Random BAC FISH of monocot plants reveals differential distribution of repetitive DNA elements in small and large chromosome species.

BAC FISH (fluorescence in situ hybridization using bacterial artificial chromosome probes) is a useful cytogenetic technique for physical mapping, chromosome marker screening, and comparative genomics. As a large genomic fragment with repetitive sequences is inserted in each BAC clone, random BAC FISH without adding competitive DNA can unveil complex chromosome organization of the repetitive elements in plants. Here we performed the comparative analysis of the random BAC FISH in monocot plants including species having small chromosomes (rice and asparagus) and those having large chromosomes (hexaploid wheat, onion, and spider lily) in order to understand a whole view of the repetitive element organization in Poales and Asparagales monocots.

14-3-3 proteins act as intracellular receptors for rice Hd3a florigen.

'Florigen' was proposed 75 years ago to be synthesized in the leaf and transported to the shoot apex, where it induces flowering. Only recently have genetic and biochemical studies established that florigen is encoded by FLOWERING LOCUS T (FT), a gene that is universally conserved in higher plants. Nonetheless, the exact function of florigen during floral induction remains poorly understood and receptors for florigen have not been identified.

The 14-3-3 protein GF14c acts as a negative regulator of flowering in rice by interacting with the florigen Hd3a.

Hd3a and FT proteins have recently been proposed to act as florigens in rice and Arabidopsis, respectively; however, the molecular mechanisms of their function remain to be determined. In this study, we identified GF14c (a 14-3-3 protein) as an Hd3a-interacting protein in a yeast two-hybrid screen. In vitro and in vivo experiments, using a combination of pull-down assays and bimolecular fluorescence complementation, confirmed the interaction between Hd3a and GF14c.