Project description:Seedlessness is an important agronomic trait for citrus, and male sterility (MS) is one main cause of seedless citrus fruit. However, the molecular mechanism of citrus seedlessness remained not well explored. An integrative strategy combining SSH (suppression subtractive hybridization) library with cDNA microarray was employed to study the underlying mechanism of seedlessness of a Ponkan mandarin seedless mutant (Citrus reticulate Blanco). Screening with custom microarray, a total of 279 differentially expressed clones were identified, and 133 unigenes (43 contigs and 90 singletons) were obtained after sequencing. Gene Ontology (GO) distribution showed that the majority of differential genes involved in metabolic process, responded to stimulus and functioned as DNA/RNA binding, catalytic activity and oxidoreductase activity. Expression dynamics of some candidate clones revealed a gene encoding male sterility protein 2 was highly up-regulated, while several transcription factors (TFs) such as AP2/EREBP, MYB, WRKY, NAC and C2C2-GATA zinc-finger domain TFs were specifically down-regulated in the seedless mutant compared with the wild type. Our research highlighted some candidate pathways that participated in the citrus male gametophyte development and could be beneficial for seedless citrus breeding in the future.
Project description:Seedlessness is an important agronomic trait for citrus, and male sterility (MS) is one main cause of seedless citrus fruit. However, the molecular mechanism of citrus seedlessness remained not well explored. An integrative strategy combining SSH (suppression subtractive hybridization) library with cDNA microarray was employed to study the underlying mechanism of seedlessness of a Ponkan mandarin seedless mutant (Citrus reticulate Blanco). Screening with custom microarray, a total of 279 differentially expressed clones were identified, and 133 unigenes (43 contigs and 90 singletons) were obtained after sequencing. Gene Ontology (GO) distribution showed that the majority of differential genes involved in metabolic process, responded to stimulus and functioned as DNA/RNA binding, catalytic activity and oxidoreductase activity. Expression dynamics of some candidate clones revealed a gene encoding male sterility protein 2 was highly up-regulated, while several transcription factors (TFs) such as AP2/EREBP, MYB, WRKY, NAC and C2C2-GATA zinc-finger domain TFs were specifically down-regulated in the seedless mutant compared with the wild type. Our research highlighted some candidate pathways that participated in the citrus male gametophyte development and could be beneficial for seedless citrus breeding in the future. Flower buds from the seedless citrus mutant and its wild type were collected at four developmental stages: quaring stage (SF, about 20 DBF), medium bud stage (MF, about 10 DBF), flowers at full bloom stage (BF) and young ovaries of 2-3 days after flowering (OV). Total RNA extracted from the mutant and the wild type was hybridized to the array. The hybridization was performed in duplicate by dye swap.
Project description:High-throughput small RNA and degradome sequencing were performed to identify a large number of miRNAs and their targets. Differential expression of several miRNAs reveals that miRNA regulatory network was closely linked to gametophyte development and male sterility in Ponkan mandarin. The expression profiles of miR156 and miR167 as well as their targets demonstrated their contribution in male sterility in the Ponkan seedless type. This study provides valuable information for better understanding of miRNAs network in plant anther development and lays a foundation to future research on male sterility in citrus and even other species. small RNA and degradome sequencing of seedy M-bM-^@M-^XEgan No.1M-bM-^@M-^Y and its male sterile and seedless mutant M-bM-^@M-^XQianyang seedlessM-bM-^@M-^Y
Project description:High-throughput small RNA and degradome sequencing were performed to identify a large number of miRNAs and their targets. Differential expression of several miRNAs reveals that miRNA regulatory network was closely linked to gametophyte development and male sterility in Ponkan mandarin. The expression profiles of miR156 and miR167 as well as their targets demonstrated their contribution in male sterility in the Ponkan seedless type. This study provides valuable information for better understanding of miRNAs network in plant anther development and lays a foundation to future research on male sterility in citrus and even other species.
Project description:Seed abortion is one of the important reasons for the formation of seedless characters in citrus. However, the molecular mechanism of seed abortion in citrus is still unclear. We identified several genes that may play an important role in seed abortion of 'Huagan 4', such as CrWRKY74. The downstream regulatory network of CrWRKY74 was identified based on DAP seq analysis to gain insight into the molecular mechanism related to seed abortion.
Project description:In this study, in order to identify miRNA targets, a degradome library derived from anthers of the WT and GMS (Genetic Male Sterility) mutant representing three stages of development was constructed and sequenced, resulting in the generation of 24.6 million raw reads. After removal of low quality sequences and adapter sequences, 24.4 million clean reads were obtained and 98% were 20 or 21 nt in length as expected in that normally length distribution peak of degradome fragment is between 20 and 21 nt [Addo-Quaye C, Eshoo TW, Bartel DP, Axtell MJ: Endogenous siRNA and miRNA targets identified by sequencing of the Arabidopsis degradome. Curr Biol 2008, 18:758-762].
Project description:Seed developmental arrest is one of the early phenotypes of seed abortion. However, the molecular mechanism underlying seed developmental arrest of citrus is still unclear. In this study, laser capture microdissection (LCM) was used to accurately divide the seeds of seedless Ponkan ‘Huagan No.4’ (Citrus reticulata) (HG) and seeded Ponkan ‘Egan No.1’ (Citrus reticulata) (EG) into nucellus and integument/seed coat tissues. The captured tissues were used for subsequent RNA-seq. Moreover, single-molecule real-time (SMRT) sequencing was used to generate full-length transcripts of EG, which were used as reference transcripts for RNA-seq. These data can be utilized to analyse the causes of citrus seedlessness formation and the molecular regulatory network in the process of seed abortion.
