Project description:The postharvest senescence processes of citrus fruits were analyzed transcriptomic. The present study was aimed to: further uncover the rind-flesh communication of hesperidium; characterize the differential storage behaviors of different citrus varieties; reveal the important changes during storing process; and demonstrate the specific non-climacteric characteristics of citrus fruits. We chose four major table fruit varieties of citrus: satsuma mandarin (Citrus unshiu Marc) (M), ponkan (Citrus reticulata Blanco) (K), newhall navel orange (Citrus sinensis L. Osbeck) (O) and shatian pummelo (Citrus grandis Osbeck) (P). They were sampled every 10 days during 50 DAH (days after harvest), almost covering the commercial storage period of loose-skin citrus.
Project description:The postharvest senescence processes of citrus fruits were analyzed transcriptomic. The present study was aimed to: further uncover the rind-flesh communication of hesperidium; characterize the differential storage behaviors of different citrus varieties; reveal the important changes during storing process; and demonstrate the specific non-climacteric characteristics of citrus fruits.
Project description:Somatic embryogenesis in nucellar tissues is widely recognized to induce polyembryony in major citrus varieties such as sweet oranges, satsuma mandarins and lemons. This capability for apomixis is attractive in agricultural production systems using hybrid seeds, and many studies have been performed to elucidate the molecular mechanisms of various types of apomixis. To identify the gene responsible for somatic embryogenesis in citrus, a custom oligo-DNA microarray including predicted genes in the citrus polyembryonic locus was used to compare the expression profiles in reproductive tissues between monoembryonic and polyembryonic varieties. The full length of CitRKD1, which was identified as a candidate gene responsible for citrus somatic embryogenesis, was isolated from satsuma mandarin and its molecular function was investigated using transgenic ‘Hamlin’ sweet orange by antisense-overexpression. The candidate gene CitRKD1, predominantly transcribed in reproductive tissues of polyembryonic varieties, is a member of the plant RWP-RK domain proteins. CitRKD1 of satsuma mandarin comprised two alleles (CitRKD1-mg1 and CitRKD1-mg2) at the polyembryonic locus controlling embryony type (mono/polyembryony) that were structurally divided into two types with or without a miniature inverted-repeat transposable element (MITE)-like insertion in the upstream region. CitRKD1-mg2 with the MITE insertion was the predominant transcript in flowers and young fruits where somatic embryogenesis of nucellar cells occurred. Loss of CitRKD1 function by antisense-overexpression abolished somatic embryogenesis in transgenic sweet orange and the transgenic T1 plants were confirmed to derive from zygotic embryos produced by self-pollination by DNA diagnosis. Genotyping PCR analysis of 95 citrus traditional and breeding varieties revealed that the CitRKD1 allele with the MITE insertion (polyembryonic allele) was dominant and major citrus varieties with the polyembryonic allele produced polyembryonic seeds.
Project description:An experiment was performed to predict citrus varieties by means of supervised learning algorithms applied to gene expression profiles
Project description:We report the application of Illumina sequencing for high-throughput profiling of miRNA in citrus root responded to long-term boron toxicity. We find miR319 is involved in citrus adapation to long-term boron toxicity via targeting a MYB gene, Ciclev10000756m.g.v1.0, which is homologus with several MYBs that modulate lateral root development in Arabidopsis.
Project description:Fruit ripening in Citrus is not well understood at the molecular level. Knowledge of the regulatory mechanism of citrus fruit ripening at the post-transcriptional level in particular is lacking. Here, we comparatively analyzed the miRNAs and their targeted genes in a spontaneous late-ripening mutant, ?Fengwan? sweet orange (MT) (Citrus sinensis L. Osbeck), and its wild-type counterpart ('Fengjie 72-1', WT). Using high-throughput sequencing of small RNAs and RNA degradome tags, we identified 107 known and 21 novel miRNAs, as well as 225 target genes. A total of 24 miRNAs (16 known miRNAs and 8 novel miRNAs) were shown to be differentially expressed between MT and WT. The expression pattern of several key miRNAs and their target genes during citrus fruit development and ripening stages was examined. Csi-miR156k, csi-miR159 and csi-miR166d suppressed specific transcription factors (GAMYBs, SPLs and ATHBs) that are supposed to be important regulators involved in citrus fruit development and ripening. In the present study, miRNA-mediated silencing of target genes was found under complicated and sensitive regulation in citrus fruit. The identification of miRNAs and their target genes provide new clues for future investigation of mechanisms that regulate citrus fruit ripening.
Project description:Penicillium digitatum is the pathogen of Green mold in Postharvest citrus. After inoculating Penicillium digitatum into the wound of citrus to infect it, transcriptome sequencing was carried out and compared with the results of transcriptome sequencing of Penicillium digitatum before inoculation in order to screen the differentially expressed genes and reveal its infection mechanism.
Project description:Purpose: We obtained RNA-seq-based differential expression profile of Valencia sweet orange plants challenged against healthy and CLas-infected psyllid infection at 1 dpi and 5 dpi. The goals of this study are to reveal the interaction between citrus and psyllid/CaLas during the early phase of infection and understand the molecular mechanisms underlying the host-pathogen interactions and the susceptibility of most citrus varieties. Methods: leaf mRNA profiles of in vitro cultured Valencia sweet orange (VAL) budwood (WT) and of VAL fed by healthy and CLas-infected psyllid were generated by RNA-seq, in triplicate (one sample is duplicate), using Illumina HiSeq platform. The sequence reads that passed quality filters were used for gene expression and DEG detection analysis by EBseq algorithms. qRT–PCR validation was performed using SYBR Green assays Results: Using the RNA-seq data analysis workflow, we mapped about 136.80M sequence reads per sample to the reference Citrus clementina v1.0 genome and a total of 32,677 genes were detected. The average total mapping of each library was 71.98%. RNA-seq data were validated with qRT–PCR. Conclusions: Our study obtained the transcriptional profiles of citrus host by feeding of psyllid transmitting Candidatus Liberibacter asiaticus at early stages of infection, with biologic replicates, generated by RNA-seq technology. The RNA-seq data analysis workflows reported here should provide a framework for comparative investigations of expression profiles. We conclude that RNA-seq based transcriptome characterization would expedite genetic network analyses and permit the dissection of complex biologic functions.
Project description:Background: Magnesium (Mg)-deficiency occurs most frequently in strongly acidic, sandy soils. Citrus are grown mainly on acidic and strong acidic soils. Mg-deficiency causes poor fruit quality and low fruit yield in some Citrus orchards. For the first time, we investigated Mg-deficiency-responsive miRNAs in ‘Xuegan’ (Citrus sinensis) roots using Illumina sequencing in order to obtain some miRNAs presumably responsible for Citrus Mg-deficiency tolerance. Results: We obtained 101 (69) miRNAs with increased (decreased) expression from Mg-starved roots. Our results suggested that the adaptation of Citrus roots to Mg-deficiency was related to the several aspects: (a) inhibiting root respiration and related gene expression via inducing miR158 and miR2919; (b) enhancing antioxidant system by down-regulating related miRNAs (miR780, miR6190, miR1044, miR5261 and miR1151) and the adaptation to low-phosphorus (miR6190); (c) activating transport-related genes by altering the expression of miR6190, miR6485, miR1044, miR5029 and miR3437; (d) elevating protein ubiquitination due to decreased expression levels of miR1044, miR5261, miR1151 and miR5029; (e) maintaining root growth by regulating miR5261, miR6485 and miR158 expression; and (f) triggering DNA repair (transcription regulation) by regulating miR5176 and miR6485 (miR6028, miR6190, miR6485, miR5621, miR160 and miR7708) expression. Mg-deficiency-responsive miRNAs involved in root signal transduction also had functions in Citrus Mg-deficiency tolerance. Conclusions: We obtained several novel Mg-deficiency-responsive miRNAs (i.e., miR5261, miR158, miR6190, miR6485, miR1151 and miR1044) possibly contributing to Mg-deficiency tolerance. These results revealed some novel clues on the miRNA-mediated adaptation to nutrient deficiencies in higher plants.