Project description:Enhancing grain production of rice (Oryza sativa L.) is a top priority in ensuring food security for human being. One approach to increase yield is to delay leaf senescence and to extend the available time for photosynthesis. microRNAs (miRNAs) are key regulators for aging and cellular senescence in eukayotes. However, miRNAs and their roles in rice leaf senescence remain unexplored. Here, we report identification of miRNAs and their putative target genes by deep sequencing of six small RNA libraries, six RNA-seq libraries and two degradome libraries from the leaves of two super hybrid rice, Nei-2-You 6 (N2Y6, age-resistant rice) and Liang-You-Pei 9 (LYP9, age-sensitive rice). Totally 372 known miRNAs and 162 miRNA candidates were identified, and 1145 targets were identified. Compared with the expression of miRNAs in the leaves of LYP9, the numbers of miRNAs up-regulated and down-regulated in the leaves of N2Y6 were 47 and 30 at early stage of grain-filling, 21 and 17 at the middle stage, and 11 and 37 at the late stage, respectively. Six miRNA families, osa-miR159, osa-miR160 osa-miR164, osa-miR167, osa-miR172 and osa-miR1848, targeting the genes encoding APETALA2 (AP2), zinc finger proteins, salicylic acid-induced protein 19 (SIP19), Auxin response factors (ARF) and NAC transcription factors, respectively, were found to be involved in leaf senescence through phytohormone signaling pathways. These results provided valuable information for understanding the miRNA-mediated leaf senescence of rice, and offered an important foundation for rice breeding. [miRNA] sample 1:The flag leaves at early stage of grain-filling of N2Y6 rice; sample 2: The flag leaves at middle stage of grain-filling of N2Y6 rice;sample 3:The flag leaves at late stage of grain-filling of N2Y6 rice; sample 4:The flag leaves at early stage of grain-filling of LYP9 rice; sample 5: The flag leaves at middle stage of grain-filling of LYP9 rice;sample 6:The flag leaves at late stage of grain-filling of LYP9 rice. [DGE]: samples 7-12 [degradome (targets)]: samples 13:The flag leaves at mixed stages of grain-filling of N2Y6 rice; sample 14:The flag leaves at mixed stages of grain-filling of LYP9 rice
Project description:Grain weight is an important crop yield component; however, its underlying regulatory mechanisms are largely unknown. Here, we identify a grain-weight quantitative trait locus (QTL) encoding a new-type GNAT-like protein that harbors intrinsic histone acetyltransferase activity (OsglHAT1). Our genetic and molecular evidences pinpointed the QTL-OsglHAT1’s allelic variations to a 1.2-kilobase region upstream of the gene body, which is consistent with its function as a positive regulator of the traits. Elevated OsglHAT1 expression enhances grain weight and yield by enlarging spikelet hulls via increasing cell number and accelerating grain filling, and increases global acetylation levels of histone H4. OsglHAT1 localizes to the nucleus, where it likely functions through the regulation of transcription. Despite its positive agronomical effects on grain weight, yield and plant biomass, the rare allele elevating OsglHAT1 expression has so far escaped human selection. Our findings reveal the first example, to our knowledge, of a QTL for a yield component trait being due to a chromatin modifier that has the potential to improve crop high-yield breeding.
Project description:Grain weight is an important crop yield component; however, its underlying regulatory mechanisms are largely unknown. Here, we identify a grain-weight quantitative trait locus (QTL) encoding a new-type GNAT-like protein that harbors intrinsic histone acetyltransferase activity (OsglHAT1). Our genetic and molecular evidences pinpointed the QTL-OsglHAT1’s allelic variations to a 1.2-kilobase region upstream of the gene body, which is consistent with its function as a positive regulator of the traits. Elevated OsglHAT1 expression enhances grain weight and yield by enlarging spikelet hulls via increasing cell number and accelerating grain filling, and increases global acetylation levels of histone H4. OsglHAT1 localizes to the nucleus, where it likely functions through the regulation of transcription. Despite its positive agronomical effects on grain weight, yield and plant biomass, the rare allele elevating OsglHAT1 expression has so far escaped human selection. Our findings reveal the first example, to our knowledge, of a QTL for a yield component trait being due to a chromatin modifier that has the potential to improve crop high-yield breeding. Two replicates of Nipponbare as control, three replicates of GW6a-4.6 substitution lines and three replicates of OsglHAT1-OE transgenic lines.
Project description:High temperature during the grain-filling stage causes deleterious effects on storage material accumulation and grain quality. But it is still unclear how high temperature affects storage materials accumulation. In this study, we systemically analyzed the expression pattern of rice genes under high temperture during the grain-filling stage.
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:RNAi mediated suppression of MADS29 severely affects seed set; the surviving seeds are smaller in size with reduced grain filling, abnormal starch grains and aberrant embryo development. To identify the affected pathways due to suppression of this transcription factor in the transgenic seeds, transcriptome analysis using microarray was carried out.
Project description:Favorable grain filling ability is crucial for seed development and plant yield1, with less fertilizer applying is the most urgent goals to meet the growing demands of green and safe food. However, the balance mechanism between grain filling and nutrient elements is still unclear so far. Here, we describe a gene GAF1, specially expressed in endosperm aleurone layer, encoding a phosphate transporter, positively controls rice grain filling and seed development and also contributes to phosphate balance was mapped in our study. To study the regulation pattern of GAF1, we performed the RNA-seq analysis of NIL-GAF1 and NIL-gaf1 at middle grain filling stage in seeds. The data shows that many pathways related to starch and sugar metabolism were enriched, and many starch synthesis related genes and phosphate response genes were up-regulated or down-regulated. These data further support that seed specific expressed GAF1 plays a key role in regulating both phosphate homeostasis and seed development. More importantly, overexpression of GAF1 can significantly improve grain filling and thus yield enhanced plant production in field.
Project description:Purpose:The purpose of this study is to explore the transcriptome analysis of the heterosis of the grain type and grain weight of the super rice WFYT025 hybrid combination at the grain filling stage.
Project description:RNAi mediated suppression of MADS29 severely affects seed set; the surviving seeds are smaller in size with reduced grain filling, abnormal starch grains and aberrant embryo development. To identify the affected pathways due to suppression of this transcription factor in the transgenic seeds, transcriptome analysis using microarray was carried out. Three biological replicates of MADS29 RNAi (silencing) lines and Wild Type PB1 (control) plants were used for microarray study