EjAP2-1, an AP2/ERF gene, is a novel regulator of fruit lignification induced by chilling injury, via interaction with EjMYB transcription factors

Plant Biotechnol J. 2015 Dec;13(9):1325-34. doi: 10.1111/pbi.12351. Epub 2015 Mar 16.


Lignin biosynthesis is regulated by many transcription factors, such as those of the MYB and NAC families. However, the roles of AP2/ERF transcription factors in lignin biosynthesis have been rarely investigated. Eighteen EjAP2/ERF genes were isolated from loquat fruit (Eriobotrya japonica), which undergoes postharvest lignification during low temperature storage. Among these, expression of EjAP2-1, a transcriptional repressor, was negatively correlated with fruit lignification. The dual-luciferase assay indicated that EjAP2-1 could trans-repress activities of promoters of lignin biosynthesis genes from both Arabidopsis and loquat. However, EjAP2-1 did not interact with the target promoters (Ej4CL1). Yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays indicated protein-protein interactions between EjAP2-1 and lignin biosynthesis-related EjMYB1 and EjMYB2. Furthermore, repression effects on the Ej4CL1 promoter were observed with the combination of EjAP2-1 and EjMYB1 or EjMYB2, while EjAP2-1 with the EAR motif mutated (mEjAP2-1) lost such repression, although mEjAP2-1 still interacted with EjMYB protein. Based on these results, it is proposed that EjAP2-1 is an indirect transcriptional repressor on lignin biosynthesis, and the repression effects were manifested by EAR motifs and were conducted via protein-protein interaction with EjMYBs.

Keywords: AP2-MYB complex; AP2/ERF; chilling injury; lignification; lignin; loquat fruit.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cold Temperature / adverse effects*
  • Eriobotrya / genetics*
  • Eriobotrya / metabolism
  • Fruit / genetics*
  • Fruit / metabolism
  • Gene Expression Regulation, Plant / genetics*
  • Genes, Plant / genetics*
  • Genes, Plant / physiology
  • Lignin / metabolism*
  • Metabolic Networks and Pathways / genetics
  • Metabolic Networks and Pathways / physiology
  • Phylogeny
  • Plant Proteins / genetics*
  • Plant Proteins / physiology
  • Transcription Factors / genetics*
  • Transcription Factors / physiology


  • Plant Proteins
  • Transcription Factors
  • Lignin

Associated data

  • GENBANK/JF815556
  • GENBANK/KM506571