The Ionomic Study of Vegetable Crops

PLoS One. 2016 Aug 1;11(8):e0160273. doi: 10.1371/journal.pone.0160273. eCollection 2016.

Abstract

Soil contains various essential and nonessential elements, all of which can be absorbed by plants. Plant ionomics is the study of the accumulation of these elements (the ionome) in plants. The ionomic profile of a plant is affected by various factors, including species, variety, organ, and environment. In this study, we cultivated various vegetable crop species and cultivars under the same field conditions and analyzed the level of accumulation of each element in the edible and nonedible parts using ionomic techniques. The concentration of each element in the edible parts differed between species, which could be partly explained by differences in the types of edible organs (root, leaf, seed, and fruit). For example, the calcium concentration was lower in seeds and fruit than in other organs because of the higher dependency of calcium accumulation on xylem transfer. The concentration of several essential microelements and nonessential elements in the edible parts also varied greatly between cultivars of the same species, knowledge of which will help in the breeding of vegetables that are biofortified or contain lower concentrations of toxic elements. Comparison of the ionomes of the fruit and leaves of tomato (Solanum lycopersicum) and eggplant (S. melongena) indicated that cadmium and boron had higher levels of accumulation in eggplant fruit, likely because of their effective transport in the phloem. We also found that homologous elements that have been reported to share the same uptake/transport system often showed significant correlation only in a few families and that the slopes of these relationships differed between families. Therefore, these differences in the characteristics of mineral accumulation are likely to affect the ionomic profiles of different families.

MeSH terms

  • Boron / analysis
  • Cadmium / analysis
  • Crops, Agricultural*
  • Food Safety
  • Fruit / chemistry
  • Fruit / metabolism
  • Mass Spectrometry
  • Plant Leaves / chemistry
  • Plant Leaves / metabolism
  • Plant Roots / chemistry
  • Plant Roots / metabolism
  • Principal Component Analysis
  • Soil Pollutants / analysis
  • Soil Pollutants / chemistry*
  • Solanum lycopersicum / chemistry*
  • Solanum lycopersicum / growth & development
  • Solanum lycopersicum / metabolism
  • Solanum melongena / chemistry*
  • Solanum melongena / growth & development
  • Solanum melongena / metabolism

Substances

  • Soil Pollutants
  • Cadmium
  • Boron

Grants and funding

This study was supported financially by Grants-in-Aid for Scientific Research No. 24580088 (https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-24580088/) (TW), No. 26660019 (https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-26660019/) (YK, TW) and No. 16H02534 (https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT 16H02534/) (YK, TW) from the Japan Society for the Promotion of Science. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.