Project description:The main objective of the present study was to analyze whether the novel phenotype of this complex three-way tetraploid interspecific hybrid, displaying mixed dominant, codominant and transgressive traits is associated with non additive expression of the two diploid parental genomes. Keywords: Comparative transcriptomic hybridization Three replicates for each sample category (C. reticulata Blanco, C. limon (L.) Burm.) and a allotetraploid somatic hybrid between both) were generated and compared by a reference design.
Project description:The main objective of the present study was to analyze whether the novel phenotype of this complex three-way tetraploid interspecific hybrid, displaying mixed dominant, codominant and transgressive traits is associated with non additive expression of the two diploid parental genomes. Keywords: Comparative transcriptomic hybridization
Project description:Citrus species are among the most important fruit crops. However, gene regulation and signaling pathways related to etiolation in this crop remain unknown. Using Illumina sequencing technology, modification of global gene expression in two hybrid citrus cultivars—Huangguogan and Shiranuhi, respectively—were investigated. More than 834.16 million clean reads and 125.12 Gb of RNA-seq data were obtained, more than 91.37% reads had a quality score of Q30 (sequencing error rate, 0.1%). 124,952 unigenes were finally generated with a mean length of 1,189 bp. Of these unigenes, 98,904 (79.15%), 105,408 (84.35%), 42,016 (33.62%), 78,872 (63.12%), 72,068 (57.67%), 72,464 (57.99%), 72464 (57.99%) and 46,308 (37.06%) had been annotated in NR, NT, KO, SwissProt, PFAM, GO and KOG databases, respectively. Further, we identified 604 differentially expressed genes (DEGs) in multicoloured and etiolated seedlings of Shiranuhi, including 180 up-regulated genes and 424 down-regulated genes. While in Huangguogan, we found 1,035 DEGs, 271 of which were increasing and the others were decreasing. 7 DEGs were commonly up-regulated, and 59 DEGs down-regulated in multicoloured and etiolated seedlings of these two cultivars, suggesting that some genes play fundamental roles in two hybrid citrus seedlings during etiolation. Functional classification of the DEGs in two cultivars using GO term indicated that biological process, cellular component and molecular function were three major groups. Our study is the first to provide the transcriptome sequence resource for seedlings etiolation of Shiranuhi and Huangguogan, and advance our knowledge of the genes involved in the complex regulatory networks of seedling etiolation.
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:To uncover the involvement of miRNAs and siRNAs in somatic embryogenesis of the perennial woody crop citrus, we carried out high-throughput (Illumina) sequencing (HTS) of sRNAs and RNA degradome tags in non-embryogenic and embryogenic tissue of Valencia sweet orange. A total of 191 stem-loop structures were identified, emanating 50 known and 45 novel miRNAs, 130 miniature inverted-repeat transposable elements (MITEs) derived small interfering RNAs (siRNAs) and 94 other siRNAs. Combining with the result of degradome sequencing, a total of 235 phased siRNAs (phasiRNAs), and 195 cleaved target genes were identified for miRNAs/siRNAs.
Project description:Mechanism, inheritance patterns and biological significance remain unclear. Here, we generated genome-wide integrated maps of H3K27me3 modification and transcriptome for Col, C24 and their F1 hybrid, and their clf mutants. We found that H3K27me3 modification profiles were divergent between Col and C24, and were inherited mainly additively in hybrid. By comparing H3K27me3 modification ratio between parents to allelic H3K27me3 modification ratio in hybrid, we identified cis- and trans-regulatory divergence for H3K27me3 modification variation between Col and C24, and found that cis-regulatory divergence was the predominant contributor to H3K27me3 variation. The majority of genes with both cis- and trans-regulatory divergence displayed "cis-trans" interaction, whereas "cis+trans" interaction resulted in higher magnitude of H3K27me3 variation. H3K27me3 modification variation was negatively correlated with gene expression variation between Col and C24, both of which might rise from the same cis-regulatory divergence. Moreover, cis-regulatory divergence could lead to the concurrent allelic H3K27me3 modification bias and allelic gene expression bias for auxin metabolic genes and stimulus responsive genes in Col×C24 hybrid. Natural variation of H3K27me3 modification and gene expression were changed upon CLF mutation, and heterosis, especially best-parent hetereosis, was largely compromised in clf hybrid. Together, our study provided a comprehensive analysis of regulatory divergence for natural variation of histone modification and its association with differential gene expression between Arabidopsis accessions and growth vigor in hybrid.