Overexpression of an EaZIP gene devoid of transit peptide sequence induced leaf variegation in tobacco

PLoS One. 2017 Apr 19;12(4):e0175995. doi: 10.1371/journal.pone.0175995. eCollection 2017.

Abstract

Leaf variegation is an ornamental trait that is not only biologically but also economically important. In our previous study, a Mg-protoporphyrin IX monomethyl ester cyclase homologue, EaZIP (Epipremnum aureum leucine zipper) was found to be associated with leaf variegation in Epipremnum aureum (Linden & Andre) G.S. Bunting. The protein product of this nuclear-encoded gene is targeted back to chloroplast involving in chlorophyll biosynthesis. Based on a web-based homology analysis, the EaZIP was found to lack a chloroplast transit peptide (cTP) sequence. In the present study, we tested if overexpression of the EaZIP cDNA with or without the cTP sequence could affect leaf variegation. Transgenic tobacco plants overexpressing EaZIP genes with (EaZIPwcTP) and without (EaZIPwocTP) cTP sequence were generated. Many plant lines harboring EaZIPwocTP showed variegated leaves, while none of the plant lines with EaZIPwcTP produced such a phenotype. Molecular analysis of T0 plants and selfed T1 progeny, as well as observations of tagged marker GFP (green fluorescent protein) did not show any other difference in patterns of gene integrity and expression. Results from this study indicate that transgenic approach for expressing EaZIPwocTP could be a novel method of generating variegated plants even through the underlying mechanisms remain to be elucidated.

MeSH terms

  • Araceae / genetics
  • Araceae / metabolism
  • Base Sequence
  • Cell Nucleus / genetics
  • Cell Nucleus / metabolism
  • Chloroplast Proteins / genetics*
  • Chloroplast Proteins / metabolism
  • Chloroplasts / genetics
  • Chloroplasts / metabolism
  • DNA, Complementary / genetics
  • DNA, Complementary / metabolism
  • Gene Expression Regulation, Plant*
  • Genetic Vectors / chemistry
  • Genetic Vectors / metabolism
  • Leucine Zippers
  • Nicotiana / genetics*
  • Nicotiana / metabolism
  • Phenotype
  • Plant Leaves / anatomy & histology
  • Plant Leaves / genetics*
  • Plant Leaves / metabolism
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism
  • Plants, Genetically Modified
  • Protein Sorting Signals / genetics*
  • Sequence Alignment
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism

Substances

  • Chloroplast Proteins
  • DNA, Complementary
  • Plant Proteins
  • Protein Sorting Signals
  • Transcription Factors
  • chloroplast transit peptides

Grants and funding

The authors would like to thank the Fujian Science and Technology Key Projects (2013NZ0002-4 and 2015N0002-1) for Construction of High-level University Program designated to Fujian Agriculture and Forestry University as Construction of High-level Horticulture Science Discipline (612014007).