Spatiotemporal analysis of shade-induced transcriptional reprogramming in Arabidopsis reveals patterns underlying organ-specific growth
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ABSTRACT: In response to neighbor proximity plants increase growth of specific organs (e.g. hypocotyl) to enhance access to sunlight. Shade enhances the activity of Phytochrome Interacting Factors (PIFs) by releasing those bHLH transcription factors from phytochrome B-mediated inhibition. PIFs promote elongation by inducing auxin production in cotyledons. In order to elucidate spatiotemporal aspects of the neighbor proximity response, we analyzed changes in transcript abundance at different time points during a shade treatment in dissected cotyledons and hypocotyls. We concentrated our analysis on these two organs because the former is considered as the primary shade-sensing organ while elongation is rapidly triggered in the hypocotyl. We conclude that PIFs initiate transcriptional reprogramming in both organs within 15 minutes comprising regulated expression of several early auxin response genes. This suggests that hypocotyl growth is elicited by both local and distal auxin signals. With time the transcriptional response diverges increasingly between organs. We identify genes whose differential expression may underlie organ-specific elongation. Finally, we uncover a growth promotion gene expression signature shared between responses to different environments and organs.
ORGANISM(S): Arabidopsis thaliana
PROVIDER: GSE81202 | GEO | 2017/01/17
SECONDARY ACCESSION(S): PRJNA320878
REPOSITORIES: GEO
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