1
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Liu C, Liu Q, Mou Z. Redox signaling and oxidative stress in systemic acquired resistance. J Exp Bot 2024:erae193. [PMID: 38693779 DOI: 10.1093/jxb/erae193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Indexed: 05/03/2024]
Abstract
Plants fully depend on their immune systems to defend against pathogens. Upon pathogen attack, plants not only activate immune responses at the infection site but also trigger a defense mechanism known as systemic acquired resistance (SAR) in distal systemic tissues to prevent subsequent infections by a broad-spectrum of pathogens. SAR is induced by mobile signals produced at the infection site. Accumulating evidence suggests that reactive oxygen species (ROS) play a central role in SAR signaling. ROS burst at the infection site is one of the earliest cellular responses following pathogen infection and can spread to systemic tissues through membrane-associated NADPH oxidase-dependent relay-production of ROS. It is well known that ROS ignite redox signaling and when in excess, cause oxidative stress damaging cellular components. In this review, we summarize current knowledge on redox regulation of several SAR signaling components. We discuss the ROS amplification loop in systemic tissues involving multiple SAR mobile signals. Moreover, we highlight the essential role of oxidative stress in generating SAR signals including azelaic acid and extracellular NAD(P) [eNAD(P)]. Finally, we propose that eNAD(P) is a damage-associated molecular pattern serving as a converging point of SAR mobile signals in systemic tissues.
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Affiliation(s)
- Cheng Liu
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL 32611, USA
| | - Qingcai Liu
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL 32611, USA
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL 32611, USA
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2
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Li Q, Zhou M, Harris F, Mou Z. A group of L-type lectin receptor kinases function redundantly in mediating extracellular NAD(P) signaling in Arabidopsis. Plant Physiol 2024:kiae224. [PMID: 38652702 DOI: 10.1093/plphys/kiae224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 03/19/2024] [Accepted: 03/28/2024] [Indexed: 04/25/2024]
Abstract
An Arabidopsis mutant lacking several L-type lectin receptor kinases shows severely reduced NAD(P)-induced local and systemic immunity and biological induction of systemic acquired resistance.
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Affiliation(s)
- Qi Li
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL 32611, USA
| | - Mingxi Zhou
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL 32611, USA
- Plant Molecular and Cellular Biology Program, University of Florida, P.O. Box 110690, Gainesville, FL 32611, USA
| | - Fiona Harris
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL 32611, USA
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL 32611, USA
- Plant Molecular and Cellular Biology Program, University of Florida, P.O. Box 110690, Gainesville, FL 32611, USA
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3
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Sarkar P, Santiago Vazquez J, Zhou M, Levy A, Mou Z, Orbović V. Multiplexed gene editing in citrus by using a multi-intron containing Cas9 gene. Transgenic Res 2024; 33:59-66. [PMID: 38564120 DOI: 10.1007/s11248-024-00380-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 03/11/2024] [Indexed: 04/04/2024]
Abstract
Several expression systems have been developed in clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 (CRISPR/Cas9) framework allowing for gene editing of disease-associated genes across diverse citrus varieties. In this study, we present a new approach employing a multi-intron containing Cas9 gene plus multiple gRNAs separated with tRNA sequences to target the phytoene desaturase gene in both 'Carrizo' citrange and 'Duncan' grapefruit. Notably, using this unified vector significantly boosted editing efficiency in both citrus varieties, showcasing mutations in all three designated targets. The implementation of this multiplex gene editing system with a multi-intron-containing Cas9 plus a gRNA-tRNA array demonstrates a promising avenue for efficient citrus genome editing, equipping us with potent tools in the ongoing battle against several diseases such as canker and huanglongbing.
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Affiliation(s)
- Poulami Sarkar
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL, 33850, USA
| | - Jorge Santiago Vazquez
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL, 33850, USA
| | - Mingxi Zhou
- Department of Plant Pathology, University of Florida, Gainesville, FL, 32602, USA
- Plant Molecular and Cellular Biology Program, University of Florida, Gainesville, FL, 32611, USA
| | - Amit Levy
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL, 33850, USA
- Department of Cell Sciences and Microbiology, University of Florida, Gainesville, FL, 32611, USA
| | - Zhonglin Mou
- Department of Plant Pathology, University of Florida, Gainesville, FL, 32602, USA
| | - Vladimir Orbović
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL, 33850, USA.
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4
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Harris FM, Mou Z. Damage-Associated Molecular Patterns and Systemic Signaling. Phytopathology 2024; 114:308-327. [PMID: 37665354 DOI: 10.1094/phyto-03-23-0104-rvw] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Cellular damage inflicted by wounding, pathogen infection, and herbivory releases a variety of host-derived metabolites, degraded structural components, and peptides into the extracellular space that act as alarm signals when perceived by adjacent cells. These so-called damage-associated molecular patterns (DAMPs) function through plasma membrane localized pattern recognition receptors to regulate wound and immune responses. In plants, DAMPs act as elicitors themselves, often inducing immune outputs such as calcium influx, reactive oxygen species generation, defense gene expression, and phytohormone signaling. Consequently, DAMP perception results in a priming effect that enhances resistance against subsequent pathogen infections. Alongside their established function in local tissues, recent evidence supports a critical role of DAMP signaling in generation and/or amplification of mobile signals that induce systemic immune priming. Here, we summarize the identity, signaling, and synergy of proposed and established plant DAMPs, with a focus on those with published roles in systemic signaling.
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Affiliation(s)
- Fiona M Harris
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL 32611
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL 32611
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5
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Li Q, Zhou M, Chhajed S, Yu F, Chen S, Zhang Y, Mou Z. N-hydroxypipecolic acid triggers systemic acquired resistance through extracellular NAD(P). Nat Commun 2023; 14:6848. [PMID: 37891163 PMCID: PMC10611778 DOI: 10.1038/s41467-023-42629-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 10/13/2023] [Indexed: 10/29/2023] Open
Abstract
Systemic acquired resistance (SAR) is a long-lasting broad-spectrum plant defense mechanism induced in distal systemic tissues by mobile signals generated at the primary infection site. Despite the discoveries of multiple potential mobile signals, how these signals cooperate to trigger downstream SAR signaling is unknown. Here, we show that endogenous extracellular nicotinamide adenine dinucleotide (phosphate) [eNAD(P)] accumulates systemically upon pathogen infection and that both eNAD(P) and the lectin receptor kinase (LecRK), LecRK-VI.2, are required in systemic tissues for the establishment of SAR. Moreover, putative mobile signals, e.g., N-hydroxypipecolic acid (NHP), trigger de novo systemic eNAD(P) accumulation largely through the respiratory burst oxidase homolog RBOHF-produced reactive oxygen species (ROS). Importantly, NHP-induced systemic immunity mainly depends on ROS, eNAD(P), LecRK-VI.2, and BAK1, indicating that NHP induces SAR primarily through the ROS-eNAD(P)-LecRK-VI.2/BAK1 signaling pathway. Our results suggest that mobile signals converge on eNAD(P) in systemic tissues to trigger SAR through LecRK-VI.2.
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Affiliation(s)
- Qi Li
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL, 32611, USA
| | - Mingxi Zhou
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL, 32611, USA
- Plant Molecular and Cellular Biology Program, University of Florida, P.O. Box 110690, Gainesville, FL, 32611, USA
| | - Shweta Chhajed
- Department of Biology, University of Florida, P.O. Box 118525, Gainesville, FL, 32611, USA
| | - Fahong Yu
- Interdisciplinary Center for Biotechnology Research, University of Florida, P.O. Box 103622, Gainesville, FL, 32610, USA
| | - Sixue Chen
- Department of Biology, University of Mississippi, Oxford, MS, 38677-1848, USA
| | - Yanping Zhang
- Interdisciplinary Center for Biotechnology Research, University of Florida, P.O. Box 103622, Gainesville, FL, 32610, USA
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL, 32611, USA.
- Plant Molecular and Cellular Biology Program, University of Florida, P.O. Box 110690, Gainesville, FL, 32611, USA.
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6
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Huang Y, Liu Q, Jibrin M, Mou Z, Dufault N, Li Y, Zhang S. Evaluating Nicotinamide Adenine Dinucleotide for Its Effects on Halo Blight of Snap Bean. Plant Dis 2023; 107:675-681. [PMID: 35881875 DOI: 10.1094/pdis-05-22-1126-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Halo blight, caused by Pseudomonas syringae pv. phaseolicola, is one of the major bacterial diseases on snap bean in Florida, and the outbreaks of this disease have occurred more often in recent years. Current management of this disease primarily depends on application of fixed copper-based bactericides but climate change and resistance development in the pathogen populations still cause hardship for management of this disease, especially in south Florida. In this study, nicotinamide adenine dinucleotide (NAD+) was evaluated in the greenhouse for its potential to reduce halo blight on snap bean. When NAD+ at 5 mM was applied by soil drench, foliar spray, or leaf infiltration, NAD+ significantly (P < 0.05) reduced disease severity of halo blight on snap bean compared with the untreated control. When NAD+ was applied by leaf infiltration, among the tested concentrations, NAD+ at 0.5 to 1.0 mM was most effective in decreasing halo blight disease. NAD+ at 2.5 mM applied as a foliar spray in rotation with Kocide 3000 (copper hydroxide) at 0.5 mg/ml further reduced disease severity compared with Kocide 3000 alone. In the in vitro study, no inhibitory effects of NAD+ were detected on the bacterial pathogen P. syringae pv. phaseolicola. Results of real-time PCR showed that the defense-related genes PR1, AZI1, EDS1, SARD1, PDF1.2, and PAL1 were upregulated in the NAD+ treatment. Taken together, these data indicated that NAD+ significantly suppressed halo blight on snap bean, and application of NAD+ has the potential in management of this important disease.
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Affiliation(s)
- Yi Huang
- Tropical Research and Education Center, University of Florida, IFAS, Homestead, FL 33031
- Department of Plant Pathology, University of Florida, IFAS, Gainesville, FL 32601
| | - Qingchun Liu
- Tropical Research and Education Center, University of Florida, IFAS, Homestead, FL 33031
| | - Mustafa Jibrin
- Tropical Research and Education Center, University of Florida, IFAS, Homestead, FL 33031
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, IFAS, Gainesville, FL 32601
| | - Nicholas Dufault
- Department of Plant Pathology, University of Florida, IFAS, Gainesville, FL 32601
| | - Yuncong Li
- Tropical Research and Education Center, University of Florida, IFAS, Homestead, FL 33031
| | - Shouan Zhang
- Tropical Research and Education Center, University of Florida, IFAS, Homestead, FL 33031
- Department of Plant Pathology, University of Florida, IFAS, Gainesville, FL 32601
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7
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Zhang G, Mou Z, Wang H, Liu H. Comprehensive proteomic analysis of the main liver
and attached liver of <i>Glyptosternum maculatum</i> on the basis
of data-independent mass spectrometry acquisition. J Anim Feed Sci 2022. [DOI: 10.22358/jafs/154070/2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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8
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Liu C, Liu Q, Mou Z. A direct link between BR and SA signaling: Negative regulation of TGA4 by BIN2. Mol Plant 2022; 15:1254-1256. [PMID: 35689390 DOI: 10.1016/j.molp.2022.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 06/07/2022] [Accepted: 06/08/2022] [Indexed: 06/15/2023]
Affiliation(s)
- Cheng Liu
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL 32611, USA
| | - Qingcai Liu
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL 32611, USA
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL 32611, USA.
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9
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Li Q, Canton M, Wu H, Zhang X, Zale J, Mou Z. Efficient artificial microRNA vectors for gene silencing in citrus. Plant Cell Rep 2021; 40:2449-2452. [PMID: 34427747 DOI: 10.1007/s00299-021-02775-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 08/12/2021] [Indexed: 06/13/2023]
Abstract
Three new artificial microRNA vectors were constructed and evaluated, and results showed that these vectors are highly efficient in the silencing of the citrus PHYTOENE DESATURASE gene.
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Affiliation(s)
- Qi Li
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, 32611, USA
| | - Michel Canton
- Citrus Research and Education Center, University of Florida, 700 Experiment Station Road, Lake Alfred, FL, 33850, USA
| | - Hao Wu
- Citrus Research and Education Center, University of Florida, 700 Experiment Station Road, Lake Alfred, FL, 33850, USA
| | - Xudong Zhang
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, 32611, USA
| | - Janice Zale
- Citrus Research and Education Center, University of Florida, 700 Experiment Station Road, Lake Alfred, FL, 33850, USA
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, 32611, USA.
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10
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Merritt BA, Zhang X, Triplett EW, Mou Z, Orbović V. Selection of transgenic citrus plants based on glyphosate tolerance conferred by a citrus 5-enolpyruvylshikimate-3-phosphate synthase variant. Plant Cell Rep 2021; 40:1947-1956. [PMID: 34313832 DOI: 10.1007/s00299-021-02760-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 07/19/2021] [Indexed: 05/21/2023]
Abstract
KEY MESSAGE We have defined the conditions for citrus transformations using glyphosate as selection agent. This protocol results in high transformation rate and low incidence of chimeric shoots. Glyphosate, the most widely used herbicide in the world, specifically inhibits 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), an essential enzyme of the shikimate pathway. Various laboratory-generated or naturally evolved glyphosate-resistant EPSPS variants have been used to produce glyphosate-tolerant transgenic crops, enabling highly effective weed control in agriculture. In this study, we explored the potential of using a citrus EPSPS variant that mimics the previously reported Eleusine indica glyphosate-resistant TIPS (T102I + P106S) mutant for selection of transgenic citrus plants in the presence of glyphosate. We found that glyphosate did not suppress bud formation on 'Duncan' grapefruit seedling explants, but inhibited non-transgenic bud outgrowth to produce shoots in a concentration-dependent manner. At certain concentrations, glyphosate had dramatic effect on the transformation rate and the percentage of non-chimeric transgenic shoots in this newly developed selection system. Specifically, at 0, 10, 20, and 50 μM of glyphosate, the citrus TIPS EPSPS-based selection resulted in transformation rates of 4.02, 5.04, 14.46, and 40.78%, respectively, and 6.41, 23.96, 42.94, and 40.17% of non-chimeric transgenic shoots, respectively. These results indicate that the citrus TIPS EPSPS-glyphosate selection system is highly efficient and can be used as an alternative to antibiotic-based selection methods in citrus genetic transformation. Furthermore, the selection conditions defined in this study are expected to greatly facilitate the production of genetically modified, market-friendly citrus plants, such as cisgenic and intragenic plants.
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Affiliation(s)
- Benjamin A Merritt
- Citrus Research and Education Center, University of Florida, 700 Experiment Station Road, Lake Alfred, FL, 33850, USA
| | - Xudong Zhang
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL, 32611, USA
| | - Eric W Triplett
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL, 32611, USA
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL, 32611, USA.
| | - Vladimir Orbović
- Citrus Research and Education Center, University of Florida, 700 Experiment Station Road, Lake Alfred, FL, 33850, USA.
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11
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Abstract
BACKGROUND Development of precise genome editing strategies is a prerequisite for producing edited plants that can aid in the study of gene function and help understand the genetic traits in a cultivar. Citrus embryogenic cell cultures can be used to rapidly produce a large population of genome edited transformed citrus lines. The ability to introduce specific mutations in the genome of these cells using two constructs (pC-PDS1 and pC-PDS2) was evaluated in this study. RESULTS Citrus sinensis 'EV2' embryogenic cell cultures are amenable to Agrobacterium-mediated CRISPR/Cas9-based genome editing. Guide RNAs (gRNAs) targeting two locations in the phytoene desaturase (PDS) gene were either driven by the Arabidopsis U6-26 promoter (pC-PDS1) or assembled as a Csy4 array under the control of the CmYLCV promoter (pC-PDS2). All transgenic embryos were completely albino and no variegated phenotype was observed. We evaluated 12 lines from each construct in this study and the majority contain either insertion (1-2 bp), substitution (1 bp), or deletion (1-3 bp) mutations that occurred close to the protospacer adjacent motif. CONCLUSIONS Both the pC-PDS1 and pC-PDS2 could successfully edit the citrus embryogenic cell cultures. However, the editing efficiency was dependent on the gRNA, confirming that the selection of a proper gRNA is essential for successful genome editing using the CRISPR/Cas9 technique. Also, utilization of embryogenic cell cultures offers another option for successful genome editing in citrus.
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Affiliation(s)
- Manjul Dutt
- Citrus Research and Education Center, University of Florida, Lake Alfred, Florida, USA.
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, USA
| | - Xudong Zhang
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, USA
| | - Sameena E Tanwir
- Citrus Research and Education Center, University of Florida, Lake Alfred, Florida, USA
| | - Jude W Grosser
- Citrus Research and Education Center, University of Florida, Lake Alfred, Florida, USA
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12
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Abstract
Plants use specific receptor proteins on the cell surface to detect host-derived danger signals released in response to attacks by pathogens or herbivores and activate immune responses against them.
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Affiliation(s)
- Qi Li
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611
| | - Chenggang Wang
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611
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13
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Fernie A, Hashida SN, Yoshimura K, Gakière B, Mou Z, Pétriacq P. Editorial: NAD Metabolism and Signaling in Plants. Front Plant Sci 2020; 11:146. [PMID: 32161612 PMCID: PMC7054218 DOI: 10.3389/fpls.2020.00146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 01/30/2020] [Indexed: 06/10/2023]
Affiliation(s)
- Alisdair Fernie
- Department of Molecular Physiology, MPI of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - Shin-nosuke Hashida
- Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry (CRIEPI), Abiko-shi, Japan
| | - Kazuya Yoshimura
- Department of Food and Nutritional Science, College of Bioscience and Biotechnology Chubu University, Kasugai, Japan
| | - Bertrand Gakière
- Institute of Plant Sciences Paris-Saclay (IPS2), UMR 9213/UMR1403, CNRS, INRAE, Université d’Evry, Université Paris-Diderot, Université Paris-Sud, Sorbonne Paris-Cité, Saclay Plant Sciences, Orsay, France
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, United States
| | - Pierre Pétriacq
- Université de Bordeaux, INRAE, UMR BFP, Plateforme Bordeaux Metabolome, Villenave d’Ornon, France
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14
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Ding Y, Dommel MR, Wang C, Li Q, Zhao Q, Zhang X, Dai S, Mou Z. Differential Quantitative Requirements for NPR1 Between Basal Immunity and Systemic Acquired Resistance in Arabidopsis thaliana. Front Plant Sci 2020; 11:570422. [PMID: 33072146 PMCID: PMC7530841 DOI: 10.3389/fpls.2020.570422] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 09/03/2020] [Indexed: 05/13/2023]
Abstract
Non-expressor of pathogenesis-related (PR) genes1 (NPR1) is a key transcription coactivator of plant basal immunity and systemic acquired resistance (SAR). Two mutant alleles, npr1-1 and npr1-3, have been extensively used for dissecting the role of NPR1 in various signaling pathways. However, it is unknown whether npr1-1 and npr1-3 are null mutants. Moreover, the NPR1 transcript levels are induced two- to threefold upon pathogen infection or salicylic acid (SA) treatment, but the biological relevance of the induction is unclear. Here, we used molecular and biochemical approaches including quantitative PCR, immunoblot analysis, site-directed mutagenesis, and CRISPR/Cas9-mediated gene editing to address these questions. We show that npr1-3 is a potential null mutant, whereas npr1-1 is not. We also demonstrated that a truncated npr1 protein longer than the hypothesized npr1-3 protein is not active in SA signaling. Furthermore, we revealed that TGACG-binding (TGA) factors are required for NPR1 induction, but the reverse TGA box in the 5'UTR of NPR1 is dispensable for the induction. Finally, we show that full induction of NPR1 is required for basal immunity, but not for SAR, whereas sufficient basal transcription is essential for full-scale establishment of SAR. Our results indicate that induced transcript accumulation may be differentially required for different functions of a specific gene. Moreover, as npr1-1 is not a null mutant, we recommend that future research should use npr1-3 and potential null T-DNA insertion mutants for dissecting NPR1's function in various physiopathological processes.
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Affiliation(s)
- Yezhang Ding
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, United States
| | - Matthew R. Dommel
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, United States
| | - Chenggang Wang
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, United States
| | - Qi Li
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, United States
| | - Qi Zhao
- Alkali Soil Natural Environmental Science Center, Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Northeast Forestry University, Harbin, China
| | - Xudong Zhang
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, United States
| | - Shaojun Dai
- Alkali Soil Natural Environmental Science Center, Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Northeast Forestry University, Harbin, China
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, United States
- *Correspondence: Zhonglin Mou,
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15
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Erpen-Dalla Corte L, M. Mahmoud L, S. Moraes T, Mou Z, W. Grosser J, Dutt M. Development of Improved Fruit, Vegetable, and Ornamental Crops Using the CRISPR/Cas9 Genome Editing Technique. Plants (Basel) 2019; 8:E601. [PMID: 31847196 PMCID: PMC6963220 DOI: 10.3390/plants8120601] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Revised: 12/06/2019] [Accepted: 12/11/2019] [Indexed: 02/06/2023]
Abstract
Horticultural crops, including fruit, vegetable, and ornamental plants are an important component of the agriculture production systems and play an important role in sustaining human life. With a steady growth in the world's population and the consequent need for more food, sustainable and increased fruit and vegetable crop production is a major challenge to guarantee future food security. Although conventional breeding techniques have significantly contributed to the development of important varieties, new approaches are required to further improve horticultural crop production. Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) has emerged as a valuable genome-editing tool able to change DNA sequences at precisely chosen loci. The CRISPR/Cas9 system was developed based on the bacterial adaptive immune system and comprises of an endonuclease guided by one or more single-guide RNAs to generate double-strand breaks. These breaks can then be repaired by the natural cellular repair mechanisms, during which genetic mutations are introduced. In a short time, the CRISPR/Cas9 system has become a popular genome-editing technique, with numerous examples of gene mutation and transcriptional regulation control in both model and crop plants. In this review, various aspects of the CRISPR/Cas9 system are explored, including a general presentation of the function of the CRISPR/Cas9 system in bacteria and its practical application as a biotechnological tool for editing plant genomes, particularly in horticultural crops.
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Affiliation(s)
| | - Lamiaa M. Mahmoud
- Pomology Department, Faculty of Agriculture, Mansoura University, 35516 Mansoura, Egypt;
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL 33850, USA;
| | - Tatiana S. Moraes
- Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba 13416-000, SP, Brazil;
| | - Zhonglin Mou
- Department of Microbiology and Cell Sciences, University of Florida, Gainesville, FL 32603, USA;
| | - Jude W. Grosser
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL 33850, USA;
| | - Manjul Dutt
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL 33850, USA;
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Shaw JP, Moore MN, Readman JW, Mou Z, Langston WJ, Lowe DM, Frickers PE, Al-Moosawi L, Pascoe C, Beesley A. Oxidative stress, lysosomal damage and dysfunctional autophagy in molluscan hepatopancreas (digestive gland) induced by chemical contaminants. Mar Environ Res 2019; 152:104825. [PMID: 31668363 DOI: 10.1016/j.marenvres.2019.104825] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 10/10/2019] [Accepted: 10/13/2019] [Indexed: 06/10/2023]
Abstract
Autophagy is a highly conserved evolutionary survival or defence process that enables cells and organisms to survive periods of environmental stress by breaking down cellular organelles and macromolecules in autolysosomes to provide a supply of nutrients for cell maintenance. However, autophagy is also a part of normal cellular physiology that facilitates the turnover of cellular constituents under normal conditions: it can be readily augmented by mild environmental stress; but becomes dysfunctional with severe oxidative stress leading to cellular pathology. The molluscan hepatopancreas or digestive gland provides a versatile and environmentally relevant model to investigate lysosomal autophagy and stress-induced dysfunctional autophagy. This latter process has been implicated in many animal and human disease conditions, including degenerative and neurodegenerative diseases, as well as obesity related conditions. Many environmental pollutants have also been found to induce dysfunctional autophagy in molluscan hepatopancreatic digestive cells, and in this study, the marine blue mussel Mytilus galloprovincialis was exposed for 7 days to: 0.1 μM, 1 μM and 10 μM concentrations of fluoranthene and phenanthrene (PAHs); chlorpyrifos and malathion (organophosphorus compounds); atrazine (triazine herbicide); copper (transition metal) and dodecylbenzene sulphonic acid (LAS, surfactant). The marine snail or periwinkle, Littorina littorea, was also exposed to phenanthrene, chlorpyrifos and copper. Indices of oxidative stress, cell injury and dysfunctional autophagy were measured (i.e., lysosomal membrane stability, protein carbonyls, lipofuscin, and lysosomal accumulation of lipid or lipidosis). Evidence of oxidative stress, based on the elevation of lipofuscin and protein carbonyls, was found for all compounds tested; with chlorpyrifos being the most toxic to both species. Dysfunctional autophagy was induced by all of the compounds tested in both species, except for atrazine in mussels. This failure of normal autophagy was consistently associated with oxidative stress. Autophagic dysfunction is an important emerging feature in the aetiology of many disease conditions in animals and humans; and an explanatory conceptual mechanistic model has been developed for dysregulation of autophagy in response to oxidative stress.
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Affiliation(s)
- J P Shaw
- Plymouth Marine Laboratory, Prospect Place, the Hoe, Plymouth, Devon, PL1 3DH, UK
| | - M N Moore
- Plymouth Marine Laboratory, Prospect Place, the Hoe, Plymouth, Devon, PL1 3DH, UK; European Centre for Environment & Human Health (ECEHH), University of Exeter Medical School, Knowledge Spa, Royal Cornwall Hospital, Truro, TR1 3HD, UK; School of Biological & Marine Sciences, University of Plymouth, Drake Circus, Plymouth, PL4 8AA, UK.
| | - J W Readman
- Plymouth Marine Laboratory, Prospect Place, the Hoe, Plymouth, Devon, PL1 3DH, UK; School of Biological & Marine Sciences, University of Plymouth, Drake Circus, Plymouth, PL4 8AA, UK
| | - Z Mou
- Plymouth Marine Laboratory, Prospect Place, the Hoe, Plymouth, Devon, PL1 3DH, UK
| | - W J Langston
- Marine Biological Association UK, Citadel Hill, Plymouth, Devon, PL1 2PB, UK
| | - D M Lowe
- Plymouth Marine Laboratory, Prospect Place, the Hoe, Plymouth, Devon, PL1 3DH, UK
| | - P E Frickers
- Plymouth Marine Laboratory, Prospect Place, the Hoe, Plymouth, Devon, PL1 3DH, UK
| | - L Al-Moosawi
- Plymouth Marine Laboratory, Prospect Place, the Hoe, Plymouth, Devon, PL1 3DH, UK
| | - C Pascoe
- Plymouth Marine Laboratory, Prospect Place, the Hoe, Plymouth, Devon, PL1 3DH, UK
| | - A Beesley
- Plymouth Marine Laboratory, Prospect Place, the Hoe, Plymouth, Devon, PL1 3DH, UK
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Murata MM, Omar AA, Mou Z, Chase CD, Grosser JW, Graham JH. Novel Plastid-Nuclear Genome Combinations Enhance Resistance to Citrus Canker in Cybrid Grapefruit. Front Plant Sci 2019; 9:1858. [PMID: 30666259 PMCID: PMC6330342 DOI: 10.3389/fpls.2018.01858] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 11/30/2018] [Indexed: 05/23/2023]
Abstract
Host disease resistance is the most desirable strategy for control of citrus canker, a disease caused by a gram-negative bacterium Xanthomonas citri subsp. citri. However, no resistant commercial citrus cultivar has been identified. Cybridization, a somatic hybridization approach that combines the organelle and nuclear genomes from different species, was used to create cybrids between citrus canker resistant 'Meiwa' kumquat (Fortunella crassifolia Swingle snym. Citrus japonica Thunb.) and susceptible grapefruit (Citrus paradisi Macfad) cultivars. From these fusions, cybrids with grapefruit nucleus, kumquat mitochondria and kumquat chloroplasts and cybrids with grapefruit nucleus, kumquat mitochondria and grapefruit chloroplasts were generated. These cybrids showed a range of citrus canker response, but all cybrids with kumquat chloroplasts had a significantly lower number of lesions and lower Xanthomonas citri subsp. citri populations than the grapefruit controls. Cybrids with grapefruit chloroplasts had a significantly higher number of lesions than those with kumquat chloroplasts. To understand the role of chloroplasts in the cybrid disease defense, quantitative PCR was performed on both cybrid types and their parents to examine changes in gene expression during Xanthomonas citri subsp. citri infection. The results revealed chloroplast influences on nuclear gene expression, since isonuclear cybrids and 'Marsh' grapefruit had different gene expression profiles. In addition, only genotypes with kumquat chloroplasts showed an early up-regulation of reactive oxygen species genes upon Xanthomonas citri subsp. citri infection. These cybrids have the potential to enhance citrus canker resistance in commercial grapefruit orchards. They also serve as models for understanding the contribution of chloroplasts to plant disease response and raise the question of whether other alien chloroplast genotypes would condition similar results.
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Affiliation(s)
- Mayara M. Murata
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL, United States
| | - Ahmad A. Omar
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL, United States
- Biochemistry Department, Zagazig University, Zagazig, Egypt
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, United States
| | - Christine D. Chase
- Horticultural Sciences Department, University of Florida, Gainesville, FL, United States
| | - Jude W. Grosser
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL, United States
| | - James H. Graham
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL, United States
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Alferez FM, Gerberich KM, Li JL, Zhang Y, Graham JH, Mou Z. Exogenous Nicotinamide Adenine Dinucleotide Induces Resistance to Citrus Canker in Citrus. Front Plant Sci 2018; 9:1472. [PMID: 30356715 PMCID: PMC6189366 DOI: 10.3389/fpls.2018.01472] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 09/20/2018] [Indexed: 05/11/2023]
Abstract
Nicotinamide adenine dinucleotide (NAD) is a universal electron carrier that participates in important intracellular metabolic reactions and signaling events. Interestingly, emerging evidence in animals indicates that cellular NAD can be actively or passively released into the extracellular space, where it is processed or perceived by ectoenzymes or cell-surface receptors. We have recently shown in Arabidopsis thaliana that exogenous NAD induces defense responses, that pathogen infection leads to release of NAD into the extracellular space at concentrations sufficient for defense activation, and that depletion of extracellular NAD (eNAD) by transgenic expression of the human NAD-hydrolyzing ectoenzyme CD38 inhibits plant immunity. We therefore hypothesize that, during plant-microbe interactions, NAD is released from dead or dying cells into the extracellular space where it interacts with adjacent naïve cells' surface receptors, which in turn activate downstream immune signaling. However, it is currently unknown whether eNAD signaling is unique to Arabidopsis or the Brassicaceae family. In this study, we treated citrus plants with exogenous NAD+ and tested NAD+-induced transcriptional changes and disease resistance. Our results show that NAD+ induces profound transcriptome changes and strong resistance to citrus canker, a serious citrus disease caused by the bacterial pathogen Xanthomonas citri subsp. citri (Xcc). Furthermore, NAD+-induced resistance persists in new flushes emerging after removal of the tissues previously treated with NAD+. Finally, NAD+ treatment primes citrus tissues, resulting in a faster and stronger induction of multiple salicylic acid pathway genes upon subsequent Xcc infection. Taken together, these results indicate that exogenous NAD+ is able to induce immune responses in citrus and suggest that eNAD may also be an elicitor in this woody plant species.
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Affiliation(s)
- Fernando M. Alferez
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL, United States
- Southwest Florida Research and Education Center, University of Florida, Immokalee, FL, United States
| | - Kayla M. Gerberich
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL, United States
| | - Jian-Liang Li
- National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, United States
| | - Yanping Zhang
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, FL, United States
| | - James H. Graham
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL, United States
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, United States
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Pereira JA, Yu F, Zhang Y, Jones JB, Mou Z. The Arabidopsis Elongator Subunit ELP3 and ELP4 Confer Resistance to Bacterial Speck in Tomato. Front Plant Sci 2018; 9:1066. [PMID: 30087688 PMCID: PMC6066517 DOI: 10.3389/fpls.2018.01066] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 06/29/2018] [Indexed: 06/08/2023]
Abstract
Although production of tomato (Solanum lycopersicum) is threatened by a number of major diseases worldwide, it has been difficult to identify effective and durable management measures against these diseases. In this study, we attempted to improve tomato disease resistance by transgenic overexpression of genes encoding the Arabidopsis thaliana Elongator (AtELP) complex subunits AtELP3 and AtELP4. We show that overexpression of AtELP3 and AtELP4 significantly enhanced resistance to tomato bacterial speck caused by the Pseudomonas syringae pv. tomato strain J4 (Pst J4) without clear detrimental effects on plant growth and development. Interestingly, the transgenic plants exhibited resistance to Pst J4 only when inoculated through foliar sprays but not through infiltration into the leaf apoplast. Although this result suggested possible involvement of stomatal immunity, we found that Pst J4 inoculation did not induce stomatal closure and there were no differences in stomatal apertures and conductance between the transgenic and control plants. Further RNA sequencing and real-time quantitative PCR analyses revealed a group of defense-related genes to be induced to higher levels after infection in the AtELP4 transgenic tomato plants than in the control, suggesting that the enhanced disease resistance of the transgenic plants may be attributed to elevated induction of defense responses. Additionally, we show that the tomato genome contains single-copy genes encoding all six Elongator subunits (SlELPs), which share high identities with the AtELP proteins, and that SlELP3 and SlELP4 complemented the Arabidopsis Atelp3 and Atelp4 mutants, respectively, indicating that the function of tomato Elongator is probably conserved. Taken together, our results not only shed new light on the tomato Elongator complex, but also revealed potential candidate genes for engineering disease resistance in tomato.
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Affiliation(s)
- Juliana A. Pereira
- Department of Plant Pathology, University of Florida, Gainesville, FL, United States
| | - Fahong Yu
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, FL, United States
| | - Yanping Zhang
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, FL, United States
| | - Jeffrey B. Jones
- Department of Plant Pathology, University of Florida, Gainesville, FL, United States
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, United States
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Wang C, Zhang X, Li J, Zhang Y, Mou Z. The Elongator complex-associated protein DRL1 plays a positive role in immune responses against necrotrophic fungal pathogens in Arabidopsis. Mol Plant Pathol 2018; 19:286-299. [PMID: 27868335 PMCID: PMC6637984 DOI: 10.1111/mpp.12516] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 11/15/2016] [Accepted: 11/18/2016] [Indexed: 05/24/2023]
Abstract
DEFORMED ROOT AND LEAVES1 (DRL1) is an Arabidopsis homologue of the yeast TOXIN TARGET4 (TOT4)/KILLER TOXIN-INSENSITIVE12 (KTI12) protein that is physically associated with the RNA polymerase II-interacting protein complex named Elongator. Mutations in DRL1 and Elongator lead to similar morphological and molecular phenotypes, suggesting that DRL1 and Elongator may functionally overlap in Arabidopsis. We have shown previously that Elongator plays an important role in both salicylic acid (SA)- and jasmonic acid (JA)/ethylene (ET)-mediated defence responses. Here, we tested whether DRL1 also plays a similar role as Elongator in plant immune responses. Our results show that, although DRL1 partially contributes to SA-induced cytotoxicity, it does not play a significant role in SA-mediated expression of PATHOGENESIS-RELATED genes and resistance to the virulent bacterial pathogen Pseudomonas syringae pv. maculicola ES4326. In contrast, DRL1 is required for JA/ET- and necrotrophic fungal pathogen Botrytis cinerea-induced defence gene expression and for resistance to B. cinerea and Alternaria brassicicola. Furthermore, unlike the TOT4/KTI12 gene which, when overexpressed in yeast, confers zymocin resistance, a phenotype of the tot4/kti12 mutant, overexpression of DRL1 does not change B. cinerea-induced defence gene expression and resistance to this pathogen. Finally, DRL1 contains an N-terminal P-loop and a C-terminal calmodulin (CaM)-binding domain and is a CaM-binding protein. We demonstrate that both the P-loop and the CaM-binding domain are essential for the function of DRL1 in B. cinerea-induced expression of PDF1.2 and ORA59, and in resistance to B. cinerea, suggesting that the function of DRL1 in plant immunity may be regulated by ATP/GTP and CaM binding.
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Affiliation(s)
- Chenggang Wang
- Department of Microbiology and Cell ScienceUniversity of Florida, PO Box 110700GainesvilleFL32611USA
| | - Xudong Zhang
- Department of Microbiology and Cell ScienceUniversity of Florida, PO Box 110700GainesvilleFL32611USA
| | - Jian‐Liang Li
- Sanford Burnham Prebys Medical Discovery Institute at Lake NonaOrlandoFL32827USA
| | - Yanping Zhang
- Interdisciplinary Center for Biotechnology Research, University of Florida, PO Box 103622GainesvilleFL32610USA
| | - Zhonglin Mou
- Department of Microbiology and Cell ScienceUniversity of Florida, PO Box 110700GainesvilleFL32611USA
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Robertson CJ, Zhang X, Gowda S, Orbović V, Dawson WO, Mou Z. Overexpression of the Arabidopsis NPR1 protein in citrus confers tolerance to Huanglongbing. ACTA ACUST UNITED AC 2018. [DOI: 10.5070/c451038911] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Silva KJP, Mahna N, Mou Z, Folta KM. NPR1 as a transgenic crop protection strategy in horticultural species. Hortic Res 2018; 5:15. [PMID: 29581883 PMCID: PMC5862871 DOI: 10.1038/s41438-018-0026-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Revised: 01/19/2018] [Accepted: 01/25/2018] [Indexed: 05/08/2023]
Abstract
The NPR1 (NONEXPRESSOR OF PATHOGENESIS RELATED GENES1) gene has a central role in the long-lasting, broad-spectrum defense response known as systemic acquired resistance (SAR). When overexpressed in a transgenic context in Arabidopsis thaliana, this gene enhances resistance to a number of biotic and abiotic stresses. Its position as a key regulator of defense across diverse plant species makes NPR1 a strong candidate gene for genetic engineering disease and stress tolerance into other crops. High-value horticultural crops face many new challenges from pests and pathogens, and their emergence exceeds the pace of traditional breeding, making the application of NPR1-based strategies potentially useful in fruit and vegetable crops. However, plants overexpressing NPR1 occasionally present detrimental morphological traits that make its application less attractive. The practical utility of NPR-based approaches will be a balance of resistance gains versus other losses. In this review, we summarize the progress on the understanding of NPR1-centered applications in horticultural and other crop plants. We also discuss the effect of the ectopic expression of the A. thaliana NPR1 gene and its orthologs in crop plants and outline the future challenges of using NPR1 in agricultural applications.
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Affiliation(s)
| | - Nasser Mahna
- Horticultural Sciences Department, University of Florida, Gainesville, FL 32611 USA
- Department of Horticultural Sciences, University of Tabriz, Tabriz, Iran
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611 USA
- Graduate Program in Plant Molecular and Cellular Biology, University of Florida, Gainesville, FL 32611 USA
| | - Kevin M. Folta
- Horticultural Sciences Department, University of Florida, Gainesville, FL 32611 USA
- Graduate Program in Plant Molecular and Cellular Biology, University of Florida, Gainesville, FL 32611 USA
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Silva KJP, Brunings AM, Pereira JA, Peres NA, Folta KM, Mou Z. The Arabidopsis ELP3/ELO3 and ELP4/ELO1 genes enhance disease resistance in Fragaria vesca L. BMC Plant Biol 2017; 17:230. [PMID: 29191170 PMCID: PMC5709926 DOI: 10.1186/s12870-017-1173-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 11/13/2017] [Indexed: 05/22/2023]
Abstract
BACKGROUND Plant immune response is associated with a large-scale transcriptional reprogramming, which is regulated by numerous transcription regulators such as the Elongator complex. Elongator is a multitasking protein complex involved in diverse cellular processes, including histone modification, DNA methylation, and tRNA modification. In recent years, Elongator is emerging as a key regulator of plant immune responses. However, characterization of Elongator's function in plant immunity has been conducted only in the model plant Arabidopsis thaliana. It is thus unclear whether Elongator's role in plant immunity is conserved in higher plants. The objective of this study is to characterize transgenic woodland strawberry (Fragaria vesca L.) overexpressing the Arabidopsis Elongator (AtELP) genes, AtELP3 and AtELP4, and to determine whether F. vesca carries a functional Elongator complex. METHODS Transgenic F. vesca and Arabidopsis plants were produced via Agrobacterium-mediated genetic transformation and characterized by morphology, PCR, real-time quantitative PCR, and disease resistance test. The Student's t test was used to analyze the data. RESULTS Overexpression of AtELP3 and AtELP4 in F. vesca impacts plant growth and development and confers enhanced resistance to anthracnose crown rot, powdery mildew, and angular leaf spot, which are caused by the hemibiotrophic fungal pathogen Colletotrichum gloeosporioides, the obligate biotrophic fungal pathogen Podosphaera aphanis, and the hemibiotrophic bacterial pathogen Xanthomonas fragariae, respectively. Moreover, the F. vesca genome encodes all six Elongator subunits by single-copy genes with the exception of FvELP4, which is encoded by two homologous genes, FvELP4-1 and FvELP4-2. We show that FvELP4-1 complemented the Arabidopsis Atelp4/elo1-1 mutant, indicating that FvELP4 is biologically functional. CONCLUSIONS This is the first report on overexpression of Elongator genes in plants. Our results indicate that the function of Elongator in plant immunity is most likely conserved in F. vesca and suggest that Elongator genes may hold potential for helping mitigate disease severity and reduce the use of fungicides in strawberry industry.
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Affiliation(s)
- Katchen Julliany P. Silva
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611 USA
- Department of Horticultural Sciences, University of Florida, Gainesville, FL 32611 USA
| | - Asha M. Brunings
- Department of Horticultural Sciences, University of Florida, Gainesville, FL 32611 USA
| | - Juliana A. Pereira
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611 USA
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611 USA
| | - Natalia A. Peres
- Department of Plant Pathology, Gulf Coast Research and Education Center, University of Florida, Wimauma, FL 33598 USA
| | - Kevin M. Folta
- Department of Horticultural Sciences, University of Florida, Gainesville, FL 32611 USA
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611 USA
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Abstract
The pyridine nucleotides nicotinamide adenine dinucleotide (NAD) and NAD phosphate (NADP) are coenzymes that function in both metabolic reactions and intracellular signaling. Emerging evidence from animal research indicates that NAD(P) also acts in the extracellular space (ECS). We have shown in the model plant Arabidopsis that (1) exogenous NAD(P) induces immune responses, (2) pathogen infection causes leakage of intracellular NAD(P) into the extracellular fluid at concentrations sufficient to induce immune responses, and (3) removal of extracellular NAD(P) [eNAD(P)] by expressing the human NAD(P)-metabolizing ectoenzyme CD38 partially compromises systemic acquired resistance. Based on these results, we hypothesize that eNAD(P) is a novel damage-associated molecular pattern (DAMP) in plants; during plant-microbe interaction, intracellular NAD(P) is released from dead or dying cells into the ECS where it interacts with the adjacent healthy cells' surface receptors/targets, which in turn activate downstream specific immune signaling pathways. Our recent identification of LecRK-I.8, a lectin receptor kinase, as the first cell surface NAD+-binding receptor has provided compelling evidence for this hypothesis. Further identification of cell surface eNAD(P) receptors/targets and their downstream signaling components in Arabidopsis as well as determination of the generality of eNAD(P) signaling in crops will help establish eNAD(P) as a conserved DAMP in plants.
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Affiliation(s)
- Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, USA
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25
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Wang C, Zhou M, Zhang X, Yao J, Zhang Y, Mou Z. A lectin receptor kinase as a potential sensor for extracellular nicotinamide adenine dinucleotide in Arabidopsis thaliana. eLife 2017; 6:e25474. [PMID: 28722654 PMCID: PMC5560858 DOI: 10.7554/elife.25474] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 07/18/2017] [Indexed: 12/20/2022] Open
Abstract
Nicotinamide adenine dinucleotide (NAD+) participates in intracellular and extracellular signaling events unrelated to metabolism. In animals, purinergic receptors are required for extracellular NAD+ (eNAD+) to evoke biological responses, indicating that eNAD+ may be sensed by cell-surface receptors. However, the identity of eNAD+-binding receptors still remains elusive. Here, we identify a lectin receptor kinase (LecRK), LecRK-I.8, as a potential eNAD+ receptor in Arabidopsis. The extracellular lectin domain of LecRK-I.8 binds NAD+ with a dissociation constant of 436.5 ± 104.8 nM, although much higher concentrations are needed to trigger in vivo responses. Mutations in LecRK-I.8 inhibit NAD+-induced immune responses, whereas overexpression of LecRK-I.8 enhances the Arabidopsis response to NAD+. Furthermore, LecRK-I.8 is required for basal resistance against bacterial pathogens, substantiating a role for eNAD+ in plant immunity. Our results demonstrate that lectin receptors can potentially function as eNAD+-binding receptors and provide direct evidence for eNAD+ being an endogenous signaling molecule in plants.
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Affiliation(s)
- Chenggang Wang
- Department of Microbiology and Cell Science, University of Florida, Gainesville, United States
| | - Mingqi Zhou
- Department of Microbiology and Cell Science, University of Florida, Gainesville, United States
| | - Xudong Zhang
- Department of Microbiology and Cell Science, University of Florida, Gainesville, United States
| | - Jin Yao
- Target Sciences, GlaxoSmithKline, King of Prussia, United States
| | - Yanping Zhang
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, United States
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, Gainesville, United States
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An C, Wang C, Mou Z. The Arabidopsis Elongator complex is required for nonhost resistance against the bacterial pathogens Xanthomonas citri subsp. citri and Pseudomonas syringae pv. phaseolicola NPS3121. New Phytol 2017; 214:1245-1259. [PMID: 28134437 DOI: 10.1111/nph.14442] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 12/16/2016] [Indexed: 05/17/2023]
Abstract
Although in recent years nonhost resistance has attracted considerable attention for its broad spectrum and durability, the genetic and mechanistic components of nonhost resistance have not been fully understood. We used molecular and histochemical approaches including quantitative PCR, chromatin immunoprecipitation, and 3,3'-diaminobenzidine and aniline blue staining. The evolutionarily conserved histone acetyltransferase complex Elongator was identified as a major component of nonhost resistance against Xanthomonas citri subsp. citri (Xcc) and Pseudomonas syringae pv. phaseolicola (Psp) NPS3121. Mutations in Elongator genes inhibit Xcc-, Psp NPS3121- and/or flg22-induced defense responses including defense gene expression, callose deposition, and reactive oxygen species (ROS) and salicylic acid (SA) accumulation. Mutations in Elongator also attenuate the ROS-SA amplification loop. We show that suppressed ROS and SA accumulation in Elongator mutants is correlated with reduced expression of the Arabidopsis respiratory burst oxidase homologue AtrbohD and the SA biosynthesis gene ISOCHORISMATE SYNTHASE1 (ICS1). Furthermore, we found that the Elongator subunit ELP2 is associated with the chromatin of AtrbohD and ICS1 and is required for maintaining basal histone H3 acetylation levels in these key defense genes. As both AtrbohD and ICS1 contribute to nonhost resistance against Xcc, our results reveal an epigenetic mechanism by which Elongator regulates nonhost resistance in Arabidopsis.
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Affiliation(s)
- Chuanfu An
- Department of Microbiology and Cell Science, University of Florida, PO Box 110700, Gainesville, FL, 32611, USA
| | - Chenggang Wang
- Department of Microbiology and Cell Science, University of Florida, PO Box 110700, Gainesville, FL, 32611, USA
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, PO Box 110700, Gainesville, FL, 32611, USA
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Wang C, Zhang X, Mou Z. Comparison of nicotinamide adenine dinucleotide phosphate-induced immune responses against biotrophic and necrotrophic pathogens in Arabidopsis thaliana. Plant Signal Behav 2016; 11:e1169358. [PMID: 27031653 PMCID: PMC4973797 DOI: 10.1080/15592324.2016.1169358] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 03/14/2016] [Accepted: 03/16/2016] [Indexed: 05/20/2023]
Abstract
The pyridine nucleotide nicotinamide adenine dinucleotide phosphate (NADP) is a universal coenzyme in anabolic reactions and also functions in intracellular signaling by serving as a substrate for production of the Ca(2+)-mobilizing agent nicotinic acid adenine dinucleotide phosphate (NAADP). It has recently been shown that, in mammalian cells, cellular NADP can be released into the extracellular compartment (ECC) upon environmental stresses by active exocytosis or diffusion through transmembrane transporters in living cells or passive leakage across the membrane in dying cells. In the ECC, NADP can either serve as a substrate for production of NAADP or act directly on purinoceptors to activate transmembrane signaling. In the last several years, extracellular NADP has also been suggested to function in plant immune responses. Here, we compared exogenous NADP-induced immune responses against biotrophic and necrotrophic pathogens in the Arabidopsis thaliana ecotype Columbia and found that NADP addition induces salicylic acid-mediated defense signaling but not jasmonic acid/ethylene-mediated defense responses. These results suggest the specificity of exogenous NADP-activated signaling in plants.
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Affiliation(s)
- Chenggang Wang
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, USA
| | - Xudong Zhang
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, USA
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, USA
- CONTACT Zhonglin Mou
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An C, Ding Y, Zhang X, Wang C, Mou Z. Elongator Plays a Positive Role in Exogenous NAD-Induced Defense Responses in Arabidopsis. Mol Plant Microbe Interact 2016; 29:396-404. [PMID: 26926998 DOI: 10.1094/mpmi-01-16-0005-r] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Extracellular NAD is emerging as an important signal molecule in animal cells, but its role in plants has not been well-established. Although it has been shown that exogenous NAD(+) activates defense responses in Arabidopsis, components in the exogenous NAD(+)-activated defense pathway remain to be fully discovered. In a genetic screen for mutants insensitive to exogenous NAD(+) (ien), we isolated a mutant named ien2. Map-based cloning revealed that IEN2 encodes ELONGATA3 (ELO3)/AtELP3, a subunit of the Arabidopsis Elongator complex, which functions in multiple biological processes, including histone modification, DNA (de)methylation, and transfer RNA modification. Mutations in the ELO3/AtELP3 gene compromise exogenous NAD(+)-induced expression of pathogenesis-related (PR) genes and resistance to the bacterial pathogen Pseudomonas syringae pv. maculicola ES4326, and transgenic expression of the coding region of ELO3/AtELP3 in elo3/Atelp3 restores NAD(+) responsiveness to the mutant plants, demonstrating that ELO3/AtELP3 is required for exogenous NAD(+)-induced defense responses. Furthermore, mutations in genes encoding the other five Arabidopsis Elongator subunits (ELO2/AtELP1, AtELP2, ELO1/AtELP4, AtELP5, and AtELP6) also compromise exogenous NAD(+)-induced PR gene expression and resistance to P. syringae pv. maculicola ES4326. These results indicate that the Elongator complex functions as a whole in exogenous NAD(+)-activated defense signaling in Arabidopsis.
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Affiliation(s)
- Chuanfu An
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL 32611, U.S.A
| | - Yezhang Ding
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL 32611, U.S.A
| | - Xudong Zhang
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL 32611, U.S.A
| | - Chenggang Wang
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL 32611, U.S.A
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL 32611, U.S.A
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Ding Y, Dommel M, Mou Z. Abscisic acid promotes proteasome-mediated degradation of the transcription coactivator NPR1 in Arabidopsis thaliana. Plant J 2016; 86:20-34. [PMID: 26865090 DOI: 10.1111/tpj.13141] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 01/12/2016] [Accepted: 02/04/2016] [Indexed: 05/20/2023]
Abstract
Proteasome-mediated turnover of the transcription coactivator NPR1 is pivotal for efficient activation of the broad-spectrum plant immune responses known as localized acquired resistance (LAR) and systemic acquired resistance (SAR) in adjacent and systemic tissues, respectively, and requires the CUL3-based E3 ligase and its adaptor proteins, NPR3 and NPR4, which are receptors for the signaling molecule salicylic acid (SA). It has been shown that SA prevents NPR1 turnover under non-inducing and LAR/SAR-inducing conditions, but how cellular NPR1 homeostasis is maintained remains unclear. Here, we show that the phytohormone abscisic acid (ABA) and SA antagonistically influence cellular NPR1 protein levels. ABA promotes NPR1 degradation via the CUL3(NPR) (3/) (NPR) (4) complex-mediated proteasome pathway, whereas SA may protect NPR1 from ABA-promoted degradation through phosphorylation. Furthermore, we demonstrate that the timing and strength of SA and ABA signaling are critical in modulating NPR1 accumulation and target gene expression. Perturbing ABA or SA signaling in adjacent tissues alters the temporal dynamic pattern of NPR1 accumulation and target gene transcription. Finally, we show that sequential SA and ABA treatment leads to dynamic changes in NPR1 protein levels and target gene expression. Our results revealed a tight correlation between sequential SA and ABA signaling and dynamic changes in NPR1 protein levels and NPR1-dependent transcription in plant immune responses.
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Affiliation(s)
- Yezhang Ding
- Department of Microbiology and Cell Science, University of Florida, PO Box 110700, Gainesville, FL 32611, USA
| | - Matthew Dommel
- Department of Microbiology and Cell Science, University of Florida, PO Box 110700, Gainesville, FL 32611, USA
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, PO Box 110700, Gainesville, FL 32611, USA
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Wang C, Du X, Mou Z. The Mediator Complex Subunits MED14, MED15, and MED16 Are Involved in Defense Signaling Crosstalk in Arabidopsis. Front Plant Sci 2016; 7:1947. [PMID: 28066497 PMCID: PMC5177743 DOI: 10.3389/fpls.2016.01947] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 12/07/2016] [Indexed: 05/20/2023]
Abstract
Mediator is a highly conserved protein complex that functions as a transcriptional coactivator in RNA polymerase II (RNAPII)-mediated transcription. The Arabidopsis Mediator complex has recently been implicated in plant immune responses. Here, we compared salicylic acid (SA)-, methyl jasmonate (MeJA)-, and the ethylene (ET) precursor 1-aminocyclopropane-1-carboxylic acid (ACC)-induced defense and/or wound-responsive gene expression in 14 Arabidopsis Mediator subunit mutants. Our results show that MED14, MED15, and MED16 are required for SA-activated expression of the defense marker gene PATHOEGNESIS-RELATED GENE1, MED25 is required for MeJA-induced expression of the wound-responsive marker gene VEGATATIVE STORAGE PROTEIN1 (VSP1), MED8, MED14, MED15, MED16, MED18, MED20a, MED25, MED31, and MED33A/B (MED33a and MED33B) are required for MeJA-induced expression of the defense maker gene PLANT DEFENSIN1.2 (PDF1.2), and MED8, MED14, MED15, MED16, MED25, and MED33A/B are also required for ACC-triggered expression of PDF1.2. Furthermore, we investigated the involvement of MED14, MED15, and MED16 in plant defense signaling crosstalk and found that MED14, MED15, and MED16 are required for SA- and ET-mediated suppression of MeJA-induced VSP1 expression. This result suggests that MED14, MED15, and MED16 not only relay defense signaling from the SA and JA/ET defense pathways to the RNAPII transcription machinery, but also fine-tune defense signaling crosstalk. Finally, we show that MED33A/B contributes to the necrotrophic fungal pathogen Botrytis cinerea-induced expression of the defense genes PDF1.2, HEVEIN-LIKE, and BASIC CHITINASE and is required for full-scale basal resistance to B. cinerea, demonstrating a positive role for MED33 in plant immunity against necrotrophic fungal pathogens.
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Affiliation(s)
- Chenggang Wang
- Department of Microbiology and Cell Science, University of Florida, GainesvilleFL, USA
| | - Xuezhu Du
- College of Life Science, Hubei UniversityWuhan, China
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, GainesvilleFL, USA
- *Correspondence: Zhonglin Mou,
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Wang C, Yao J, Du X, Zhang Y, Sun Y, Rollins JA, Mou Z. The Arabidopsis Mediator Complex Subunit16 Is a Key Component of Basal Resistance against the Necrotrophic Fungal Pathogen Sclerotinia sclerotiorum. Plant Physiol 2015; 169:856-72. [PMID: 26143252 PMCID: PMC4577384 DOI: 10.1104/pp.15.00351] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 07/01/2015] [Indexed: 05/19/2023]
Abstract
Although Sclerotinia sclerotiorum is a devastating necrotrophic fungal plant pathogen in agriculture, the virulence mechanisms utilized by S. sclerotiorum and the host defense mechanisms against this pathogen have not been fully understood. Here, we report that the Arabidopsis (Arabidopsis thaliana) Mediator complex subunit MED16 is a key component of basal resistance against S. sclerotiorum. Mutants of MED16 are markedly more susceptible to S. sclerotiorum than mutants of 13 other Mediator subunits, and med16 has a much stronger effect on S. sclerotiorum-induced transcriptome changes compared with med8, a mutation not altering susceptibility to S. sclerotiorum. Interestingly, med16 is also more susceptible to S. sclerotiorum than coronatine-insensitive1-1 (coi1-1), which is the most susceptible mutant reported so far. Although the jasmonic acid (JA)/ethylene (ET) defense pathway marker gene PLANT DEFENSIN1.2 (PDF1.2) cannot be induced in either med16 or coi1-1, basal transcript levels of PDF1.2 in med16 are significantly lower than in coi1-1. Furthermore, ET-induced suppression of JA-activated wound responses is compromised in med16, suggesting a role for MED16 in JA-ET cross talk. Additionally, MED16 is required for the recruitment of RNA polymerase II to PDF1.2 and OCTADECANOID-RESPONSIVE ARABIDOPSIS ETHYLENE/ETHYLENE-RESPONSIVE FACTOR59 (ORA59), two target genes of both JA/ET-mediated and the transcription factor WRKY33-activated defense pathways. Finally, MED16 is physically associated with WRKY33 in yeast and in planta, and WRKY33-activated transcription of PDF1.2 and ORA59 as well as resistance to S. sclerotiorum depends on MED16. Taken together, these results indicate that MED16 regulates resistance to S. sclerotiorum by governing both JA/ET-mediated and WRKY33-activated defense signaling in Arabidopsis.
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Affiliation(s)
- Chenggang Wang
- Department of Microbiology and Cell Science (C.W., Z.M.) and Department of Plant Pathology (J.A.R.), University of Florida, Gainesville, Florida 32611;Department of Microbiology and Immunology, University of Buffalo, Buffalo, New York 14203 (J.Y., Y.S.);College of Life Science, Hubei University, Wuhan 430062, China (X.D.); andInterdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32601 (Y.Z.)
| | - Jin Yao
- Department of Microbiology and Cell Science (C.W., Z.M.) and Department of Plant Pathology (J.A.R.), University of Florida, Gainesville, Florida 32611;Department of Microbiology and Immunology, University of Buffalo, Buffalo, New York 14203 (J.Y., Y.S.);College of Life Science, Hubei University, Wuhan 430062, China (X.D.); andInterdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32601 (Y.Z.)
| | - Xuezhu Du
- Department of Microbiology and Cell Science (C.W., Z.M.) and Department of Plant Pathology (J.A.R.), University of Florida, Gainesville, Florida 32611;Department of Microbiology and Immunology, University of Buffalo, Buffalo, New York 14203 (J.Y., Y.S.);College of Life Science, Hubei University, Wuhan 430062, China (X.D.); andInterdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32601 (Y.Z.)
| | - Yanping Zhang
- Department of Microbiology and Cell Science (C.W., Z.M.) and Department of Plant Pathology (J.A.R.), University of Florida, Gainesville, Florida 32611;Department of Microbiology and Immunology, University of Buffalo, Buffalo, New York 14203 (J.Y., Y.S.);College of Life Science, Hubei University, Wuhan 430062, China (X.D.); andInterdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32601 (Y.Z.)
| | - Yijun Sun
- Department of Microbiology and Cell Science (C.W., Z.M.) and Department of Plant Pathology (J.A.R.), University of Florida, Gainesville, Florida 32611;Department of Microbiology and Immunology, University of Buffalo, Buffalo, New York 14203 (J.Y., Y.S.);College of Life Science, Hubei University, Wuhan 430062, China (X.D.); andInterdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32601 (Y.Z.)
| | - Jeffrey A Rollins
- Department of Microbiology and Cell Science (C.W., Z.M.) and Department of Plant Pathology (J.A.R.), University of Florida, Gainesville, Florida 32611;Department of Microbiology and Immunology, University of Buffalo, Buffalo, New York 14203 (J.Y., Y.S.);College of Life Science, Hubei University, Wuhan 430062, China (X.D.); andInterdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32601 (Y.Z.)
| | - Zhonglin Mou
- Department of Microbiology and Cell Science (C.W., Z.M.) and Department of Plant Pathology (J.A.R.), University of Florida, Gainesville, Florida 32611;Department of Microbiology and Immunology, University of Buffalo, Buffalo, New York 14203 (J.Y., Y.S.);College of Life Science, Hubei University, Wuhan 430062, China (X.D.); andInterdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32601 (Y.Z.)
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Wang C, Ding Y, Yao J, Zhang Y, Sun Y, Colee J, Mou Z. Arabidopsis Elongator subunit 2 positively contributes to resistance to the necrotrophic fungal pathogens Botrytis cinerea and Alternaria brassicicola. Plant J 2015; 83:1019-1033. [PMID: 26216741 DOI: 10.1111/tpj.12946] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 07/09/2015] [Accepted: 07/15/2015] [Indexed: 05/17/2023]
Abstract
The evolutionarily conserved Elongator complex functions in diverse biological processes including salicylic acid-mediated immune response. However, how Elongator functions in jasmonic acid (JA)/ethylene (ET)-mediated defense is unknown. Here, we show that Elongator is required for full induction of the JA/ET defense pathway marker gene PLANT DEFENSIN1.2 (PDF1.2) and for resistance to the necrotrophic fungal pathogens Botrytis cinerea and Alternaria brassicicola. A loss-of-function mutation in the Arabidopsis Elongator subunit 2 (ELP2) alters B. cinerea-induced transcriptome reprogramming. Interestingly, in elp2, expression of WRKY33, OCTADECANOID-RESPONSIVE ARABIDOPSIS AP2/ERF59 (ORA59), and PDF1.2 is inhibited, whereas transcription of MYC2 and its target genes is enhanced. However, overexpression of WRKY33 or ORA59 and mutation of MYC2 fail to restore PDF1.2 expression and B. cinerea resistance in elp2, suggesting that ELP2 is required for induction of not only WRKY33 and ORA59 but also PDF1.2. Moreover, elp2 is as susceptible as coronatine-insensitive1 (coi1) and ethylene-insensitive2 (ein2) to B. cinerea, indicating that ELP2 is an important player in B. cinerea resistance. Further analysis of the lesion sizes on the double mutants elp2 coi1 and elp2 ein2 and the corresponding single mutants revealed that the function of ELP2 overlaps with COI1 and is additive to EIN2 for B. cinerea resistance. Finally, basal histone acetylation levels in the coding regions of WRKY33, ORA59, and PDF1.2 are reduced in elp2 and a functional ELP2-GFP fusion protein binds to the chromatin of these genes, suggesting that constitutive ELP2-mediated histone acetylation may be required for full activation of the WRKY33/ORA59/PDF1.2 transcriptional cascade.
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Affiliation(s)
- Chenggang Wang
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL, 32611, USA
| | - Yezhang Ding
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL, 32611, USA
| | - Jin Yao
- Department of Microbiology and Immunology, University of Buffalo, Buffalo, NY, 14203, USA
| | - Yanping Zhang
- Interdisciplinary Center for Biotechnology Research, University of Florida, P.O. Box 103622, Gainesville, FL, 32610, USA
| | - Yijun Sun
- Department of Microbiology and Immunology, University of Buffalo, Buffalo, NY, 14203, USA
| | - James Colee
- Department of Statistics, University of Florida, P.O. Box 118545, Gainesville, FL, 32611, USA
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL, 32611, USA
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Silva KJP, Brunings A, Peres NA, Mou Z, Folta KM. The Arabidopsis NPR1 gene confers broad-spectrum disease resistance in strawberry. Transgenic Res 2015; 24:693-704. [DOI: 10.1007/s11248-015-9869-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 03/19/2015] [Indexed: 11/25/2022]
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Adler-Wailes DC, Alberobello AT, Ma X, Hugendubler L, Stern EA, Mou Z, Han JC, Kim PW, Sumner AE, Yanovski JA, Mueller E. Analysis of variants and mutations in the human winged helix FOXA3 gene and associations with metabolic traits. Int J Obes (Lond) 2015; 39:888-92. [PMID: 25672906 PMCID: PMC4462767 DOI: 10.1038/ijo.2015.17] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 11/12/2014] [Accepted: 11/23/2014] [Indexed: 11/09/2022]
Abstract
BACKGROUND/OBJECTIVES The forkhead factor Foxa3 is involved in the early transcriptional events controlling adipocyte differentiation and plays a critical function in fat depot expansion in response to high-fat diet regimens and during aging in mice. No studies to date have assessed the potential associations of genetic variants in FOXA3 with human metabolic outcomes. SUBJECTS/METHODS In this study, we sequenced FOXA3 in 392 children, adolescents and young adults selected from several cohorts of subjects recruited at the National Institute of Child Health and Human Development of the National Institutes of Health based on the availability of dual-energy X-ray absorptiometry data, magnetic resonance imaging scans and DNA samples. We assessed the association between variants present in these subjects and metabolic traits and performed in vitro functional analysis of two novel FOXA3 missense mutations identified. RESULTS Our analysis identified 14 novel variants and showed that the common single-nucleotide polymorphism (SNP) rs28666870 is significantly associated with greater body mass index, lean body mass and appendicular lean mass (P values 0.009, 0.010 and 0.013 respectively). In vitro functional studies showed increased adipogenic function for the FOXA3 missense mutations c.185C>T (p.Ser62Leu) and c.731C>T (p.Ala244Val) compared with FOXA3-WT. CONCLUSIONS Our study identified novel FOXA3 variants and mutations, assessed the adipogenic capacity of two novel missense alterations in vitro and demonstrated for the first time the associations between FOXA3 SNP rs28666870 with metabolic phenotypes in humans.
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Affiliation(s)
- D C Adler-Wailes
- Genetics of Development and Disease Branch, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD, USA
| | - A T Alberobello
- Genetics of Development and Disease Branch, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD, USA
| | - X Ma
- Genetics of Development and Disease Branch, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD, USA
| | - L Hugendubler
- Genetics of Development and Disease Branch, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD, USA
| | - E A Stern
- Section on Growth and Obesity, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Z Mou
- Section on Growth and Obesity, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - J C Han
- Section on Growth and Obesity, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - P W Kim
- National Institute of Arthritis and Musculoskeletal and Skin Disease, National Institutes of Health, Bethesda, MD, USA
| | - A E Sumner
- Diabetes, Endocrinology and Obesity Branch, Section on Ethnicity and Health, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD, USA
| | - J A Yanovski
- Section on Growth and Obesity, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - E Mueller
- Genetics of Development and Disease Branch, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD, USA
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Ding Y, Mou Z. Elongator and its epigenetic role in plant development and responses to abiotic and biotic stresses. Front Plant Sci 2015; 6:296. [PMID: 25972888 PMCID: PMC4413731 DOI: 10.3389/fpls.2015.00296] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 04/13/2015] [Indexed: 05/20/2023]
Abstract
Elongator, a six-subunit protein complex, was initially isolated as an interactor of hyperphosphorylated RNA polymerase II in yeast, and was subsequently identified in animals and plants. Elongator has been implicated in multiple cellular activities or biological processes including tRNA modification, histone modification, DNA demethylation or methylation, tubulin acetylation, and exocytosis. Studies in the model plant Arabidopsis thaliana suggest that the structure of Elongator and its functions are highly conserved between plants and yeast. Disruption of the Elongator complex in plants leads to aberrant growth and development, resistance to abiotic stresses, and susceptibility to plant pathogens. The morphological and physiological phenotypes of Arabidopsis Elongator mutants are associated with decreased histone acetylation and/or altered DNA methylation. This review summarizes recent findings related to the epigenetic function of Elongator in plant development and responses to abiotic and biotic stresses.
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Affiliation(s)
| | - Zhonglin Mou
- *Correspondence: Zhonglin Mou, Department of Microbiology and Cell Science, University of Florida, Museum Road, Building 981, Gainesville, FL 32611, USA
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Tang J, Xiao P, Luo X, Bai J, Xia W, Chen W, Li J, Yu Q, Shi S, Xu Y, Mou Z, Wang Y, Li H. Increased IL-22 level in allergic rhinitis significantly correlates with clinical severity. Am J Rhinol Allergy 2014; 28:197-201. [PMID: 25514475 DOI: 10.2500/ajra.2014.28.4088] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND IL-22 regulates various processes and has been linked to diverse effects. However, the importance of IL-22 in the pathogenesis of allergic rhinitis (AR) remains poorly understood. This study sought to evaluate the levels of IL-22 and IL-17A in AR patients and their association with clinical severity ofN AR. METHODS Thirty-six AR patients and 22 normal controls were enrolled in this study. The frequencies of IL-22(+), IL-17A(+), and IL-9(+) T helper (Th) cells in peripheral blood of AR patients and normal controls were examined by flow cytometry. Serum levels of IL-22 and IL-17A in AR patients and normal controls were determined by ELISA. The clinical relevance of the percentages of IL-22(+) and IL-17A(+) Th cells as well as serum IL-22 and IL-17A levels were evaluated. RESULTS The frequencies of IL-22(+) and IL-17A(+) Th cells, but not IL-9(+) Th cells, were significantly increased compared with those in normal controls (p < 0.05). Frequencies of IL-22(+) and IL-17A(+) Th cells in peripheral blood of AR patients significantly correlated with visual analog scale scores of nasal symptoms (nasal congestion and rhinorrhea; p < 0.05). Moreover, the serum levels of IL-22 and IL-17A were significantly increased compared with those in normal controls (p < 0.05) and significantly correlated with the levels of Dermatophagoides pteronyssinus and Dermatophagoides farinae specific IgE in AR patients. CONCLUSION Our findings suggested that IL-22 as well as IL-17A may play an important role in the regulation of Th2-skewed inflammation in AR patients.
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Affiliation(s)
- Jun Tang
- Department of Otolaryngology, The First People's Hospital of Foshan City, Foshan, China
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Luo X, Ma R, Wu X, Xian D, Li J, Mou Z, Li H. Azelastine enhances the clinical efficacy of glucocorticoid by modulating MKP-1 expression in allergic rhinitis. Eur Arch Otorhinolaryngol 2014; 272:1165-73. [PMID: 25060977 DOI: 10.1007/s00405-014-3191-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 07/01/2014] [Indexed: 12/20/2022]
Abstract
Azelastine was suggested as a supplementary choice of glucocorticoid for the control of moderate to severe allergic rhinitis (AR). However, the underlying mechanism has not been completely understood. In this study, primary cultured nasal epithelial cells and bronchial epithelial cells were stimulated with proinflammatory cytokines (IL-1β and IL-17A) and anti-inflammatory agents (azelastine and budesonide) in vitro. The expression of intercellular adhesion molecule 1 (ICAM-1) and mitogen-activated protein kinase phosphatase-1 (MKP-1) was examined using qPCR and ELISA, respectively. Moreover, the additive effects of azelastine and budesonide nasal spray on nasal ICAM-1 level and total nasal symptom scores were evaluated in six uncontrolled severe AR patients by budesonide nasal spray alone. We found azelastine significantly inhibited cytokine-induced ICAM-1 upregulation, which is reversed by MKP-1 silencing. Azelastine and budesonide additively increased MKP-1 expression and inhibited ICAM-1 expression in vitro. After treatment for two consecutive weeks, combined azelastine and budesonide nasal spray significantly decreased nasal ICAM-1 level and TNSS in six uncontrolled AR patients. Our findings suggested that azelastine is able to additively enhance the anti-inflammatory effect of budesonide by modulating MKP-1 expression, which may implicate in the treatment of uncontrolled severe AR.
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Affiliation(s)
- Xi Luo
- Allergy and Cancer Center, Otorhinolaryngology Hospital, The First Affiliated Hospital of Sun Yat-sen University, No. 58, Zhongshan 2nd Road, Guangzhou, 510080, China
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Ding Y, Shaholli D, Mou Z. A large-scale genetic screen for mutants with altered salicylic acid accumulation in Arabidopsis. Front Plant Sci 2014; 5:763. [PMID: 25610446 PMCID: PMC4285869 DOI: 10.3389/fpls.2014.00763] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 12/10/2014] [Indexed: 05/03/2023]
Abstract
Salicylic acid (SA) is a key defense signal molecule against biotrophic and hemibiotrophic pathogens in plants, but how SA is synthesized in plant cells still remains elusive. Identification of new components involved in pathogen-induced SA accumulation would help address this question. To this end, we performed a large-scale genetic screen for mutants with altered SA accumulation during pathogen infection in Arabidopsis using a bacterial biosensor Acinetobacter sp. ADPWH_lux-based SA quantification method. A total of 35,000 M2 plants in the npr1-3 mutant background have been individually analyzed for the bacterial pathogen Pseudomonas syringae pv. maculicola (Psm) ES4326-induced SA accumulation. Among the mutants isolated, 19 had SA levels lower than npr1 (sln) and two exhibited increased SA accumulation in npr1 (isn). Complementation tests revealed that seven of the sln mutants are new alleles of eds5/sid1, two are sid2/eds16 alleles, one is allelic to pad4, and the remaining seven sln and two isn mutants are new non-allelic SA accumulation mutants. Interestingly, a large group of mutants (in the npr1-3 background), in which Psm ES4326-induced SA levels were similar to those in the wild-type Columbia plants, were identified, suggesting that the signaling network fine-tuning pathogen-induced SA accumulation is complex. We further characterized the sln1 single mutant and found that Psm ES4326-induced defense responses were compromised in this mutant. These defense response defects could be rescued by exogenous SA, suggesting that SLN1 functions upstream of SA. The sln1 mutation was mapped to a region on the north arm of chromosome I, which contains no known genes regulating pathogen-induced SA accumulation, indicating that SLN1 likely encodes a new regulator of SA biosynthesis. Thus, the new sln and isn mutants identified in this genetic screen are valuable for dissecting the molecular mechanisms underlying pathogen-induced SA accumulation in plants.
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Affiliation(s)
| | | | - Zhonglin Mou
- *Correspondence: Zhonglin Mou, Department of Microbiology and Cell Science, University of Florida, Museum Road, Building 981, Gainesville, FL 32611, USA e-mail:
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Hohenadel MG, Thearle MS, Grice BA, Huang H, Dai MH, Tao YX, Hunter LA, Palaguachi GI, Mou Z, Kim RC, Tsang MM, Haack K, Voruganti VS, Cole SA, Butte NF, Comuzzie AG, Muller YL, Baier LJ, Krakoff J, Knowler WC, Yanovski JA, Han JC. Brain-derived neurotrophic factor in human subjects with function-altering melanocortin-4 receptor variants. Int J Obes (Lond) 2013; 38:1068-74. [PMID: 24276017 PMCID: PMC4033711 DOI: 10.1038/ijo.2013.221] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 10/17/2013] [Accepted: 11/04/2013] [Indexed: 12/29/2022]
Abstract
Background In rodents, hypothalamic brain-derived neurotrophic factor (BDNF) expression appears to be regulated by melanocortin-4 receptor (MC4R) activity. The impact of MC4R genetic variation on circulating BDNF in humans is unknown. Objective To compare BDNF concentrations of subjects with loss-of-function (LOF) and gain-of-function (GOF) MC4R variants to those of controls with common sequence MC4R. Methods Circulating BDNF was measured in two cohorts with known MC4R sequence: 148 subjects of Pima Indian heritage ([mean±SD]: age 15.7±6.5y, BMI-Z 1.63±1.03), and 69 subjects of Hispanic heritage (10.8±3.6y, BMI-Z 1.57±1.07). MC4R variants were characterized in vitro by cell surface expression, receptor binding, and cAMP response after agonist administration. BDNF single nucleotide polymorphisms (SNPs) rs12291186, rs6265, and rs7124442 were also genotyped. Results In the Pima cohort, no significant differences in serum BDNF was observed for 43 LOF-subjects versus 65 LOF-matched controls [age-, sex-, and BMI-matched] (P=0.29), or 20 GOF-subjects versus 20 GOF-matched controls (P=0.40). Serum BDNF was significantly associated with genotype for BDNF rs12291186 (P=0.006) and rs6265 (P=0.009), but not rs7124442 (P=0.99); BDNF SNPs did not interact with MC4R status to predict serum BDNF. In the Hispanic cohort, plasma BDNF was not significantly different among 21 LOF-subjects, 20 GOF-subjects, and 28 controls (P=0.79); plasma BDNF was not predicted by BDNF genotype or BDNF-x-MC4R genotype interaction. Conclusions Circulating BDNF concentrations were not significantly associated with MC4R functional status, suggesting that peripheral BDNF does not directly reflect hypothalamic BDNF secretion and/or that MC4R signaling is not a significant regulator of the bulk of BDNF expression in humans.
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Affiliation(s)
- M G Hohenadel
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health (NIH), Phoenix, AZ, USA
| | - M S Thearle
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health (NIH), Phoenix, AZ, USA
| | - B A Grice
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health (NIH), Phoenix, AZ, USA
| | - H Huang
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA
| | - M-H Dai
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA
| | - Y-X Tao
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA
| | - L A Hunter
- 1] Unit on Metabolism and Neuroendocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA [2] Section on Growth and Obesity, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - G I Palaguachi
- 1] Unit on Metabolism and Neuroendocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA [2] Section on Growth and Obesity, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - Z Mou
- 1] Unit on Metabolism and Neuroendocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA [2] Section on Growth and Obesity, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - R C Kim
- 1] Unit on Metabolism and Neuroendocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA [2] Section on Growth and Obesity, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - M M Tsang
- 1] Unit on Metabolism and Neuroendocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA [2] Section on Growth and Obesity, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - K Haack
- Department of Genetics, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - V S Voruganti
- Department of Genetics, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - S A Cole
- Department of Genetics, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - N F Butte
- USDA/ARS Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX, USA
| | - A G Comuzzie
- Department of Genetics, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - Y L Muller
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health (NIH), Phoenix, AZ, USA
| | - L J Baier
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health (NIH), Phoenix, AZ, USA
| | - J Krakoff
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health (NIH), Phoenix, AZ, USA
| | - W C Knowler
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health (NIH), Phoenix, AZ, USA
| | - J A Yanovski
- Section on Growth and Obesity, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - J C Han
- 1] Unit on Metabolism and Neuroendocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA [2] Section on Growth and Obesity, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
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Zhang X, Yao J, Zhang Y, Sun Y, Mou Z. The Arabidopsis Mediator complex subunits MED14/SWP and MED16/SFR6/IEN1 differentially regulate defense gene expression in plant immune responses. Plant J 2013; 75:484-97. [PMID: 23607369 DOI: 10.1111/tpj.12216] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 04/17/2013] [Accepted: 04/19/2013] [Indexed: 05/20/2023]
Abstract
Pathogen infection in plants triggers large-scale transcriptional changes, both locally and systemically. Emerging evidence suggests that the Arabidopsis Mediator complex plays a crucial role in these transcriptional changes. Mediator is highly conserved in eukaryotes, and its core comprises more than 20 subunits organized into three modules named head, middle and tail. The head and middle modules interact with general transcription factors and RNA polymerase II, whereas the tail module associates with activators, and signals through the head and middle modules to the basal transcription machinery. In Arabidopsis, three tail module subunits, MED14, MED15 and MED16, have been identified. Both MED15 and MED16 have been implicated in plant immunity, but the role of MED14 has not been established. Here, we report the characterization of an Arabidopsis T-DNA insertion mutant of the MED14 gene. Similarly to the med15 and/or med16 mutations, the med14 mutation significantly suppresses salicylic acid-induced defense responses, alters transcriptional changes induced by the avirulent bacterial pathogen Pseudomonas syringae pv. tomato (Pst) DC3000/avrRpt2, and renders plants susceptible to both Pst DC3000/avrRpt2 and Pst DC3000. The med14 mutation also completely compromises biological induction of systemic acquired resistance (SAR), indicating that the tail module as a whole is essential for SAR. Interestingly, unlike the med16 mutation, which differentially affects expression of several SAR positive and negative regulators, med14 inhibits induction of a large group of defense genes, including both SAR positive and negative regulators, suggesting that individual subunits of the Mediator tail module employ distinct mechanisms to regulate plant immune responses.
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Affiliation(s)
- Xudong Zhang
- Department of Microbiology and Cell Science, University of Florida, PO Box 110700, Gainesville, FL 32611, USA
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DeFraia CT, Wang Y, Yao J, Mou Z. Elongator subunit 3 positively regulates plant immunity through its histone acetyltransferase and radical S-adenosylmethionine domains. BMC Plant Biol 2013; 13:102. [PMID: 23856002 PMCID: PMC3728140 DOI: 10.1186/1471-2229-13-102] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 07/12/2013] [Indexed: 05/17/2023]
Abstract
BACKGROUND Pathogen infection triggers a large-scale transcriptional reprogramming in plants, and the speed of this reprogramming affects the outcome of the infection. Our understanding of this process has significantly benefited from mutants that display either delayed or accelerated defense gene induction. In our previous work we demonstrated that the Arabidopsis Elongator complex subunit 2 (AtELP2) plays an important role in both basal immunity and effector-triggered immunity (ETI), and more recently showed that AtELP2 is involved in dynamic changes in histone acetylation and DNA methylation at several defense genes. However, the function of other Elongator subunits in plant immunity has not been characterized. RESULTS In the same genetic screen used to identify Atelp2, we found another Elongator mutant, Atelp3-10, which mimics Atelp2 in that it exhibits a delay in defense gene induction following salicylic acid treatment or pathogen infection. Similarly to AtELP2, AtELP3 is required for basal immunity and ETI, but not for systemic acquired resistance (SAR). Furthermore, we demonstrate that both the histone acetyltransferase and radical S-adenosylmethionine domains of AtELP3 are essential for its function in plant immunity. CONCLUSION Our results indicate that the entire Elongator complex is involved in basal immunity and ETI, but not in SAR, and support that Elongator may play a role in facilitating the transcriptional induction of defense genes through alterations to their chromatin.
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Affiliation(s)
- Christopher T DeFraia
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL 32611, USA
- Current address: Department of Molecular Genetics, Ohio State University, Columbus, OH 43210, USA
| | - Yongsheng Wang
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL 32611, USA
| | - Jiqiang Yao
- Interdisciplinary Center for Biotechnology Research, University of Florida, P.O. Box 103622, Gainesville, FL 32610, USA
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL 32611, USA
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Abstract
Upon pathogen infection, plants undergo dramatic transcriptome reprogramming to shift from normal growth and development to immune response. During this rapid process, the multiprotein Mediator complex has been recognized as an important player to fine-tune gene-specific and pathway-specific transcriptional reprogramming by acting as an adaptor/coregulator between sequence-specific transcription factor and RNA polymerase II (RNAPII). Here, we review current understanding of the role of five functionally characterized Mediator subunits (MED8, MED15, MED16, MED21 and MED25) in plant immunity. All these Mediator subunits positively regulate resistance against leaf-infecting biotrophic bacteria or necrotrophic fungi. While MED21 appears to regulate defense against fungal pathogens via relaying signals from upstream regulators and chromatin modification to RNAPII, the other four Mediator subunits locate at different positions of the defense network to convey phytohormone signal(s). Fully understanding the role of Mediator in plant immunity needs to characterize more Mediator subunits in both Arabidopsis and other plant species. Identification of interacting proteins of Mediator subunits will further help to reveal their specific regulatory mechanisms in plant immunity.
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Wang Y, An C, Zhang X, Yao J, Zhang Y, Sun Y, Yu F, Amador DM, Mou Z. The Arabidopsis elongator complex subunit2 epigenetically regulates plant immune responses. Plant Cell 2013; 25:762-76. [PMID: 23435660 PMCID: PMC3608791 DOI: 10.1105/tpc.113.109116] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Revised: 01/29/2013] [Accepted: 02/04/2013] [Indexed: 05/17/2023]
Abstract
The Arabidopsis thaliana Elongator complex subunit2 (ELP2) genetically interacts with NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 (NPR1), a key transcription coactivator of plant immunity, and regulates the induction kinetics of defense genes. However, the mechanistic relationship between ELP2 and NPR1 and how ELP2 regulates the kinetics of defense gene induction are unclear. Here, we demonstrate that ELP2 is an epigenetic regulator required for pathogen-induced rapid transcriptome reprogramming. We show that ELP2 functions in a transcriptional feed-forward loop regulating both NPR1 and its target genes. An elp2 mutation increases the total methylcytosine number, reduces the average methylation levels of methylcytosines, and alters (increases or decreases) methylation levels of specific methylcytosines. Interestingly, infection of plants with the avirulent bacterial pathogen Pseudomonas syringae pv tomato DC3000/avrRpt2 induces biphasic changes in DNA methylation levels of NPR1 and PHYTOALEXIN DEFICIENT4 (PAD4), which encodes another key regulator of plant immunity. These dynamic changes are blocked by the elp2 mutation, which is correlated with delayed induction of NPR1 and PAD4. The elp2 mutation also reduces basal histone acetylation levels in the coding regions of several defense genes. Together, our data demonstrate a new role for Elongator in somatic DNA demethylation/methylation and suggest a function for Elongator-mediated chromatin regulation in pathogen-induced transcriptome reprogramming.
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Affiliation(s)
- Yongsheng Wang
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611
| | - Chuanfu An
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611
| | - Xudong Zhang
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611
| | - Jiqiang Yao
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610
| | - Yanping Zhang
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610
| | - Yijun Sun
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610
| | - Fahong Yu
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610
| | - David Moraga Amador
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611
- Address correspondence to
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Amador D, Wang C, Holland K, Mou Z. Library Construction for Genome-wide Bisulfite Sequencing in Plants. Bio Protoc 2013. [DOI: 10.21769/bioprotoc.1013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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Zhang X, Wang C, Zhang Y, Sun Y, Mou Z. The Arabidopsis mediator complex subunit16 positively regulates salicylate-mediated systemic acquired resistance and jasmonate/ethylene-induced defense pathways. Plant Cell 2012; 24:4294-309. [PMID: 23064320 PMCID: PMC3517251 DOI: 10.1105/tpc.112.103317] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Revised: 09/14/2012] [Accepted: 09/26/2012] [Indexed: 05/18/2023]
Abstract
Systemic acquired resistance (SAR) is a long-lasting plant immunity against a broad spectrum of pathogens. Biological induction of SAR requires the signal molecule salicylic acid (SA) and involves profound transcriptional changes that are largely controlled by the transcription coactivator nonexpressor of pathogenesis-related genes1 (NPR1). However, it is unclear how SAR signals are transduced from the NPR1 signaling node to the general transcription machinery. Here, we report that the Arabidopsis thaliana Mediator subunit16 (MED16) is an essential positive regulator of SAR. Mutations in MED16 reduced NPR1 protein levels and completely compromised biological induction of SAR. These mutations also significantly suppressed SA-induced defense responses, altered the transcriptional changes induced by the avirulent bacterial pathogen Pseudomonas syringae pv tomato (Pst) DC3000/avrRpt2, and rendered plants susceptible to both Pst DC3000/avrRpt2 and Pst DC3000. In addition, mutations in MED16 blocked the induction of several jasmonic acid (JA)/ethylene (ET)-responsive genes and compromised resistance to the necrotrophic fungal pathogens Botrytis cinerea and Alternaria brassicicola. The Mediator complex acts as a bridge between specific transcriptional activators and the RNA polymerase II transcription machinery; therefore, our data suggest that MED16 may be a signaling component in the gap between the NPR1 signaling node and the general transcription machinery and may relay signals from both the SA and the JA/ET pathways.
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Affiliation(s)
- Xudong Zhang
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611
| | - Chenggang Wang
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611
| | - Yanping Zhang
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610
| | - Yijun Sun
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611
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Zhang X, Mou Z. Expression of the human NAD(P)-metabolizing ectoenzyme CD38 compromises systemic acquired resistance in Arabidopsis. Mol Plant Microbe Interact 2012; 25:1209-18. [PMID: 22670756 DOI: 10.1094/mpmi-10-11-0278] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Plant systemic acquired resistance (SAR) is a long-lasting, broad-spectrum immune response that is mounted after primary pathogen infection. Although SAR has been extensively researched, the molecular mechanisms underlying its activation have not been completely understood. We have previously shown that the electron carrier NAD(P) leaks into the plant extracellular compartment upon pathogen attack and that exogenous NAD(P) activates defense gene expression and disease resistance in local treated leaves, suggesting that extracellular NAD(P) [eNAD(P)] might function as a signal molecule activating plant immune responses. To further establish the function of eNAD(P) in plant immunity, we tested the effect of exogenous NAD(P) on resistance gene-mediated hypersensitive response (HR) and SAR. We found that exogenous NAD(P) completely suppresses HR-mediated cell death but does not affect HR-mediated disease resistance. Local application of exogenous NAD(P) is unable to induce SAR in distal tissues, indicating that eNAD(P) is not a sufficient signal for SAR activation. Using transgenic Arabidopsis plants expressing the human NAD(P)-metabolizing ectoenzyme CD38, we demonstrated that altering eNAD(P) concentration or signaling compromises biological induction of SAR. This result suggests that eNAD(P) may play a critical signaling role in activation of SAR.
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Affiliation(s)
- Xudong Zhang
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, USA
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Abstract
Citrus canker, caused by Xanthomonas citri subsp. citri (Xcc), is one of the most destructive diseases of citrus. Progress of breeding citrus canker-resistant varieties is modest due to limited resistant germplasm resources and lack of candidate genes for genetic manipulation. The objective of this study is to establish a novel heterologous pathosystem between Xcc and the well-established model plant Arabidopsis thaliana for defense mechanism dissection and resistance gene identification. Our results indicate that Xcc bacteria neither grow nor decline in Arabidopsis, but induce multiple defense responses including callose deposition, reactive oxygen species and salicylic aicd (SA) production, and defense gene expression, indicating that Xcc activates non-host resistance in Arabidopsis. Moreover, Xcc-induced defense gene expression is suppressed or attenuated in several well-characterized SA signaling mutants including eds1, pad4, eds5, sid2, and npr1. Interestingly, resistance to Xcc is compromised only in eds1, pad4, and eds5, but not in sid2 and npr1. However, combining sid2 and npr1 in the sid2npr1 double mutant compromises resistance to Xcc, suggesting genetic interactions likely exist between SID2 and NPR1 in the non-host resistance against Xcc in Arabidopsis. These results demonstrate that the SA signaling pathway plays a critical role in regulating non-host defense against Xcc in Arabidopsis and suggest that the SA signaling pathway genes may hold great potential for breeding citrus canker-resistant varieties through modern gene transfer technology.
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Affiliation(s)
- Chuanfu An
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, United States of America
| | - Zhonglin Mou
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, United States of America
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Abstract
The small phenolic compound salicylic acid (SA) plays an important regulatory role in multiple physiological processes including plant immune response. Significant progress has been made during the past two decades in understanding the SA-mediated defense signaling network. Characterization of a number of genes functioning in SA biosynthesis, conjugation, accumulation, signaling, and crosstalk with other hormones such as jasmonic acid, ethylene, abscisic acid, auxin, gibberellic acid, cytokinin, brassinosteroid, and peptide hormones has sketched the finely tuned immune response network. Full understanding of the mechanism of plant immunity will need to take advantage of fast developing genomics tools and bioinformatics techniques. However, elucidating genetic components involved in these pathways by conventional genetics, biochemistry, and molecular biology approaches will continue to be a major task of the community. High-throughput method for SA quantification holds the potential for isolating additional mutants related to SA-mediated defense signaling.
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Affiliation(s)
- Chuanfu An
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA
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Lin J, Mou Z, Kuang G, Yi H. [The diagnosis and countermeasure for the nose-source otitis media]. Lin Chuang Er Bi Yan Hou Tou Jing Wai Ke Za Zhi 2011; 25:301-306. [PMID: 21710716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
OBJECTIVE To propose the concept of rhinogenic otitis media and explore its pathomechanism through analyzing the diagnosis and treatment on secretory otitis media caused by unhealthy nasal cavity structure. METHOD Conservative treatment and correlative operation under nasoscope were undertaken in 176 otitis media patients with unhealthy nasal cavity structure. RESULT Of 176 cases, 156 cases recovered completely (88.64%), 18 cases got effective treatment (10.23%), and 2 cases got ineffective treatment (1.14%). CONCLUSION One important cause of the secretory otitis media is unhealthy nasal cavity structure, so correcting the unhealthy nasal cavity structure is the main ways to treat rhinogenic otitis media.
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Affiliation(s)
- Jie Lin
- Department of Otolaryngology Head and Neck Surgery, People's Hospital of Hainan, Haikou, 570311, China.
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