The Role of OsWRKY Genes in Rice When Faced with Single and Multiple Abiotic Stresses

The WRKY genes are one of the largest families of transcription factors (TFs) and play a crucial role in certain processes in plants including stress signaling, regulation of transcriptional reprogramming associated with stress responses, and other regulatory networks. This study aims to investigate the WRKY gene family in the C3 model plant, Oryza sativa L., using a genome-wide in silico expression analysis. Firstly, 104 WRKY TF family members were identified, and then their molecular properties and expression signatures were analyzed systematically. In silico spatio-temporal and hormonal expression profiling revealed the roles of OsWRKY genes and their dynamism in diverse developmental tissues and hormones, respectively. Comparative mapping between OsWRKY genes and their synteny with C4 panicoid genomes showed the evolutionary insights of the WRKY TF family. Interactions of OsWRKY coding gene sequences represented the complexity of abiotic stress (AbS) and their molecular cross-talks. The expression signature of 26 novel candidate genes in response to stresses exhibited the putative involvement of individual and combined AbS (CAbS) responses. These novel findings unravel the in-depth insights into OsWRKY TF genes and delineate the plant developmental metabolisms and their functional regulations in individual and CAbS conditions.

Download Full-text

Identification of Key Tissue-Specific, Biological Processes by Integrating Enhancer Information in Maize Gene Regulatory Networks

Frontiers in Genetics ◽

10.3389/fgene.2020.606285 ◽

2021 ◽

Vol 11 ◽

Author(s):

Maud Fagny ◽

Marieke Lydia Kuijjer ◽

Maike Stam ◽

Johann Joets ◽

Olivier Turc ◽

...

Keyword(s):

Regulatory Network ◽

Regulatory Networks ◽

Target Genes ◽

Cell Wall Modification ◽

Regulatory Modules ◽

Genome Wide ◽

A Genome ◽

Spatio Temporal ◽

Enhancer Sequences

Enhancers are key players in the spatio-temporal coordination of gene expression during numerous crucial processes, including tissue differentiation across development. Characterizing the transcription factors (TFs) and genes they connect, and the molecular functions underpinned is important to better characterize developmental processes. In plants, the recent molecular characterization of enhancers revealed their capacity to activate the expression of several target genes. Nevertheless, identifying these target genes at a genome-wide level is challenging, particularly for large-genome species, where enhancers and target genes can be hundreds of kilobases away. Therefore, the contribution of enhancers to plant regulatory networks remains poorly understood. Here, we investigate the enhancer-driven regulatory network of two maize tissues at different stages: leaves at seedling stage (V2-IST) and husks (bracts) at flowering. Using systems biology, we integrate genomic, epigenomic, and transcriptomic data to model the regulatory relationships between TFs and their potential target genes, and identify regulatory modules specific to husk and V2-IST. We show that leaves at the V2-IST stage are characterized by the response to hormones and macromolecules biogenesis and assembly, which are regulated by the BBR/BPC and AP2/ERF TF families, respectively. In contrast, husks are characterized by cell wall modification and response to abiotic stresses, which are, respectively, orchestrated by the C2C2/DOF and AP2/EREB families. Analysis of the corresponding enhancer sequences reveals that two different transposable element families (TIR transposon Mutator and MITE Pif/Harbinger) have shaped part of the regulatory network in each tissue, and that MITEs have provided potential new TF binding sites involved in husk tissue-specificity.

Download Full-text

A Genome-Wide Analysis of Pathogenesis-Related Protein-1 (PR-1) Genes from Piper nigrum Reveals Its Critical Role during Phytophthora capsici Infection

Genes ◽

10.3390/genes12071007 ◽

2021 ◽

Vol 12 (7) ◽

pp. 1007

Author(s):

Divya Kattupalli ◽

Asha Sreenivasan ◽

Eppurathu Vasudevan Soniya

Keyword(s):

Phytophthora Capsici ◽

Regulatory Elements ◽

Piper Nigrum ◽

Binding Motif ◽

Altered Expression ◽

Genome Wide ◽

A Genome ◽

Pathogenesis Related Protein ◽

Pathogenesis Related

Black pepper (Piper nigrum L.) is a prominent spice that is an indispensable ingredient in cuisine and traditional medicine. Phytophthora capsici, the causative agent of footrot disease, causes a drastic constraint in P. nigrum cultivation and productivity. To counterattack various biotic and abiotic stresses, plants employ a broad array of mechanisms that includes the accumulation of pathogenesis-related (PR) proteins. Through a genome-wide survey, eleven PR-1 genes that belong to a CAP superfamily protein with a caveolin-binding motif (CBM) and a CAP-derived peptide (CAPE) were identified from P. nigrum. Despite the critical functional domains, PnPR-1 homologs differ in their signal peptide motifs and core amino acid composition in the functional protein domains. The conserved motifs of PnPR-1 proteins were identified using MEME. Most of the PnPR-1 proteins were basic in nature. Secondary and 3D structure analyses of the PnPR-1 proteins were also predicted, which may be linked to a functional role in P. nigrum. The GO and KEGG functional annotations predicted their function in the defense responses of plant-pathogen interactions. Furthermore, a transcriptome-assisted FPKM analysis revealed PnPR-1 genes mapped to the P. nigrum-P. capsici interaction pathway. An altered expression pattern was detected for PnPR-1 transcripts among which a significant upregulation was noted for basic PnPR-1 genes such as CL10113.C1 and Unigene17664. The drastic variation in the transcript levels of CL10113.C1 was further validated through qRT-PCR and it showed a significant upregulation in infected leaf samples compared with the control. A subsequent analysis revealed the structural details, phylogenetic relationships, conserved sequence motifs and critical cis-regulatory elements of PnPR-1 genes. This is the first genome-wide study that identified the role of PR-1 genes during P. nigrum-P. capsici interactions. The detailed in silico experimental analysis revealed the vital role of PnPR-1 genes in regulating the first layer of defense towards a P. capsici infection in Panniyur-1 plants.

Download Full-text

Identification of Bacterial Blight Resistance Loci in Rice (Oryza sativa L.) against Diverse Xoo Thai Strains by Genome-Wide Association Study

Plants ◽

10.3390/plants10030518 ◽

2021 ◽

Vol 10 (3) ◽

pp. 518

Author(s):

Siriporn Korinsak ◽

Clive T. Darwell ◽

Samart Wanchana ◽

Lawan Praphaisal ◽

Siripar Korinsak ◽

...

Keyword(s):

Association Study ◽

Genome Wide Association Study ◽

Oryza Sativa L ◽

Genome Wide Association ◽

Rice Agriculture ◽

Large Numbers ◽

Genome Wide ◽

Resistant Varieties ◽

A Genome ◽

Serious Disease

Bacterial leaf blight (BLB) is a serious disease affecting global rice agriculture caused by Xanthomonas oryzae pv. oryzae (Xoo). Most resistant rice lines are dependent on single genes that are vulnerable to resistance breakdown caused by pathogen mutation. Here we describe a genome-wide association study of 222 predominantly Thai rice accessions assayed by phenotypic screening against 20 Xoo isolates. Loci corresponding to BLB resistance were detected using >142,000 SNPs. We identified 147 genes according to employed significance thresholds across chromosomes 1–6, 8, 9 and 11. Moreover, 127 of identified genes are located on chromosomal regions outside estimated Linkage Disequilibrium influences of known resistance genes, potentially indicating novel BLB resistance markers. However, significantly associated SNPs only occurred across a maximum of six Xoo isolates indicating that the development of broad-spectrum Xoo strain varieties may prove challenging. Analyses indicated a range of gene functions likely underpinning BLB resistance. In accordance with previous studies of accession panels focusing on indica varieties, our germplasm displays large numbers of SNPs associated with resistance. Despite encouraging data suggesting that many loci contribute to resistance, our findings corroborate previous inferences that multi-strain resistant varieties may not be easily realised in breeding programs without resorting to multi-locus strategies.

Download Full-text

WRKY Transcription Factors in Cassava Contribute to Regulation of Tolerance and Susceptibility to Cassava Mosaic Disease through Stress Responses

Viruses ◽

10.3390/v13091820 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1820

Author(s):

Warren Freeborough ◽

Nikki Gentle ◽

Marie E. C. Rey

Keyword(s):

Transcription Factors ◽

Stress Responses ◽

Regulatory Networks ◽

Large Scale ◽

Mosaic Disease ◽

African Cassava Mosaic Virus ◽

Cassava Mosaic Disease ◽

Manihot Esculenta Crantz ◽

Transcriptional Reprogramming ◽

Negative Role

Among the numerous biological constraints that hinder cassava (Manihot esculenta Crantz) production, foremost is cassava mosaic disease (CMD) caused by virus members of the family Geminiviridae, genus Begomovirus. The mechanisms of CMD tolerance and susceptibility are not fully understood; however, CMD susceptible T200 and tolerant TME3 cassava landraces have been shown to exhibit different large-scale transcriptional reprogramming in response to South African cassava mosaic virus (SACMV). Recent identification of 85 MeWRKY transcription factors in cassava demonstrated high orthology with those in Arabidopsis, however, little is known about their roles in virus responses in this non-model crop. Significant differences in MeWRKY expression and regulatory networks between the T200 and TME3 landraces were demonstrated. Overall, WRKY expression and associated hormone and enriched biological processes in both landraces reflect oxidative and other biotic stress responses to SACMV. Notably, MeWRKY11 and MeWRKY81 were uniquely up and downregulated at 12 and 67 days post infection (dpi) respectively in TME3, implicating a role in tolerance and symptom recovery. AtWRKY28 and AtWRKY40 homologs of MeWRKY81 and MeWRKY11, respectively, have been shown to be involved in regulation of jasmonic and salicylic acid signaling in Arabidopsis. AtWRKY28 is an interactor in the RPW8-NBS resistance (R) protein network and downregulation of its homolog MeWRKY81 at 67 dpi in TME3 suggests a negative role for this WRKY in SACMV tolerance. In contrast, in T200, nine MeWRKYs were differentially expressed from early (12 dpi), middle (32 dpi) to late (67 dpi) infection. MeWRKY27 (homolog AtWRKY33) and MeWRKY55 (homolog AtWRKY53) were uniquely up-regulated at 12, 32 and 67 dpi in T200. AtWRKY33 and AtWRKY53 are positive regulators of leaf senescence and oxidative stress in Arabidopsis, suggesting MeWRKY55 and 27 contribute to susceptibility in T200.

Download Full-text

Comprehensive Genomic Discovery of Non-Coding Transcriptional Enhancers in the African Malaria Vector Anopheles coluzzii

Frontiers in Genetics ◽

10.3389/fgene.2021.785934 ◽

2022 ◽

Vol 12 ◽

Author(s):

Inge Holm ◽

Luisa Nardini ◽

Adrien Pain ◽

Emmanuel Bischoff ◽

Cameron E. Anderson ◽

...

Keyword(s):

Malaria Vector ◽

Regulatory Elements ◽

Specific Cell ◽

Insect Vector ◽

Anopheles Coluzzii ◽

Gene Promoters ◽

Transcriptional Enhancers ◽

Genome Wide ◽

A Genome

Almost all regulation of gene expression in eukaryotic genomes is mediated by the action of distant non-coding transcriptional enhancers upon proximal gene promoters. Enhancer locations cannot be accurately predicted bioinformatically because of the absence of a defined sequence code, and thus functional assays are required for their direct detection. Here we used a massively parallel reporter assay, Self-Transcribing Active Regulatory Region sequencing (STARR-seq), to generate the first comprehensive genome-wide map of enhancers in Anopheles coluzzii, a major African malaria vector in the Gambiae species complex. The screen was carried out by transfecting reporter libraries created from the genomic DNA of 60 wild A. coluzzii from Burkina Faso into A. coluzzii 4a3A cells, in order to functionally query enhancer activity of the natural population within the homologous cellular context. We report a catalog of 3,288 active genomic enhancers that were significant across three biological replicates, 74% of them located in intergenic and intronic regions. The STARR-seq enhancer screen is chromatin-free and thus detects inherent activity of a comprehensive catalog of enhancers that may be restricted in vivo to specific cell types or developmental stages. Testing of a validation panel of enhancer candidates using manual luciferase assays confirmed enhancer function in 26 of 28 (93%) of the candidates over a wide dynamic range of activity from two to at least 16-fold activity above baseline. The enhancers occupy only 0.7% of the genome, and display distinct composition features. The enhancer compartment is significantly enriched for 15 transcription factor binding site signatures, and displays divergence for specific dinucleotide repeats, as compared to matched non-enhancer genomic controls. The genome-wide catalog of A. coluzzii enhancers is publicly available in a simple searchable graphic format. This enhancer catalogue will be valuable in linking genetic and phenotypic variation, in identifying regulatory elements that could be employed in vector manipulation, and in better targeting of chromosome editing to minimize extraneous regulation influences on the introduced sequences.Importance: Understanding the role of the non-coding regulatory genome in complex disease phenotypes is essential, but even in well-characterized model organisms, identification of regulatory regions within the vast non-coding genome remains a challenge. We used a large-scale assay to generate a genome wide map of transcriptional enhancers. Such a catalogue for the important malaria vector, Anopheles coluzzii, will be an important research tool as the role of non-coding regulatory variation in differential susceptibility to malaria infection is explored and as a public resource for research on this important insect vector of disease.

Download Full-text

The S1/S2 boundary of SARS-CoV-2 spike protein modulates cell entry pathways and transmission

10.1101/2020.08.25.266775 ◽

2020 ◽

Cited By ~ 8

Author(s):

Yunkai Zhu ◽

Fei Feng ◽

Gaowei Hu ◽

Yuyan Wang ◽

Yin Yu ◽

...

Keyword(s):

Critical Role ◽

Surface Expression ◽

Spike Protein ◽

Hamster Model ◽

Entry Pathway ◽

Genome Wide ◽

A Genome ◽

Model Animal ◽

Public Health Challenges

SUMMARYThe global spread of SARS-CoV-2 is posing major public health challenges. One unique feature of SARS-CoV-2 spike protein is the insertion of multi-basic residues at the S1/S2 subunit cleavage site, the function of which remains uncertain. We found that the virus with intact spike (Sfull) preferentially enters cells via fusion at the plasma membrane, whereas a clone (Sdel) with deletion disrupting the multi-basic S1/S2 site instead utilizes a less efficient endosomal entry pathway. This idea was supported by the identification of a suite of endosomal entry factors specific to Sdel virus by a genome-wide CRISPR-Cas9 screen. A panel of host factors regulating the surface expression of ACE2 was identified for both viruses. Using a hamster model, animal-to-animal transmission with the Sdel virus was almost completely abrogated, unlike with Sfull. These findings highlight the critical role of the S1/S2 boundary of the SARS-CoV-2 spike protein in modulating virus entry and transmission.

Download Full-text

Comprehensive Genome-Wide Analysis of The Catalase Enzyme Toolbox In Potato (Solanum Tuberosum L.)

10.21203/rs.3.rs-1020759/v1 ◽

2021 ◽

Author(s):

Rania Jbir Koubaa ◽

Mariem Ayadi ◽

Mohamed Najib Saidi ◽

Safa Charfeddine ◽

Radhia Gargouri Bouzid ◽

...

Keyword(s):

Stress Responses ◽

Expression Profiling ◽

Phylogenetic Trees ◽

Solanum Tuberosum L ◽

Potato Cultivar ◽

Promoter Sequence ◽

3D Protein Structure ◽

Genome Wide Analysis ◽

Genome Wide ◽

A Genome

Abstract As antioxidant enzymes, catalase (CAT) protects organisms from oxidative stress via the production of reactive oxygen species (ROS). These enzymes play important roles in diverse biological processes. However, little is known about the CAT genes in potato plants despite its important economical rank of this crop in the world. Yet, abiotic and biotic stresses severely hinder growth and development of the plants which affects the production and quality of the crop. To define the possible roles of CAT genes under various stresses, a genome-wide analysis of CAT gene family has been performed in potato plant.In this study, the StCAT gene’s structure, secondary and 3D protein structure, physicochemical properties, synteny analysis, phylogenetic tree and also expression profiling under various developmental and environmental cues were predicted using bioinformatics tools. The expression analysis by RT-PCR was performed using commercial potato cultivar. Three genes encoding StCAT that code for three proteins each of size 492 aa, interrupted by seven introns have been identified in potatoes. StCAT proteins were found to be localized in the peroxisome which is judged as the main H2O2 cell production site during different processes. Many regulating cis-elements related to stress responses and plant hormones signaling were found in the promoter sequence of each gene. The analysis of motifs and phylogenetic trees showed that StCAT are closer to their homologous in S. lycopersicum and share a 41% – 95% identity with other plants’ CATs. Expression profiling revealed that StCAT1 is the constitutively expressive member; while StCAT2 and StCAT3 are the stress-responsive members.

Download Full-text

Genome-wide identification and analysis of cystatin family genes in Sorghum (Sorghum bicolor (L.) Moench)

PeerJ ◽

10.7717/peerj.10617 ◽

2021 ◽

Vol 9 ◽

pp. e10617

Author(s):

Jie Li ◽

Xinhao Liu ◽

Qingmei Wang ◽

Junyan Sun ◽

Dexian He

Keyword(s):

Gene Family ◽

Seed Development ◽

Stress Responses ◽

Abiotic Stresses ◽

Expression Profiles ◽

Seed Formation ◽

Aphid Infestation ◽

Genome Wide ◽

A Genome ◽

Cystatin Family

To set a systematic study of the Sorghum cystatins (SbCys) gene family, a genome-wide analysis of the SbCys family genes was performed by bioinformatics-based methods. In total, 18 SbCys genes were identified in Sorghum, which were distributed unevenly on chromosomes, and two genes were involved in a tandem duplication event. All SbCys genes had similar exon/intron structure and motifs, indicating their high evolutionary conservation. Transcriptome analysis showed that 16 SbCys genes were expressed in different tissues, and most genes displayed higher expression levels in reproductive tissues than in vegetative tissues, indicating that the SbCys genes participated in the regulation of seed formation. Furthermore, the expression profiles of the SbCys genes revealed that seven cystatin family genes were induced during Bipolaris sorghicola infection and only two genes were responsive to aphid infestation. In addition, quantitative real-time polymerase chain reaction (qRT-PCR) confirmed that 17 SbCys genes were induced by one or two abiotic stresses (dehydration, salt, and ABA stresses). The interaction network indicated that SbCys proteins were associated with several biological processes, including seed development and stress responses. Notably, the expression of SbCys4 was up-regulated under biotic and abiotic stresses, suggesting its potential roles in mediating the responses of Sorghum to adverse environmental impact. Our results provide new insights into the structural and functional characteristics of the SbCys gene family, which lay the foundation for better understanding the roles and regulatory mechanism of Sorghum cystatins in seed development and responses to different stress conditions.

Download Full-text

Combining in silico prediction and ribosome profiling in a genome-wide search for novel putatively coding sORFs

BMC Genomics ◽

10.1186/1471-2164-14-648 ◽

2013 ◽

Vol 14 (1) ◽

pp. 648 ◽

Cited By ~ 58

Author(s):

Jeroen Crappé ◽

Wim Van Criekinge ◽

Geert Trooskens ◽

Eisuke Hayakawa ◽

Walter Luyten ◽

...

Keyword(s):

In Silico ◽

Ribosome Profiling ◽

In Silico Prediction ◽

Genome Wide ◽

A Genome ◽

Genome Wide Search

Download Full-text

Genome-Wide Expression of MicroRNAs Is Regulated by DNA Methylation in Hepatocarcinogenesis

Gastroenterology Research and Practice ◽

10.1155/2015/230642 ◽

2015 ◽

Vol 2015 ◽

pp. 1-12 ◽

Cited By ~ 11

Author(s):

Jing Shen ◽

Shuang Wang ◽

Abby B. Siegel ◽

Helen Remotti ◽

Qiao Wang ◽

...

Keyword(s):

Dna Methylation ◽

Potential Role ◽

Dna Hypermethylation ◽

Two Phase ◽

Genome Wide ◽

Phase Study ◽

A Genome ◽

Genome Wide Expression ◽

Inactive Chromatin

Background.Previous studies, including ours, have examined the regulation of microRNAs (miRNAs) by DNA methylation, but whether this regulation occurs at a genome-wide level in hepatocellular carcinoma (HCC) is unclear.Subjects/Methods.Using a two-phase study design, we conducted genome-wide screening for DNA methylation and miRNA expression to explore the potential role of methylation alterations in miRNAs regulation.Results.We found that expressions of 25 miRNAs were statistically significantly different between tumor and nontumor tissues and perfectly differentiated HCC tumor from nontumor. Six miRNAs were overexpressed, and 19 were repressed in tumors. Among 133 miRNAs with inverse correlations between methylation and expression, 8 miRNAs (6%) showed statistically significant differences in expression between tumor and nontumor tissues. Six miRNAs were validated in 56 additional paired HCC tissues, and significant inverse correlations were observed for miR-125b and miR-199a, which is consistent with the inactive chromatin pattern found in HepG2 cells.Conclusion.These data suggest that the expressions of miR-125b and miR-199a are dramatically regulated by DNA hypermethylation that plays a key role in hepatocarcinogenesis.

Download Full-text