Project description:The debate on the origin and evolution of flowers has recently entered the field of developmental genetics, with focus on the design of the ancestral floral regulatory program. Flowers can differ dramatically among angiosperm lineages, but in general, sterile perianth organs surrounding stamens (male reproductive organs) and carpels (female reproductive organs) constitute the basic floral structure. However, the basal angiosperm lineages exhibit spectacular diversity in the number, arrangement, and structure, of floral organs, while the evolutionarily derived monocot and eudicot lineages share a far more uniform floral ground plan. As such, regulatory mechanisms underlying the archetypal floral plan, for instance that of the eudicot genetic model Arabidopsis thaliana, are unlikely to apply to the original flowers. Here we show that broadly overlapping transcriptional programs characterise the floral transcriptome of the basal angiosperm Persea americana (avocado), while floral gene expression domains are typically organ-specific in Arabidopsis. Our findings extend the “fading borders” model for basal angiosperms from organ identity genes to the downstream floral transcriptome, and suggest that the combinatorial mechanism for organ identity may not operate in basal angiosperms as it does in Arabidopsis. Furthermore, fading expression of components of the stamen transcriptome in central and peripheral regions of Persea flowers resembles the developmental program of the hypothesized gymnosperm “floral progenitor”. Accordingly, in contrast to the canalized organ-specific regulatory apparatus of Arabidopsis, floral development may have been originally regulated by overlapping transcriptional cascades with fading gradients of influence from focal to bordering organs.
Project description:We conducted micro-array analysis to quantify the global transcriptome variations in floral organs of a male and female tree allowing for identification of sex-linked transcripts. We used RNA samples from male floral buds in August and female floral buds in Spetemeber. Bud scale were removed. While the sampling time differed, the developmental stage of the floral organs was similar between the male and female.
Project description:Investigation of differentially expressed gene in floral tissues of of Brassica rapa in comparison with leaves as control To unravel the transcriptomic changes associated with small early floral buds (<2 mm; FB2), large early floral buds (2-4 mm; FB4), stamen (ST) and carpel (CP) tissues, transcriptome profiling was carried out with Br300K oligo microarray.
Project description:Flower development is a dynamics process in which floral organs are produced from pools of stem cells residing in meristems (Smyth et al., 1990). In order to obtain a high resolution map of the changes of gene expression during this process thus to provide insights into specific expression patterns and their underlying gene regulatory networks, an inducible system which allows us to obtain synchronized flowers (Wellmer et al., 2006) was used to collect stage-specific floral tissues at four stages (stages 0, 2, 4 and 8) for transcriptome profiling by RNA-seq . These stages represent the status of inflorescence meristem, floral meristem specification, floral organ specification and floral organ differentiation, respectively during Arabidopsis flower development.
Project description:We conducted micro-array analysis to quantify the global transcriptome variations in floral organs of a male and female tree allowing for identification of sex-linked transcripts. We used RNA samples from male floral buds in August and female floral buds in September. Bud scale were removed. While the sampling time differed, the developmental stage of the floral organs was similar between the male and female. Five independent samples of floral bud tissues with bud scales removes were collected from the upper crown of a sexually mature male tree and female tree. RNA was extracted from tissues and hybridized on Affymetrix Genechip Poplar Genome Array.
Project description:The debate on the origin and evolution of flowers has recently entered the field of developmental genetics, with focus on the design of the ancestral floral regulatory program. Flowers can differ dramatically among angiosperm lineages, but in general, sterile perianth organs surrounding stamens (male reproductive organs) and carpels (female reproductive organs) constitute the basic floral structure. However, the basal angiosperm lineages exhibit spectacular diversity in the number, arrangement, and structure, of floral organs, while the evolutionarily derived monocot and eudicot lineages share a far more uniform floral ground plan. As such, regulatory mechanisms underlying the archetypal floral plan, for instance that of the eudicot genetic model Arabidopsis thaliana, are unlikely to apply to the original flowers. Here we show that broadly overlapping transcriptional programs characterise the floral transcriptome of the basal angiosperm Persea americana (avocado), while floral gene expression domains are typically organ-specific in Arabidopsis. Our findings extend the âfading bordersâ model for basal angiosperms from organ identity genes to the downstream floral transcriptome, and suggest that the combinatorial mechanism for organ identity may not operate in basal angiosperms as it does in Arabidopsis. Furthermore, fading expression of components of the stamen transcriptome in central and peripheral regions of Persea flowers resembles the developmental program of the hypothesized gymnosperm âfloral progenitorâ. Accordingly, in contrast to the canalized organ-specific regulatory apparatus of Arabidopsis, floral development may have been originally regulated by overlapping transcriptional cascades with fading gradients of influence from focal to bordering organs. Expression profiles of inflorescence buds, pre-meiotic floral buds, inner and outer tepals, stamens, carpels, initiating fruit, and leaves were assessed in an interwoven double loop design for eight samples with 16 arrays. Sample materials were collected from two individuals (biological replicates) cultivated on the University of Floridaâs Gainesville campus, and RNA was isolated twice for technical replication. Thus, four RNA extractions from each of the eight tissue types listed above were individually labeled with Cy3 (twice) or Cy5 (twice) and hybridized with four other Cy3 or Cy5 labeled samples as a dual channel array system.
Project description:The current experiment was designed to obtain a broad characterization of the genetic pathways acting in early Aquilegia coerulea floral meristem development. We conducted an in-depth transcriptome profiling of early floral development in A. coerulea at four finely dissected developmental stages, with eight biological replicates per stage. . The developmental window we sequenced sampled stages that started with a late phase of stamen initiation, covered the period of FM termination, and ended with the initial stage of morphogenesis of the floral organs.
Project description:We conducted micro-array analysis to quantify the global transcriptome variations in floral buds through the course of the year allowing for identification of changing developmental signals. We used RNA samples from floral buds, with bud scale removed, in the upper crown of a sexually mature Populus deltoides tree 2 hours after sunrise.