scholarly journals Arabidopsis Topless-related 1 mitigates physiological damage and growth penalties of induced immunity

2021 ◽  
Author(s):  
Thomas Griebel ◽  
Dmitry Lapin ◽  
Federica Locci ◽  
Barbara Kracher ◽  
Jaqueline Bautor ◽  
...  

Transcriptional corepressors of the Topless family are important regulators of plant hormone and immunity signaling. The lack of a genome-wide profile of their chromatin associations limits understanding of transcriptional regulation in plant immune responses. Chromatin immunoprecipitation with sequencing (ChIP-seq) was performed on GFP-tagged Topless-related 1 (TPR1) expressed in Arabidopsis thaliana lines with and without constitutive immunity dependent on Enhanced Disease Susceptibility 1 (EDS1). RNA-seq profiling of pathogen-infected tpl/tpr mutants and assessments of growth and physiological parameters were employed to determine TPL/TPR roles in transcriptional immunity and defense homeostasis. TPR1 bound to promoter regions of ~1,400 genes and ~10% of the detected binding required EDS1 immunity signaling. A tpr1 tpl tpr4 (t3) mutant displayed mildly enhanced defense-related transcriptional reprogramming upon bacterial infection but not increased bacterial resistance. Bacteria or pep1 phytocytokine-challenged t3 plants exhibited, respectively, photosystem II dysfunction and exacerbated root growth inhibition. Transgenic expression of TPR1 restored the t3 physiological defects. We propose that TPR1 and TPL-family proteins function in Arabidopsis to reduce detrimental effects associated with activated transcriptional immunity.

2021 ◽  
Author(s):  
Chitvan Mittal ◽  
Matthew J. Rossi ◽  
B. Franklin Pugh

AbstractChEC-seq is a method used to identify protein-DNA interactions across a genome. It involves fusing micrococcal nuclease (MNase) to a protein of interest. In principle, specific genome-wide interactions of the fusion protein with chromatin result in local DNA cleavages that can be mapped by DNA sequencing. ChEC-seq has been used to draw conclusions about broad gene-specificities of certain protein-DNA interactions. In particular, the transcriptional regulators SAGA, TFIID, and Mediator are reported to generally occupy the promoter/UAS of genes transcribed by RNA polymerase II in yeast. Here we compare published yeast ChEC-seq data performed with a variety of protein fusions across essentially all genes, and find high similarities with negative controls. We conclude that ChEC-seq patterning for SAGA, TFIID, and Mediator differ little from background at most promoter regions, and thus cannot be used to draw conclusions about broad gene specificity of these factors.


2021 ◽  
Vol 22 (22) ◽  
pp. 12317
Author(s):  
Heng Zhang ◽  
Xu Zhang ◽  
Jia Zhao ◽  
Li Sun ◽  
Haiyan Wang ◽  
...  

GDSL-type esterase/lipase proteins (GELPs) characterized by a conserved GDSL motif at their N-terminus belong to the lipid hydrolysis enzyme superfamily. In plants, GELPs play an important role in plant growth, development and stress response. The studies of the identification and characterization of the GELP gene family in Triticeae have not been reported. In this study, 193 DvGELPs were identified in Dasypyrum villosum and classified into 11 groups (clade A–K) by means of phylogenetic analysis. Most DvGELPs contain only one GDSL domain, only four DvGELPs contain other domains besides the GDSL domain. Gene structure analysis indicated 35.2% DvGELP genes have four introns and five exons. In the promoter regions of the identified DvGELPs, we detected 4502 putative cis-elements, which were associated with plant hormones, plant growth, environmental stress and light responsiveness. Expression profiling revealed 36, 44 and 17 DvGELPs were highly expressed in the spike, the root and the grain, respectively. Further investigation of a root-specific expressing GELP, DvGELP53, indicated it was induced by a variety of biotic and abiotic stresses. The knockdown of DvGELP53 inhibited long-distance movement of BSMV in the tissue of D. villosum. This research provides a genome-wide glimpse of the D. villosum GELP genes and hints at the participation of DvGELP53 in the interaction between virus and plants.


Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1669
Author(s):  
Angelo De Paolis ◽  
Sofia Caretto ◽  
Angela Quarta ◽  
Gian-Pietro Di Sansebastiano ◽  
Irene Sbrocca ◽  
...  

Artemisia annua L. is well-known as the plant source of artemisinin, a sesquiterpene lactone with effective antimalarial activity. Here, a putative ortholog of the Arabidopsis thaliana WRKY40 transcription factor (TF) was isolated via reverse transcription-polymerase chain reaction and rapid amplification of cDNA ends in A. annua and named AaWRKY40. A putative nuclear localization domain was identified in silico and experimentally confirmed by using protoplasts of A. annua transiently transformed with AaWRKY40-GFP. A genome-wide analysis identified 122 WRKY genes in A. annua, and a manually curated database was obtained. The deduced proteins were categorized into the major WRKY groups, with group IIa containing eight WRKY members including AaWRKY40. Protein motifs, gene structure, and promoter regions of group IIa WRKY TFs of A. annua were characterized. The promoter region of AaWRKY group IIa genes contained several abiotic stress cis-acting regulatory elements, among which a highly conserved W-box motif was identified. Expression analysis of AaWRKY40 compared to AaWRKY1 in A. annua cell cultures treated with methyl jasmonate known to enhance artemisinin production, suggested a possible involvement of AaWRKY40 in terpenoid metabolism. Further investigation is necessary to study the role of AaWRKY40 and possible interactions with other TFs in A. annua.


Author(s):  
Alejandro Alonso-Díaz ◽  
Santosh B Satbhai ◽  
Roger de Pedro-Jové ◽  
Hannah M Berry ◽  
Christian Göschl ◽  
...  

Abstract Bacterial wilt caused by the soil-borne pathogen Ralstonia solancearum is economically devastating, with no effective methods to fight the disease. This pathogen invades plants through their roots and colonizes their xylem, clogging the vasculature and causing rapid wilting. Key to preventing colonization are the early defense responses triggered in the host’s root upon infection, which remain mostly unknown. Here, we have taken advantage of a high-throughput in vitro infection system to screen natural variability associated to the root growth inhibition phenotype caused by R. solanacearum in Arabidopsis during the first hours of infection. To analyze the genetic determinants of this trait, we have performed a Genome-Wide Association Study, identifying allelic variation at several loci related to cytokinin metabolism, including genes responsible for biosynthesis and degradation of cytokinin. Further, our data clearly demonstrate that cytokinin signaling is induced early during the infection process and cytokinin contributes to immunity against R. solanacearum. This study highlights a new role of cytokinin in root immunity, paving the way for future research that will help understanding the mechanisms underpinning root defenses.


2021 ◽  
Vol 22 (22) ◽  
pp. 12515
Author(s):  
Yisheng Fang ◽  
Dong Cao ◽  
Hongli Yang ◽  
Wei Guo ◽  
Wenqi Ouyang ◽  
...  

The LOR (LURP-one related) family genes encode proteins containing a conserved LOR domain. Several members of the LOR family genes are required for defense against Hyaloperonospora parasitica (Hpa) in Arabidopsis. However, there are few reports of LOR genes in response to abiotic stresses in plants. In this study, a genome-wide survey and expression levels in response to abiotic stresses of 36 LOR genes from Glycine max were conducted. The results indicated that the GmLOR gene family was divided into eight subgroups, distributed on 14 chromosomes. A majority of members contained three extremely conservative motifs. There were four pairs of tandem duplicated GmLORs and nineteen pairs of segmental duplicated genes identified, which led to the expansion of the number of GmLOR genes. The expansion patterns of the GmLOR family were mainly segmental duplication. A heatmap of soybean LOR family genes showed that 36 GmLOR genes exhibited various expression patterns in different tissues. The cis-acting elements in promoter regions of GmLORs include abiotic stress-responsive elements, such as dehydration-responsive elements and drought-inducible elements. Real-time quantitative PCR was used to detect the expression level of GmLOR genes, and most of them were expressed in the leaf or root except that GmLOR6 was induced by osmotic and salt stresses. Moreover, GmLOR4/10/14/19 were significantly upregulated after PEG and salt treatments, indicating important roles in the improvement of plant tolerance to abiotic stress. Overall, our study provides a foundation for future investigations of GmLOR gene functions in soybean.


2021 ◽  
Vol 9 ◽  
Author(s):  
Jasmin Gegner ◽  
Heiko Vogel ◽  
André Billion ◽  
Frank Förster ◽  
Andreas Vilcinskas

The transition between morphologically distinct phenotypes during complete metamorphosis in holometabolous insects is accompanied by fundamental transcriptional reprogramming. Using the tobacco hornworm (Manduca sexta), a powerful model for the analysis of insect evolution and development, we conducted a genome-wide comparative analysis of gene expression and DNA methylation in caterpillars and adults to determine whether complete metamorphosis has an epigenetic basis in this species. Bisulfite sequencing indicated a generally low level of DNA methylation with a unimodal CpGO/E distribution. Expression analysis revealed that 24 % of all known M. sexta genes (3.729) were upregulated in last-instar larvae relative to the adult moth, whereas 26 % (4.077) were downregulated. We also identified 4.946 loci and 4.960 regions showing stage-specific differential methylation. Interestingly, genes encoding histone acetyltransferases and histone deacetylases were differentially methylated in the larvae and adults, indicating there is crosstalk between different epigenetic mechanisms. The distinct sets of methylated genes in M. sexta larvae and adults suggest that complete metamorphosis involves epigenetic modifications associated with profound transcriptional reprogramming, involving approximately half of all the genes in this species.


2021 ◽  
Vol 12 ◽  
Author(s):  
Wenying Xu ◽  
Tong Liu ◽  
Huiying Zhang ◽  
Hong Zhu

DIRIGENT (DIR) genes are key players in environmental stress responses that have been identified in many vascular plant species. However, few studies have examined the VrDIR genes in mungbean. In this study, we characterized 37 VrDIR genes in mungbean using a genome-wide identification method. VrDIRs were distributed on seven of the 11 mungbean chromosomes, and chromosome three contained the most VrDIR genes, with seven members. Thirty-two of the 37 VrDIRs contained a typical DIR gene structure, with one exon; the conserved DIR domain (i.e., Pfam domain) occupied most of the protein in 33 of the 37 VrDIRs. The gene structures of VrDIR genes were analyzed, and a total of 19 distinct motifs were detected. VrDIR genes were classified into five groups based on their phylogenetic relationships, and 13 duplicated gene pairs were identified. In addition, a total of 92 cis-acting elements were detected in all 37 VrDIR promoter regions, and VrDIR genes contained different numbers and types of cis-acting elements. As a result, VrDIR genes showed distinct expression patterns in different tissues and in response to salt and drought stress.


2020 ◽  
Vol 48 (11) ◽  
pp. 5953-5966
Author(s):  
Soonkap Kim ◽  
Sophie J M Piquerez ◽  
Juan S Ramirez-Prado ◽  
Emmanouil Mastorakis ◽  
Alaguraj Veluchamy ◽  
...  

Abstract The modification of histones by acetyl groups has a key role in the regulation of chromatin structure and transcription. The Arabidopsis thaliana histone acetyltransferase GCN5 regulates histone modifications as part of the Spt-Ada-Gcn5 Acetyltransferase (SAGA) transcriptional coactivator complex. GCN5 was previously shown to acetylate lysine 14 of histone 3 (H3K14ac) in the promoter regions of its target genes even though GCN5 binding did not systematically correlate with gene activation. Here, we explored the mechanism through which GCN5 controls transcription. First, we fine-mapped its GCN5 binding sites genome-wide and then used several global methodologies (ATAC-seq, ChIP-seq and RNA-seq) to assess the effect of GCN5 loss-of-function on the expression and epigenetic regulation of its target genes. These analyses provided evidence that GCN5 has a dual role in the regulation of H3K14ac levels in their 5′ and 3′ ends of its target genes. While the gcn5 mutation led to a genome-wide decrease of H3K14ac in the 5′ end of the GCN5 down-regulated targets, it also led to an increase of H3K14ac in the 3′ ends of GCN5 up-regulated targets. Furthermore, genome-wide changes in H3K14ac levels in the gcn5 mutant correlated with changes in H3K9ac at both 5′ and 3′ ends, providing evidence for a molecular link between the depositions of these two histone modifications. To understand the biological relevance of these regulations, we showed that GCN5 participates in the responses to biotic stress by repressing salicylic acid (SA) accumulation and SA-mediated immunity, highlighting the role of this protein in the regulation of the crosstalk between diverse developmental and stress-responsive physiological programs. Hence, our results demonstrate that GCN5, through the modulation of H3K14ac levels on its targets, controls the balance between biotic and abiotic stress responses and is a master regulator of plant-environmental interactions.


Agronomy ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 206 ◽  
Author(s):  
Yong Zhou ◽  
Jingwen Li ◽  
Junhong Wang ◽  
Wenting Yang ◽  
Youxin Yang

Plant glutathione peroxidase (GPX) is an important antioxidant enzyme to maintain H2O2 homeostasis and regulate plant response to abiotic stress. In this paper, we present the first report of a genome-wide identification of GPX genes in watermelon. A total of six genes (ClGPX1–ClGPX6) were identified, which were unevenly located on four chromosomes of the watermelon genome. Based on phylogenetic analysis, the GPX genes of Arabidopsis, rice, cucumber, and sorghum were classified into four groups. Through analyzing the promoter regions of ClGPX genes, many development-, stress-, and hormone-responsive cis-acting regulatory elements were also identified. Expression pattern analysis by qRT-PCR indicated that all ClGPX genes were actively expressed in flowers and fruits, and exhibited relatively lower expression in other tissues, particularly roots and stems. In addition, the expression of ClGPX genes was significantly induced by salt, drought, and cold stresses, as well as abscisic acid (ABA) treatment at different time points, suggesting that they may be involved in response to abiotic stress and ABA. Taken together, our findings demonstrated that ClGPX genes might function in watermelon development, especially in flower and fruit tissue, as well as in response to abiotic stress and hormones.


2009 ◽  
Vol 29 (13) ◽  
pp. 3556-3568 ◽  
Author(s):  
Nan Jiang ◽  
Eldon Emberly ◽  
Olivier Cuvier ◽  
Craig M. Hart

ABSTRACT Insulator elements play a role in gene regulation that is potentially linked to nuclear organization. Boundary element-associated factors (BEAFs) 32A and 32B associate with hundreds of sites on Drosophila polytene chromosomes. We hybridized DNA isolated by chromatin immunoprecipitation to genome tiling microarrays to construct a genome-wide map of BEAF binding locations. A distinct difference in the association of 32A and 32B with chromatin was noted. We identified 1,820 BEAF peaks and found that more than 85% were less than 300 bp from transcription start sites. Half are between head-to-head gene pairs. BEAF-associated genes are transcriptionally active as judged by the presence of RNA polymerase II, dimethylated histone H3 K4, and the alternative histone H3.3. Forty percent of these genes are also associated with the polymerase negative elongation factor NELF. Like NELF-associated genes, most BEAF-associated genes are highly expressed. Using quantitative reverse transcription-PCR, we found that the expression levels of most BEAF-associated genes decrease in embryos and cultured cells lacking BEAF. These results provide an unexpected link between BEAF and transcription, suggesting that BEAF plays a role in maintaining most associated promoter regions in an environment that facilitates high transcription levels.


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