Abstract
The seed maturation program is repressed during germination and seedling development so that embryonic genes are not expressed in vegetative organs. Here, we describe a regulator that represses the expression of embryonic seed maturation genes in vegetative tissues. ASIL1 (for Arabidopsis 6b-interacting protein 1-like 1) was isolated by its interaction with the Arabidopsis thaliana 2S3 promoter. ASIL1 possesses domains conserved in the plant-specific trihelix family of DNA binding proteins and belongs to a subfamily of 6b-interacting protein 1-like factors. The seedlings of asil1 mutants exhibited a global shift in gene expression to a profile resembling late embryogenesis. LEAFY COTYLEDON1 and 2 were markedly derepressed during early germination, as was a large subset of seed maturation genes, such as those encoding seed storage proteins and oleosins, in seedlings of asil1 mutants. Consistent with this, asil1 seedlings accumulated 2S albumin and oil with a fatty acid composition similar to that of seed-derived lipid. Moreover, ASIL1 specifically recognized a GT element that overlaps the G-box and is in close proximity to the RY repeats of the 2S promoters. We suggest that ASIL1 targets GT-box-containing embryonic genes by competing with the binding of transcriptional activators to this promoter region.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.