Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

Angiosperms (flowering plants) evolved relatively recently and are substantially diverged from early land plants (bryophytes, lycophytes, and others [1]). The phytohormone gibberellin (GA) adaptively regulates angiosperm growth via the GA-DELLA signaling mechanism [2-7]. GA binds to GA receptors (GID1s), thus stimulating interactions between GID1s and the growth-repressing DELLAs [8-12]. Subsequent 26S proteasome-mediated destruction of the DELLAs promotes growth [13-17]. Here we outline the evolution of the GA-DELLA mechanism. We show that the interaction between GID1 and DELLA components from Selaginella kraussiana (a lycophyte) is GA stimulated. In contrast, GID1-like (GLP1) and DELLA components from Physcomitrella patens (a bryophyte) do not interact, suggesting that GA-stimulated GID1-DELLA interactions arose in the land-plant lineage after the bryophyte divergence ( approximately 430 million years ago [1]). We further show that a DELLA-deficient P. patens mutant strain lacks the derepressed growth characteristic of DELLA-deficient angiosperms, and that both S. kraussiana and P. patens lack detectable growth responses to GA. These observations indicate that early land-plant DELLAs do not repress growth in situ. However, S. kraussiana and P. patens DELLAs function as growth-repressors when expressed in the angiosperm Arabidopsis thaliana. We conclude that the GA-DELLA growth-regulatory mechanism arose during land-plant evolution and via independent stepwise recruitment of GA-stimulated GID1-DELLA interaction and DELLA growth-repression functions.

Original publication

DOI

10.1016/j.cub.2007.06.037

Type

Journal article

Journal

Curr Biol

Publication Date

17/07/2007

Volume

17

Pages

1225 - 1230

Keywords

Amino Acid Sequence, Arabidopsis, Arabidopsis Proteins, Biological Evolution, Bryopsida, Gibberellins, Molecular Sequence Data, Plant Development, Plant Growth Regulators, Plants, Receptors, Cell Surface, Selaginellaceae, Signal Transduction, Transcription Factors