Overexpression of OsERF48 causes regulation of OsCML16, a calmodulin-like protein gene that enhances root growth and drought tolerance

Plant Biotechnol J. 2017 Oct;15(10):1295-1308. doi: 10.1111/pbi.12716. Epub 2017 Mar 27.


The AP2/ERF family is a plant-specific transcription factor family whose members have been associated with various developmental processes and stress tolerance. Here, we functionally characterized the drought-inducible OsERF48, a group Ib member of the rice ERF family with four conserved motifs, CMI-1, -2, -3 and -4. A transactivation assay in yeast revealed that the C-terminal CMI-1 motif was essential for OsERF48 transcriptional activity. When OsERF48 was overexpressed in an either a root-specific (ROXOsERF48 ) or whole-body (OXOsERF48 ) manner, transgenic plants showed a longer and denser root phenotype compared to the nontransgenic (NT) controls. When plants were grown on a 40% polyethylene glycol-infused medium under in vitro drought conditions, ROXOsERF48 plants showed a more vigorous root growth than OXOsERF48 and NT plants. In addition, the ROXOsERF48 plants exhibited higher grain yield than OXOsERF48 and NT plants under field-drought conditions. We constructed a putative OsERF48 regulatory network by cross-referencing ROXOsERF48 root-specific RNA-seq data with a co-expression network database, from which we inferred the involvement of 20 drought-related genes in OsERF48-mediated responses. These included genes annotated as being involved in stress signalling, carbohydrate metabolism, cell-wall proteins and drought responses. They included, OsCML16, a key gene in calcium signalling during abiotic stress, which was shown to be a direct target of OsERF48 by chromatin immunoprecipitation-qPCR analysis and a transient protoplast expression assay. Our results demonstrated that OsERF48 regulates OsCML16, a calmodulin-like protein gene that enhances root growth and drought tolerance.

Keywords: OsERF48; calmodulin-like protein; co-regulatory network; drought tolerance; root growth.

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Biomass
  • Calcium Signaling
  • Droughts*
  • Gene Expression Regulation, Plant*
  • Gene Regulatory Networks
  • Oryza / growth & development
  • Oryza / metabolism*
  • Plant Proteins / metabolism
  • Plant Roots / growth & development*
  • Plants, Genetically Modified
  • Promoter Regions, Genetic
  • Stress, Physiological
  • Transcription Factors / metabolism*


  • Plant Proteins
  • Transcription Factors

Associated data

  • GENBANK/EF090408
  • GENBANK/EF090412.1