Project description:To identify genes associated with genic male sterility (GMS) that could be useful for hybrid breeding in Chinese cabbage (Brassica rapa ssp. pekinensis), floral bud transcriptome analysis was carried out using a B. rapa microarray with 300,000 probes (Br300K). Among 47,548 clones deposited on a Br300K microarray with seven probes of 60 nt length within the 3' 150 bp region, a total of 10,622 genes were differentially expressed between fertile and sterile floral buds; 4,774 and 5,848 genes were up-regulated over 2-fold in fertile and sterile buds, respectively. However, the expression of 1,413 and 199 genes showed fertile and sterile bud-specific features, respectively. Genes expressed specifically in fertile buds, possibly GMS-related genes, included homologs of several Arabidopsis male sterility-related genes, genes associated with the cell wall and synthesis of its surface proteins, pollen wall and coat components, signaling components, and nutrient supplies. However, most early genes for pollen development, genes for primexine and callose formation, and genes for pollen maturation and anther dehiscence showed no difference in expression between fertile and sterile buds. Some of the known genes associated with Arabidopsis pollen development showed similar expression patterns to those seen in this study, while others did not. BrbHLH89 and BrMYP99 are putative GMS genes. Additionally, 17 novel genes identified only in B. rapa were specifically and highly expressed only in fertile buds, implying the possible involvement in male fertility. All data suggest that Chinese cabbage GMS might be controlled by genes acting in post-meiotic tapetal development that are different from those known to be associated with Arabidopsis male sterility. A total of 14 chips were used for the microarray experiment. Experiments were performed with two biological replicates.
Project description:To identify genes associated with genic male sterility (GMS) that could be useful for hybrid breeding in Chinese cabbage (Brassica rapa ssp. pekinensis), floral bud transcriptome analysis was carried out using a B. rapa microarray with 300,000 probes (Br300K). Among 47,548 clones deposited on a Br300K microarray with seven probes of 60 nt length within the 3' 150 bp region, a total of 10,622 genes were differentially expressed between fertile and sterile floral buds; 4,774 and 5,848 genes were up-regulated over 2-fold in fertile and sterile buds, respectively. However, the expression of 1,413 and 199 genes showed fertile and sterile bud-specific features, respectively. Genes expressed specifically in fertile buds, possibly GMS-related genes, included homologs of several Arabidopsis male sterility-related genes, genes associated with the cell wall and synthesis of its surface proteins, pollen wall and coat components, signaling components, and nutrient supplies. However, most early genes for pollen development, genes for primexine and callose formation, and genes for pollen maturation and anther dehiscence showed no difference in expression between fertile and sterile buds. Some of the known genes associated with Arabidopsis pollen development showed similar expression patterns to those seen in this study, while others did not. BrbHLH89 and BrMYP99 are putative GMS genes. Additionally, 17 novel genes identified only in B. rapa were specifically and highly expressed only in fertile buds, implying the possible involvement in male fertility. All data suggest that Chinese cabbage GMS might be controlled by genes acting in post-meiotic tapetal development that are different from those known to be associated with Arabidopsis male sterility.
Project description:We identified the nup1 mutant rice that exhibited specific male sterility due to the absence of Ubisch body formation and pollen grain production. We cloned the causal gene and demonstrated that NUP1, a class III peroxidase predominantly expressed in the anther wall, mediated ROS scavenging. The loss-of-function of NUP1 resulted in ROS burst in anthers, which disrupted the oxidation-reduction process and carbohydrate and lipid metabolisms, and thereby led to loss of tapetal Ubisch bodies and ultimately resulted in male sterility in rice. Our study expands the understanding of the molecular mechanisms by which ROS homeostasis regulates cell metabolism, tapetal Ubisch body formation and male fertility in plants.
Project description:The hybrid seed production was performed using the male sterility line, which is an important way of heterosis utilization in Chinese cabbage. A stably inherited male sterile mutant msm was obtained from a Chinese cabbage DH line ‘FT’ using the isolated microspore culture combined with 60Co γ-rays mutagenesis. Compared to the wild type ‘FT’, the msm exhibited completely degenerated stamens and no pollen phenotype, and other characters had no significant difference except for stamen. The genetic analysis indicated that the msm mutant phenotype was controlled by a single recessive nuclear gene. Cytological observation showed that the stamen abortion of msm began at the tetrad period, and tapetum cells were abnormally expanded and highly vacuolated, leading to microspore abortion. Comparative transcriptome analysis on the flower buds of ‘FT’ and msm using RNA-Seq technology revealed a total of 1,653 differentially expressed genes (DEGs). Among which, a large number of genes associated with male sterility were found, including 64 pollen development and pollen tube growth-related genes, 94 pollen wall development-related genes, 11 phytohormone-related genes and 16 transcription factor-related genes, and the overwhelming majority of these genes were down-regulated in the msm vs. ‘FT’ comparison. Furthermore, KEGG pathway analysis indicated that a variety of carbohydrate metabolic and lipid metabolic pathways were significantly enriched, which may be related to pollen abortion. The expression patterns of 24 male sterility-related genes were analyzed using qRT-PCR. In addition, a total of 24,476 single nucleotide polymorphisms and 413,073 insertion-deletion events were specifically detected in msm. These results facilitate to elucidate the regulatory mechanisms of male sterility in Chinese cabbage.
Project description:The successful fusion of sperms and eggs need firstly the reception of pollens by stigmatic papillae, and then the unobstructed transmitting tract (TT) providing an extension channel for pollen tubes carrying with sperm cells. However, the genes involved in transmitting tract specification and cavity formation in cucumber remained largely unknown. Here, we characterized the bHLH gene, Cucumis sativus SPATULA (CsSPT) and its redundant function with Cucumis sativus ALCATRAZ (CsALC) in TT development and stigma convergence in cucumber.
Project description:we show that a short moderate heat stress during the tetrad stage of pollen development targets vital metabolic pathways ultimately leading to sterility and yield losses in maize.
Project description:We studied the causes of sterility underlying multiple-allele-inherited male sterility in Chinese cabbage by identifying differentially expressed genes (DEGs) related to pollen sterility between fertile and sterile flower buds. In this work,we performed transcriptome analysis of mRNA isolated from fertile and sterile buds using Illumina HiSeq 2000 platform sequencing. Approximately 80% of ~229 million high quality paired-end reads were uniquely mapped to the reference genome. In sterile buds, 699 genes were significantly up-regulated and 4,096 genes were down-regulated. Among the DEGs, 28 pollen cell wall-related genes, 53 transcription factor genes, 45 phytohormone-related genes, 20 anther and pollen-related genes, 212 specifically expressed transcripts (SETs), and 417 DEGs located in linkage group R07 were identified. Six transcription factor genes BrAMS, BrMS1, BrbHLH089, BrbHLH091, BrAtMYB103, and BrANAC025, were identified as putative sterility-related genes. The weak auxin signal that is regulated by BrABP1 may be one of the key factors causing pollen sterility observed here. Moreover, several significantly enriched GO terms “cell wall organization or biogenesis” (GO:0071554), “intrinsic to membrane” (GO:0031224), “integral to membrane” (GO:0016021), “hydrolase activity, acting on ester bonds” (GO:0016788) and one significantly enriched pathway “starch and sucrose metabolism” (ath00500) were obtained in this work. qRT-PCR and in situ hybridization validated that our RNA-seq transcriptome analysis was accurate and reliable. This study will lay the foundation for elucidating the molecular mechanism(s) underlying sterility, and provide valuable information for studying multiple-allele-inherited male sterility in Chinese cabbage line ‘AB01’.
Project description:The coordination of pollen viability, stamen filament elongation and anther dehiscence is essential for the successful pollination and reproduction in angiosperms. The hormone jasmonic acid (JA) are crucial for these processes. However, the tight regulation of JA biosynthesis during stamen development is still largely unknown. Here, we demonstrate that the rice (Oryza sativa) ERF-associated amphiphilic repression (EAR) motif-containing protein TCP INTERACTOR CONTAINING EAR MOTIF PROTEIN1 (OsTIE1) tightly regulates JA biosynthesis by repressing TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATINGCELLFACTORS (TCP) transcription factor OsTCP1/PCF5 during stamen development. The loss of OsTIE1 function in ostie1 mutants causes male sterility. The ostie1 mutants display inviable pollen, the early stamen filament elongation and the precocious anther dehiscence. JA biosynthesis is activated earlier and JA level is precociously increased in anthers of ostie1. The expression of OsTIE1 is developmentally regulated during stamen development. OsTIE1 is localized in nuclei and has transcriptional repression activity. We further show that OsTIE1 directly interacts with OsTCP1, and overexpression of OsTCP1 caused early anther dehiscence resembling that of ostie1. The expression of genes encoding key enzymes of JA biosynthesis including Oryza sativa lipoxygenase (OsLOX) genes is regulated by the OsTIE1-OsTCP1 complex. Our findings discover that the OsTIE1-OsTCP1 module plays critical roles in stamen development by finely tuning JA biosynthesis, and provides a new foundation to create male sterile plants for hybrid seed production.
Project description:The CLAVATA3/ESR-RELATED (CLE) peptide hormones are required for numerous plant growth and developmental processes. However, little is known regarding the function and working mechanism of the CLEs in the anther. Here, using RNA in situ hybridization analyses, we identified 7 CLE genes that are specifically expressed in the tapetum and microsporocytes in the anther, and the dominant-negative mutant plants of each of these genes exhibited significantly reduced anther size, pollen number, and abnormal pollen wall formation. Further transcriptomic and proteomic studies on cle19, DN-CLE19, and CLE19-OX mutant lines revealed that CLE19 affected the expression of more than 1,000 genes at the RNA level and 595 at the protein level, including genes involved in pollen coat and pollen exine formation, lipid metabolism, pollen germination, and hormone metabolism processes. Phenotypic analyses of mutants of the CLE19 downstream genes GRP20, ACOS5 and MEE48 revealed that the formation of pollen exine was affected in these mutants, confirming that these genes function downstream of CLE19 in the regulation of pollen wall formation. These findings demonstrate the function and downstream genes of CLE19 and redundant genes, providing insights into working pathways of the peptide hormones in pollen development.