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:Strawberry is economically important and widely grown but susceptible to a large variety of phytopathogenic organisms. Among them, Xanthomonas fragariae is a quarantine bacterial pathogen threatening strawberry productions by causing angular leaf spots. Using whole transcriptome sequencing, gene expression of both plant and bacteria in planta was analyzed at two time points, 12- and 29-days post inoculation, in order to compare pathogen and host response between the stages of early visible and of well-developed symptoms. Among 28’588 known genes in strawberry and 4’046 known genes in X. fragariae expressed at both time points, a total of 361 plant and 144 bacterial genes were significantly differentially expressed, respectively. The identified higher expressed genes in the plants were pathogen-associated molecular pattern receptors and pathogenesis related thaumatin encoding genes, whereas the more expressed early genes were related to chloroplast metabolism as well as photosynthesis related coding genes. Most of X. fragariae genes involved in host interactions, recognitions and pathogenesis, were lower expressed at late-phase infection. This study gives a first insight on the interaction of X. fragariae with its host. The strawberry plant changed its metabolism consistently with the progression of infection.
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 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