Plant Molecular Biology

, Volume 75, Issue 1, pp 107–127

Functional characterization of four APETALA2-family genes (RAP2.6, RAP2.6L, DREB19 and DREB26) in Arabidopsis

  • Sowmya Krishnaswamy
  • Shiv Verma
  • Muhammad H. Rahman
  • Nat N. V. Kav
Article

DOI: 10.1007/s11103-010-9711-7

Cite this article as:
Krishnaswamy, S., Verma, S., Rahman, M.H. et al. Plant Mol Biol (2011) 75: 107. doi:10.1007/s11103-010-9711-7

Abstract

APETALA2 (AP2) transcription factors (TFs) play very important roles in plant growth and development and in defense response. Here, we report functional characterization of four AP2 TF family genes [(RAP2.6 (At1g43160), RAP2.6L (At5g13330), DREB 26 (At1g21910) and DREB19 (At2g38340)] that were identified among NaCl inducible transcripts in abscisic acid responsive 17 (ABR17) transgenic Arabidopsis in our previous microarray analyses. DREB19 and DREB26 function as transactivators and localize in the nucleus. All four genes were abundant in early vegetative and flowering stages, although the magnitude of the expression varied. We observed tissue specific expression patterns for RAP2.6, RAP2.6L, DREB19 and DREB26 in flowers and other organs. RAP2.6 and RAP2.6L were responsive to stress hormones like jasmonic acid, salicylic acid, abscisic acid and ethylene in addition to salt and drought. DREB19 and DREB26 were less responsive to stress hormones, but the former was highly responsive to salt, heat and drought. Overexpression of RAP2.6 in Arabidopsis resulted in a dwarf phenotype with extensive secondary branching and small siliques, and DREB26 overexpression resulted in deformed plants. However, overexpression of RAP2.6L and DREB19 enhanced performance under salt and drought stresses without affecting phenotype. In summary, we have demonstrated that RAP2.6, RAP2.6L, DREB26 and DREB19 are transactivators, they exhibit tissue specific expression, and they participate in plant developmental processes as well as biotic and/or abiotic stress signaling. It is possible that the results from this study on these transcription factors, in particular RAP2.6L and DREB19, can be utilized in developing salt and drought tolerant plants in the future.

Keywords

ArabidopsisAP2Transcription factorsStress tolerance

Supplementary material

11103_2010_9711_MOESM1_ESM.pdf (159 kb)
Supplementary material 1 (PDF 158 kb)

Copyright information

© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  • Sowmya Krishnaswamy
    • 1
  • Shiv Verma
    • 1
  • Muhammad H. Rahman
    • 1
  • Nat N. V. Kav
    • 1
  1. 1.Department of Agricultural, Food and Nutritional ScienceUniversity of AlbertaEdmontonCanada