Genome wide binding sites of the Arabidopsis B3 domain protein FUSCA3
Ontology highlight
ABSTRACT: FUSCA3 (FUS3) is a B3 domain transcription factor that is a member of the LEAFY COTYLEDON (LEC) group of genes. The LEC genes encode proteins that also include LEC2, a B3 domain factor related to FUS3, and LEC1, a CCAAT box binding factor. LEC1, LEC2 and FUS3 are essential for plant embryo development. We report ChIP-chip experiments using the Affymetrix tiling array to globally map binding sites for FUS3. Fangfang Wang and Sharyn E. Perry (2013) Plant Physiology preview FUSCA3 was expressed by the native promoter and included a C-terminal 10x-c-myc tag. This transgene was able to rescue the fus3-3 mutant. A second transgene (35S:AGL15) was present to allow establishment of stable somatic embryo cultures. ChIP was performed using anti-c-myc antibody (Myc-Tag (9B11) Mouse mAb; Cell Signaling 2276S) on tissue expressing FUS3-myc (three biological replicates) and on three controls of tissue expressing FUS3 (no epitope tag).
Project description:FUSCA3 (FUS3) is a B3 domain transcription factor that is a member of the LEAFY COTYLEDON (LEC) group of genes. The LEC genes encode proteins that also include LEC2, a B3 domain factor related to FUS3, and LEC1, a CCAAT box binding factor. LEC1, LEC2 and FUS3 are essential for plant embryo development. We report ChIP-chip experiments using the Affymetrix tiling array to globally map binding sites for FUS3. Fangfang Wang and Sharyn E. Perry (2013) Plant Physiology preview
Project description:During seed maturation, the embryo accumulates nutrition storage compounds such as oil and reserve proteins, and acquires dormancy and desiccation tolerance. Arabidopsis transcription factors LEC1, LEC2, FUS3 and ABI3 are known as the master regulators of seed maturation because all these events during the seed maturation are severely affected by the respective mutants. In addition, the lec1, lec2 and fus3 mutants exhibit some heterochronic characteristics, as exemplified by the development of true leaf-like cotyledons during embryogenesis. To characterize these mutants at the whole genome expression level, microarray experiments were performed. Developing seeds were dissected from the siliques of the lec1-1, lec2-1, or fus3-3 homozygous plants or the respective wild type plants (Col-0 for fus3-3, WS for lec1-1 and lec2-1) at 8 and 12 days after flowering. Seeds samples were obtained from triplicate batches of plants and used for RNA preparation.
Project description:During seed maturation, the embryo accumulates nutrition storage compounds such as oil and reservve proteins, and acquires dormancy and desiccation tolerance. Arabidopsis transcription factors LEC1, LEC2, FUS3 and ABI3 are known as the master regulators of seed maturation because all these events during the seed maturation are severely affected by the respective mutants. In addition, the lec1, lec2 and fus3 mutants exhibit some heterochronic characteristics, as exemplified by the development of true leaf-like cotyledons during embryogenesis. To characterize these mutants at the whole genome expression level, microarray experiments were performed.
Project description:During seed maturation, the embryo accumulates nutrition storage compounds such as oil and reservve proteins, and acquires dormancy and desiccation tolerance. Arabidopsis transcription factors LEC1, LEC2, FUS3 and ABI3 are known as the master regulators of seed maturation because all these events during the seed maturation are severely affected by the respective mutants. In addition, the lec1, lec2 and fus3 mutants exhibit some heterochronic characteristics, as exemplified by the development of true leaf-like cotyledons during embryogenesis. To characterize these mutants at the whole genome expression level, microarray experiments were performed.
Project description:During seed maturation, the embryo accumulates nutrition storage compounds such as oil and reserve proteins, and acquires dormancy and desiccation tolerance. Arabidopsis transcription factors LEC1, LEC2, FUS3 and ABI3 are known as the master regulators of seed maturation because all these events during the seed maturation are severely affected by the respective mutants. In addition, the lec1, lec2 and fus3 mutants exhibit some heterochronic characteristics, as exemplified by the development of true leaf-like cotyledons during embryogenesis. To characterize these mutants at the whole genome expression level, microarray experiments were performed. Developing seeds were dissected from the siliques of the abi3-6 homozygous plants or the respective wild type plants (Col-0) at 12 and 16 days after flowering. Seeds samples were obtained from triplicate batches of plants and used for RNA preparation.
Project description:Desiccation tolerance (DT) allowed seed plants to conquer ecosystems with long periods of limited water availability. This adaptive features allows seeds to remain dried for very long times without losing their ability to germinate. There is little information about all the signaling components required to achieve DT and on how transcription factors (TFs) modulate global DT processes. We performed RNA-seq experiment and carbohydrates profiles of lec1, lec2, fus3 and abi3, as well as their corresponding wild types, at three stages of seed development 15, 17 and 21 DAF (day after open flower) belonging to the seed desiccation period. A complex experimental design approach and regulatory networks prediction were used to identify differentially expressed genes specifically involved in DT process. In order to identify mechanisms involved in the acquisition of DT during seed development, we designed a comparative transcriptomic analysis between the seed desiccation intolerant (DI) mutants lec1-1, abi3-5 and fus3-3, the desiccation tolerant mutant lec2-1 and the desiccation tolerant weak allele of abi3 (abi3-1) with their respective wild type controls. This analysis should allow to identify genes that are differentially expressed in the desiccation intolerant mutants respect to tolerant mutants and WT controls.
Project description:Triacylglycerol (TAG) is the main storage lipid in plant seeds and the major form of plant oil used for food and, increasingly, for industrial and biofuel applications. Several transcription factors, including FUSCA3 (At3g26790, FUS3), are associated with regulation of embryo 3maturation and oil biosynthesis in seeds. However, the ability of FUS3 to increase TAG biosynthesis in other tissues has not been quantitatively examined. Here, we evaluated the ability of FUS3 to activate TAG accumulation in non-seed tissues. Overexpression of FUS3 driven by an estradiol-inducible promoter increased oil contents in Arabidopsis seedlings up to 6% of dry weight; more than 50 fold over controls. Eicosenoic acid, a characteristic fatty acid of Arabidopsis seed oil, accumulated to over 20% of fatty acids in cotyledons and leaves. These large increases depended on added sucrose, although without sucrose TAG increased 3-4 fold. Inducing the expression of FUS3 in tobacco BY2 cells also increased TAG accumulation, and co-expression of FUS3 and diacylglycerol acyltransferase 1 (DGAT1) further increased TAG levels to 4% of dry weight. BY2 cell growth was not altered by FUS3 expression, although Arabidopsis seedling development was impaired, consistent with the ability of FUS3 to induce embryo characteristics in non-seed tissues. Microarrays of Arabidopsis seedlings revealed that FUS3 overexpression increased expression of a higher proportion of genes involved in TAG biosynthesis than genes involved in fatty acid biosynthesis or other lipid pathways. Together these results provide additional insights into FUS3 functions in TAG metabolism and suggest complementary strategies for engineering vegetative oil accumulation.
Project description:The embryonic temporal regulator FUSCA3 (FUS3) plays major roles in the establishment of embryonic leaf identity and regulation of developmental timing. Loss-of-function mutations of this B3-domain transcription factor result in replacement of cotyledons with leaves and precocious germination, while constitutive misexpression causes the conversion of leaves into cotyledon-like organs and delays vegetative and reproductive phase transitions. To identify downstream targets of FUS3 involved in vegetative phase transitions, we performed microarray analysis on seedlings that transiently activate FUS3 using the AtML1:FUS3-GR-DEX inducible system. Using this construct, FUS3 is ectopically expressed in the ML1 or epidermal layer and becomes activated upon addition of dexamethasone. We found that activation of FUS3 after germination dampens the expression of genes involved in the biosynthesis and response to the plant hormone ethylene, while a loss-of-function fus3 mutant shows many phenotypes consistent with increased ethylene signaling. This FUS3-dependent regulation of ethylene signaling also impinges on timing functions outside of embryogenesis. Loss of FUS3 function results in accelerated vegetative phase change and this is again partially dependent on functional ethylene action. This alteration in vegetative phase transition is dependent on both embryonic and vegetative FUS3 function, suggesting that this important transcriptional regulator controls both embryonic and vegetative developmental timing. This study indicates that the embryonic regulator FUS3 not only regulates the embryonic-to-vegetative phase transition through hormonal regulation, but also functions postembryonically to modulate vegetative phase transitions by negatively regulating ethylene action.