Transcriptional regulation of abscisic acid biosynthesis and signal transduction, and anthocyanin biosynthesis in 'Bluecrop' highbush blueberry fruit during ripening

PLoS One. 2019 Jul 18;14(7):e0220015. doi: 10.1371/journal.pone.0220015. eCollection 2019.

Abstract

Highbush blueberry (Vaccinium corymbosum) fruit accumulate high levels of anthocyanins during ripening, which might be controlled by abscisic acid (ABA), a signal molecule in non-climacteric fruits. For an integrated view of the ripening process from ABA to anthocyanin biosynthesis, we analyzed the transcriptomes of 'Bluecrop' highbush blueberry fruit using RNA-Seq at three ripening stages, categorized based on fruit skin coloration: pale green at ca. 30 days after full bloom (DAFB), reddish purple at ca. 40 DAFB, and dark purple at ca. 50 DAFB. Mapping the trimmed reads against the reference sequences yielded 25,766 transcripts. Of these, 143 transcripts were annotated to encode five ABA biosynthesis enzymes, four ABA signal transduction regulators, four ABA-responsive transcription factors, and 12 anthocyanin biosynthesis enzymes. The analysis of differentially expressed genes between the ripening stages revealed that 11 transcripts, including those encoding nine-cis-epoxycarotenoid dioxygenase, SQUAMOSA-class MADS box transcription factor, and flavonoid 3',5'-hydroxylase, were significantly up-regulated throughout the entire ripening stages. In fruit treated with 1 g L-1 ABA, at least nine transcripts of these 11 transcripts as well as one transcript encoding flavonoid 3'-hydroxylase were up-regulated, presumably promoting anthocyanin accumulation and fruit skin coloration. These results will provide fundamental information demonstrating that ABA biosynthesis and signal transduction, and anthocyanin biosynthesis are closely associated with anthocyanin accumulation and skin coloration in highbush blueberry fruit during ripening.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abscisic Acid / metabolism*
  • Anthocyanins / biosynthesis*
  • Blueberry Plants / genetics*
  • Blueberry Plants / metabolism*
  • Computational Biology / methods
  • Fruit / genetics*
  • Fruit / metabolism*
  • Gene Expression Regulation, Plant*
  • Gene Ontology
  • Molecular Sequence Annotation
  • Phenotype
  • Signal Transduction*
  • Transcriptome

Substances

  • Anthocyanins
  • Abscisic Acid

Grants and funding

This work was supported by the Basic Science Research Program of the National Research Foundation of Korea, funded by the Ministry of Education (NRF-2013R1A1A2011925 to HJL). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.