JOURNAL ARTICLE

IMB1, a bromodomain protein induced during seed imbibition, regulates ABA- and phyA-mediated responses of germination in Arabidopsis

Paula Duque, Nam-Hai Chua
Plant Journal 2003, 35 (6): 787-99
12969431
We report the characterization of a plant gene encoding a member of the BET subgroup of bromodomain proteins, a novel class of putative transcription factors. Imbibition-inducible 1 (IMB1) appears to be a nuclear protein as suggested by subcellular localization in onion epidermal cells using an IMB1-yellow fluorescent protein (YFP) fusion protein. In Arabidopsis thaliana, IMB1 is expressed at very low levels in dry seeds, but is markedly induced during seed imbibition. In addition, IMB1 transcript levels are down regulated during germination. Seeds of a loss-of-function mutant allele, imb1, show impaired cotyledon greening during germination in abscisic acid (ABA) and express higher levels of ABI5 protein than the wild type. Moreover, imb1 seeds are deficient in the phytochrome A (phyA)-mediated very-low-fluence response of germination. Microarray analysis revealed that genes included in different functional categories, such as cell-wall metabolism or plastid function, are repressed in imbibed imb1 seeds. Mutant imb1 plants appear normal, indicating that IMB1 is involved in regulating a specific developmental stage. Taken together, these results show that IMB1 plays a role in the promotion of seed germination by both negatively and positively regulating the ABA and phyA transduction pathways, respectively. In imbibed seeds, IMB1 modulates the transcription of a battery of genes, providing clues on its mode of action.

Full Text Links

Find Full Text Links for this Article

Discussion

You are not logged in. Sign Up or Log In to join the discussion.

Trending Papers

Remove bar
Read by QxMD icon Read
12969431
×

Save your favorite articles in one place with a free QxMD account.

×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"