Tolleranza e accumulo di Nichel in cultivar di pomodoro:potenziale allergenicit� di piante Ni-free, pratiche agronomiche
Creators: name: NICOSIA, ELENA
Publisher: name: Universit� degli studi di Genova
Year: 2020

description: ?NICKEL TOLERANCE AND STORAGE IN TOMATO CULTIVARS: POTENTIAL ALLERGENICITY OF NI-FREE PLANTS, AGRONOMIC PRACTICES?
Nickel (Ni) is a ubiquitous trace element occurring in water, soil, air and in the biosphere. This element is essential for several plants, microorganisms and vertebrates. However, human requirement for Ni has not been conclusively demonstrated. Food, specifically vegetables, represents a major source of Ni exposure. Environmental contamination and cultural practices can increase Ni amount in vegetables posing significant risk for human health. The UE commission raised awareness on Ni in food and adopted recommendation (EU) 2016/1111 to monitor this metal in food in all Member States from 2016 to 2018 by sampling most representative foods including tomatoes. 
Tomato (Solanum lycopersicum L.) is a vegetable of key importance worldwide, the second most important after potato. The fruit is produced for fresh consumption and processed products (e.g., tomato sauce, tomato paste, etc.). Tomato was the top fruit produced in EU and, among vegetable crops of EU, tomato occupies the largest cultivated area, accounting for 11.4% of the total area used for vegetables (Eurostat, 2018). 
The significant rise in tomato consumption during the latest 20 years (e.g., Greece with 104 kg/capita, Italy with 55 kg/capita, Denmark with 30 kg/capita) is suspected to increase the health risks from high Ni uptake. 
Ni allergy is common worldwide and in EU, where it affects 10?15% of women (Uter et al. 2016). The epidemiological data showed that 12.3?17.7% of the population is allergic to Ni (Uter et al. 2016) and must follow a Ni-avoidance diet (e.g., Italy, Spain and Poland which have the highest incidence of Ni allergies). Low-Ni tomato products would be of great importance for these patients. 
To date, several tomato allergens have been identified and registered by the WHO/IUIS Nomenclature. The most common are Lipid transfer Protein (LTP), small, basic, highly stable proteins and they are ubiquitous in plant tissues (Radauer et al., 2008), and Profilin. The plant LTP family includes two subfamilies, 9k-LTP and 7k-LTP, according to their molecular masses corresponding to 9 kDa and 7 kDa, respectively (Giangrieco et al., 2015). Their ingestion, inhalation and contact can cause symptoms that may include all the clinical severity levels of allergic reactions: oral allergy syndrome (OAS), gastrointestinal symptoms, urticaria-angioedema syndrome, food-dependent exercise-induced anaphylaxis and even anaphylactic shock (Fern�ndez-Rivas et al., 2006; Romano et al., 2012).
The list of tomato allergens includes a 7k-LTP (Sola l 6) and different isoforms of 9k-LTP (Sola l 3), Sola l 1, a 14 kDa profilin; Sola l 2, a 50 kDa betafructofuranosidase; Sola l 4, an intracellular pathogenesis-related protein TSI-1 of the Bet v 1 family (Welter et al., 2013), Sola l 5, a cyclophilin. Additional allergens, or putative allergens, not yet included in the WHO-IUIS nomenclature, (such as, 11 S globulin, ribosomal protein P2, chitinase, glucanase, peroxidase, polygalacturonase, pectin methylesterase, thaumatin and vicilin) have been reported and entered in the Allergome database (www.allergome.org), referenced accordingly to available literature.
In most cases, tomato genotypes have been analysed from agronomic and technological point of view without considering Ni content and allergenic protein production that could increase the risk of allergies. Key geochemical processes that lead to limited Ni plant uptake in plant tissues at various growth stages can then be induced in field using different agricultural practices (irrigation, soil amendments, etc.).
This work aimed at assessing the S. lycopersicum response to Ni on the agronomic yield of tomatoes (i.e., plant biomass and fruit production) and the potential impact of Ni on the production of allergenic proteins (i.e., LTP, TLP, etc.).