Os06g0139000

Please input one-sentence summary here.

Annotated Information

Introduction

F-box proteins are characterized by a conserved ‘F-box’ motif consisting of approximately 50 amino acids at the N terminus (Bai et al., 1994; Kipreos and Pagano, 2000). Most F-box proteins reported so far have been identified as components of the Skp, Cullin, F-box-containing (SCF) complex that functions in defining substrate specificity in the ubiquitin–proteasome pathway. Several other F-box proteins with function in non-SCF complex have also been found (Clifford et al., 2000; Galan et al., 2001). F-box genes belong to a large family in plants, containing 42 groups, each of which has a distinct domain organization (Xu et al.,2009). Studies have indicated that F-box genes play crucial roles in a number of biological processes in plants, including flower development, self-incompatibility, hormone response, circadian clock and photomorphogenesis,senescence, defense response, embryogenesis and seedling development (Moon et al., 2004;..

Keywords: Oryza sativa L., dwarf and deformed flower 1, F-box, vegetative growth, floral organ development

Function

Figure 1. Comparison of morphological characters between ddf1-1 and wild-type plants .(from reference)).

Figure 2. Histological characterization of the leaf, root and stem of ddf1-1 plants .(from reference)).

controlling monocot vegetative and reproductive development ddf1-1 exhibits significant size reduction in the whole plant, except the spikelet.Cell division and cell expansion are inhibited in ddf1-1. The expression of cell division/expansion-related genes is downregulated in ddf1-1.ddf1-1 also shows significant structural abnormalities in florets.The ddf1-1 phenotype is caused by a single nucleotide substitution.DDF1 encodes an LRR-type F-box protein, anchored in nucleolus.The expression pattern of DDF1 is consistent with the phenotypes of ddf1-1.DDF1 regulates the expression of several floral organ specification genes.DDF1 encodes an LRR-type F-box protein, anchored in nucleolus.The expression pattern of DDF1 is consistent with the phenotypes of ddf1-1.DDF1 regulates the expression of several floral organ specification genes.

Expression

Figure 3. ddf1-1, all the mutant phenotypes (including dwarf stature,smaller stems, leaves, roots and panicles, and aberrant spikelet) were rescued (Figure 6d,e). Thus, the DDF1 gene was confirmed. .(from reference)).

discovered from a breeding population.The ddf1-1 plant is much shorter and thinner than the wild type, and this difference is distinct at the early seedling stage and becomes more apparent as the plants develop. The final plant height of the mutant reaches only about half of that of the wild type (Figure 1a–e and Figure S1). All vegetative organs in ddf1-1, including stems, internodes, leaves and roots (both fibrous and lateral), are significantly shorter and thinner than in the wild type (Figure 1f–j and Figures S2 and S3). In addition, the ddf1-1 panicle is also notably shorter and smaller, consisting of fewer primary and secondary branches and spikelets (Figure 1e,f; Figure S4). These phenotypes suggest that plant growth in ddf1-1 is seriously stunted. However, the size of the spikelet, the numbers of various vegetative organs (e.g. internodes and tillers; Figure S5) and the time from sowing to heading (Figure 1e) remain unaffected in ddf1-1.

Evolution

You can also add sub-section(s) at will. Studies have indicated that F-box genes play crucial roles in a number of biological processes in plants,including flower development, self-incompatibility, hormone，response, circadian clock and photomorphogenesis,senescence, defense response, embryogenesis and seedling development (Moon et al., 2004; Lechner et al., 2006;Jain et al., 2007; Schumann et al., 2011). Until now, however,our knowledge about the functions of F-box genes in plants has remained very limited. Fewer than 5% inArabidopsis F-box proteins (Schumann et al., 2011) and only a few proteins in Oryza sativa (rice; Gomi et al., 2004; ª 2012 The Authors 829The Plant Journal ª 2012 Blackwell Publishing LtdThe Plant Journal (2012) 72, 829–842 doi: 10.1111/j.1365-313X.2012.05126.xIkeda et al., 2007; Jain et al., 2007) have been characterizedfor their functions.The model is also applicable to rice, with modifications,although monocot flowers are quite different from eudicot in morphology(Ambrose et al., 2000; Lee et al., 2003; Nagasawa et al., 2003; Whipple et al., 2004; Kater et al., 2006; Yamaguchi et al., 2006; Dreni et al., 2007; Ikeda et al., 2007). In rice, the functions of B-class genes OsMADS4 and OsMADS16 were proven to be largely conserved (Nagasawa et al., 2003), whereas the functions of C-class genes OsMADS3 and OsMADS58 were shown to have diverged from the Arabidopsis AGAMOUS gene, and the carpel specification appeared to be mainly determined by a distinct non-MADS-box homeotic gene DROOPINGLEAF (DL; Yamaguchi et al., 2004, 2006). Nevertheless, a recent study on the Osmads3 Osmads58 double mutant suggestedthat the two genes together exhibit a complete C-function in rice (Dreni et al., 2011).

Labs working on this gene

• Plant materials
• Microscopic observation
• Scanning electron microscopy observation
• Positional cloning of DDF1
• Promoter activity analysis
• Subcellular localization
• Real-time quantitative PCR
• mRNA in situ hybridization

summary

DDF1 controls organ size by regulating both cell division and cell expansion. In theddf1-1 spikelet, the specification of floral organs in whorls 2 and 3 is altered, with most lodicules and stamens being transformed into glume-like organs and pistil-like organs, respectively, but the specification of lemma/ palea and pistil in whorls 1 and 4 is not affected. DDF1 encodes an F-box protein anchored in the nucleolus, and is expressed in almost all vegetative and reproductive tissues. Consistent with the mutant floral phenotype, DDF1 positively regulates B-class genes OsMADS4 and OsMADS16, and negatively regulates pistil specification gene DL. In addition, DDF1 also negatively regulates the Arabidopsis LFY ortholog APO2, implying a functional connection between DDF1 and APO2. Collectively, these results revealed that DDF1, as a newly identified F-box gene, is a crucial genetic factor with pleiotropic functions for both vegetative growth and floral organ specification in rice.