Microarray Results for Selected Floral Regulatory Genes

Log10-transformed signal intensities at the individual time points of the experiment are shown.

(A) Expression dynamics of previously identified AP1 response genes that regulate the initiation of flower formation (see Figure 1). The floral meristem identity gene LEAFY (LFY) is rapidly upregulated upon AP1-GR activation, whereas TERMINAL FLOWER1 (TFL1) and AGAMOUS-LIKE 24 (AGL24) are repressed. The slight reduction in expression of FRUITFULL (FUL) was not judged statistically significant in our analysis.

(B) Repression of AGAMOUS-LIKE42 (AGL42), SHORT VEGETATIVE PHASE (SVP), and SUPPRESSOR OF OVEREXPRESSION OF CO 1 (SOC1).

(C) Expression dynamics of genes involved in specifying the identity of floral organs. AP3: APETALA3; PI: PISTILLATA; AG: AGAMOUS; SEP3: SEPALLATA3; AP2: APETALA2.

(D) Activation of genes involved in floral patterning (SUP: SUPERMAN) or organ primordia formation (RBE: RABBIT EARS; PRS: PRESSED FLOWERS).

(E) Induction of genes involved in carpel or stamen primordia development was detected towards the end of the time course experiment (SHP1: SHATTERPROOF1; SHP2: SHATTERPROOF2; CRC: CRABS CLAW; NZZ/SPL: NOZZLE/SPOROCYTELESS). Expression of SHP1 was not judged significantly changed in the experiment in contrast to that of its paralog SHP2. This result is in agreement with the reported induction of SHP2 at stage 6, one stage earlier than that of SHP1 [61,62].

(F) The meristem regulatory genes WUSCHEL (WUS) and CLAVATA3 (CLV3) were gradually downregulated during the course of the experiment. The increase in WUS expression on day 5 likely marks the onset of its expression in stamen primordia [16].

(G) Similar expression profiles (correlation coefficient of 0.84) were observed for FILAMENTOUS FLOWER (FIL) and YABBY3 (YAB3) in agreement with their largely identical expression patterns in developing flowers [29].

(H) Co-expression of JAGGED (JAG) and its paralog NUBBIN (NUB). Gene identifiers and references are listed in Table S1.