Screening for genes differentially expressed in different tomato pedicel regions by expression microarray analysis. (A) Flower pedicel regions used in this study. Tomato abscission zones (AZs) form in an intermediate region in the pedicels and have a knuckle-like structure in which a groove forms for abscission. The pedicel region between the AZ and the main stem of the inflorescence is referred to as the proximal region (Prox) and the region between the AZ and the flower is referred to as the distal region (Dis). RNA from each region was extracted from five to twenty pedicels at anthesis. (B) A schematic of the genome-wide transcriptome screen for genes up-regulated in the AZ. Expression was compared between AZ and Prox or Dis at anthesis by microarray analyses with 3 independently prepared samples. Two circles in the Venn diagram indicate the number of probes showing higher signal from AZ than that from Prox or Dis, and the 112 probes in the overlap were further investigated in this study. By merging results for probes encoding the same gene, we found 89 independent genes up-regulated in the AZ. (C) A schematic of the screening for transcription factor and phytohormone-related genes differentially expressed between Prox and Dis. The expression profiles of Prox and Dis examined by microarray analyses were compared and genes for transcription factors or phytohormone-related activity were selected from the genes exhibiting significantly different expression patterns between the two regions.
Nakano et al. BMC Plant Biology 2013 13:40 doi:10.1186/1471-2229-13-40