CNR Institute of Agro-environmental and Forest Biology
Porano, Italy
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Migliaccio F.,CNR Institute of Agro-environmental and Forest Biology | Tassone P.,CNR Institute of Agro-environmental and Forest Biology | Fortunati A.,Edmund Machinery Foundation
American Journal of Botany | Year: 2013

Although publications on circumnutation of the aerial parts of fl owering plants are numerous and primarily from the time between Darwin (1880) and the 1950s, reports on circumnutation of roots are scarce. With the introduction of modern molecular biology techniques, many topics in the plant sciences have been revitalized; among these is root circumnutation. The most important research in this area has been done on Arabidopsis thaliana, which has roots that behave differently from those of many other plants; roots grown on inclined agar dishes produce a pattern of half waves slanted to one side. When grown instead on horizontally set dishes, the roots grow in loops or in tight right-handed coils that are characterized by a tight torsion to the left-hand. The roots of the few plants that differ from Arabidopsis and have been similarly tested do not present such patterns, because even if they circumnutate generally in a helical pattern, they subsequently straighten. Research on plants in space or on a clinostat has allowed the testing of these roots in a habitat lacking gravity or simulating the lack. Recently, molecular geneticists have started to connect various root behaviors to specifi c groups of genes. For example, anomalies in auxin responses caused by some genes can be overcome by complementation with wild-type genes. Such important studies contribute to understanding the mechanisms of growth and elongation, processes that are only superfi cially understood. © 2013 Botanical Society of America.

Passatore L.,CNR Institute of Agro-environmental and Forest Biology | Passatore L.,University of Tuscia | Rossetti S.,CNR Water Research Institute | Juwarkar A.A.,Indian National Environmental Engineering Research Institute | Massacci A.,CNR Institute of Agro-environmental and Forest Biology
Journal of Hazardous Materials | Year: 2014

This review summarizes the bioremediation and phytoremediation technologies proposed so far to detoxify PCB-contaminated sites. A critical analysis about the potential and limits of the PCB pollution treatment strategies by means of plants, fungi and bacteria are elucidated, including the new insights emerged from recent studies on the rhizosphere potential and on the implementation of simultaneous aerobic and anaerobic biodegradation processes.The review describes the biodegradation and phytoremediation processes and elaborates on the environmental variables affecting contaminant degradation rates, summarizing the amendments recommended to enhance PCB degradation. Additionally, issues connected with PCB toxicology, actual field remediation strategies and economical evaluation are discussed. © 2014 Elsevier B.V.

Cammarano M.,CNR Institute of Agro-environmental and Forest Biology | Cammarano M.,University of Tuscia
Journal of Theoretical Biology | Year: 2011

Forests that are composed of two or more tree species with similar ecological strategies appear to contradict the competitive exclusion principle. Beech-maple communities are a well-known example of such a system. On a local scale, a number of mechanisms have been proposed to explain the coexistence of these two species. These are reciprocal replacement, external factors that favour alternatively one or the other species and demographic stochasticity. This paper presents and analyses a simple mathematical model that shows that external factors are not an essential requirement for coexistence. Rather, coexistence requires interspecific differences in light transmissivity through the crowns of adult trees. However, all the three mechanisms mentioned above can be interpreted within the framework of the model. Furthermore, many models of forest dynamics make use of shade tolerance as a key feature in describing successional dynamics. Despite its importance, however, shade tolerance does not have a commonly accepted quantitative definition. Here, a simple scheme is proposed where the relationship between shade tolerance, individual traits (growth and survival) and successional status is defined. This might have important implications in understanding the overall dynamics. Theoretical results have been compared with a number of studies carried out in North American forests. In particular, coexistence in beech-maple communities and the relation between shade tolerance and successional status in a beech-hemlock-birch community have been discussed. © 2011 Elsevier Ltd.

Lukac M.,Imperial College London | Calfapietra C.,CNR Institute of Agro-environmental and Forest Biology | Lagomarsino A.,University of Tuscia | Loreto F.,CNR Plant Protection Institute
Tree Physiology | Year: 2010

Although tree nutrition has not been the primary focus of large climate change experiments on trees, we are beginning to understand its links to elevated atmospheric CO2 and temperature changes. This review focuses on the major nutrients, namely N and P, and deals with the effects of climate change on the processes that alter their cycling and availability. Current knowledge regarding biotic and abiotic agents of weathering, mobilization and immobilization of these elements will be discussed. To date, controlled environment studies have identified possible effects of climate change on tree nutrition. Only some of these findings, however, were verified in ecosystem scale experiments. Moreover, to be able to predict future effects of climate change on tree nutrition at this scale, we need to progress from studying effects of single factors to analysing interactions between factors such as elevated CO2 temperature or water availability. © The Author 2010. Published by Oxford University Press. All rights reserved.

Guidolotti G.,CNR Institute of Agro-environmental and Forest Biology | Guidolotti G.,University of Tuscia | Calfapietra C.,CNR Institute of Agro-environmental and Forest Biology | Loreto F.,CNR Plant Protection Institute
Physiologia Plantarum | Year: 2011

Poplars (Populus sp.) are among the strongest isoprene (Iso)-emitting plants. Ten poplar genotypes belonging to four different species were grown under the same environmental conditions in a common garden experiment, to study the influence of the genetic variability on Iso emission and on the relationship between Iso and photosynthesis. Photosynthesis ranged from 13 to 20 μmol CO 2 m -2 s -1, whereas Iso emission ranged from 18.2 to 45.2 nmol m -2 s -1. There was no clear association between Iso emission and photosynthesis. In most genotypes, photosynthetic capacity developed earlier than Iso emission capacity. The emission of Iso was inversely correlated with the intercellular CO 2 concentration (C i) and positively correlated with instantaneous water use efficiency. It is speculated that, by regulating C i, stomatal opening also indirectly controls Iso emission in poplars. A positive linear correlation between the fraction of recently assimilated carbon emitted as Iso and Iso emission rate was found. The slope of this relationship indicated that each nanomole of Iso emitted requires a fixed fraction of photosynthetic carbon regardless of the intra- and interspecific variability in the Populus genus, and of leaf ontogeny. A comparison with data from recent studies showed that the slope of this relationship increases in drought-stressed leaves. However, this might be explained by an increasing contribution of carbon sources for Iso biosynthesis from stored photosynthates. If this is true, then the amount of carbon directly shunted from photosynthesis into Iso is constant in all poplars and is not influenced by abiotic stresses. © Physiologia Plantarum 2011.

Morani A.,CNR Institute of Agro-environmental and Forest Biology | Nowak D.J.,U.S. Department of Agriculture | Hirabayashi S.,U.S. Department of Agriculture | Calfapietra C.,CNR Institute of Agro-environmental and Forest Biology
Environmental Pollution | Year: 2011

Highest priority zones for tree planting within New York City were selected by using a planting priority index developed combining three main indicators: pollution concentration, population density and low canopy cover. This new tree population was projected through time to estimate potential air quality and carbon benefits. Those trees will likely remove more than 10 000 tons of air pollutants and a maximum of 1500 tons of carbon over the next 100 years given a 4% annual mortality rate. Cumulative carbon storage will be reduced through time as carbon loss through tree mortality outweighs carbon accumulation through tree growth. Model projections are strongly affected by mortality rate whose uncertainties limit estimations accuracy. Increasing mortality rate from 4 to 8% per year produce a significant decrease in the total pollution removal over a 100 year period from 11 000 tons to 3000 tons. © 2010 Elsevier Ltd. All rights reserved.

Kuzyakov Y.,University of Bayreuth | Gavrichkova O.,CNR Institute of Agro-environmental and Forest Biology
Global Change Biology | Year: 2010

CO2 efflux from soil depends on the availability of organic substances respired by roots and microorganisms. Therefore, photosynthetic activity supplying carbohydrates from leaves to roots and rhizosphere is a key driver of soil CO2. This fact has been overlooked in most soil CO2 studies because temperature variations are highly correlated with solar radiation and mask the direct effect of photosynthesis on substrate availability in soil. This review highlights the importance of photosynthesis for rhizosphere processes and evaluates the time lag between carbon (C) assimilation and CO2 release from soil. Mechanisms and processes contributing to the lag were evaluated. We compared the advantages and shortcomings of four main approaches used to estimate this time lag: (1) interruption of assimilate flow from leaves into the roots and rhizosphere, and analysis of the decrease of CO2 efflux from soil, (2) time series analysis (TSA) of CO2 fluxes from soil and photosynthesis proxies, (3) analysis of natural δ13C variation in CO2 with photosynthesis-related parameters or δ13C in the phloem and leaves, and (4) pulse labeling of plants in artificial 14CO2 or 13CO2 atmosphere with subsequent tracing of 14C or 13C in CO2 efflux from soil. We concluded that pulse labeling is the most advantageous approach. It allows clear evaluation not only of the time lag, but also of the label dynamics in soil CO2, and helps estimate the mean residence time of recently assimilated C in various above- and belowground C pools. The impossibility of tracing the phloem pressure-concentration waves by labeling approach may be overcome by its combination with approaches based on TSA of CO2 fluxes and its δ13C with photosynthesis proxies. Numerous studies showed that the time lag for grasses is about 12.5±7.5 (SD) h. The time lag for mature trees was much longer (4-5 days). Tree height slightly affected the lag, with increasing delay of 0.1daym-1. By evaluating bottle-neck processes responsible for the time lag, we conclude that, for trees, the transport of assimilates in phloem is the rate-limiting step. However, it was not possible to predict the lag based on the phloem transport rates reported in the literature. We conclude that studies of CO2 fluxes from soil, especially in ecosystems with a high contribution of root-derived CO2, should consider photosynthesis as one of the main drivers of C fluxes. This calls for incorporating photosynthesis in soil C turnover models. © 2010 Blackwell Publishing Ltd.

Iori V.,CNR Institute of Agro-environmental and Forest Biology | Pietrini F.,CNR Institute of Agro-environmental and Forest Biology | Zacchini M.,CNR Institute of Agro-environmental and Forest Biology
Journal of Hazardous Materials | Year: 2012

Release of pharmaceuticals in the environment has been emerging as a great concern for ecosystem and human health. Ibuprofen (IBU) represents one of the most widespread pharmaceuticals in surface waters and sediments in spite of the high removal rates occurring in conventional wastewater technologies. To assess the potentiality of phytoremediation in assisting these technologies, the screening of plant species for tolerance and removal ability of pollutants is a very important issue. In this study, the effects of different IBU concentrations on callus cultures of Populus nigra L., a pioneer tree species in the riparian ecosystem, were investigated. Results evidenced a notable tolerance of poplar cells to IBU, especially at high concentrations (IBU 30mgL-1), which even stimulated growth. At this concentration, the ability to withstand IBU was accompanied by inhibition of lipoxygenase (LOX) activity, reduction of lipid peroxide content and increase of membrane redox activity. Irrespective of initial IBU concentrations, a complete removal of this compound from the growth medium by poplar cells during a subculture occurred. Antioxidative enzyme activities and polyamine content were stimulated by IBU 0.03mgL-1, while no effect was found in cells exposed to IBU 30mgL-1, except for a decrease of guaiacol peroxidase (GPX) activity. These findings put in evidence a notable potential of this plant species for the phytoremediation of IBU-contaminated substrates. © 2012 Elsevier B.V.

Calfapietra C.,CNR Institute of Agro-environmental and Forest Biology
Environmental pollution (Barking, Essex : 1987) | Year: 2013

Biogenic Volatile Organic Compounds (BVOC) play a critical role in biosphere-atmosphere interactions and are key factors of the physical and chemical properties of the atmosphere and climate. However, few studies have been carried out at urban level to investigate the interactions between BVOC emissions and ozone (O3) concentration. The contribution of urban vegetation to the load of BVOCs in the air and the interactions between biogenic emissions and urban pollution, including the likely formation of O3, needs to be investigated, but also the effects of O3 on the biochemical reactions and physiological conditions leading to BVOC emissions are largely unknown. The effect of BVOC emission on the O3 uptake by the trees is further complicating the interactions BVOC-O3, thus making challenging the estimation of the calculation of BVOC effect on O3 concentration at urban level. Copyright © 2013 Elsevier Ltd. All rights reserved.

Iori V.,CNR Institute of Agro-environmental and Forest Biology | Zacchini M.,CNR Institute of Agro-environmental and Forest Biology | Pietrini F.,CNR Institute of Agro-environmental and Forest Biology
Journal of Hazardous Materials | Year: 2013

Ibuprofen (IBU) is one of the most widespread pharmaceuticals in the aquatic ecosystem, despite the high removal rate that occurs in wastewater treatment plants. Phytoremediation represents a technology to improve the performance of existing wastewater treatment. This study was conducted under hydroponics to evaluate the ability of Salicaceae plants to tolerate and reduce IBU concentration in contaminated water. To this end, we combined growth, physiological and biochemical data to study the effects of different IBU concentrations on two clones of Salix alba L. Data demonstrated that clone SS5 was more tolerant and showed a higher ability to reduce IBU concentration in the solution than clone SP3. The high tolerance to IBU shown by SS5 was likely due to several mechanisms including the capacity to maintain an elevated photosynthetic activity and an efficient antioxidative defence. These results illustrate the remarkable potential of willow to phytoremediate IBU-contaminated waters in natural and constructed wetlands. © 2013 Elsevier B.V.

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