LEAFY target genes reveal a link between flower development and biotic stimulus response (II)

The transition from vegetative growth to flower formation is critical for the survival of flowering plants. The plant-specific transcription factor LEAFY (LFY) has central, evolutionarily conserved roles in this process, both in the formation of the first flower and later in floral patterning. We performed genome-wide binding and expression studies to elucidate the molecular mechanisms by which LFY executes these roles. Our study reveals that LFY directs an intricate regulatory network in control of floral homeotic gene expression and, unexpectedly, controls the expression of genes regulating the response to external stimuli in Arabidopsis. We further show that LFY dampens responses to a bacterial MAMP (microbe-associated molecular pattern) and to pathogen challenge. Our findings suggest a molecular mechanism for the coordination of reproductive stage development and disease response programs in plants. Regulation of these distinct survival programs by a single transcription factor may ensure optimal allocation of plant resources for reproductive fitness. Genome binding/occupancy profiling by genome tiling array used to identity genes bound by endogenous LFY in inflorescences. ChIP-chip of 19-day-old WT (Landsberg erecta) inflorescences using a LFY antibody. Five biological replicate immunoprecipated samples were compared to their corresponding genomic input DNA (taken prior to immunoprecipitation). As a negative control, one 19-day-old Ify6 (Landsberg erecta) IP and its corresponding Input sample were also hybridized.