Genetically Engineering And Functional Ectopic Expression Of RFCA-RRM2 And OsPDCD5 Genes In Oryza Sativa

Genetic engineering offers a powerful tool for plant improvement complementing traditional breeding approaches. As the rice genome is sequenced, gene discovery and assignment of gene function would be the prime target of functional genomics. The chief aim of the present study was designed to manipulate, transfer and investigate the ectopic expression analysis of rice genes including: Second RNA-recognition motif (RRM2) encoding by rice putative FCA-homolog gene of controlling flowering time (rFCA-RRM2) and programmed cell death 5 (OsPDCD5) gene in rice (Oryza sativa).The achieved experiments of this study were carried out using two different tools of gene engineering techniques. The plasmid vector pBY520 which carries bar gene as selectable marker was constructed by inserting the cDNA of rFCA-RRM2 driven by rice Actl-5' promoter and Pin2-3' terminator in sense orientation and used for insert the rFCA-RRM2 into rice cells using particle bombardment transformation technique. The binary plasmid vector pCAMBIA1304, which carries kanamycin resistance gene as bacterial selection and hygromycin phosphotransferase gene as plant transformation selection, was constructed by inserting the cDNA of OsPDCD5 gene in sense orientation driven by CaMV 35S promoter and Nos-3' terminator. This constructed binary vector was used to transfer 0sPDCD5 into rice cells using Agrobacterium-mediated transformation techniques. Rice (Oryza sativa L. japonica var. ZhongHua 11) embryogenic calli was used in this study.The potential results of this study are summarized as follow: Results show that the first manifestation of ectopic expression of rFCA-RRM2 can independently play a role in determining seed mass in the transgenic rice lines and increase seed weight by more than 60 % comparing with the control seeds. Results demonstrate that rFCA-RRM2 acts through increasing cell volume to control seed size and weight without any modulation of fertility rate. Additionally, rFCA-RRM2 has the function to regulate some homeotic MADS-box genes. These results show that rFCA-RRM2 activity can be manipulated to control seed yield in rice. Ectopic expression of OsPDCDS induced programmed cell death (PCD) in transgenic rice plants. PCD was accompanied by typical features including inhibition of developmental growth, reduction of fresh weight, degradation of the total protein content, and fragmentation of the genomic DNA. These results suggest that OsPDCD5 plays an essential role in regulation of PCD in plant. Taking together, we can conclude that the results developed during this study increase our understanding of ectopic expression of rice gene via genetic engineering technology.