Involvement of DkTGA1 Transcription Factor in Anaerobic Response Leading to Persimmon Fruit Postharvest De-Astringency

PLoS One. 2016 May 19;11(5):e0155916. doi: 10.1371/journal.pone.0155916. eCollection 2016.

Abstract

Persimmon fruit are unique in accumulating proanthocyanidins (tannins) during development, which cause astringency in mature fruit. In 'Mopanshi' persimmon, astringency can be removed by treatment with 95% CO2, which increases the concentrations of ethanol and acetaldehyde by glycolysis, and precipitates the soluble tannin. A TGA transcription factor, DkTGA1, belonging to the bZIP super family, was isolated from an RNA-seq database and real-time quantitative PCR indicated that DkTGA1 was up-regulated by CO2 treatment, in concert with the removal of astringency from persimmon fruit. Dual-luciferase assay revealed that DkTGA1 had a small (less than 2-fold), but significant effect on the promoters of de-astringency-related genes DkADH1, DkPDC2 and DkPDC3, which encode enzymes catalyzing formation of acetaldehyde and ethanol. A combination of DkTGA1 and a second transcription factor, DkERF9, shown previously to be related to de-astringency, showed additive effects on the activation of the DkPDC2 promoter. Yeast one-hybrid assay showed that DkERF9, but not DkTGA1, could bind to the DkPDC2 promoter. Thus, although DkTGA1 expression is positively associated with persimmon fruit de-astringency, trans-activation analyses with DkPDC2 indicates it is likely to act by binding indirectly DkPDC2 promoter, might with helps of DkERF9.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetaldehyde / metabolism
  • Diospyros / genetics*
  • Diospyros / metabolism
  • Ethanol / metabolism
  • Fruit / genetics
  • Fruit / metabolism
  • Oxygen / metabolism
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism
  • Proanthocyanidins / genetics
  • Proanthocyanidins / metabolism*
  • Promoter Regions, Genetic
  • Protein Binding
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism

Substances

  • Plant Proteins
  • Proanthocyanidins
  • Transcription Factors
  • Ethanol
  • Acetaldehyde
  • Oxygen

Grants and funding

This research was supported by the Special Fund for Agro-scientific Research in the Public Interest [no. 201203047], National Natural Science Foundation of China [no. 31372114], Program of International Science and Technology Cooperation [2011DFB31580] and the Natural Science Foundation of Zhejiang Province, China [LR16C150001]. There was no additional external funding received for this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.