Zinc Concentration and Distribution in Vineyard Soils and Grapevine Leaves from Valdepeñas Designation of Origin (Central Spain)

(1) Background: The purpose of this study was to investigate zinc contents in leaves and soils of the Valdepeñas Protected Designation of Origin (PDO), situated in central Spain. Zn distribution maps of leaves and soils were obtained. (2) Methods: Ninety soil profiles were described, sampled and analyzed. Furthermore, vineyard leaves were collected randomly in each of the analyzed soil vineyard profiles. Soil and leaf samples were analyzed by X-ray fluorescence. (3) Results: The mean total Zn concentrations in vineyard soils were in the range of 16.2–153.7 mg·kg−1, with a mean of 47.5 mg·kg−1. The obtained values above the 95th percentile (between 81.3 and 153.7 mg·kg−1) could be affected by different parent materials or Zn agricultural treatments in vineyards. Contents in different soils follow the order Entisol > Alfisol > Inceptisol. The average Zn content value in leaves was 23.8 mg·kg−1 and oscillated between 11.5 and 93.3 mg·kg−1; minor differences were detected between soil types, with the highest value in plants grown on soils without carbonates. (4) Conclusions: The obtained values are optimal for vine cultivation. The bioaccumulation factors in leaves were lower than unity (0.24–0.53 range). This means that the Zn bioaccumulation process is relatively low in the soil–grapevine system. This study serves as a reference to identify areas that present Zn deficiencies or risk of contamination.

The Effect of Rotation Speed and Dwell Time on the Zn Distribution of the Dissimilar Metals Friction Stir Spot Welded between Aluminum Alloy and Galvanized Steel

Zink (Zn) in galvanized steel has a positive effect on improving the properties of the dissimilar metals weld between aluminum alloy and galvanized steel. Its distribution is important to be evaluated. The aim of this work is to investigate the effect of rotation speed and dwell time on the Zn distribution of the friction-stir-spot-welded (FSSW) dissimilar metals between aluminum alloy and galvanized steel. FSSW was subjected to 3 mm thick of Aluminum and 1 mm thick of galvanized steel with a plunge depth of 2.7 mm and a penetration rate of 0.9 mm/s. High strength steel (HSS) with a hardness of 70 HRC and a diameter of 12 mm was used as FSSW tool. Tool rotation was varied at 1000 rpm, 1200 rpm, 1600 rpm, and 2000 rpm while dwell time was varied of 3 s, 5 s, and 7 s. A Scanning Electron Microscope (SEM) was performed to reveal the Zn distribution after cross-sectioning, polishing, and etching. During the FSSW process, the heat was generated, Zn softened, and carried away by the materials flow due to tool rotation. Both the rotation speed and the dwell time played a role in increasing the distance and the amount of Zn flow in the welded zone. FSSW process in dissimilar metals between aluminum and galvanized steel formed the unique pattern of Zn distribution.

Quantify the Requirements to Achieve Grain Zn Biofortification of High-yield Wheat on Calcareous Soils

The solution to address global human Zn deficiency is Zn biofortification of staple food crops, aimed at high grain Zn concentration as well as high yield. However, the desired high grain Zn concentration above 40 mg kg-1 is rarely observed for high-yield wheat on worldwide calcareous soils, due to inadequate Zn uptake or Zn distribution to grain. The present study aims to investigate how much Zn uptake or distribution is adequate to achieve the Zn.t of high-yield wheat on calcareous soils with low available Zn (∼ 0.5 mg kg-1). Of the 123 cultivars tested in a three-year field experiment, 19 high-yield cultivars were identified with similar yields around 7.0 t ha-1 and various grain Zn concentrations from 9.3 to 26.7 mg kg-1. The adequate Zn distribution to grain was defined from the view of Zn biofortification, as the situation where the Zn distribution to grain (Zn harvest index) increased to the observed maximum of ∼ 91.0% and the Zn concentration of vegetative parts (straw Zn concentration) decreased to the observed minimum of ∼ 1.5 mg kg-1 (Zn.m). Under the assumed condition of adequate Zn distribution to grain (∼ 91.0%), all the extra Zn above Zn.m was remobilized from straw to grain and the grain Zn concentration would be increased to its highest attainable level, which was 14.5 ∼ 31.3 mg kg-1 for the 19 high-yield cultivars but still lower than 40 mg kg-1. Thus, even with the adequate Zn distribution to grain, the current Zn uptake is still not adequate and needs to be increased to 308 g ha-1 or higher to achieve Zn.t for high-yield wheat (7.0 t ha-1) on low-Zn calcareous soils. Besides, the established method here can also provide the priority measures and quantitative guidelines to achieve Zn biofortification in other wheat production regions.

Sample preparation with sucrose cryoprotection dramatically alters Zn distribution in the rodent hippocampus, as revealed by elemental mapping

Transition metal ions (Fe, Mn, Cu, Zn) are essential for healthy brain function, but common sample preparations, such as sucrose cryo-protection alter their distribution, which can confound studies of brain disease.

Dietary Zinc and Fibre Source can Influence the Mineral and Antioxidant Status of Piglets

The study investigated the effect of dietary zinc glycine chelate and potato fibre on the absorption and utilisation of Zn, Cu, Fe, and Mn; the activity of Zn-containing enzymes (superoxide dismutase, SOD; alkaline phosphatase, ALP); and zinc transporter concentrations (metalothionein1, MT1; zinc transporter1, ZnT1) in tissues, with a special emphasis on the small intestine. Twenty-four barrows (Danbred × Duroc) were randomly allotted to four diets (supplemented with 10 g/kg of crude fibre and 120 mg Zn/kg) that consisted of cellulose and either zinc sulphate (C) or zinc glycinate (ZnGly), or contained potato fibre supplemented with ZnSO4 (PF) or ZnGly (PF + ZnGly). Feeding PF can influence the Zn absorption in the small intestine due to reduced zinc transporters MT1 and ZnT1 in the jejunum. The activity of antioxidant enzyme SOD and liver ZnT1, and duodenal iron concentrations were increased in the PF treatments. Dietary ZnGly did not significantly influence the Zn distribution, but it may alter the absorption of Fe and Mn. Given the elevated content of thiol groups and the Zn/Cu ratio in plasma, as well as the altered SOD activity and MT content in the tissues, we can conclude that feeding PF and ZnGly can influence the mineral and antioxidant status of growing piglets. However, further research is needed in order to elucidate the effect of both dietary sources on the transport systems of other minerals in enterocytes.