Plant Cell Reports

, Volume 33, Issue 1, pp 35–45 | Cite as

Characterization of two tomato AP2/ERF genes, SlCRF1 and SlCRF2 in hormone and stress responses

  • Xiuling Shi
  • Sarika Gupta
  • Aaron M. RashotteEmail author
Original Paper


Key message

SlCRF1 and SlCRF2 are expressed throughout the plant, prominently in vascular tissue. Each SlCRF has a distinct pattern of cytokinin induction and regulation by abiotic stresses in different organs.


Cytokinin is an essential plant hormone involved in the regulation of many growth and developmental processes. While many cytokinin signaling pathway components have been well characterized, the cytokinin response factors (CRFs) that form a branch of this pathway are less well understood. This study examines the tomato (Solanum lycopersicum (L.)) CRF genes, SlCRF1 and SlCRF2 presenting a detailed and novel characterization of their developmental expression patterns, transcriptional regulation by hormones particularly cytokinin, and response to abiotic stresses. Both SlCRF1 and SlCRF2 were predominantly expressed in vasculature in tissues throughout the plant, with an overall trend for greater SlCRF2 expression in younger organs. Hormone regulation of SlCRF1 and SlCRF2 transcripts is primarily by cytokinin, which induced both SlCRFs in different organs over a range of developmental stages. The strongest cytokinin induction was found in leaves, with SlCRF2 induced to a higher level than SlCRF1. Examination of SlCRF transcripts during abiotic stress responses revealed that SlCRF1 and SlCRF2 have distinct patterns of regulation from each other and between leaves and roots. Novel connections between SlCRFs and stresses were found in particular including a strong induction of SlCRF1 by cold stress and a strong induction of SlCRF2 by oxidative stress in roots and unique patterns of induction/repression linking both SlCRFs to drought stress and response during recovery. Overall, this study provides a clear picture of SlCRF1 and SlCRF2 expression patterns across tissues during development and in response to cytokinin and specific stresses, indicating their importance in plant growth and environmental responses.


SlCRF Cytokinin Tomato Abiotic stress 



We thank all Rashotte lab members for their help during this study. This work was funded by USDA-NRI Grant 2008-35304-04457 and AAES-HATCH Grant 370220-310007-2055.

Supplementary material

299_2013_1510_MOESM1_ESM.tif (1.2 mb)
Online Resource 1 Microarray data for SlCRF1 expression from the tomato eFP browser at The strong expression of SlCRF1 in leaves and unripe fruits supports the spatial expression of SlCRF1observed through SlCRF1 promoter::GUS reporter line analysis (TIFF 1259 kb)
299_2013_1510_MOESM2_ESM.tif (1.2 mb)
Online Resource 2 Microarray data for SlCRF2 expression from the tomato eFP browser at The expression of SlCRF2 in leaves and roots supports the spatial expression of SlCRF2 observed through SlCRF2 promoter::GUS reporter line analysis (TIFF 1247 kb)


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Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  1. 1.Department of Biological SciencesAuburn UniversityAuburnUSA

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