with chlorophyll (Chl) regulation alleviated oxidative damage during the hot and dry summers and help recover photosynthesis in autumn. In P. lentiscus, high abscisic acid levels allowed a strict control of stomata, while fine Chla/Chlb regulation concurred to avoid photoinhibition in summer. Temperature resulted the most important climatic factor controlling the physiological and biochemical status of these coexisting shrubs and, thus, in determining plant performances in this Mediterranean coastal habitat.

In patients with disorder of consciousness (DOC), awareness preservation is related to a better outcome prognosis (34). The dissociation of identified signs of awareness by laboratory assessment while undetected by bedside behavioural examination, is defined as cognitive motor dissociation (CMD) (1, 22-27). The rate of misdiagnosis is about 30% (18-21). Current researches emphasize enlarged bedside evaluation as it is easily administered and more economical (26). The Motor Behavioural Tool (MBT) had provided accurate insight into the content of consciousness, and had improved significantly the correlation with the outcome prediction during the acute stage, while the CRS-R sub-scores per se did not (1). We propose to further the exploration of supplementary motor behavioural signs by studying the predictability of the emergence defined by the CRS-R as well as the ability to detect CMD of the clinical items of three existing scales: The FOUR, the GCS and the NCS. We enrolled 35 patients with first CRS-R, MBT and the 3 aforementioned scales evaluation performed within 28 days post-injury. One evaluation of each scale was selected for every patient. The FOUR has 4 items, the GCS 3, and the NCS 4, that means 11 items, all rated with a sub-score which were the analysed variables. A first class of 8 group and 4 comparisons were made depending on the first and last CRS-R assessment, the latter defining the emergence: DOC patient emerging (1a) vs not emerged (1b), UWS (1c) and MCS (1e) emerging vs not emerged (1d) and (1f), and patients showing no CRS-R change (1g) vs those showing upper class of CRS-R (1h). A second class of 5 groups with 3 comparisons were made according to the MBT assessment at the admission and the last CRS-R evaluation : CMD patients (2a) vs true DOC (2b) at the entry in the unit, true DOC with DOC at last CRS-R (2c) vs CMD with emergence at last CRS-R (2e), and CMD with DOC at last CRS-R (2d) vs CMD with emergence at last CRS-R (2e). The statistical testing was based on a non-parametric Mann-Whitney U test to see whether there is a difference of sub-scores when comparing two groups for the same item. The p-value was > 0.05 for all comparisons; in other word, none item enables to predict the outcome defined by the last CRS-S classification or to make the CMD diagnosis according to the MBT. Moreover, 26% of CMD patients were classified as DOC on the last CRS-R which can be related to the rate of misdiagnosis found in the literature. Those findings address explicitly the issue of how performing the clinical evaluation to overcome this underestimation of the degree and level of consciousness, and how essential it is to develop and render more accurate the bedside evaluation of awareness.

The research project 'Moon Mapping' has been established in 2014 between the Italian and Chinese Governments to promote cooperation and exchange between undergraduate students from both countries. The operational phase of the project started in early 2015, and will end in 2017, for a total length of three years. The main aim is to train new scholars to be able to work on different kinds of remotely-sensed data collected over the Moon surface by the Chinese space missions Chang'E-1/2. The project coordination has been assigned to the Italian Space Agency for the Italian side and to the Center of Space Exploration, China Ministry of Education, for the Chinese side. Several Chinese universities and Italian national research institutes and universities have been officially involved in this project. Six main research topics have been identified: (1) map of the solar wind ion; (2) geomorphological map of the Moon; (3) data preprocessing of Chang'E-1 mission; (4) map of element distribution; (5) establishment of 3D digital visualization system; and (6) compilation and publication of a tutorial on joint lunar mapping.

The hypothesis was tested that isoprenoids and phenylpropanoids play a prominent role in countering photooxidative stress, following the depletion of antioxidant enzyme activity in plants exposed to severe drought stress under high solar irradiance and high temperatures. Platanus 9 acerifolia, a high isoprene-emitting species, was drought-stressed during summer (WS) and compared with unstressed controls (WW). Water relations and photosynthetic parameters were measured under mild, moderate, and severe drought stress conditions. Volatile and nonvolatile isoprenoids, antioxidant enzymes, and phenylpropanoids were measured with the same time course, but in four different periods of the day. Drought severely inhibited photosynthesis, whereas it did not markedly affect the photochemical machinery. Isoprene emission and zeaxanthin concentration were higher in WS than in WW leaves, particularly at mild and moderate stresses, and during the hottest hours of the day. The activities of catalase and ascorbate peroxidase steeply declined during the day, while the activity of guaiacol peroxidase and the concentration of quercetin increased during the day, peaking in the hottest hours in both WWand WS plants. Our experiment reveals a sequence of antioxidants that were used daily by plants to orchestrate defense against oxidative stress induced by drought and associated high light and high temperature. Secondary metabolites seem valuable complements of antioxidant enzymes to counter oxidative stress during the hottest daily hours.