Rice Morphology To The Completion Of Gene Function Studies

In this research work, we study the expression and regulation of the key genes, which play important roles in the architecture formation and the development of rice, the monocotyledonous model plant.We have isolated three genes, Oscenl, Oscen2, Oscen3, by screening the rice genomic library with the homologus probe and RT-PCR. The DNA sequences of the three genes have high similarity. All of the genes are composed of four exons and three introns. Using the GCG software, each of the three cDNA encodes a putative protein of 173 AA. The similarity of OSCEN1 and OSCEN2 is 96.5%. The similarity of OSCEN1 and OSCEN3 is 89.6%. The similarity of OSCEN2 and OSCEN3 is 88.4%. The three OSCEN proteins have about 80% similarity with the CEN protein in Antirrhinum and TFL1 in Arabidopsis, respectively. All of them belong to the family of phosphatidyl ethanolamine-binding proteins(PEBPs), which is widely conserved among eukaryotes.The RT-PCR result shows that Oscenl was expressed in all tissues, such as leaves, root, stem and flower etc. When using the methods of RNA in situ, we did not detect the Oscenl signals in any special area. At the same time, RT-PCR result shows that Oscenl has 2 different splicing patterns. In the first splicing pattern, the cDNA has a long open reading frame which encodes a normal OSCEN1 protein of 173 AA. In the second splicing pattern, the cDNA has a short open reading frame which encodes a protein of 38 AA. The RT-PCR result shows that Oscen2 was expressed in all tissues. But RNA in situ results shows that Oscen2 was expressed in special tissues and organs. In reproductive growth phase, Oscenl was strongly expressed in the intercalary meristem of the stem. In addition, Oscenl was expressed in the vascular bundles of leaves, stem, adventitious root, mesocotyl, and the junction area of adventitious root and mesocotyl. RNA in situ results shows that Oscen3 was expressed in the base area of leaves in the vegetative and reproductive growth phases. In the axillary buds, Oscen3 was also expressed in the young leaves. In addition, OscenS was expressed in the vascular bundles of adventitious root. We did not detect any signals of Oscenl, Oscen2, and Oscen3 in the vegetative and reproductive SAM(shoot apical meristem), rachis branch primodium,.spikelet meristem or floral organs. The study of the temporal and spatial expression of Oscenl, Oscen2, and Oscen3 hints us that they play important roles in the rice development of basic...