Project description:rs09-09_della-dark - della-regulation in darkness versus light - Identification of DELLA-dependent downstream targets in darkness - Aim was to determine downstream target of DELLA proteins involved in skotomorphogenesis. Wt, ga1-3, ga1-3_rga_gai_rgl1_rgl2_rgl3 global seeds were sterilized, sown on MS agar plates then put for stratification for 3 days at 4°C. Plates were placed in growth cabinet at 22°C for 5 days in darkness or in continous light. Keywords: gene knock out
Project description:rs09-09_della-dark - della-regulation in darkness versus light - Identification of DELLA-dependent downstream targets in darkness - Aim was to determine downstream target of DELLA proteins involved in skotomorphogenesis. Wt, ga1-3, ga1-3_rga_gai_rgl1_rgl2_rgl3 global seeds were sterilized, sown on MS agar plates then put for stratification for 3 days at 4°C. Plates were placed in growth cabinet at 22°C for 5 days in darkness or in continous light. Keywords: gene knock out 9 dye-swap - CATMA arrays
Project description:Use 3ʹ region extraction and deep sequencing (3'READS) and bioinformatics techniques to profile alternative polyadenylation and gene regulation in plant Arabidopsis thaliana exposed to light and darkness
Project description:The developmental switch from skotomorphogenesis to photomorphogenesis is critical for the survival and growth of plants, but its regulatory mechanism remains unclear. Here, we report that the steroid hormone brassinosteroids (BRs) play crucial roles in the transition from skotomorphogenesis to photomorphogenesis by regulating chlorophyll biosynthesis to promote the greening of etiolated seedlings upon light exposure. Seedlings of BR-deficient mutant det2-1 accumulated excess protochlorophyllide when grown in darkness, resulting in photo-oxidative damage upon exposure to light. Conversely, the gain-of-function mutant bzr1-1D suppressed the protochlorophyllide-accumulated phenotype of det2-1, thereby promoting greening of etiolated seedlings. Genetic analysis indicated that phytochrome-interacting factors (PIFs) were required for BZR1-promoted seedlings greening. Furthermore, we revealed that the GROWTH REGULATING FACTOR 7 (GRF7) and GRF8 were induced by BZR1 and PIF4 to repress the chlorophyll biosynthesis and promote seedling greening. Suppression the functions of GRFs by overexpressing microRNA396a (miR396a) caused the high-accumulated photochlorophyllide in darkness and more serious photobleach upon light exposure. Additionally, BZR1, PIF4 and GRF7 interact with each other and precisely regulate the expression of chlorophyll biosynthetic genes. Our findings revealed an essential role of brassinosteroid in promoting seedling development and survival during the critical initial emergence of seedlings from subterranean darkness to sunlight.
Project description:The hormones gibberellins (GA) control many aspects of plant growth and development thruough the whole life cycle of the plant. For instance, GA participate in the establishment of the skotomorphogenic developmental program that is triggered when seeds germinate in darkness, i.e. under the soil. Under these conditions seedlings appear etiolated and developmental features usually triggered by light are kept repressed. The GA signaling elements GAI and RGA have a major, partially redundant role in this process. These proteins belong to the DELLA family of transcriptional regulators and are destabilized by GA, acting as negative regulators of the pathway. In order to understand the molecular basis of the regulation of the skotomorphogenesis by GA, we sought to identify early target genes of the activity of GAI in etiolated seedlings. For that purpose we analyzed rapid, global changes in gene expression in response to a transient accummulation of a dominant version of GAI, gai-1, which is resistant to GA-induced destabilization.
Project description:DELLA proteins act as hubs that relay environmental information to the multiple transcriptional circuits that control growth and development through physical interaction with transcription factors from different families. We have analyzed the presence of one DELLA protein at the Arabidopsis genome by chromatin immunoprecipitation coupled to large-scale sequencing and we find that it binds at the promoters of multiple genes. Enrichment analysis shows a strong preference for cis elements recognized by specific transcription factor families. In particular, we demonstrate that DELLA proteins are recruited by type-B ARABIDOPSIS RESPONSE REGULATORS (ARR) to the promoters of cytokinin-regulated genes, where they act as transcriptional co-activators. The biological relevance of this mechanism is underpinned by the necessity of simultaneous presence of DELLAs and ARRs to restrict root meristem growth and to promote photomorphogenesis.
Project description:To understand how GA functions in regulating embryo development, a genome-wide transcriptomic analysis was carried out using 9DAF seeds dissected from siliques of dellaq (rga28 gai rgl1 rgl2) and the wild-type (col-0-2) grown in full-spectrum white fluorescent light at 22°C under long day conditions (16 h light/8 h dark). Then we found that GA regulates embryo development via DELLA-LEC1interaction, a subsequent genome-wide transcriptomic analysis was carried out using 9DAF seeds dissected from siliques of lec1-4 and the wild-type (col-0-1) in the same growth condition. Basing on the criteria of 1.5-fold cutoff for the genes with 5% false discovery rate, we first identified the differentially expressed genes in dellaq vs col-0-2, lec1-4 vs Col-0-1 subsets, which are referred to as DELLA and LEC1 regulated genes. These data reveal that DELLAs and LEC1 co-target a set of common genes in late embryogenesis, strongly supporting the role of DELLA-LEC1 in embryo development.
Project description:Transcriptional profiling of Arabidopsis thaliana Ler wildtype and eid3 (empfindlicher im dunkelroten Licht 3) mutant seedlings in darkness and 45 min after a red-light pulse.
Project description:We report the changes in H3K9ac in Arabidopsis thaliana seedlings grown in continuous white light, darkness or darkness and 1 hour of red light