Genome-Wide Analysis of Transcript Factors to Identify Genes Contributing to Photoperiodic Flowering in .

Photoperiod sensitivity is a dominant determinant for the phase transition in cereal crops. () transcription factors (TFs) are involved in many physiological functions including the regulation of the photoperiodic flowering. However, the functional roles of TFs have not been elucidated in the wild progenitors of crops. In this study, we identified 41 TFs, including 19 , 17 , and five TFs in , the presumed wild ancestor of Asian cultivated rice. There are thirty-eight orthologous genes in , of which ten pairs of duplicated TFs are shared with . We investigated daily expression patterns, showing that 36 genes exhibited circadian rhythmic expression. A total of thirteen genes were identified as putative flowering suppressors in based on rhythmic and developmental expression patterns and transgenic phenotypes. We propose that , , and are the strong functional alleles of rice , , and , respectively. The SD treatment at 80 DAG stimulated flowering of the LD-grown plants. Our results further showed that the nine genes were significantly downregulated under the treatment. Our findings would provide valuable information for the construction of photoperiodic flowering regulatory network and functional characterization of the TFs in both and .