Abstract
Ten sweetpotato genotypes were exposed to 10 mg L-1 Pb (lead as aqueous Pb(NO3)2) during 60 days of growth. Total lead content in the sweet potato flesh was determined by separating the flesh from the skins, acid digestion of the flesh and analysis by inductively coupled plasma mass spectrometry (ICP-MS). All genotypes exposed to lead accumulated lead at least five-fold above background levels. Variation in lead accumulation among genotypes was observed with higher accumulating genotypes retaining about 3 times more lead in storage root flesh tissue than lower accumulators. This dataset can assist growers in their efforts to grow safer food and also assist breeders in developing sweetpotato varieties that accumulate less lead.
Keywords: Germplasm screening, Heavy metals, Lead, Ipomoea batatas, Food safety, Toxic elements
Specifications Table
| Subject | Biology |
| Specific subject area | Agricultural Sciences |
| Type of data | Table, Figure |
| Data collection | A dataset of sweetpotato storage root flesh tissue with the skins removed was obtained for 10 genotypes that were exposed to 10 mg l-1 lead. The lead concentration in the flesh tissue was obtained via digestion of the flesh and analysis of digestates with a single quadrupole inductively coupled plasma mass spectrometer (ICP-MS, Agilent 7900 ICP-MS). |
| Data source location | Institution: United States Department of Agriculture, U.S. Vegetable Laboratory City/Town/Region: Charleston, South Carolina Country: United States of America |
| Data accessibility | Repository name: Ag Data Commons Data identification number: 10.15482/USDA.ADC/30009949 Direct URL to data: https://figshare.com/s/303ba4d4bff634979a83 |
1. Value of the Data
-
•
This dataset is the first documented analysis of lead (Pb) accumulation in the flesh tissue of sweetpotato germplasm from the United States of America and includes the two most widely grown cultivars in the country (Beauregard and Covington)
-
•
The dataset can be used to identify genotypes that accumulate lower levels of lead in the flesh and can be used in breeding efforts to develop new varieties with lower levels of lead
-
•
The dataset can be used by other researchers to develop estimated daily intake and health risk assessments based on consumption levels
2. Background
Consumption of vegetables is one of the most common pathways by which toxic elements enter the food chain [1,2]. Leafy greens and root crops retain more toxic elements than most other types of fruits and vegetables [2,3]. A report published by Healthy Babies Bright Futures [4] noted that consumption of baby foods containing sweetpotatoes (Ipomoea batatas) leads to high risk of exposure to lead. In response the U.S. Food and Drug Administration (FDA) developed the action plan Closer to Zero [5] to reduce exposure to toxic elements (As, Cd, Hg, and Pb) from foods eaten by babies and young children—to as low as possible. An effective and economically feasible method to deal with production of food crops in heavy metal contaminated soils is the screening and breeding of heavy metal resistant and/or low accumulating crops. This study aimed to collect baseline data on lead accumulation in the flesh of United States of America sweetpotato germplasm that will be used to identify low accumulating genotypes that can be used in breeding efforts to reduce lead concentration in food products containing sweetpotato.
3. Data Description
The concentration (µg l-1) of lead in sweetpotato flesh samples was analysed using ICP-MS [6]. Proper controls were employed as described [6], and the calibration curve for Pb had an R2 value of 0.9997. The dataset showing variation in lead concentration in the tissue samples is presented in Fig. 1 and the data is available in the Ag Data Commons repository (https://figshare.com/s/303ba4d4bff634979a83).
Fig. 1.
Lead content (ppb) in flesh tissue for 10 sweetpotato genotypes replicated 3 times that were exposed to 10 mg l-1 lead. Beauregard – C and Regal – C were untreated controls. Different letters indicate significant differences (p ≤ 0.05) using a protected least significant difference test.
3. Experimental Design, Materials and Methods
3.1. Plant material and experimental conditions
Sweetpotato plants were grown in a greenhouse at the United States Department of Agriculture, Agricultural Research Service, U. S. Vegetable Laboratory in Charleston, SC, USA (32° 47′ N, 79° 55′ W). The following genoyptes of I. batatas were tested and arranged in a randomized complete block design with three replications: ‘Averre’, ‘Beauregard’, ‘Covington’, ‘Dune’, ‘Jewel’, W-209, ‘Purple Majesty’, ‘Regal’, USDA-05–097, and USDA-09–130. Plants were grown in pots (10 × 10 × 28 cm) containing 80 % washed sand and 20 % potting media (Sungro). Plants were watered with 10 % Hoagland's solution [7] (PhytoTech Labs) containing 50 µM Pb2+from Pb(NO3)2 and equimolar EDTA (50 µM ethylene diamine tetra-acetic acid) to chelate the Pb2+ions, thus preventing precipitation of lead phosphate. The 10 % Hoagland's solution contains: 77 µM (NH4)3PO4, 5 µM H3BO3, 400 µM Ca(NO3)2, 32 nM CuSO4, 9 µM FeSO4, 9 µM EDTA, 200 µM MgSO4, 91.5 nM MnCl2, 11 nM MoO3, 600 µM KNO3, and 94 nM ZnSO4. During the first 5 days of establishment, cuttings were watered daily with 150 mL of media. Thereafter, plants were watered with 200 or 250 mL as needed, approximately every other day, until harvesting at 60 days after planting. Over the course of the experiment each plant received a total of 5 L of 10 % Hoagland's solution for a total of 50 mg of Pb2+. Upon harvesting, roots were soaked briefly in 100 µM CaCl2 to displace loosely adhered lead ions and washed thouroughly with distilled water. A ceramic knife was used to remove the skin. For each sample, ∼250 mg of flesh tissue was disgested in 5 mL of concentrated nitric acid (50 %) containing 6 % hydrogen peroxide using a microwave system (MARS6, CEM). Total lead in the digestates was determined by inductively coupled plasma mass spectrometry (ICP-MS) following a previously published method [6]. Lead concentration data were subjected to ANOVA and means were separated by Fisher's protected least significant difference at the 5 % probability level (SAS version 9.4).
Limitations
Not applicable.
Ethics Statement
All authors have read and followed the ethical requirements for publication in Data in Brief and confirm that the current work does not involve human subjects, animal experiments, or any data collected from social media platforms.
CRediT Author Statement
Robert R. Bowers: Methodology, Formal analysis, Visualization, Writing-original draft, review and editing; Mahendranath Arambewela: Methodology, Formal analysis, review and editing of original draft; Todd P. Luxton: Methodology, Data curation, Review and editing of original draft; Phillip A. Wadl: Conceptualization, Funding acquisition, Methodology, Data curation, Formal Analysis, Writing-original draft, review and editing.
Acknowledgements
This work was funded by the United States Department of Agriculture, the United States Food and Drug Administration, and the United States Environmental Protection Agency.
Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Data Availability
References
- 1.Guerra F., Trevizam A.R., Muraoka T., Marcante N.C., Canniatti-Brazaca S.G. Heavy metals in vegetables and potential risk for human health. Sci. Agric. 2012;69(1):54–60. [Google Scholar]
- 2.Zhou H., Yang W.T., Zhou X., Liu L., Gu J.F., Wang W.L., Zou J.L., Tian T., Peng P.Q., Liao B.H. Accumulation of heavy metals in vegetable species planted in contaminated soils and the health risk assessment. Int. J. Environ. Res. Public Health. 2016;13(3) doi: 10.3390/ijerph13030289. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Gardener H., Bowen J., Callan S.P. Lead and cadmium contamination in a large sample of United States infant formulas and baby foods. Sci. Total Environ. 2019;651:822–827. doi: 10.1016/j.scitotenv.2018.09.026. [DOI] [PubMed] [Google Scholar]
- 4.Houlihan J., Brody, C.:. What’s in my baby food? Healthy babies bright futures. 2019. https://hbbf.org/solutions/healthy-baby-foods
- 5.FDA Closer to zero action plan: impacts of toxic element exposure and nutrition at different crucial developmental stages; public meeting; request for comments. Fed. Regist. 2021;86:56711–56713. https://www.federalregister.gov/d/2021-22109 [Google Scholar]
- 6.Gray P.J., Cunningham W. Inductively coupled plasma collision cell quadrupole mass spectrometric determination of extractible arsenic, cadmium, chromium, lead, mercury, and other elements in food using microwave-assisted digestion: results from an FDA interlaboratory study. J. AOAC Int. 2019;102(2):590–604. doi: 10.5740/jaoacint.18-0129. [DOI] [PubMed] [Google Scholar]
- 7.D.R. Hoagland, D.I. Arnon, The water-culture method for growing plants without soil. Berkely,: the college of agriculture; 1950.
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.