Project description:The tissues of male flowers, female flowers and hermaphrodite are collected and stored in liquid nitrigen immediately. Total RNA was isolated from male, hermaphrodite, and female flowers using the Trizol reagent (Invitrogen USA). Low molecular weight RNA was enriched from the total RNA by precipitating with 0.4M NaCl and polyethylene glycol (PEG). The enriched low molecular weight RNA was then separated on a denaturing 15% polyacrylamide gel. The band corresponding to the RNA standard of 18-30 nucleotides was then excised from the gel and eluted overnight in 0.4M NaCl at 4 degrees Celsius, and subsequently ligated with 5’ and 3’ Illumina small RNA adapters. The adapter ligated library was converted into cDNA and amplified by using PCR and sequenced by Illumina Genome Analyzer II.

2014-12-31 | GSE54097 | GEO

High-throughput sequencing of small RNAs in Carica papaya

Project description:Small RNAs (21-24 nt) are pivotal regulators of gene expression that guide both transcriptional and post-transcriptional silencing mechanisms in diverse eukaryotes, including most if not all plants. MicroRNAs (miRNAs) and short interfering RNAs (siRNAs) are the two major types, both of which have a demonstrated and important role in plant development, stress responses and pathogen resistance. In this work, we used a deep sequencing approach (Sequencing-By-Synthesis, or SBS) to develop sequence resources of small RNAs from different Carica papaya tissues (including leaves and flowers). The high depth of the resulting datasets enabled us to examine in detail critical small RNA features, such as size distribution, tissue-specific regulation and sequence conservation between different organs in this species. We also developed database resources and a dedicated website (http://smallrna.udel.edu/) with computational tools for allowing other users to identify new miRNAs or siRNAs involved in specific regulatory pathways, verify the degree of conservation of these sequences in other plant species and map small RNAs on genes or larger regions of the maize genome under study. Small RNA libraries were derived from leaves, virus-infected leaves and female flowers of Carica papaya. Total RNA was isolated using the TriReagent (Molecular Research Center) and submitted to Illumina (Hayward, CA, http://www.illumina.com) for small RNA library construction using approaches described in (Lu et al., 2007) with minor modifications. The small RNA libraries were sequenced with the Sequencing-By-Synthesis (SBS) technology by Illumina. PERL scripts were designed to remove the adapter sequences and determine the abundance of each distinct small RNA. We thank Ray Ming and Qingyi Yu for providing the plant material, as well as Kan Nobuta and Gayathri Mahalingam for assistance with the computational methods.

2011-04-29 | E-GEOD-28753 | biostudies-arrayexpress

Carica papaya microRNAs are responsive to Papaya meleira virus infection.

Project description:MicroRNAs are implicated in the response to biotic stresses. Papaya meleira virus (PMeV) is the causal agent of sticky disease, a commercially important pathology in papaya for which there are currently no resistant varieties. PMeV has a number of unusual features, such as residence in the laticifers of infected plants, and the response of the papaya to PMeV infection is not well understood. The protein levels of 20S proteasome subunits increase during PMeV infection, suggesting that proteolysis could be an important aspect of the plant defense response mechanism. To date, 10,598 plant microRNAs have been identified in the Plant miRNAs Database, but only two, miR162 and miR403, are from papaya. In this study, known plant microRNA sequences were used to search for potential microRNAs in the papaya genome. A total of 462 microRNAs, representing 72 microRNA families, were identified. The expression of 11 microRNAs, whose targets are involved in 20S and 26S proteasomal degradation and in other stress response pathways, was compared by real-time PCR in healthy and infected papaya leaf tissue. We found that the expression of miRNAs involved in proteasomal degradation increased in response to very low levels of PMeV titre and decreased as the viral titre increased. In contrast, miRNAs implicated in the plant response to biotic stress decreased their expression at very low level of PMeV and increased at high PMeV levels. Corroborating with this results, analysed target genes for this miRNAs had their expression modulated in a dependent manner. This study represents a comprehensive identification of conserved miRNAs inpapaya. The data presented here might help to complement the available molecular and genomic tools for the study of papaya. The differential expression of some miRNAs and identifying their target genes will be helpful for understanding the regulation and interaction of PMeV and papaya.

| S-EPMC4114745 | biostudies-literature

Carica papaya

Project description:Gene Expression Profiling of Papaya (Carica papaya L.) Immune Response Induced by CTS-N after inoculating PLDMV

| PRJNA591254 | ENA

Carica papaya

Project description:Carica papaya Genome sequencing

| PRJNA271489 | ENA

Carica papaya

Project description:Digital transcriptome analysis of genes on sex chromosomes in papaya (Carica papaya)

| PRJNA143415 | ENA

Carica papaya

Project description:Carica papaya Raw sequence reads