Project description:Members of the ARGONAUTE gene family are known to have roles in RNA-mediated silencing during development. One of these, MEL1, was shown to be germ-cell specific and essential for progression through sporogenesis at both premeiotic mitosis and meiosis. To understand how the MEL1 gene product is responsible for these effects requires analysis of the changes of the transcriptome. The mel1 gene was identified by TOS 17 insertion mutagenesis of Oryza sativa Japonica, cultivar Nipponbare. The TOS 17 insertion line of mel1 and the wild-type parent were the sources of RNA. RNA was extracted from rice panicle (3 cM) of rice grown under natural conditions in rice fields. Small RNAs associated with MEL1 and small RNAs in total RNA were sequenced by Illumina GAII.
Project description:Hybrids and allopolyploids typically exhibit radically altered gene expression patterns relative to their parents, a phenomenon termed “transcriptomic shock.” To distinguish the effects of hybridization from polyploidization on coregulation of divergent alleles, we analyzed expression of parental copies (homoeologs) of 11,608 genes using RNA-seq-based transcriptome profiling in reciprocal hybrids and tetraploids constructed from subspecies japonica and indica of Asian rice (Oryza sativa L.)
Project description:Male sterility is a useful agronomic trait for breeding of self-pollinating crops and is often observed in the progenies of hybrids of distantly related species, for example, Oryza sativa L. subsp. indica and O. sativa L. subsp. japonica. To explore new male sterile lines in rice, we performed successive backcrosses using a japonica cultivar Taichung 65 (T65) as a recurrent pollen parent and various indica cultivars as the initial female parents.We observed male sterile plants in the backcross progeny from an indica cultivar, Lebed. Both fertile and sterile plants were present in the BC4F1 generation. The sterile plants segregated for fertile and sterile plants when backcrossed with T65 in BC5F1, BC6F1 and BC7F1 with a ratio of 1:1. Conversely, all the backcross progenies from the fertile BC4F1 were consistently fertile. Anthers of the male sterile line were stunted and did not shed pollen; cross-sectional observations revealed defects in sporophytic cells. The male sterility appears to be caused by heterozygous alleles derived from T65 and Lebed. A male sterility gene was mapped between two INDEL markers on the long arm of chromosome 10, which corresponded to a 407 kb region in the Nipponbare genome.Since the heterozygous Lebed allele acts as dominant sporophytic pollen killer, it would be useful for recurrent selection breeding of japonica rice.
Project description:BACKGROUND:The availability of thousands of complete rice genome sequences from diverse varieties and accessions has laid the foundation for in-depth exploration of the rice genome. One drawback to these collections is that most of these rice varieties have long life cycles, and/or low transformation efficiencies, which limits their usefulness as model organisms for functional genomics studies. In contrast, the rice variety Kitaake has a rapid life cycle (9?weeks seed to seed) and is easy to transform and propagate. For these reasons, Kitaake has emerged as a model for studies of diverse monocotyledonous species. RESULTS:Here, we report the de novo genome sequencing and analysis of Oryza sativa ssp. japonica variety KitaakeX, a Kitaake plant carrying the rice XA21 immune receptor. Our KitaakeX sequence assembly contains 377.6?Mb, consisting of 33 scaffolds (476 contigs) with a contig N50 of 1.4?Mb. Complementing the assembly are detailed gene annotations of 35,594 protein coding genes. We identified 331,335 genomic variations between KitaakeX and Nipponbare (ssp. japonica), and 2,785,991 variations between KitaakeX and Zhenshan97 (ssp. indica). We also compared Kitaake resequencing reads to the KitaakeX assembly and identified 219 small variations. The high-quality genome of the model rice plant KitaakeX will accelerate rice functional genomics. CONCLUSIONS:The high quality, de novo assembly of the KitaakeX genome will serve as a useful reference genome for rice and will accelerate functional genomics studies of rice and other species.
Project description:In this study, we examined the transcriptome dynamics within the matured fully expanded rice leaf and used strand-specific RNA sequencing to generate a comprehensive transcriptome dataset for the mature rice leaf. The rice Nipponbare (Oryza sativa l. japonica) seedlings were grown in the greenhouse. About 20 days after planting, the fully opened 4th leaves was cut it into seven 3-cm segments, from bottom to tip and labeled as sections 1 to 7, respectively. The tissues were immediately frozen in liquid nitrogen for total RNA extraction. Two biological replicates were collected for each section. Note: All samples in SRA were assigned the same sample accession (SRS685294). This is incorrect as there are different samples, hence “Source Name” was replaced with new values. Comment[ENA_SAMPLE] contains the original SRA sample accessions.
Project description:Rice mature anther and mature pollen at anthesis stage from Dongin cultivar (Oryza sativa L. japonica) We collected the sample from our field using RNA Later to reveal differentially expressed genes.
Project description:The associated files are mass spec data from individual fractions of mixed-bed ion exchange or size exclusion fractionations of native extract made from rice leaves (Oryza sativa, Kitaake cultivar).