Project description:Phosphate starvation/sufficient rice seedling, root or shoot Pi-starvation or Pi-sufficient stresses responsible rice genes, including previously unannotated genes were identified by Illumina mRNA-seq technology. 53 million reads from Pi-starvation or Pi-sufficient root or shoot tissues were uniquely mapped to the rice genome, and these included 40574 RAP3 transcripts in root and 39748 RAP3 transcripts in shoot. We compared our mRNA-seq expression data with that from Rice 44K oligomicroarray, and about 95.5% (root) and 95.4% (shoot) transcripts supported by the array were confirmed expression both by the array and by mRNA-seq, Moreover, 11888 (root) and 11098 (shoot) RAP genes which were not supported by array, were evidenced expression with mRNA-seq. Furthermore, we discovered 8590 (root) and 8193 (shoot) previously unannotated transcripts upon Pi-starvation and/or Pi-sufficient.
Project description:OsbZIP58 is a regulator of starch synthesis in rice endosperm. T-DNA insertion null mutants of this gene showed a white belly phenotype indicating an altered starch composition and content. We further investigated how reduction of OsbZIP58 gene expression caused these changes by analyzing the transcriptomes in the immature endosperm at 9 DAF of the wild-type and osbzip58-1 mutants by microarray analysis.
Project description:Cellularization is a key event during the development of the endosperm. Our understanding of the developmental regulation of cellularization has been limited for plants other than Arabidopsis. We found that the activation of OsbZIP76 coincided with the initiation of cellularization of rice. Either knockdown or knockout of OsbZIP76 led to precocious cellularization. Many genes involved in endosperm development or starch biosynthesis were prematurely activated in the caryopsis at two days after fertilization. The results implied that OsbZIP76 is involved in the regulation of cellularization in rice. As a putative transcription factor, OsbZIP76 alone lacked transcriptional activation activity. However, it was able to interact with OsNF-YB9 and OsNF-YB1, two nuclear factor Y (NF-Y) family transcription factors, both in yeast and in planta. OsbZIP76 and OsNF-YB9 showed similar endosperm-preferential expression patterns and the transiently expressed proteins were colocalized in the epidermal cells of tobacco. As with osnf-yb1 mutants, the osbzip76 mutants showed reduced seed size and reduced apparent amylose content of the seeds. We also confirmed that OsbZIP76 is an imprinted gene in rice, the expression of which depended on the genetic background. Our results suggested that OsbZIP76 is an endosperm-expressed imprinted gene to regulate development of the endosperm in rice.
Project description:OsbZIP58 is a regulator of starch synthesis in rice endosperm. T-DNA insertion null mutants of this gene showed a white belly phenotype indicating an altered starch composition and content. We further investigated how reduction of OsbZIP58 gene expression caused these changes by analyzing the transcriptomes in the immature endosperm at 9 DAF of the wild-type and osbzip58-1 mutants by microarray analysis. 9 DAF endosperm of Dongjin (wild type) and osbzip58-1 were used to compare the gene expresion, and three independent biological replicates for each material.
