Dehydration and rehydration differently affect photosynthesis and volatile monoterpenes in bryophytes with contrasting ecological traits.

Bryophytes desiccate rapidly when relative humidity decreases. The capacity to withstand dehydration depends on several ecological and physiological factors. Volatile organic compounds (VOCs) may have a role in enhancing tolerance to desiccating bryophytes.

Ep2.2 inhibits growth of through the emission of volatile organic compounds, restricts leaf infection and primes defense genes.

The bacterium is known to be beneficial for plants and has been frequently isolated from the rhizosphere of crops. In the present work, we isolated from the phyllosphere of an ornamental plant an epiphytic strain of that we named Ep2.2 and investigated its possible application in crop protection.

Impact of High Light Intensity and Low Temperature on the Growth and Phenylpropanoid Profile of .

Exposure to high light intensity (HL) and cold treatment (CT) induces reddish pigmentation in , an aquatic fern. Nevertheless, how these conditions, alone or in combination, influence growth and pigment synthesis remains to be fully elucidated. Likewise, the regulatory network underpinning the accumulation of flavonoids in ferns is still unclear.

Real-time air concentrations and turbulent fluxes of volatile organic compounds (VOCs) over historic closed landfills to assess their potential environmental impact.

For the first time, emission/deposition fluxes of volatile organic compounds (VOCs) and HS from a historic closed landfill site in Southern Italy were determined by Eddy Covariance (EC) using Proton Transfer Reaction Time-of-Flight Mass Spectrometry (PTR-TOF-MS). This was done in two field campaigns of one week performed in July and October 2016, where fluxes of CO and CH were also measured. Many compounds not previously identified in the biogas were detected by PTR-TOF-MS, but only in July some of them produced positive fluxes exceeding the flux limit of detection.

Root Exposure to 5-Aminolevulinic Acid (ALA) Affects Leaf Element Accumulation, Isoprene Emission, Phytohormonal Balance, and Photosynthesis of Salt-Stressed .

has been recognized as a promising crop for biomass production on marginal lands due to its superior productivity and stress tolerance. However, salt stress negatively impacts growth and photosynthesis. In this study, we tested whether the tolerance of to salinity stress can be enhanced by the addition of 5-aminolevulinic acid (ALA), a known promoter of plant growth and abiotic stress tolerance.

Exposure to different light intensities affects emission of volatiles and accumulations of both pigments and phenolics in Azolla filiculoides.

Many agronomic trials demonstrated the nitrogen-fixing ability of the ferns Azolla spp. and its obligate cyanobiont Trichormus azollae. In this study, we have screened the emission of volatile organic compounds (VOCs) and analyzed pigments (chlorophylls, carotenoids) as well as phenolic compounds in Azolla filiculoides-T.

Real-time monitoring of Arundo donax response to saline stress through the application of in vivo sensing technology.

One of the main impacts of climate change on agriculture production is the dramatic increase of saline (Na) content in substrate, that will impair crop performance and productivity. Here we demonstrate how the application of smart technologies such as an in vivo sensor, termed bioristor, allows to continuously monitor in real-time the dynamic changes of ion concentration in the sap of Arundo donax L. (common name giant reed or giant cane), when exposed to a progressive salinity stress.

Ozone impairs the response of isoprene emission to foliar nitrogen and phosphorus in poplar.

Tropospheric ozone (O) impairs physiological processes of plants while nitrogen (N) deposition may cause imbalances in soil N and other nutrients such as phosphorus (P) suggesting an increase of P demand for plants. However, the combined effect of O, soil N and P on isoprene emission from leaves has never been tested. We therefore examined isoprene emission in leaves of Oxford poplar clone exposed to O (ambient, AA [35.

Arbuscular Mycorrhizal Symbiosis Primes Tolerance to Cucumber Mosaic Virus in Tomato.

Tomato plants can establish symbiotic interactions with arbuscular mycorrhizal fungi (AMF) able to promote plant nutrition and prime systemic plant defenses against pathogens attack; the mechanism involved is known as mycorrhiza-induced resistance (MIR). However, studies on the effect of AMF on viral infection, still limited and not conclusive, indicate that AMF colonization may have a detrimental effect on plant defenses against viruses, so that the term "mycorrhiza-induced susceptibility" (MIS) has been proposed for these cases. To expand the case studies to a not yet tested viral family, that is, Bromoviridae, we investigated the effect of the colonization by the AMF on cucumber mosaic virus (CMV) infection in tomato by phenotypic, physiological, biochemical, and transcriptional analyses.

Impact of spontaneous mutations on physiological traits and biocontrol activity of Pseudomonas chlororaphis M71.

Three morphological mutants (M71a, M71b, M71c) of the antagonist Pseudomonas chlororaphis M71, naturally arose during a biocontrol trial against the phytopathogenic fungus Fusarium oxysporum f.sp. radicis-lycopersisci.

The excess of phosphorus in soil reduces physiological performances over time but enhances prompt recovery of salt-stressed Arundo donax plants.

Arundo donax L. is an invasive grass species with high tolerance to a wide range of environmental stresses. The response of potted A.

Impact of high or low levels of phosphorus and high sodium in soils on productivity and stress tolerance of Arundo donax plants.

The potential of Arundo donax to grow in degraded soils, characterized by excess of salinity (Na+), and phosphorus deficiency (-P) or excess (+P) also coupled with salinity (+NaP), was investigated by combining in vivo plant phenotyping, quantification of metabolites and ultrastructural imaging of leaves with a transcriptome-wide screening. Photosynthesis and growth were impaired by + Na, -P and + NaP. While + Na caused stomatal closure, enhanced biosynthesis of carotenoids, sucrose and isoprene and impaired anatomy of cell walls, +P negatively affected starch production and isoprene emission, and damaged chloroplasts.

Exploiting Plant Volatile Organic Compounds (VOCs) in Agriculture to Improve Sustainable Defense Strategies and Productivity of Crops.

There is an urgent need for new sustainable solutions to support agriculture in facing current environmental challenges. In particular, intensification of productivity and food security needs require sustainable exploitation of natural resources and metabolites. Here, we bring the attention to the agronomic potential of volatile organic compounds (VOCs) emitted from leaves, as a natural and eco-friendly solution to defend plants from stresses and to enhance crop production.

Root colonization by Pseudomonas chlororaphis primes tomato (Lycopersicum esculentum) plants for enhanced tolerance to water stress.

Previous research demonstrated that Pseudomonas chlororaphis subsp. aureofaciens strain M71, a plant growth promoting bacterium (PGPB), exerts beneficial effects on plant metabolism and primes tolerance mechanisms against biotic stresses in tomatoes. We designed an experiment to assess whether root colonization with P.

Plants for Sustainable Improvement of Indoor Air Quality.

Indoor pollution poses a serious threat to human health. Plants represent a sustainable but underexploited solution to enhance indoor air quality. However, the current selection of plants suitable for indoors fails to consider the physiological processes and mechanisms involved in phytoremediation.

Interaction between isoprene and ozone fluxes in a poplar plantation and its impact on air quality at the European level.

The emission of isoprene and other biogenic volatile organic compounds from vegetation plays an important role in tropospheric ozone (O3) formation. The potentially large expansion of isoprene emitting species (e.g.

Rapid leaf development drives the seasonal pattern of volatile organic compound (VOC) fluxes in a 'coppiced' bioenergy poplar plantation.

Leaves of fast-growing, woody bioenergy crops often emit volatile organic compounds (VOC). Some reactive VOC (especially isoprene) play a key role in climate forcing and may negatively affect local air quality. We monitored the seasonal exchange of VOC using the eddy covariance technique in a 'coppiced' poplar plantation.

Bidirectional Flux of Methyl Vinyl Ketone and Methacrolein in Trees with Different Isoprenoid Emission under Realistic Ambient Concentrations.

Methyl vinyl ketone (MVK) and methacrolein (MAC) are key oxidation products (iox) of isoprene, the most abundant volatile organic compound (VOC) emitted by vascular plants in the atmosphere. Increasing attention has been dedicated to iox, as they are involved in the photochemical cycles ultimately leading to ozone (O3) and particle formation. However, the capacity of plants to exchange iox under low and realistic ambient concentrations of iox needs to be assessed.

Ultradian variation of isoprene emission, photosynthesis, mesophyll conductance, and optimum temperature sensitivity for isoprene emission in water-stressed Eucalyptus citriodora saplings.

Water availability is a major limiting factor on plant growth and productivity. Considering that Eucalyptus spp. are among the few plant species able to produce both isoprene and monoterpenes, experiments were designed to investigate the response of isoprene emission and isoprenoid concentrations in Eucalyptus citriodora saplings exposed to decreasing fraction of transpirable soil water (FTSW).

Qualitative and quantitative characterization of volatile organic compound emissions from cut grass.

Mechanical wounding of plants triggers the release of a blend of reactive biogenic volatile organic compounds (BVOCs). During and after mowing and harvesting of managed grasslands, significant BVOC emissions have the potential to alter the physical and chemical properties of the atmosphere and lead to ozone and aerosol formation with consequences for regional air quality. We show that the amount and composition of BVOCs emitted per unit dry weight of plant material is comparable between laboratory enclosure measurements of artificially severed grassland plant species and in situ ecosystem-scale flux measurements above a temperate mountain grassland during and after periodic mowing and harvesting.

Leaf and ecosystem response to soil water availability in mountain grasslands.

Climate change is expected to affect the Alps by increasing the frequency and intensity of summer drought events with negative impacts on ecosystem water resources. The response of CO and HO exchange of a mountain grassland to natural fluctuations of soil water content was evaluated during 2001-2009. In addition, the physiological performance of individual mountain forb and graminoid plant species under progressive soil water shortage was explored in a laboratory drought experiment.

Carbonyl sulfide (COS) as a tracer for canopy photosynthesis, transpiration and stomatal conductance: potential and limitations.

The theoretical basis for the link between the leaf exchange of carbonyl sulfide (COS), carbon dioxide (CO(2)) and water vapour (H(2)O) and the assumptions that need to be made in order to use COS as a tracer for canopy net photosynthesis, transpiration and stomatal conductance, are reviewed. The ratios of COS to CO(2) and H(2)O deposition velocities used to this end are shown to vary with the ratio of the internal to ambient CO(2) and H(2)O mole fractions and the relative limitations by boundary layer, stomatal and internal conductance for COS. It is suggested that these deposition velocity ratios exhibit considerable variability, a finding that challenges current parameterizations, which treat these as vegetation-specific constants.

Comparative study of transcriptional and physiological responses to salinity stress in two contrasting Populus alba L. genotypes.

Soil salinity is an important limiting factor to tree growth and productivity. Populus alba L. is a moderately salt-tolerant species and its natural populations are adapted to contrasting environments, thus providing genetic resources to identify key genes for tolerance to abiotic stress, such as salinity.

Detection of plant volatiles after leaf wounding and darkening by proton transfer reaction "time-of-flight" mass spectrometry (PTR-TOF).

Proton transfer reaction-time of flight (PTR-TOF) mass spectrometry was used to improve detection of biogenic volatiles organic compounds (BVOCs) induced by leaf wounding and darkening. PTR-TOF measurements unambiguously captured the kinetic of the large emissions of green leaf volatiles (GLVs) and acetaldehyde after wounding and darkening. GLVs emission correlated with the extent of wounding, thus confirming to be an excellent indicator of mechanical damage.

Different sensitivity of isoprene emission, respiration and photosynthesis to high growth temperature coupled with drought stress in black poplar (Populus nigra) saplings.

The effects of the interaction between high growth temperatures and water stress on gas-exchange properties of Populus nigra saplings were investigated. Water stress was expressed as a function of soil water content (SWC) or fraction of transpirable soil water (FTSW). Isoprene emission and photosynthesis (A) did not acclimate in response to elevated temperature, whereas dark (R(n)) and light (R(d)) respiration underwent thermal acclimation.