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:With the development of high throughput sequencing technologies, plenty of non-coding RNAs (ncRNAs) have been discovered to play important roles in diverse plant biological processes. Although these ncRNAs extensively exist in plant, their biological functions are still remained to characterize. To obtain a comprehensive understanding of long non-coding RNA (lncRNA) function in strawberry fruit ripening progress, we performed transcriptomic analyses on the diploid strawberry Fragaria vesca in a time-course during fruit ripening. Here, we have identified 25,613 lncRNAs based on RNA-seq data from poly(A)-depleted libraries and rRNA-depleted libraries. Among them, most of lncRNAs exhibit stage-specific expression pattern. Functional analysis on F.vesca endogenous FRUIT RIPENING-RELATED LONG ANTISENSE INTERGENIC RNA (FRILAIR) in octaploid strawberry Falandi, we found that overexpression FRILAIR can compete miR397 to regulate its target laccase genes (LACs), and it may contribute to strawberry ripening. Our findings demonstrate that FRILAIR can act as a competing endogenous RNA (ceRNA) by disturbing miR397 to repress expression level of LACs, and would be valuable for strawberry ripening.
Project description:Breeding day-neutral strawberry (Fragaria x ananassa Duchesne) is pivotal to extend fruit-bearing season and increase the efficiency of production. However, genetic improvement of day-neutrality by the means of molecular marker technologies remains slow due to genome complexity of octoploid strawberry. This study employs an innovative approach by integrating the Subtracted Diversity Array (SDA) technology and Bulked Segregant Analysis (BSA) to facilitate the identification of molecular markers associated with day-neutrality in octoploid strawberry. A Fragaria Discovery Panel (FDP) containing 287 features specific to strawberry genome was constructed as a platform for rapid screening of DNA polymorphism between one short day (SD) strawberry DNA bulk and three day-neutral (DN) bulks varrying in flowering strength. Differential array hybridisation patterns between the DN and SD bulks revealed a novel molecular marker, FaP2E11, closely linked to CYTOKININ OXIDASE 1 (CKX1) gene possibly involved in promoting flowering under non-inductive condition. Interestingly, a 12 bp deletion was observed within the FaP2E11 sequence cloned from SD genotypes but not DN genotypes. As cytokinin is required to induce flowering, this result indicates that full sequence of FaP2E11 and the sequence with deletion are allelic variants linked to the low enzyme activity CKX1 and the wild type alleles, respectively.
Project description:The wild strawberry Fragaria vesca has recently emerged as an excellent model for investigating flower and fruit traits in economically important fruit crops. Its history of physiological studies combined with sequenced genome and full complements of molecular genetic tools facilitate investigations into mechanisms of its unique biological processes such as fleshy fruit development from the enlarged stem tip called receptacle. Sequencing of nine small RNA libraries encompassing vegetative, flower, and fruit tissues led to the identification of 22 conserved and 10 less-conserved miRNAs as well as 41 novel miRNAs that are likely specific to the strawberry. High throughput Parallel Analyses of RNA ends (PARE) were performed to identify miRNA-guided cleavage events and corresponding target genes. We found that most conserved miRNAs developed species-specific target genes in addition to conserved targets, highlighting the dynamic and fluid nature of the miRNA_target relations. Significantly, we discovered two novel clusters of miRNAs, which together target up to 94 F-box genes. Within one of the clusters is a 22 nt novel miRNA, miRN39, that was expressed preferentially in the developing receptacle fruit and triggered phased siRNA production from six primary FBX PHAS loci. This miRN39-phasiFBX pathway may be involved in regulating disease resistance in the receptacle fruit. In addition, a modified “two-hit” mode of tasiRNA processing was identified in F. vesca, suggesting flexibility in applying previously set rules. A major theme that emerges from this work is that novel miRNAs and miRNA-phasiRNA networks may have evolved to regulate recently expanded gene families so as to control species-specific biological or physiological processes.
Project description:In this RNA-seq study, we compared the transcriptome of three Fragaria vesca genotypes in response to Phytophthora cactorum. The goal of our study was to dissect the resistance mechanism of the diploid strawberry (F. vesca) that are resistant to P. cactorum. A susceptible genotype (NCGR1218) and two resistant (NCGR1603 and Bukammen) F. vesca genotypes were used for the comparative transcriptome analyses. Plants were inoculated with P. cactorum zoospores (2mL of 2 × 105 spores/mL) in the crown (rhizome) and sampled 48 hours later. The appropriate controls for each genotype were i) samples wounded and inoculated with water and sampled 48 hours after the treatment and ii) untreated samples. Four biological replicates, each consisting of four individual test plants from each genotype were used for the transcriptome study. All the samples were collected from the crown, flash-frozen in liquid nitrogen and stored at -80 °C until RNA isolation. Total RNA was isolated using the SpectrumTM Plant Total RNA Kit (Sigma-Aldrich, USA) according to the manufacturer’s instructions. For sequencing, the libraries were prepared using the TruSeqTM stranded total RNA library prep kit (Illumina, USA), indexed and pooled, and sequenced in four lanes using the Illumina HiSeq 3/4000 (2×150 bp) System by the Norwegian Sequencing Centre, Oslo, Norway. Raw reads were quality filtered, de novo assembled into transcripts and were analysed for differentially expressed genes between the inoculated and control samples.