ABSTRACT: In this study, we sequenced the sRNAs population from embryos of 0, 12, and 24 HAI rice seeds using next-generation deep sequencing technology. A series of miRNAs were identified, including both known and novel miRNAs. We also predicted the potential targets for the miRNAs. RT-PCR and 5’ RACE assay were performed to confirm some deep sequencing and target prediction results. This study provides the unique composition and expressional profiles of miRNAs and their potential regulations in the embryo at the early stages of rice seed germination.
Project description:Purpose: To identify the potential genes that regulate seed germination speed in maize, we performed a time-series transcriptome analysis with two inbred maize lines (72-3 fast germination, F9721 slow germination) during the seed germination and compared the differentially expressed genes (DEGs) in transcriptome with genes identified by GWAS Methods: Methods: mRNA profiles of two maize inbred lines 72-3 and F9721 showing divergent seed germination at six stages during germination were generated by deep sequencing, in triplicate, using Illumina Hiseq2500. The sequence reads that passed quality filters were analyzed at the gene level. Hisat2 was used to align clean reads to maize B73 reference genome, and HTSeq was used to count transcript abundance. DESeq2 models were used to compare DEGs at each germination stage within or between samples Results: Comparative transcriptome study identified 12 hours after imbibition (HAI) as the critical stage responsible for the variation of germination speed. The DEGs between 72-3 and F9721 were mainly enriched in metabolic pathways, biosynthesis of secondary metabolites, oxidoreductase activity pathways, hormone signal transduction, and amino acid transporter activity pathways Conclusions: Combined with evidence from gene expression data, GWAS, and gene synteny with other model species, we finally anchored three genes as the likely candidate genes regulating germination speed in maize
Project description:affy_rice_2011_03 - affy_compartimentation_rice_albumen_embryon - During germination, the rice seed goes from a dry quiescent state to an active metabolism. As with all cereals, the rice seed is highly differentiated between the embryo (that will give rise to the future plantlet) and the endosperm (that contains the seed storage compounds and that will degenerate). The molecular mechanisms operating in the rice seed embryo have begun to be described. Yet, very few studies have focused specifically on the endosperm during the germination process. In particular, the endosperm is mostly addressed with regards to its storage proteins but we have detected a large protein diversity by two-dimensional electrophoresis. Similarly, the endosperm is rich in total RNA which suggest that gene expression coming from seed maturation could play a role during the germination process. In this context, we want to compare the transcriptome of the embryo and the endosperm during rice seed germination. -We germinate rice seeds of the first sequenced rice cultivar i.e. Nipponbare during 0, 4, 8, 12, 16 and 24h of imbibition in sterile distilled water. Germination occurs under constant air bubbling, in the dark at 30°C. These rice seeds are then manually dissected into embryo and endosperm fractions. -The embryo-derived samples are abbreviated in “E” while the endosperm samples are abbreviated “A”. The germination time-point is indicated after the letter (e.g. E8 for embryo samples harvested after 8 hours of germination). Finally, the biological repetition number is indicated before the letter and the time digit (e.g. 1-E8 for an embryo sample from the first repetition at 8 hours of imbibition).
Project description:Chloramphenicol (CAM) is recognized as one such factor that influence the seed germination. However, the mechanism by which CAM induced suppression on rice germination remains uncertain. To investigate the effect of CAM on rice seed germination, changes in the global profile of phosphorylated proteins induced by CAM were analyzed using LC-MS/MS.
Project description:affy_rice_2011_03 - affy_compartimentation_rice_albumen_embryon - During germination, the rice seed goes from a dry quiescent state to an active metabolism. As with all cereals, the rice seed is highly differentiated between the embryo (that will give rise to the future plantlet) and the endosperm (that contains the seed storage compounds and that will degenerate). The molecular mechanisms operating in the rice seed embryo have begun to be described. Yet, very few studies have focused specifically on the endosperm during the germination process. In particular, the endosperm is mostly addressed with regards to its storage proteins but we have detected a large protein diversity by two-dimensional electrophoresis. Similarly, the endosperm is rich in total RNA which suggest that gene expression coming from seed maturation could play a role during the germination process. In this context, we want to compare the transcriptome of the embryo and the endosperm during rice seed germination. -We germinate rice seeds of the first sequenced rice cultivar i.e. Nipponbare during 0, 4, 8, 12, 16 and 24h of imbibition in sterile distilled water. Germination occurs under constant air bubbling, in the dark at 30M-BM-0C. These rice seeds are then manually dissected into embryo and endosperm fractions. -The embryo-derived samples are abbreviated in M-bM-^@M-^\EM-bM-^@M-^] while the endosperm samples are abbreviated M-bM-^@M-^\AM-bM-^@M-^]. The germination time-point is indicated after the letter (e.g. E8 for embryo samples harvested after 8 hours of germination). Finally, the biological repetition number is indicated before the letter and the time digit (e.g. 1-E8 for an embryo sample from the first repetition at 8 hours of imbibition). 36 arrays - rice; organ comparison,time course
Project description:Rapid and uniform seed germination is required for modern cropping system. Thus, it is important to optimize germination performance through breeding strategies in maize, in which identification for key regulators is needed. Here, we characterized an AP2/ERF transcription factor, ZmEREB92, as a negative regulator of seed germination in maize. Enhanced germination in ereb92 mutants is contributed by elevated ethylene signaling and starch degradation. Consistently, an ethylene signaling gene ZmEIL7 and an α-amylase gene ZmAMYa2 are identified as direct targets repressed by ZmEREB92. OsERF74, the rice ortholog of ZmEREB92, shows conserved function in negatively regulating seed germination in rice. Importantly, this orthologous gene pair is likely experienced convergently selection during maize and rice domestication. Besides, mutation of ZmEREB92 and OsERF74 both lead to enhanced germination under cold condition, suggesting their regulation on seed germination might be coupled with temperature sensitivity. Collectively, our findings uncovered the ZmEREB92-mediated regulatory mechanism of seed germination in maize and provide breeding targets for maize and rice to optimize seed germination performance towards changing climates.
Project description:Sucrose non-fermenting-1-related protein kinase 1 (SnRK1) is a central regulator of metabolism and developmental transition in plant. Compound 991 is a well-known 5′-adenosine monophosphate activated protein kinase (AMPK) activator in mammals. SnRK1 and AMPK are highly conserved. However, whether 991 could also act as a SnRK1 activator is unknown. Adding 991 significantly increased the activity of SnRK1 in desalted extracts from germinating rice seeds in vitro. To determine whether 991 has biological activity in plant, rice seeds were treated with different concentrations of 991. Low concentration of 991 promoted rice seed germination, while high concentration of 991 inhibited rice germination. The effect of 991 on rice germination is similar to the effect of OsSnRK1a overexpression on germination. To explore whether 991 affects germination by specifically affecting SnRK1, the germination status of the snrk1a mutant and WT under 1 μM 991 treatment were compared. The snrk1a mutant exhibited insensitivity to 991. Through phosphoproteomic analysis, we found that the differential phosphopeptides caused by 991 treatments and overexpression of OsSnRK1a are largely overlapped. Phosphoproteomic analysis also revealed that SnRK1 might affect rice germination by regulating the phosphorylation levels of S285-PIP2;4, S1013-SOS1 and S110-ABI5. These results showed that 991 is a specific and workable SnRK1 activator in rice. The promotion and inhibition of 991 treatments on germination also exist in wheat seeds. 991 is expected to be used for exploring the function of SnRK1 in more detail and depth and chemical regulation of growth and development in crops.
Project description:TITLE: Transcriptional profiling of Rgene-mediated responses in rice PROJECT DESCRIPTION: The dominant gene Xa7 and the recessive gene xa5 of rice confer resistance to several races of the bacterial blight pathogen Xanthomonas oryzae pv. oryzae (Xoo). To reveal the modes of action and the defense responses these genes initiate, we decided to obtain the global transcriptional profiles of the rice cultivars IRBB7, IRBB5 (which harbor Xa7 and xa5, respectively) and IR24 undergoing early infection by the Xoo Race 2 strain PXO86. Both IRBB7 and IRBB5 are resistant to PXO86 (which carry the corresponding avirulence genes avrXa7 and avrxa5), whereas IR24 is susceptible. We inoculated by vacuum infiltration the three rice cultivars ten days after seed germination (or 2 weeks after sowing) and collected inoculated tissue at 5 different timepoints within the first day after inoculation. The transcriptional profiles obtained will provide valuable insight into the similarities and differences between incompatible interactions mediated by a dominant and a recessive Rgene, in comparison to a compatible interaction. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, David O Nino-Liu. The equivalent experiment is OS4 at PLEXdb.] genotype: IR24 - time: 0 hai(3-replications); genotype: IR24 - time: 3 hai(3-replications); genotype: IR24 - time: 6 hai(3-replications); genotype: IR24 - time: 12 hai(3-replications); genotype: IR24 - time: 24 hai(3-replications); genotype: IRBB5 - time: 0 hai(3-replications); genotype: IRBB5 - time: 3 hai(3-replications); genotype: IRBB5 - time: 6 hai(3-replications); genotype: IRBB5 - time: 12 hai(3-replications); genotype: IRBB5 - time: 24 hai(3-replications); genotype: IRBB7 - time: 0 hai(3-replications); genotype: IRBB7 - time: 3 hai(3-replications); genotype: IRBB7 - time: 6 hai(3-replications); genotype: IRBB7 - time: 12 hai(3-replications); genotype: IRBB7 - time: 24 hai(3-replications)
Project description:Melatonin plays a potential role in multiple plant developmental processes and stress response. However, there are no reports regarding exogenous melatonin promoting rice seed germination under salinity and nor about the underlying molecular mechanisms at genome-wide. Here, we revealed that exogenous application of melatonin conferred roles in promoting rice seed germination under salinity. The putative molecular mechanisms of exogenous melatonin in promoting rice seed germination under high salinity were further investigated through metabolomic and transcriptomic analyses. The results state clearly that the phytohormone contents were reprogrammed, the activities of SOD, CAT, POD were enhanced, and the total antioxidant capacity was activated under salinity by exogenous melatonin. Additionally, melatonin-pre-treated seeds exhibited higher concentrations of glycosides than non-treated seeds under salinity. Furthermore, exogenous melatonin alleviated the accumulation of fatty acids induced by salinity. Genome-wide transcriptomic profiling identified 7160 transcripts that were differentially expressed in NaCl, MT100 and control. Pathway and GO term enrichment analysis revealed that genes involved in the response to oxidative stress, hormone metabolism, heme building, mitochondrion, tricarboxylic acid transformation were altered after melatonin pre-treatment under salinity. This study provides the first evidence of the protective roles of exogenous melatonin in increasing rice seed germination under salt stress, mainly via activation of antioxidants and modulation of metabolic homeostasis.
Project description:Low temperature is one of the major factors affecting rice germination, and low tempera-ture germination (LTG) is an important agronomic trait. Although genetic variation is abundant in rice germplasm resources, the molecular mechanism of LTG remains poorly understood. In this study, we first proved that weedy rice WR04-6 had significantly better low-temperature germination (LTG) ability at 10°C than the cultivated rice Qishanzhan (QSZ). RNA-seq was used to investigate the gene expression of WR04-6 and QSZ at 10, 12 and 14 days of seed germination at 10°C. The results of GO enrichment and KEGG en-richment revealed that the differentially expressed genes between WR04-6 and QSZ were mainly concentrated on the response to starch catabolic processes and the response to ab-scisic acid. This is consistent with the results of α-amylase activity, ABA and GA treat-ment. A recombinant inbred line (RIL) population derived from a cross between WR04-6 and QSZ and its high density SNP genetic map were used to detect quantitative trait loci (QTL) for low temperature germination rates at 10°C for 14 days. The results showed that two new QTLs were located on chromosome 3 and chromosome 12. Combined with the mapped QTLs and RNA-seq differential genes (DEGs), sixteen candidate genes potentially associated with LTG were identified. Validation of expression of the candidates by qRT-PCR were consistent with the RNA-seq data. These results will enable us to under-stand the genetic basis of LTG in weedy rice and provide new genetic resources for gener-ation of rice germplasm with LTG.
Project description:our works provide evidences that radicle elongation will be hindered in presence of calcium ion mobilization inhibitors during rice seed germination.