Cloning And Expression Analysis Of Ramosa Gene In Wheat

Wheat (Triticum aestivum) as one of the important food crops, their production directly affected by the inflorescence structure. Therefore, completion of a study on the inflorescence of wheat is of great significance. Branched spike is one of the wheat inflorescence morphology mutants, the main feature is many branched spikes growing upon the main spike node, thus the number of spikelets may effectively increase yield due to the more spikes. The phenomenon of spike branching is not only beneficial to clarify morphological development of spike, but also can be used in the yield of wheat breeding.The RAMOSA pathway in maize regulate inflorescence morphological development, interaction determine meristem differentiation. Is there ramosa homologous gene in wheat, the existence of a similar RAMOSA pathway like maize, which the department for spike morphogenesis mechanism has far-reaching significance. To further illustrate the relationship of spike branching and RAMOSA pathway, the following results obtained in this paper:1. The field statistical results show that the average height of wheat FEN33 76.9cm, ear length 13.3 cm, spike number of branches to 11, 118 grains per panicle. FEN33 is better than other non-branching types of wheat with good ear characteristics. SEM showed that the phenotypes of young panicle are consistent in early development edge of FEN33 and CS. There is one more primordium differentiation in the lower part of main spike of FEN33 than ordinary wheat from floret differentiation stage to pistil and stamen differentiation stage.?2. Cloned 4 wheat varieties ra3 homologous fragment and found a specific variation in FEN33, suggesting that this gene mutations most likely generate spike branching phenotype of one of the reasons.3. Wheat ra3 gene deduced amino acid sequence homology search showed that wheat RA3 is HAD_like family members, including TPP enzyme domain. Homology analysis showed that wheat RA3 has the significantly sequence similarity (68%, 67%, 65%, 64% and 67%) with 5 kinds of gramineae grasses (Brachypodium distachyon, Setaria viridis, Zea mays, Oryza sativa, Sorghum bicolor).4. In situ hybridization showed that wheat ra2 mRNA and ra3 mRNA in spike higher near the top of the growth cone expression, indicating that ra2 and ra3 has a close relationship with the architecture of spike development, most likely participate in and control of ear shape completion of key genes.5. 2 series high-level expression vectors of pAHC25 (containing the Ubiquitin promoter and bar selection gene) and pBI121 was constructed for wheat ramosa RNA interference, they provide an effective tool for the next transgenic experiments.In conclusion, the wheat RA3 may play an important role in ear morphogenesis, sugar signal transduction and to resist water stress, the research of spike branching finally clarify the mechanism of its molecular breeding for the production of wheat laid basis.