Plant Molecular Biology

, Volume 71, Issue 1–2, pp 39–50 | Cite as

Over-expression of an AT-hook gene, AHL22, delays flowering and inhibits the elongation of the hypocotyl in Arabidopsis thaliana

Article

Abstract

The Arabidopsis genome encodes 29 AHL (AT-hook motif nuclear localized) proteins, but the function for most of them remains unknown. We report here a study of the AHL22 gene, which was originally identified as a gain-of-function allele that enhanced the phenotype of the cry1 cry2 mutant. AHL22 is a nuclear protein with the binding activity for an AT-rich DNA sequence. AHL22 overexpression delayed flowering and caused a constitutive photomorphogenic phenotype. The loss-of-function AHL22 mutant showed no clear phenotype on flowering, but slightly longer hypocotyls. However, silencing four AHL genes (AHL22, AHL18, AHL27, and AHL29) resulted in early flowering and enhanced ahl22-1 mutant phenotype on the growth of hypocotyls, suggesting genetic redundancy of AHL22 with other AHL genes on these plant developmental events. Further analysis showed that AHL22 controlled flowering and hypocotyl elongation might result from primarily the regulation of FT and PIF4 expression, respectively.

Keywords

Arabidopsis thaliana AT-hook Flowering time Hypocotyl Photomorphogenesis 

Supplementary material

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Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  1. 1.Institute of Crop Sciences, The National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI)Chinese Academy of Agricultural SciencesHaidian District, BeijingPeople’s Republic of China
  2. 2.Department of Molecular, Cell & Developmental BiologyUniversity of CaliforniaLos AngelesUSA

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