High-throughput sequencing and degradome analysis identify miRNAs and their targets involved in fruit senescence of Fragaria ananassa
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ABSTRACT: To identify miRNAs involved in senescence of strawberry fruit, two independent small RNA libraries and one degradome library from strawberry fruits stored at 20 M-BM-0C for 0 and 24 h were constructed. A total of 18,759,735 and 20,293,492 mappable small RNA sequences were generated in the two small RNA libraries, respectively, and 88 known and 1224 new candidate miRNAs were obtained. Among them, 94 miRNAs were up-regulated and 64 were down-regulated in the senescence of strawberry fruit. Through degradome sequencing, 103 targets cleaved by 19 known miRNAs families and 55 new candidate miRNAs were identified. 14 targets, including NAC transcription factor, Auxin response factors (ARF) and Myb transcription factors, cleaved by 6 known miRNA families and 6 predicted candidates, were found to be involved in regulating fruit senescence. sample 1: Examination of small RNA in strawberry fruits stored at 20 M-BM-0C for 0; sample 2: Examination of small RNA in strawberry fruits stored at 20 M-BM-0C for 24 h
Project description:To identify miRNAs involved in senescence of strawberry fruit, two independent small RNA libraries and one degradome library from strawberry fruits stored at 20 °C for 0 and 24 h were constructed. A total of 18,759,735 and 20,293,492 mappable small RNA sequences were generated in the two small RNA libraries, respectively, and 88 known and 1224 new candidate miRNAs were obtained. Among them, 94 miRNAs were up-regulated and 64 were down-regulated in the senescence of strawberry fruit. Through degradome sequencing, 103 targets cleaved by 19 known miRNAs families and 55 new candidate miRNAs were identified. 14 targets, including NAC transcription factor, Auxin response factors (ARF) and Myb transcription factors, cleaved by 6 known miRNA families and 6 predicted candidates, were found to be involved in regulating fruit senescence.
Project description:By using parallel analysis of RNA ends (PARE) for global identification of miRNA targets and comparing four different stages of tomato fruit development we identified a large number of target genes of miRNAs. PARE libraries were produced, one each, for tomato fruits at 5 days after pollination, mature green fruit, Breaker fruit, and 7 days after Breaker stge fruits
Project description:Topping is an important cultivating measure for flue-cured tobacco, and many genes had been found to be differentially expressed in response to topping. But it is still unclear how these genes are regulated. MiRNAs play a critical role in post-transcriptional gene regulation, so we sequenced two sRNA libraries from tobacco roots before and after topping, with a view to exploring transcriptional differences in miRNAs.Two sRNA libraries were generated from tobacco roots before and after topping. Solexa high-throughput sequencing of tobacco small RNAs revealed a total of 12,104,207 and 11,292,018 reads representing 3,633,398 and 3,084,102 distinct sequences before and after topping. The expressions of 136 conserved miRNAs (belonging to 32 families) and 126 new miRNAs (belonging to 77 families) were determined. There were three major conserved miRNAs families (nta-miR156, nta-miR172 and nta-miR171) and two major new miRNAs families (nta-miRn2 and nta-miRn26). All of these identified miRNAs can be folded into characteristic miRNA stem-loop secondary hairpin structures, and qRT-PCR was adopted to validate and measure the expression of miRNAs. Putative targets were identified for 133 out of 136 conserved miRNAs and 126 new miRNAs. Of these miRNAs whose targets had been identified, the miRNAs which change markedly (>2 folds) belong to 53 families and their targets have different biological functions including development, response to stress, response to hormone, N metabolism, C metabolism, signal transduction, nucleic acid metabolism and other metabolism. Some interesting targets for miRNAs had been determined. 2 samples examined:roots before and after topping
Project description:DNA methylation is a conserved epigenetic mark that influences diverse biological processes in many eukaryotes. Recently, DNA methylation was proposed to regulate fleshy fruit ripening. Fleshy fruits can be distinguished by their ripening process as climacteric fruits, such as tomatoes, or non-climacteric fruits, such as strawberries. Tomatoes undergo a global decrease in DNA methylation during ripening, due to increased expression of a DNA demethylase gene. The dynamics and biological relevance of DNA methylation during ripening of non-climacteric fruits, or other climacteric fruits, are unknown. Here, we generated and characterized single-base resolution maps of the DNA methylome in strawberry fruit, from immature to ripe stages. We observed an overall loss of DNA methylation during strawberry fruit ripening. Thus, ripening-induced DNA hypomethylation occurs not only in climacteric fruit, but also in non-climacteric fruit. However, we discovered that the mechanisms underlying DNA hypomethylation during ripening of tomato and strawberry are distinct. Unlike in tomatoes, DNA demethylase genes were not up-regulated during ripening of strawberries. Instead, genes involved in RNA-directed DNA methylation were down-regulated during strawberry ripening. Further, ripening-induced DNA hypomethylation was associated with decreased siRNA levels, consistent with reduced RdDM activity. Therefore, we propose that DNA hypomethylation during strawberry ripening is caused by diminished RdDM activity. Finally, hundreds of ripening-related genes displayed altered expression that was associated with, and thus potentially regulated by, DNA hypomethylation during ripening. Our findings provide new insight into the DNA methylation dynamics during the ripening of non-climateric fruit and reveal a novel function of RdDM in regulating an important process in plant development.
Project description:Fragaria vesca, a diploid woodland strawberry with a small and sequenced genome, is an excellent model for studying fruit development. The strawberry fruit is unique in that the edible flesh is actually enlarged receptacle tissue. The true fruit are the numerous dry achenes dotting the receptacleM-^Rs surface. Auxin produced from the achene is essential for the receptacle fruit set, a paradigm for studying crosstalk between hormone signaling and development. To investigate the molecular mechanism underlying strawberry fruit set, next-generation sequencing was employed to profile early-stage fruit development with five fruit tissue types and five developmental stages from floral anthesis to enlarged fruits. This two-dimensional data set provides a systems-level view of molecular events with precise spatial and temporal resolution.
Project description:In plants, MicroRNAs (miRNAs) are a new class of endogenous small RNAs that play essential regulatory roles in plant growth, development and stress response. Extensive studies of miRNAs have been performed in model plants such as rice, Arabidopsis thaliana and other plants. However, the number of miRNAs discovered in maize is relatively low and little is known about miRNAs involved in the four stages during maize ear development. Here, we use deep-sequencing, miRNA microarray assays and computational methods to identify, proM-oM-,M-^Ale, and describe conserved and non-conserved miRNAs at four developmental stages. A total of 27 conserved miRNA families were identiM-oM-,M-^Aed in all four stages, In addition to known miRNAs, we also found 23 new maize-specific miRNAs together with their star strands. We have also shown that almost all of them originated from single genes. We have found that many known and new miRNAs showed temporally expression. Finally, a total of 251 transcripts (140 genes) targeted by 102 small RNAs including 98 miRNAs and 4 ta-siRNAs were identified by genomic-scale high-throughput sequencing of miRNA cleaved mRNAs.This study led to the confirmation of the authenticity of 27 conserved miRNA families and the discovery of 23 novel miRNAs in maize. In addition, we have identified 130 targets of known and new miRNAs and ta-siRNA using recently developed tools for the global identification of miRNA targets. Identification and characterization of this important class of regulatory genes in maize may improve our understanding of molecular mechanism controlling flower development. The seeds of maize inbred line B73 were first sterilized and germinated in an incubator, then grown in a controlled environment with 28M-BM-0C/21M-BM-0C (day/night) under a 16-h day/8-h night photoperiod with a relative humidity of 70%. Ear development can be divided into four stages: the growth point elongation phase, spikelet differentiation phase, the floret primordium differentiation phase and floret organ differentiation phase. Plant materials (ears) were collected as described previously. In brief, ears were manually collected at the four developmental stages according to the plant features (number of visible leaves, leaf age index, and number of unfolded and folded leaves) combined with microscopic observation.
Project description:In contrast to climacteric fruits such as tomato, the knowledge on key regulatory genes controlling the ripening of strawberry, a non-climacteric fruit, is still limited. NAC transcription factors mediate different developmental processes in plants. Here, we identified and characterized FaRIF (Ripening Inducing Factor), a NAC transcription factor that is highly expressed and induced in strawberry receptacles during ripening. Functional analyses based on stable transgenic lines aimed at silencing FaRIF by RNA interference, either from a constitutive promoter or the ripe receptacle-specific EXP2 promoter, as well as overexpression lines showed that FaRIF controls critical ripening-related processes such as fruit softening and pigment and sugar accumulation. Physiological, metabolome and transcriptome analyses of receptacles of FaRIF-silenced and overexpression lines point to FaRIF as a key regulator of strawberry fruit ripening from early developmental stages, controlling abscisic acid (ABA) biosynthesis and signaling, cell wall degradation and modification, the phenylpropanoid pathway, volatiles production, and the balance of the aerobic/anaerobic metabolism. FaRIF is therefore a target to be modified/edited to control the quality of strawberry fruits.
Project description:The aim of this study was to determine the role of genes encoding polygalacturonases in strawberry fruit softening. To this purpose, several transgenic lines, cv. Chandler, were generated: plants with PG genes FaPG1 or FaPG2 downregulated, alone or in combination, by antisense transformation. Plants were grown in a confined greenhouse and fruits were harvested at the stage of full ripeness (100% of fruit surface red). The results obtained indicate that the silencing of these genes reduced fruit softening at similar level but there is not a sinergistic effect on fruit firmness.
Project description:We performed small RNA deep sequencing and identified 47 peach-specific and 47 known miRNAs or families with distinct expression patterns. Together, the identified miRNAs targeted 80 genes, many of which have not been reported previously. Like the model plant systems, peach has two of the three conserved trans-acting siRNA biogenesis pathways with similar mechanistic features and target specificity. Unique to peach, three of the miRNAs collectively target 49 MYBs, 19 of which are known to regulate phenylpropanoid metabolism, a key pathway associated with stone hardening and fruit color development, highlighting a critical role of miRNAs in regulation of peach fruit development and ripening. We also found that the majority of the miRNAs were differentially regulated in different tissues, in part due to differential processing of miRNA precursors. Up to 16% of the peach-specific miRNAs were differentially processed from their precursors in a tissue specific fashion, which has been rarely observed in plant cells. The miRNA precursor processing activity appeared not to be coupled with its transcriptional activity but rather acted independently in peach. Collectively, the data characterizes the unique expression pattern and processing regulation of peach miRNAs and demonstrates the presence of a complex, multi-level miRNA regulatory network capable of targeting a wide variety of biological functions, including phenylpropanoid pathways which play a multifaceted spatial-temporal role in peach fruit development. Identification of peach miRNAs and their targets from four different tissues
Project description:We used Illumina sequencing to investigate the global transcriptomic expression of hormonal pathway genes in ABA initiated strawberry receptacle ripening. Expression profiles of hormone synthetic and signaling genes further demonstrated the positive roles of ABA and GA, and the negative role of auxin in receptacle ripening. We also evaluated the transcript profiling of ethylene and JA pathway genes, and the results suggested that both ethylene and JA participated in receptacle ripening. Furthermore, two novel miRNAs and three conserved miRNAs were identified and validated to target genes in ABA and auxin pathways, respectively. Our analyses reveal the molecular mechanism of hormonal regulation during strawberry receptacle ripening. The data also provide an abundant of genetic information for molecular manipulation on non-climacteric fruit ripening. Sample 1: CK0 (Strawberry fruit two weeks after athesis treated with water, set as day 0); Sample 2: CK5 (fruit treated with water on day 5); Sample 3: CK8 (fruit treated with water on day 8); Sample 4: ABA5 (fruit treated with ABA on day 5); Sample 5: ABA8 (fruit treated with ABA on day 5); Sample 6: NDGA5 (fruit treated with water on day 5); Sample 7: NDGA8 (fruit treated with NDGA on day 8).