Project description:Plants possess various defense strategies to counter attacks from microorganisms or herbivores. For example, plants reduce the cell-wall-macerating activity of pathogen- or insect-derived polygalacturonases (PGs) by expressing PG-inhibiting proteins (PGIPs). PGs and PGIPs belong to multi-gene families believed to have been shaped by an evolutionary arms race. The mustard leaf beetle Phaedon cochleariae expresses both active PGs and catalytically inactive PG pseudoenzymes. Previous studies demonstrated that (i) PGIPs target beetle PGs and (ii) the role of PG pseudoenzymes remains elusive, despite having been linked to the pectin degradation pathway. For further insight into the interaction between plant PGIPs and beetle PG family members, we combined affinity purification with proteomics and gene expression analyses, and identified novel inhibitors of beetle PGs from Chinese cabbage (Brassica rapa ssp. pekinensis). A beetle PG pseudoenzyme was not targeted by PGIPs, but instead interacted with PGIP-like proteins. Phylogenetic analysis revealed that PGIP-like proteins clustered apart from classical PGIPs but together with proteins, which have been involved in developmental processes. Our results indicate that PGIP-like proteins represent not only interesting novel PG inhibitor candidates in addition to classical PGIPs, but also fascinating new players in the arms race between herbivorous beetles and plant defenses.
Project description:Deep sequencing provided evidence that a novel subset of small RNAs were derived from the chloroplast genome of Chinese cabbage (Brassica rapa) and Arabidopsis (Ler). The chloroplast small RNAs (csRNAs) include those derived from mRNA, rRNA, tRNA and intergenic RNA. The rRNA-derived csRNA were preferentially located at the 3M-CM-"M-BM-^@M-BM-^Y-ends of the rRNAs, while the tRNA-derived csRNAs were mainly located at 5M-CM-"M-BM-^@M-BM-^Y-termini of the tRNAs. After heat treatment, the abundance of csRNAs decreased in chinese cabbage seedlings, except those of 24 nt in length. The novel heat-responsive csRNAs and their locations in the chloroplast were verified by Northern blotting. The regulation of some csRNAs to the putative target genes were identified by real-time PCR. Our results indicated that high temperature regulated the production of some csRNAs, which may have potential roles in transcriptional or post-transcriptional regulation, and affected putative target genes expression in chloroplast. Examination of two replicates of heat treated (HT) and control (MT) Chinese cabbage sample respectively, and one Arabidopsis (Ler) RNA sample.
Project description:Deep sequencing provided evidence that a novel subset of small RNAs were derived from the chloroplast genome of Chinese cabbage (Brassica rapa) and Arabidopsis (Ler). The chloroplast small RNAs (csRNAs) include those derived from mRNA, rRNA, tRNA and intergenic RNA. The rRNA-derived csRNA were preferentially located at the 3â-ends of the rRNAs, while the tRNA-derived csRNAs were mainly located at 5â-termini of the tRNAs. After heat treatment, the abundance of csRNAs decreased in chinese cabbage seedlings, except those of 24 nt in length. The novel heat-responsive csRNAs and their locations in the chloroplast were verified by Northern blotting. The regulation of some csRNAs to the putative target genes were identified by real-time PCR. Our results indicated that high temperature regulated the production of some csRNAs, which may have potential roles in transcriptional or post-transcriptional regulation, and affected putative target genes expression in chloroplast.
Project description:We conducted a RNA-Seq analysis of MeJA-treated Chinese cabbage leaf transcriptome. Total 14,619,469 sequence reads were generated to produce 27,461 detected genes, among which 1,451 genes were up-regulated and 991 genes were down-regulated as differentially expressed genes (DEGs) (log2 ratio â¥1, false discovery rate â¤0.001). More than 90% of the DEGs (2,278) were between 1.0- and 3.0-fold (log2 ratio). The most highly represented pathways by 1,674 annotated DEGs were related to âmetabolic pathwaysâ (333 members), âribosomeâ (314 members), âbiosynthesis of secondary metabolitesâ (218 members), âplant-pathogen interactionâ (146 members), and âplant hormone signal transductionâ (99 members). Fourteen genes involved in JA biosynthesis pathway were up-regulated. As many as 182 genes for the biosynthesis of several secondary metabolites were induced, and the level of indole glucosinolate was highly increased by MeJA treatment. The genes encoding sugar catabolism and some amino acids synthesis were up-regulated, which could supply structural intermediates and energy for the biosynthesis of secondary metabolites. The results demonstrated a high degree of transcriptional complexity with dynamic coordinated changes in global gene expression of Chinese cabbage in response to MeJA treatment. It expands our understanding of the complex molecular events on JA-induced plant resistance and accumulation of secondary metabolites. It also provides a foundation for further studies on the molecular mechanisms of different pathways in other Brassica crops under MeJA treatment. Transcriptomic analysis of MeJA-treated Chinese cabbage leaf
Project description:Using 300K′-high density microarray covering the chinese cabbage whole genome, genome-wide expression analyses of cold stress conditions.
Project description:Background: The growth and development of leaf and petiole have an important influence on the photosynthesis of plants. The research on molecular mechanism of leaf and petiole development is of great significance, whether it is to improve plant photosynthetic efficiency, cultivate varieties with high photosynthetic efficiency, or improve the yield of crops using leaves as food organs. In this study, we aimed to identify the mRNAs, long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs) related to leaf and petiole development in Chinese cabbage (Brassica campestris L. ssp. pekinensis). These data were then used to construct competitive endogenous RNA (ceRNA) networks, which can provide valuable information for better understanding the mechanism of leaf and petiole development. Results: In this study, the leaf and petiole of the baby Chinese cabbage inbred line ‘PHL’ were used as research materials for whole-transcriptome sequencing. A total of 10646 differentially expressed (DE) mRNAs, 303 DE lncRNAs, 7 DE circRNAs, and 195 DE miRNAs were identified between the leaf and petiole. Some transcription factors or proteins that play important roles in leaf and petiole development were identified, such as xyloglucan endotransglucosylase/hydrolase (XTH) protein, expansion protein, TCP15 transcription factor, bHLH transcription factor, LOB domain protein, cellulose synthase (CESA), MOR1-like protein, and plant hormone biosynthesis related genes. Additionally, we constructed a leaf and petiole development-related ceRNA regulatory network, and obtained 85 pairs of ceRNA relationships, including 71 DEmiRNA-DEmRNA, 12 DEmiRNA-DElncRNA and 2 DEmiRNA-DEcircRNA. Three LSH genes (BrLSH1, BrLSH2 and BrLSH3) with significant differential expression between leaf and petiole of baby Chinese cabbage were screened from transcriptome data for subcellular localization analysis and overexpression transgenic verification. The results showed that BrLSH1, BrLSH2 and BrLSH3 were nucleoprotein and BrLSH2 has an obvious inhibitory effect on the growth and development of Arabidopsis thaliana. Conclusions: Our results revealed the potential mRNAs and non-coding RNAs (ncRNAs) involved in leaf and petiole development, which laid a foundation for further research on the molecular mechanism of leaf and petiole development in Chinese cabbage.
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:The leaf of Chinese cabbage is the major place of photosynthesis, the mutation of leaf may directly affect the rate of plant growth and development and the formation of leafy head, and ultimately influence the yield and quality of Chinese cabbage. We identified a developmentally retarded mutant (drm) exhibiting stable inheritance, which was derived from Chinese cabbage DH line âFTâ using a combination of isolated microspore culture and radiation treatment (60Co γ-rays). The drm exhibited slow growth and development at the seedling and heading stages, leading to the production of a tiny, leafy head, as well as chlorophyll-deficient leaves, especially in seedlings. Genetic analysis indicated that the phenotype of drm was controlled by a single recessive nuclear gene. Compared with wild-type line âFTâ, the drmâs chlorophyll content was significantly reduced and its chloroplast structure was abnormal. Moreover, the photosynthetic efficiency and chlorophyll fluorescence parameters were significantly decreased. The changes in leaf color, combined with these altered physiological characters may influence the growth and development of plant, ultimately resulting in the developmentally retarded phenotype of drm. To further understand the molecular regulatory mechanisms of phenotypic differences between âFTâ and drm, comparative transcriptome analysis were performed using RNA-Seq, a total of 338 differentially expressed genes (DEGs) were detected between âFTâ and drm. According to GO and KEGG pathway analysis, a number of DEGs which involved in the chlorophyll degradation and photosynthesis were identified, such as chlorophyllase and ribulose-1,5-bisphosphate carboxylase/oxygenase. In addition, the expression patterns of 12 DEGs, including three chlorophyll degradation- and photosynthesis-related genes and nine randomly selected genes, were confirmed by qRT-PCR. Numerous single nucleotide polymorphisms were also identified, providing a valuable resource for research and molecular marker-assistant breeding in Chinese cabbage. These results contribute to our understanding of the molecular regulatory mechanisms underlying growth and development and lay the foundation for future genetic and functional genomics studies in Chinese cabbage. The RNA from the third true leaves (day 15 to day 24 after the appearance of the third true leaves) of a developmentally retarded mutant (drm) and its wild type âFTâ in Chinese cabbage were sequenced by RNA-Seq, in triplicate.