Arbuscular mycorrhizal (AM) fungi are very widespread, forming symbiotic associations with ∼80% of land plant species, including almost all crop plants. These fungi are considered of great interest for their use as biofertilizer in low-input and organic agriculture. In addition to an improvement in plant nutrition, AM fungi have been reported to enhance plant tolerance to important abiotic and biotic environmental conditions, especially to a reduced availability of resources. These features, to be exploited and applied in the field, require a thorough identification of mechanisms involved in nutrient transfer, metabolic pathways induced by single and multiple stresses, physiological and eco-physiological mechanisms resulting in improved tolerance. However, cooperation between host plants and AM fungi is often related to the specificity of symbiotic partners, the environmental conditions and the availability of resources. In this study, the impact of two AM fungal species (Funneliformis mosseae and Rhizophagus intraradices) on the water stress tolerance of a commercial tomato cultivar (San Marzano nano) has been evaluated in pots. Biometric and eco-physiological parameters have been recorded and gene expression analyses in tomato roots have been focused on plant and fungal genes involved in inorganic phosphate (Pi) uptake and transport. R. intraradices, which resulted to be more efficient than F. mosseae to improve physiological performances, was selected to assess the role of AM symbiosis on tomato plants subjected to combined stresses (moderate water stress and aphid infestation) in controlled conditions. A positive effect on the tomato indirect defense toward aphids in terms of enhanced attraction of their natural enemies was observed, in agreement with the characterization of volatile organic compound (VOC) released. In conclusion, our results offer new insights for understanding the molecular and physiological mechanisms involved in the tolerance toward water deficit as mediated by a specific AM fungus. Moreover, they open new perspectives for the exploitation of AM symbiosis to enhance crop tolerance to abiotic and biotic stresses in a scenario of global change.

An effective framework for early warning and rapid response is a crucial element to prevent or mitigate the impact of biological invasions of plant pathogens, especially at ports of entry. Molecular detection of pathogens by using PCR-based methods usually requires a well-equipped laboratory. Rapid detection tools that can be applied as point-of-care diagnostics are highly desirable, especially to intercept quarantine plant pathogens such as Xylella fastidiosa , Ceratocystis platani and Phytophthora ramorum , three of the most devastating pathogens of trees and ornamental plants in Europe and North America. To this aim, in this study we developed three different loop mediated isothermal amplification (LAMP) assays able to detect each target pathogen both in DNA extracted from axenic culture and in infected plant tissues. By using the portable instrument Genie ® II, the LAMP assay was able to recognize X. fastidiosa , C. platani and P. ramorum DNA within 30 min of isothermal amplification reaction, with high levels of specificity and sensitivity (up to 0.02 pg µL −1 of DNA). These new LAMP-based tools, allowing an on-site rapid detection of pathogens, are especially suited for being used at ports of entry, but they can be also profitably used to monitor and prevent the possible spread of invasive pathogens in natural ecosystems.

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Fusarium circinatum and Caliciopsis pinea are the causal agents of Pitch canker and Caliciopsis canker, respectively. These diseases affect pines and other conifers both in Europe and North America. The two pathogens cause similar bleeding cankers, especially at the early stage of colonization. Symptoms closely resembling those due to F. circinatum can be instead associated with C. pinea. Since F. circinatum is a quarantine organism, subjected to provisional emergency measures, its report immediately causes serious economic implications, while C. pinea, even if now emerging, is not regulated in the EU nor in the USA. For this reason, a reliable and accurate diagnostic tool able to distinguish between the two organisms was considered a priority. In this study, we developed and standardized a duplex real-time PCR assay allowing the simultaneous recognition of C. pinea and F. circinatum DNA in pine tissue in a reasonably short time and for amounts as small as 0.06 pg/μl. The molecular assay is, therefore, able to detect the infection even before symptoms have fully developed. The test was challenged with a very large set of strains (110 different isolates) collected in different regions of the world and host trees, and gave reliable results. The high efficiency of this method suggests its use as a standard diagnostic tool during phytosanitary controls. In addition, the duplex real-time PCR assay presented here is the first DNA-based method designed to detect C. pinea, which is becoming an increasing threat to pine stands both in North America and in Europe.

Drought stress modulates secondary metabolites in Brassica oleracea L. convar. acephala (DC) Alef, var. sabellica L. Abstract BACKGROUND: Consumer preference today is for the consumption of functional food and the reduction of chemical preservatives. Moreover, the antimicrobial properties and health-promoting qualities of plant secondary metabolites are well known. Due to forecasted climate changes and increasing human population, agricultural practices for saving water have become a concern. In the present study, the physiological responses of curly kale Brassica oleracea L. convar. Acephala (DC) var. sabellica to drought stress and the impact of water limitation on the concentration of selected secondary metabolites were investigated under laboratory-controlled conditions. RESULTS: Results indicated that drought stress increased the content of trans-2-hexenal, phytol and -tocopherol, and decreased chlorophyll content. Moreover, drought stress increased antioxidant capacity and the expression of AOP2, a gene associated with the biosynthesis of aliphatic alkenyl glucosinolates, and of three genes -TGG1, TGGE and PEN2 -encoding for myrosinases, the enzymes involved in glucosinolate breakdown.CONCLUSION: The present study shows that water limitation during the growing phase might be exploited as a sustainable practice for producing curly kale with a high concentration of nutritionally important health-promoting bioactive metabolites. Impact of drought on chlorophyll, total, , tocopherols and volatile compound concentrationDrought stress significantly decreased the concentration of total chlorophylls (Fig. 2a), while increasing the concentration of total, J Sci Food Agric 2019; 99: 5533-5540

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There is a large population of sweet chestnut (Castanea sativa Mill.) in northern Azerbaijan. Unfortunately, for several years, Caucasian chestnut orchards have been considered to be at risk of extinction due to insect pests and pathogens, amongst which Cryphonectria parasitica (Murr.) Barr, the causal agent of chestnut blight disease is highly significant and was detected in Azerbaijan in 2003(Aghayeva & Harrington, 2008. In Europe, recovery of C. sativa trees affected by chestnut blight was observed (Heiniger & Rigling, 1994) due to the infection of the fungus by a mycovirus, Cryphonectria hypovirus 1 (CHV1), a capsid-free RNA virus in the family Hypoviridae, which reduces mycelial growth, virulence and sporulation of the pathogen.In addition, CHV1 induces a noticeable reduction of the activity of laccase, a phenol oxidase containing copper, with many functions in pathogenic fungi during host colonization (Rigling et al., 1989). To our knowledge, the presence of CHV1 in C. parasitica has not been reported previously in Azerbaijan (Aghayeva et al., 2017; Forgia et al., 2021). Therefore, a small-scale survey in four of the eight Azerbaijan chestnut growing districts was conducted in July 2016 to determine whether CHV1 was present in C. parasitica strains from Azerbaijan. | MATERIAL S AND ME THODS | Cryphonectria parasitica sampling in chestnut growing districtsThe four chestnut growing districts where C. parasitica (Murr) Barr strains were collected, namely Zagatala (1), Shaki (2), Qabala (3) and Quba (4) are shown in Figure S1 (in Supporting information). Chestnut trees were visually inspected for chestnut blight disease symptoms and one bark sample (ca 2 x 2 cm) per canker per tree collected. Twenty bark samples were collected from twenty trees in each district, except in Quba, where eight samples were collected from eight trees. In total sixty-eight cankers were sampled.