%0 Journal Article
%T Insights into the molecular mechanism of RGL2-mediated inhibition of seed germination in Arabidopsis thaliana
%A Petra Stamm
%A Pratibha Ravindran
%A Bijayalaxmi Mohanty
%A Ee Tan
%A Hao Yu
%A Prakash P Kumar
%J BMC Plant Biology
%D 2012
%I BioMed Central
%R 10.1186/1471-2229-12-179
%X Gene ontology of the transcriptome differentially regulated by RGL2, as well as extensive cross-comparison with other available microarray data indicates that RGL2-mediated inhibition of germination causes seeds to enter a state of dormancy. RGL2 also appears to differentially regulate a number of transcription factors, many of which are known to be involved in light- or phytohormone-mediated aspects of germination. A promoter analysis of differentially expressed genes identified an enrichment of several motifs that can be bound by specific transcription factors, for example GAMYB, ARF1, or Dof-type zinc fingers. We show that Dof-binding motifs indeed play a role in RGL2-mediated transcription. Using Chromatin Immunoprecipitation (ChIP), we show that RGL2 directly downregulates at least one cell wall modifying enzyme, which is predicted to constrain cell growth thereby leading to inhibition of seed germination.Our results reveal that RGL2 controls various aspects of germination. Through the repression of cell wall modifying enzymes, cell growth is directly constrained to inhibit germination. Furthermore, RGL2 likely interacts with various types of proteins to regulate transcription, and differentially regulates several transcription factors. Collectively, our data indicate that gibberellins, acting via RGL2, control several aspects of seed germination.Gibberellins are phytohormones regulating growth and development throughout a plant¡¯s life cycle; they are essential in processes such as stem elongation, floral development and seed germination [1-4]. The importance of gibberellins in these processes is most obvious in gibberellin-deficient mutants; GIBBERELLIC ACID REQUIRING 1 (GA1) encodes for the ent-kaurene synthetase A of the gibberellin biosynthetic pathway, ga1 plants are therefore unable to synthesise gibberellins. These mutants are extremely dwarfed, male-sterile, and most importantly their seeds fail to germinate without exogenous gibberellin [5,6].Significa
%K RGL2
%K Seed germination
%K Dormancy
%K Gibberellins
%K DELLAs
%K Arabidopsis microarray
%U http://www.biomedcentral.com/1471-2229/12/179