Light releases the TCP4-SAUR16/50 transcription module from the repression of PIF3 to facilitate cotyledon opening during de-etiolation [ChIP-Seq]
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ABSTRACT: Etiolated Arabidopsis seedlings open their cotyledons and halt rapid elongation of hypocotyl when exposed to light (de-etiolation). Major light responsive components in this process have been identified and signaling pathways revealed, yet how the organ-specific light responses are achieved remains unknown. Here we report that a developmental regulator TCP4 (TEOSINTE BRANCHED1, CYCLOIDEA, and PCF) participates in photomorphogenesis and facilitates light-induced cotyledon-opening. We demonstrate that TCP4-like transcriptional factors, which predominantly express in cotyledons of both light and dark seedlings, activate SAUR16 and SAUR50 in response to light. Light repressor PIF3 (or PIFs, phytochrome-interacting factors), which accumulates in etiolated seedlings and rapidly declines upon light exposure, inhibits TCP4 promoter-binding and prevents activation of SAUR16/50 in darkness. Our study reveals how an interplay between light responsive factors and developmental regulators leads to signal-dependent and tissue-specific regulation of gene expressions, which ultimately resulted in organ-specific light responses during de-etiolation.
ORGANISM(S): Arabidopsis thaliana
PROVIDER: GSE115358 | GEO | 2019/03/28
REPOSITORIES: GEO
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