Project description:The aim of this study was to examine the roles of Auxin Response Factors (ARFs) in flower gene expression. Flowers from arf6 arf8 plants undergo a developmental arrest at approximately stage 12, just prior to flower opening. Wild-type, ARF6/arf6 arf8/arf8, and arf6 arf8 plants were treated with 10 uM indole-3-acetic acid for thirty minutes to identify genes that respond rapidly to auxin in an ARF6/ARF8-dependent manner. Experiment Overall Design: Wild-type, ARF6/arf6 arf8/arf8, and arf6 arf8 plants were sprayed with 10 mM indole-3-acetic acid in 1% methanol, 0.05% Tween-20. Thirty minutes after treatment, flowers (stage 1-14) were collected, frozen in liquid nitrogen, and used for RNA extraction.
Project description:The aim of this study was to examine the roles of Auxin Response Factors (ARFs) in flower gene expression. Flowers from arf6 arf8 plants undergo a developmental arrest at approximately stage 12, just prior to flower opening. Wild-type, ARF6/arf6 arf8/arf8, and arf6 arf8 plants were treated with 10 uM indole-3-acetic acid for thirty minutes to identify genes that respond rapidly to auxin in an ARF6/ARF8-dependent manner. Keywords: auxin response; comparison of wild type and arf6 arf8 mutants
Project description:Flower maturation consists of several events that contribute to reproductive success as flowers open, including petal expansion, stamen filament elongation, pollen release, nectary maturation, stigma growth, and gynoecium maturation to support pollen tube growth. The Arabidopsis transcription factors ARF6 (Auxin Response Factor 6) and ARF8 regulate all of these processes, in part by activating jasmonate biosynthesis. Jasmonates in turn activate genes encoding the transcription factors MYB21 and MYB24, which mediate a subset of the processes controlled by ARF6 and ARF8. This experiment was designed to characterize gene expression in flowers before and after they open, and to determine how arf6 arf8 and myb21 myb24 mutation combinations affect these gene expression patterns. Three biological replicates were prepared at each of two developmental stages, stage 12 (oldest closed buds) and stage 13 (youngest open flowers), for three genotypes (Wild type, arf6-2 arf8-3, and myb21-5 myb24-5). For the mutant genotypes, stage 13 flowers do not actually open, so corresponding flowers of equivalent age were chosen based on the position of open flowers in wild-type inflorescences.
Project description:The aim of this study was to examine the contribution of ARF6 and ARF8 to flower gene expression. Flowers from arf6 arf8 plants undergo a developmental arrest at approximately stage 12, just prior to flower opening. Flowers from wild-type, arf6/arf6 ARF8/arf8, and arf6 arf8 plants were separated into stage 1-10 flowers, stage 11+12 flowers, and stage 13-14 flowers to define the developmental stages at which ARF6 and ARF8 are required for gene expression.
Project description:The aim of this study was to examine the contribution of ARF6 and ARF8 to flower gene expression. Flowers from arf6 arf8 plants undergo a developmental arrest at approximately stage 12, just prior to flower opening. Flowers from wild-type, ARF6/arf6 arf8/arf8, and arf6 arf8 plants were separated into stage 1-10 flowers, stage 11+12 flowers, and stage 13-14 flowers to define the developmental stages at which ARF6 and ARF8 are required for gene expression. Keywords: comparison of wild type and arf6 arf8 mutants
Project description:Flower maturation consists of several events that contribute to reproductive success as flowers open, including petal expansion, stamen filament elongation, pollen release, nectary maturation, stigma growth, and gynoecium maturation to support pollen tube growth. The Arabidopsis transcription factors ARF6 (Auxin Response Factor 6) and ARF8 regulate all of these processes, in part by activating jasmonate biosynthesis. Jasmonates in turn activate genes encoding the transcription factors MYB21 and MYB24, which mediate a subset of the processes controlled by ARF6 and ARF8. This experiment was designed to characterize gene expression in flowers before and after they open, and to determine how arf6 arf8 and myb21 myb24 mutation combinations affect these gene expression patterns.
Project description:Auxin is a major plant hormone for both development and environmental adaptation. Auxin responses are context dependent and highly modulated by light, temperature, the circadian clock, brassinosteroid, and gibberellin, but the underlying mechanisms remain unclear. Here, we show that auxin signaling integrates with other signals through direct interactions of AUXIN RESPONSE FACTOR6 (ARF6) with PHYTOCHROME INTERACTING FACTOR4 (PIF4), the brassinosteroid-signaling transcription factor BZR1, and the gibberellin-signaling repressor RGA. ChIP-Seq and RNA-Seq experiments show that ARF6, PIF4, and BZR1 bind to largely overlapping targets in the genome and synergistically activate gene expression. In vitro and in vivo assays show that ARF6-promoter binding is enhanced by PIF4 and BZR1 but blocked by RGA. Furthermore, a tripartite HLH/bHLH module feedback regulates PIF activity and thus modulates auxin sensitivity according to additional developmental and environmental cues. Our results demonstrate a central growth-regulation transcriptional network that coordinates hormonal, environmental, and developmental control of cell elongation and plant growth. Genome-wide identification of ARF6 DNA-binding sites in etiolated Arabidopsis seedlings.
Project description:Auxin is a major plant hormone for both development and environmental adaptation. Auxin responses are context dependent and highly modulated by light, temperature, the circadian clock, brassinosteroid, and gibberellin, but the underlying mechanisms remain unclear. Here, we show that auxin signaling integrates with other signals through direct interactions of AUXIN RESPONSE FACTOR6 (ARF6) with PHYTOCHROME INTERACTING FACTOR4 (PIF4), the brassinosteroid-signaling transcription factor BZR1, and the gibberellin-signaling repressor RGA. ChIP-Seq and RNA-Seq experiments show that ARF6, PIF4, and BZR1 bind to largely overlapping targets in the genome and synergistically activate gene expression. In vitro and in vivo assays show that ARF6-promoter binding is enhanced by PIF4 and BZR1 but blocked by RGA. Furthermore, a tripartite HLH/bHLH module feedback regulates PIF activity and thus modulates auxin sensitivity according to additional developmental and environmental cues. Our results demonstrate a central growth-regulation transcriptional network that coordinates hormonal, environmental, and developmental control of cell elongation and plant growth.