Project description:We aimed to identify differential expression of microRNAs between superior and inferior spikelets by using a deep sequencing approach developed by Solexa (Illumina). Two small RNA libraries were constructed from superior and inferior spikelets at 18 days after fertilization, and more than nine million small RNA sequence reads were generated for each library. Totals of 351 and 312 known miRNAs were obtained from the superior and inferior spikelets, respectively. Analysis of the expression profiles of these miRNAs showed that 189 miRNAs were differentially expressed between superior spikelets and inferior spikelets. In addition, 43 novel miRNAs were identified mostly by the accumulations of miRNA*s were also expressed differentially. Further analysis shows that these miRNAs may individually participate in regulating hormone metabolism, carbohydrate metabolic pathways, and cell division during rice grain development. These results indicate that slow grain filling and low grain weight of rice inferior spikelets probably relation to the expression and function differences between superior and inferior spikelet miRNAs. Examination of 2 different small RNA expression profilings in superior and inferior spikelets at 18 days after fertilization.
Project description:We aimed to identify differential expression of microRNAs between superior and inferior spikelets by using a deep sequencing approach developed by Solexa (Illumina). Two small RNA libraries were constructed from superior and inferior spikelets at 18 days after fertilization, and more than nine million small RNA sequence reads were generated for each library. Totals of 351 and 312 known miRNAs were obtained from the superior and inferior spikelets, respectively. Analysis of the expression profiles of these miRNAs showed that 189 miRNAs were differentially expressed between superior spikelets and inferior spikelets. In addition, 43 novel miRNAs were identified mostly by the accumulations of miRNA*s were also expressed differentially. Further analysis shows that these miRNAs may individually participate in regulating hormone metabolism, carbohydrate metabolic pathways, and cell division during rice grain development. These results indicate that slow grain filling and low grain weight of rice inferior spikelets probably relation to the expression and function differences between superior and inferior spikelet miRNAs.
Project description:The biological functions of differently expressed proteins between superior and inferior spikelet grains were investigated based on the isobaric tags for relative and absolute quantification to further clarify the mechanism of rice grain filling at the proteomic level, as well as the response of inferior spikelets to drought dress (-20 kPa or -40 kPa). Compared with superior spikelets, inferior ones had lower sink strength due to the lower sink activities (lower expressions of ADP-glucose pyrophosphorylase, granule-bound starch synthase, starch branching enzyme and pullulanase) and smaller sink sizes (lower abundances of structural proteins). The slower and later grain filling resulted from the weaker decomposition and conversion of photoassimilate and the slower cell division. Moderate drought stress (-20 kPa) promoted the grain filling of inferior spikelets through regulating the proteins associated with photoassimilate supply and conversion. These proteins may be important targets for rice breeding programs that raise the rice yield under drought condition. The findings offer new insights into rice grain-filling and provide theoretical evidences for better quality control and scientific improvement of super rice in practice.
Project description:Modern rice cultivars have large panicle, however, yield potential of these cultivars is often not fully achieved due to the poor grain-filling of their late-flowering inferior spikelets (IS). Our earlier work suggests broad transcriptional reprogramming during grain filling and shows a difference in gene expression between IS and the earlier-flowering superior spikelets (SS). However, the links between the abundance of transcripts and their corresponding proteins are unclear. In this study, a SWATH-MS (sequential window acquisition of all theoretical spectra-mass spectrometry) -based quantitative proteomic analysis has been applied between SS and IS. A total of 304 proteins, ranging from cellular components to biological processes, were observed to be differentially expressed between IS and SS. Detailed gene ontology analysis indicated that several biological processes including photosynthesis, protein metabolism, and energy metabolism are differentially regulated. Further correlation analysis revealed that abundance of most of the differentially expressed proteins is not correlated to the transcript levels, indicating an extra layer of gene regulation which may exist during rice grain filling. These findings raise an intriguing possibility that these candidate proteins may be crucial in determining the poor grain-filling of IS. Therefore, we hypothesize that the regulation of proteome changes not only occurs at the transcriptional, but also at the post-transcriptional level, during grain filling in rice.
Project description:Purpose: The goal of our study is to compare two different ecotypes of Oryza sativa L., PHS-susceptible rice trait and PHS-resistant rice trait under three different maturation stages in rice seed embryo with profile of miRNA-seq. Methods: Oryza sativa. L miRNA profiles of two different ecotypes with 3 different maturation stages of rice seed embryo were generated by NGS, in duplicate, following Illumina NGS workflow. Results: We found the differentially expressed microRNAs between PHS-susceptible rice trait and PHS-resistant rice trait according to the three different seed maturation stages. Target transcripts of differentially expressed microRNAs have been predicted via psRNATarget web server, and a part of those target genes are likely to be regulated by microRNAs, affecting overall responses to heat stress and the regulation of seed dormancy during maturation. Conclusions: Our study represents the analysis of rice seed small RNAs, specifically microRNAs, under two different ecotypes, three different seed maturation stages in rice seed embryo. Our results show that microRNAs are involved in response to heat stress and the regulation of seed dormancy. This study will provide a foundation for understanding dynamics of seed dormancy during the seed development and overcoming pre-harvest sprouting.
Project description:Purpose: In the C57BL/6J mouse retina, hyperoxia-induced degeneration of photoreceptors shows strong regional variation, beginning at a locus ~0.5mm inferior to the optic disc. To identify gene expression differences that might underlie this variability in vulnerability, we have used microarray techniques to describe regional (superior-inferior) variations in gene expression in the retina. Methods: Young adult C57BL/6J mice raised in dim cyclic illumination (12h 5lux, 12h darkness) were exposed to hyperoxia (75% oxygen for 2w). Retinas were collected from hyperoxia-exposed and control animals without fixation, and divided into superior and inferior halves. RNA was extracted from each sample, purified and hybridised to mouse 1.0 ST arrays (Affymetrix). The consistency of the microarray results was assessed with quantitative PCR for selected genes. Expression data were analysed to identify genes and ncRNAs whose differential expression between superior and inferior retina could be associated with relative vulnerability to hyperoxia.
Project description:In rice (Oryza sativa L.), chilling-induced male sterility increased when plants experienced low water temperature (Tw, 18 °C for 14 days) before panicle initiation. The number of mature pollen grains after chilling at the booting stage (12 °C for 5 days) was only approximately 45% of total pollen grains in low-Tw plants, whereas it was approximately 71% in normal-Tw plants (Tw not controlled; approximately 23 °C under air temperature of 26 °C/21 °C, day/night). Microarray and quantitative PCR analyses showed that many stress-responsive genes (including OsFKBP65 and genes encoding a large heat shock protein OsHSP90.1, heat-stress transcription factors, and many small heat shock proteins) were strongly up-regulated by chilling in normal-Tw spikelets, but were not or rather down-regulated by chilling in low Tw spikelets. OsAPX2 and genes encoding some other antioxidative enzymes were also significantly down-regulated by low Tw in the chilled spikelets. In low-Tw plants, lipid peroxidation products (malondialdehyde equivalents) were significantly increased in the spikelets after chilling, and ascorbate peroxidase activity in the chilled spikelets was significantly lower than that in normal-Tw plants. Our data suggest that an OsFKBP65-related chilling response, which protects proteins from oxidative damage, is indispensable for chilling tolerance but is lost in low-Tw spikelets.
Project description:MicroRNAs (miRNAs) play important roles in various aspects of plant physiology and metabolism. The expression level of miR164c is negatively correlated with seed vigor in rice (Oryza sativa L.); however, the mechanism of seed vigor regulation by miR164c remains unknown. Here, we studied the proteomic difference between seeds of the wild-type rice cultivar ‘Kasalath’ and its transgenic derivatives, miR164c-silenced line (MIM164c) and miR164c overexpression line (OE164c), with significant differences in anti-aging capacity. We hope that it can provide new insights into the mechanism of miRNA on regulating seed vigor.
Project description:MicroRNAs (miRNAs) play important roles in various aspects of plant physiology and metabolism. The expression level of miR164c is negatively correlated with seed vigor in rice (Oryza sativa L.); however, the mechanism of seed vigor regulation by miR164c remains unknown. Here, we studied the proteomic difference between artificially aged seeds of the wild-type rice cultivar ‘Kasalath’ and its transgenic derivatives, miR164c-silenced line (MIM164c) and miR164c overexpression line (OE164c), with significant differences in anti-aging capacity. We hope that it can provide new insights into the mechanism of miRNA on regulating seed vigor.
Project description:In rice (Oryza sativa L.), chilling-induced male sterility increased when plants experienced low water temperature (Tw, 18 M-BM-0C for 14 days) before panicle initiation. The number of mature pollen grains after chilling at the booting stage (12 M-BM-0C for 5 days) was only approximately 45% of total pollen grains in low-Tw plants, whereas it was approximately 71% in normal-Tw plants (Tw not controlled; approximately 23 M-BM-0C under air temperature of 26 M-BM-0C/21 M-BM-0C, day/night). Microarray and quantitative PCR analyses showed that many stress-responsive genes (including OsFKBP65 and genes encoding a large heat shock protein OsHSP90.1, heat shock factors, and many small heat shock proteins) were strongly up-regulated by chilling in normal-Tw spikelets, but were not or rather down-regulated by chilling in low Tw spikelets. OsAPX2 and genes encoding some other antioxidative enzymes were also significantly down-regulated by low Tw in the chilled spikelets. In low-Tw plants, lipid peroxidation products (malondialdehyde equivalents) were significantly increased in the spikelets after chilling, and ascorbate peroxidase activity in the chilled spikelets was significantly lower than that in normal-Tw plants. Our data suggest that an OsFKBP65-related chilling response, which protects proteins from oxidative damage, is indispensable for chilling tolerance but is lost in low-Tw spikelets. Four conditions used: low Tw and chilled, low Tw and not chilled, normal Tw and chilled, normal Tw and not chilled, before panicle initiation and at the booting stage, respectively. Biological replicates: 4 for each treatment.