Immune regulation of neurodevelopment at the mother–foetus interface: the case of autism

Autism spectrum disorder (ASD) is a neurodevelopmental disorder defined by deficits in social communication and stereotypical behaviours. ASD’s aetiology remains mostly unclear, because of a complex interaction between genetic and environmental factors. Recently, a strong consensus has developed around ASD’s immune-mediated pathophysiology, which is the subject of this review. For many years, neuroimmunological studies tried to understand ASD as a prototypical antibody- or cell-mediated disease. Other findings indicated the importance of autoimmune mechanisms such as familial and individual autoimmunity, adaptive immune abnormalities and the influence of infections during gestation. However, recent studies have challenged the idea that autism may be a classical autoimmune disease. Modern neurodevelopmental immunology shows the double-edged nature of many immune effectors, which can be either beneficial or detrimental depending on tissue homeostasis, stressors, neurodevelopmental stage, inherited and de novo gene mutations and other variables. Nowadays, mother–child interactions in the prenatal environment appear to be crucial for the occurrence of ASD. Studies of animal maternal–foetal immune interaction are being fruitfully carried out using different combinations of type and timing of infection, of maternal immune response and foetal vulnerability and of resilience factors to hostile events. The derailed neuroimmune crosstalk through the placenta initiates and maintains a chronic foetal neuroglial activation, eventually causing the alteration of neurogenesis, migration, synapse formation and pruning. The importance of pregnancy can also allow early immune interventions, which can significantly reduce the increasing risk of ASD and its heavy social burden

Genome Resources of Verticillium dahliae VdGL16: the causal agent of vascular wilt on the invasive species Ailanthus altissima

Verticillium species are known as plant pathogens responsible for wilt diseases in a large variety of dicotyledon plants and crops in many parts of the world. Here we present the draft genome sequence of Verticillium dahliae Kleb. (strain VdGL16) isolated in Italy from the invasive alien species Ailanthus altissima (Mill.; commonly known as tree-of-heaven) showing Verticillium wilt symptoms. The comparison between the newly sequenced genome with those publicly available revealed candidate genes putatively involved in pathogenicity. The genome represents a new useful source for future research on Verticillium genetics and biology as well as research on novel approaches in the control of A. altissima

First report of powdery mildew caused by Erysiphe platani in Ailanthus altissima, the tree-of-heaven, in the Mediterranean basin, Italy

In August 2018, a tree-of-heaven (Ailanthus altissima) showing symptoms of powdery mildew was found in Pisa, Italy. Morphological characteristics of the anamorph and molecular sequence analysis of the internal transcribed spacer region of rDNA verified the fungus as Erysiphe platani. In a pathogenicity test, powdery mildew patches were present on leaf surfaces 2 weeks after inoculation with the isolate. This is the first report of E. platani causing powdery mildew on ailanthus in the Mediterranean basin. The fungus, whose historical host range was confined to the genus Platanus, has expanded its host range to Ailanthus in Italy

Ecophysiological and biochemical events associated with the challenge of Verticillium dahliae to eggplant

Verticillium dahliae (Kleb.) is a soil-borne pathogen able to cause yield losses in eggplant, Solanum melongena L., one of the most important vegetable crops in the Mediterranean basin. In this study, an experiment was conducted to assess physiological and biochemical mechanisms modulating the interactions between S. melongena cv. Violetta di Rimini and V. dahliae strain VdGL16 in leaves at different age (mature, intermediate and young; ML, IL and YL) up to 25 days post artificial root inoculation (dpi). At 8 dpi, infected ML showed a marked reduction of photosynthetic rate (4-fold lower than controls) associated with stomatal (reduced stomatal conductance) and mesophyll (concomitant increase of intercellular CO2 concentration) limitations. Cell membrane integrity was compromised, and phylloptosis/death occurred. At 8 and 18 dpi, stomatal closure (−40 and − 53%, respectively) and biochemical alterations occurred in IL. At 18 dpi, the consumption of secondary metabolites suggested that antioxidant- and antimicrobial-defence responses were activated. However, photoinhibition, oxidative stress and water deficit were observed at the end of the experiment. These mechanisms were observed also in YL, as confirmed by the strong increase of tannins (+46%) followed by accumulation of other phenylpropanoids. Despite plant growth being maintained, reduction of leaf area and water deficit occurred. This study highlights the capacity of eggplant to activate dynamic biochemical mechanisms in response to fungal infection, even in susceptible genotypes, a starting point for comparisons with resistant material for selection

Transient waterlogging events impair shoot and root physiology and reduce grain yield of durum wheat cultivars

Durum wheat (Triticum turgidum L. subsp. durum (Desf.) Husn) is a staple crop of the Mediterranean countries, where more frequent waterlogging events are predicted due to climate change. However, few investigations have been conducted on the physiological and agronomic responses of this crop to waterlogging. The present study provides a comprehensive evaluation of the effects of two waterlogging durations (i.e., 14 and 35 days) on two durum wheat cultivars (i.e., Svevo and Emilio Lepido). An integrated analysis of an array of physiological, biochemical, biometric, and yield parameters was performed at the end of the waterlogging events, during recovery, and at physiological maturity. Results established that effects on durum wheat varied depending on waterlogging duration. This stress imposed at tillering impaired photosynthetic activity of leaves and determined oxidative injury of the roots. The physiological damages could not be fully recovered, subsequently slowing down tiller formation and crop growth, and depressing the final grain yield. Furthermore, differences in waterlogging tolerance between cultivars were discovered. Our results demonstrate that in durum wheat, the energy maintenance, the cytosolic ion homeostasis, and the ROS control and detoxification can be useful physiological and biochemical parameters to consider for the waterlogging tolerance of genotypes, with regard to sustaining biomass production and grain yield

Nutrient fertilization mitigates the effects of ozone exposure on poplar plants.

The progressive salinization of soils irrigated with salty water and salt-water intrusion of groundwater bodies can limit crop production in many areas, especially in the Mediterranean basin. The current background tropospheric ozone (O3) levels are high enough to negatively affect plant physiological and productive performances. In this work, one-year-old saplings of pomegranate (Punica granatum L., cv. ‘Dente di cavallo’) were exposed to two levels of O3 [AOT40 values were 21.51 in ambient air (AA), and 58.74 ppm h, in 2AA] and two levels of salinity, denoted as No Salt (NS) and Salt (S, the electrical conductivity and pH of the irrigation water were 5.5 mS cm-1 and 7.6 with 50 mM of NaCl) for four consecutive months in an O3 FACE open air facility. Under O3 (alone or in combination with salt), plants developed visible stipples of browning tissue localized in the interveinal adaxial leaf surface. At ecophysiological level, salt stress further affected the photosynthetic performance (-17% compared to AA_NS). By contrast, salinity did not induce oxidative damage [as confirmed by unchanged malondialdehyde (MDA) levels]. Under 2AA conditions, O3 alone reduced the stress tolerance, as confirmed by the production of reactive oxygen species (+10 and +225% of anion superoxide and hydrogen peroxide, respectively), the increase of superoxide dismutase activity (+9%) and the concomitant membrane denaturation (+198% of MDA content). According to Bansal calculation, the combination of both stressors had a synergistic effect in terms of oxidative damage and increased activity of catalase

Can nutrient fertilization mitigate the effects of ozone exposure on an ozone-sensitive poplar clone?

We tested the independent and interactive effects of nitrogen (N; 0 and 80 kg ha−1), phosphorus (P; 0, 40 and 80 kg ha−1), and ozone (O3) application/exposure [ambient concentration (AA), 1.5 × AA and 2.0 × AA] for five consecutive months on biochemical traits of the O3-sensitive Oxford poplar clone. Plants exposed to O3 showed visible injury and an alteration of membrane integrity, as confirmed by the malondialdehyde byproduct accumulation (+3 and +17% under 1.5 × AA and 2.0 × AA conditions, in comparison to AA). This was probably due to O3-induced oxidative damage, as documented by the production of superoxide anion radical (O2•−,+27 and+63%, respectively). Ozone per se, independently from the concentrations, induced multiple signals (e.g., alteration of cellular redox state, increase of abscisic acid/indole-3-acetic acid ratio and reduction of proline content) that might be part of premature leaf senescence processes. By contrast, nutrient fertilization (both N and P) reduced reactive oxygen species accumulation (as confirmed by the decreasedO2•−and hydrogen peroxide content), resulting in enhanced membrane stability. This was probably due to the simultaneous involvement of antioxidant compounds (e.g., carotenoids, ascorbate and glutathione) and osmoprotectants (e.g., proline) that regulate the detoxification processes of coping with oxidative stress by reducing the O3 sensitivity of Oxford clone. These mitigation effects were effective only under AA and 1.5 × AA conditions. Nitrogen and P supply activated a free radical scavenging system that was not able to delay leaf senescence and mitigate the adverse effects of a general peroxidation due to the highest O3 concentrations