Common garden experiment reveals altered nutritional values and DNA methylation profiles in micropropagated three elite Ghanaian sweet potato genotypes

PLoS One. 2019 Apr 26;14(4):e0208214. doi: 10.1371/journal.pone.0208214. eCollection 2019.

Abstract

Micronutrient deficiency is the cause of multiple diseases in developing countries. Staple crop biofortification is an efficient means to combat such deficiencies in the diets of local consumers. Biofortified lines of sweet potato (Ipomoea batata L. Lam) with enhanced beta-carotene content have been developed in Ghana to alleviate Vitamin A Deficiency. These genotypes are propagated using meristem micropropagation to ensure the generation of virus-free propagules. In vitro culture exposes micropropagated plants to conditions that can lead to the accumulation of somaclonal variation with the potential to generate unwanted aberrant phenotypes. However, the effect of micropropagation induced somaclonal variation on the production of key nutrients by field-grown plants has not been previously studied. Here we assessed the extent of in vitro culture induced somaclonal variation, at a phenotypic, compositional and genetic/epigenetic level, by comparing field-maintained and micropropagated lines of three elite Ghanaian sweet potato genotypes grown in a common garden. Although micropropagated plants presented no observable morphological abnormalities compared to field maintained lines, they presented significantly lower levels of iron, total protein, zinc, and glucose. Methylation Sensitive Amplification Polymorphism analysis showed a high level of in vitro culture induced molecular variation in micropropagated plants. Epigenetic, rather than genetic variation, accounts for most of the observed molecular variability. Taken collectively, our results highlight the importance of ensuring the clonal fidelity of the micropropagated biofortified lines in order to reduce potential losses in the nutritional value prior to their commercial release.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biofortification* / methods
  • DNA Methylation*
  • DNA, Plant / genetics
  • Ghana
  • Humans
  • Ipomoea batatas / genetics*
  • Ipomoea batatas / metabolism
  • Nutritive Value
  • Vitamin A Deficiency / prevention & control
  • beta Carotene / metabolism

Substances

  • DNA, Plant
  • beta Carotene

Grants and funding

This work was supported by the Bill & Melinda Gates Foundation (https://www.gatesfoundation.org) through the International Centre for Genetic Engineering and Biotechnology (https://www.icgeb.org/home.html) to BA, as a capacity building initiative in biotechnology regulation in sub-Saharan Africa, funded this research. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.