Project description:This experiment aimed to investigate which genes are involved in the early photomorphogenic root development of dark grown roots when only the shoot was exposed to light.
Project description:To identify and characterize genes required for tissue-specific phytochrome responses during hypocotyl development in far-red-light grown bvr lines, we performed gene transcriptional profiling using bvr lines with mesophyll-specific phytochrome inactivation (cab3: :pBVR2). We identified several candidate genes whose expression is significantly altered in lines with mesophyll tissue-specific BVR expression (Cab3::pBVR2), compared to constitutive phytochrome inactivation lines, i.e. 35S-driven BVR lines (35S::pBVR3). No-0 is used as wild-type (WT)
Project description:Arabidopsis seedlings undergo photomorphogenic development even in darkness when the function of De-etiolated 1 (DET1), a repressor of photomorphogenesis, is disrupted. Our results indicate that DET1 directly interacts with a group of transcription factors known as the phytochrome-interacting factors (PIFs). Furthermore, our results suggest that DET1 positively regulates PIF protein levels primarily by stabilizing PIF proteins in the dark. Genomic analysis also revealed that DET1 may control the expression of light-regulated genes to mediate photomorphogenesis partially through PIFs.
Project description:Jasmonates are key regulators of the balance between defence and growth in plants. However, the molecular mechanisms by which activation of defences reduces growth are not yet understood. Here, we analyze the role of MYC transcription factors (TFs) and JA in photomorphogenic growth. We found that multiple myc mutants share light-related phenotypes with mutants of the phytochrome B photoreceptor, regarding seed germination and hypocotyl growth. Over-expression of MYC2 in a phyB background partially suppressed its long hypocotyl phenotype. We show that the activity of MYC TFs is partially independent of COI1 and that JA inhibition of hypocotyl growth acts through alteration of auxin homeostasis and is partially independent of the classical JA signalling pathway. Transcriptomic analysis of multiple myc mutants confirmed that MYCs are required for full expression of R-light regulated genes, including the master regulator HY5. ChIP-Seq analyses revealed that MYC2 and MYC3 directly bind to the promoter of HY5 and that HY5 gene expression and protein levels are compromised in multiple myc mutants. Moreover, MYC2 and MYC3 share a high amount of direct targets with PIFs, and have an opposite effect on gene expression of these targets. Altogether, our results pinpoint MYCs as photomorphogenic TFs that regulate phytochrome responses by regulating PIFs targets and activating HY5 expression. This has important implication to understand the trade-off between growth and defence, since the same TFs that activate defence responses are photomorphogenic growth regulators.
Project description:Arabidopsis seedlings undergo photomorphogenic development even in darkness when the function of De-etiolated 1 (DET1), a repressor of photomorphogenesis, is disrupted. Our results indicate that DET1 directly interacts with a group of transcription factors known as the phytochrome-interacting factors (PIFs). Furthermore, our results suggest that DET1 positively regulates PIF protein levels primarily by stabilizing PIF proteins in the dark. Genomic analysis also revealed that DET1 may control the expression of light-regulated genes to mediate photomorphogenesis partially through PIFs. Total of twelve samples, two treatments and three genotypes, and each have three replicates.
