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To use different types of promoters in transgenic rice research, the 1.1 kb 5'-upstream regulation region of one of the tomato (Solanum tuberosum L.) Rubisco small subunit gene, rbcS3A, was cloned and its sequences were confirmed by comparison with the known sequences in GenBank. The cloned rbcS3A promoter was fused to the 5'-upstream of GUS (beta-glucuronidase) coding region in a binary vector, and introduced into an elite japonica rice variety by Agrogacterium-mediated transformation. The integration of the GUS fusion gene into the genome of transgenic rice was confirmed by both PCR and Southern blot analysis. The results of both histochemical staining and quantitative analysis of GUS activity showed that the expression level of GUS fusion gene was significantly stronger in stem, leaf blade and sheath than in other organs of transgenic rice plants, and showed highest in the stem, which implies that the tomato rbcS3A promoter can make tissue-specific, in particular in the stem, expression of foreign genes in transgenic rice. The results present here also demonstrate that light induction had no effect on the expression of the foreign gene when regulated by the tomato rbcS3A promoter in transgenic rice. Our results show that the cloned tomato rbcS3A promoter might be very useful for the expression of target genes in transgenic rice, with particularly high efficiency in stem tissues.

Transgenic plant is an attractive bioreactor to produce recombinant protein, such as safe and economic vaccine. In present study, a plant expression binary vector pUNDV, containing the 1.7 kb fusion protein gene of Newcastle Disease Virus (NDV F) under the control of maize ubiquitin (Ubi) promoter and nos terminator was constructed, in which, the Hygromycin phosphotransferase (HPT) gene was used as the selectable marker. The expression cassette was introduced into a japonica rice variety by Agrobacterium-mediated transformation, and 6 independent transgenic rice lines were regenerated and verified by hygromycin resistance selection. The integration of target gene in transgenic plants was confirmed by PCR analysis. The results from ELISA and Western blot analyses revealed that NDV F could be expressed in the leaf of several transgenic plants. The total salt soluble proteins were extracted from leaf of transgenic plant F5, which contained the highest expressing level of NDV F protein, and used in immunization of BALB/c mice. The specific antibodies could be elicited in mice immunized with NDV F protein expressed in transgenic rice.

The mature embryos of a Japonica rice, Guanglingxiangnuo, were used for the study on optimization of Agrobacterium-mediated transformation. Several factors affecting the transformation were investigated and a suitable transformation system was set up. For this transformation system, the HRM medium, based on the MS medium, was suitable for inducing callus from rice mature embryos. The suitable time span of initial culture in this medium was 7-8 days before co-culturing with Agrobacterium and suitable medium for selection was CC medium. Using this transformation system, the Metr gene was introduced into Guanglingxiangnuo, and many transgenic plants were obtained. Most of these transgenic rice plants were confirmed by PCR technique and basta resistance, indicating the T-DNA had been integrated into the genome of transgenic rice plants.

To use different types of promoters in transgenic rice research, the 5'-upstream regulation region of rice Rubisco small subunit gene (rbcS) was cloned from a Chinese cultivar Wuyunjing 8, and its sequences were confirmed by comparison with the known genome sequences of both japonica and indica rice. The cloned rbcS promoter was fused to the 5'-upstream of GUS (beta-glucuronidase) coding region in a binary vector, and introduced into rice by Agrogacterium-mediated transformation. The integration of the rbcS-GUS fusion gene in transgenic rice was confirmed by PCR analysis. The results of both histochemical staining and quantitative analysis of GUS activity showed that the expression level of GUS fusion gene was significantly stronger in leaf blade and sheath than in other organs of transgenic rice plants, and the GUS activity was restricted to the mesophyll cells of leaf tissue, which showed that the rice rbcS promoter could control not only the tissue- but also the cell-specific expression of foreign genes in transgenic rice. The present results also demonstrated that light induction had a significant effect on the enhancement of transgene's expression when regulated by the rice rbcS promoter in transgenic rice. Our results showed that the rice rbcS promoter might be very useful for the expression of target genes in transgenic rice, with particularly high efficiency in leaf tissues.

The aneuploid with isochromosome or telochromosome is ideal material for exploring the position of centromere in lingkage map. For obtaining these aneuploids in rice, the primary trisomics from triplo-1 to triplo-12 and the aneuploids derived from a triploid of indica rice variety Zhongxian 3037 were carefully investigated. From the offsprings of triplo-10, a primary trisomic of chromosome 10 of the variety, an isotetrasomic "triplo-10-1" was obtained. Cytological investigation revealed that a pair of extra isochromosomes of triplo-10-1 were come from the short arm of chromosome 10. In the offsprings of the isotetrasomic, a secondary trisomic "triplo-10-2", in which the extra- chromosome was an isochromosome derived from the short arm of chromosome 10, was identified. With the isotetrasomic, secondary trisomic, primary trisomic and diploid of variety Zhongxian 3037, different molecular markers were used for exploring the position of the centromere of chromosome 10. Based on the DNA dosage effect, it was verified that the molecular markers G1125, G333 and L169 were located on the short arm, G1084 and other 16 available molecular markers were on the long arm of chromosome 10. So the centromere of chromosome 10 was located somewhere between G1125 and G1084 according to the RFLP linkage map given by Kurata et al[1]. The distance from G1125 to G1084 was about 3.2 cM.