Embryo-specific expression of a visual reporter gene as a selection system for citrus transformation

PLoS One. 2018 Jan 2;13(1):e0190413. doi: 10.1371/journal.pone.0190413. eCollection 2018.

Abstract

The embryo-specific Dc3 gene promoter driving the VvMybA1 anthocyanin regulatory gene was used to develop a visual selection system for the genetic transformation of citrus. Agrobacterium-mediated transformation of cell suspension cultures resulted in the production of purple transgenic somatic embryos that could be easily separated from the green non-transgenic embryos. The somatic embryos produced phenotypically normal plants devoid of any visual purple coloration. These results were also confirmed using protoplast transformation. There was minimal gene expression in unstressed one-year-old transgenic lines. Cold and drought stress did not have any effect on gene expression, while exogenous ABA and NaCl application resulted in a minor change in gene expression in several transgenic lines. When gas exchange was measured in intact leaves, the transgenic lines were similar to controls under the same environment. Our results provide conclusive evidence for the utilization of a plant-derived, embryo-specific visual reporter system for the genetic transformation of citrus. Such a system could aid in the development of an all-plant, consumer-friendly GM citrus tree.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Citrus / embryology
  • Citrus / genetics*
  • Genes, Reporter*
  • Plants, Genetically Modified
  • Selection, Genetic*
  • Transformation, Genetic*

Grants and funding

This work was supported by the Citrus Research & Development Foundation (www.citrusrdf.org/). The Citrus Research & Development Foundation provided support in the form of salaries for author MD, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.