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.