Identification Of Genes Related To Floral Organ Development In Rice Using DNA Chips

Rice mutant is a powerful experiment material to study the development of floral organ in rice. At present, the amount of rice mutants we have found is still very low. Most of the cloned genes associated with the development of floral organ in rice were seperated by the way of homologous cloning. We found a rice mutant by the mutagenizing way of UV radiation, whose development of floral organ was suppressed.And we entitled it psd2 .The phenotype of psd2 mutant plants seems to be normal. However, the spikelets of psd2 are larger than the normal ones, and its stamens and pistils are totally degenerated, with many lays of glumes instead. Our lab had proved that the mutation phenotype of psd2 is controlled by a gene's recessive mutation and obtained the candidate gene by finely mapping the gene which was entiled PSD2. According to the mutation phenotype of psd2, PSD2 should be the key gene of controlling the development of pistil and stamen in rice. The mutation of PSD2 gene may arise the change of expression of a series of genes which are related to the development of floral organ in rice. So this research used cDNA microarray to identify the differentialy expressed genes involed in the development of pistil and stamen of psd2 mutant and wild type in the hope of disvovering other genes which are related to the development of floral organ in rice, and laying the foundation of anatomizeing deep into the gene network of floral organ development in rice.We sampled young panicles in the shoot tip of psd2 mutant and wild-type in the pistil and stamen formation stage,which were 2 to 10mm long.Then we extracted their total RNA to do cDNA microarray hybridizing, And then we scaned the hybridized arrays,collected the data and analyzed the data.According to that the ratio of the cDNA experiment in which we adopted the dye labeling way of "psd2 + Cy3/PSD2+Cy5" is larger than or equal to 2,and the ratio of "psd2 + Cy5/PSD2+Cy3"is larger than 1,we identified 36 differentialy expressed genes in psd2, of which 24 is up-regulated, 12 is down-regulated.So through identifying by the way of cDNA microarray, we screened out 36 genes related to rice floral organ development.Further analysis of the 36 related genes showed that 3 genes are MADS-box genes which play important roles in the development of rice floral organ and are all down-regulated in psd2; 4 genes are relate to stress/defense, including two genes...