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Jiang Z, Yao L, Zhu X, Hao G, Ding Y, Zhao H, Wang S, Wen CK, Xu X, Xin XF. Ethylene signaling modulates air humidity responses in plants. Plant J 2024; 117:653-668. [PMID: 37997486 DOI: 10.1111/tpj.16556] [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] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 11/02/2023] [Accepted: 11/08/2023] [Indexed: 11/25/2023]
Abstract
Air humidity significantly impacts plant physiology. However, the upstream elements that mediate humidity sensing and adaptive responses in plants remain largely unexplored. In this study, we define high humidity-induced cellular features of Arabidopsis plants and take a quantitative phosphoproteomics approach to obtain a high humidity-responsive landscape of membrane proteins, which we reason are likely the early checkpoints of humidity signaling. We found that a brief high humidity exposure (i.e., 0.5 h) is sufficient to trigger extensive changes in membrane protein abundance and phosphorylation. Enrichment analysis of differentially regulated proteins reveals high humidity-sensitive processes such as 'transmembrane transport', 'response to abscisic acid', and 'stomatal movement'. We further performed a targeted screen of mutants, in which high humidity-responsive pathways/proteins are disabled, to uncover genes mediating high humidity sensitivity. Interestingly, ethylene pathway mutants (i.e., ein2 and ein3eil1) display a range of altered responses, including hyponasty, reactive oxygen species level, and responsive gene expression, to high humidity. Furthermore, we observed a rapid induction of ethylene biosynthesis genes and ethylene evolution after high humidity treatment. Our study sheds light on the potential early signaling events in humidity perception, a fundamental but understudied question in plant biology, and reveals ethylene as a key modulator of high humidity responses in plants.
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Affiliation(s)
- Zeyu Jiang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Lingya Yao
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xiangmei Zhu
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Guodong Hao
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yanxia Ding
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Hangwei Zhao
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Shanshan Wang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Chi-Kuang Wen
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xiaoyan Xu
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xiu-Fang Xin
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
- Chinese Academy of Sciences (CAS) and CAS John Innes Centre of Excellence for Plant and Microbial Sciences, Shanghai, China
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2
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Hu Y, Xin XF. A sweet story from Phytophthora-soybean interaction. Trends Microbiol 2023; 31:1093-1095. [PMID: 37770374 DOI: 10.1016/j.tim.2023.09.004] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 08/31/2023] [Accepted: 09/11/2023] [Indexed: 09/30/2023]
Abstract
Phytopathogenic microbes obtain nutrients from host plants to support their growth and metabolism. A recent study by Zhu et al. revealed that the oomycete pathogen Phytophthora sojae upregulates the activity of soybean trehalose 6-phosphate synthase 6 (GmTPS6) and increases trehalose accumulation (through an effector PsAvh413) to promote nutritional gain.
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Affiliation(s)
- Yezhou Hu
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Xiu-Fang Xin
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; University of the Chinese Academy of Sciences, Beijing 100049, China; Chinese Academy of Sciences (CAS) and CAS John Innes Centre of Excellence for Plant and Microbial Sciences, Shanghai 200032, China.
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3
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Wu J, Mei X, Zhang J, Ye L, Hu Y, Chen T, Wang Y, Liu M, Zhang Y, Xin XF. CURLY LEAF modulates apoplast liquid water status in Arabidopsis leaves. Plant Physiol 2023; 193:792-808. [PMID: 37300539 DOI: 10.1093/plphys/kiad336] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 04/26/2023] [Accepted: 05/11/2023] [Indexed: 06/12/2023]
Abstract
The apoplast of plant leaves, the intercellular space between mesophyll cells, is normally largely filled with air with a minimal amount of liquid water in it, which is essential for key physiological processes such as gas exchange to occur. Phytopathogens exploit virulence factors to induce a water-rich environment, or "water-soaked" area, in the apoplast of the infected leaf tissue to promote disease. We propose that plants evolved a "water soaking" pathway, which normally keeps a nonflooded leaf apoplast for plant growth but is disturbed by microbial pathogens to facilitate infection. Investigation of the "water soaking" pathway and leaf water control mechanisms is a fundamental, yet previously overlooked, aspect of plant physiology. To identify key components in the "water soaking" pathway, we performed a genetic screen to isolate Arabidopsis (Arabidopsis thaliana) severe water soaking (sws) mutants that show liquid water overaccumulation in the leaf under high air humidity, a condition required for visible water soaking. Here, we report the sws1 mutant, which displays rapid water soaking upon high humidity treatment due to a loss-of-function mutation in CURLY LEAF (CLF), encoding a histone methyltransferase in the POLYCOMB REPRESSIVE COMPLEX 2 (PRC2). We found that the sws1 (clf) mutant exhibits enhanced abscisic acid (ABA) levels and stomatal closure, which are indispensable for its water soaking phenotype and mediated by CLF's epigenetic regulation of a group of ABA-associated NAM, ATAF, and CUC (NAC) transcription factor genes, NAC019/055/072. The clf mutant showed weakened immunity, which likely also contributes to the water soaking phenotype. In addition, the clf plant supports a substantially higher level of Pseudomonas syringae pathogen-induced water soaking and bacterial multiplication, in an ABA pathway and NAC019/055/072-dependent manner. Collectively, our study sheds light on an important question in plant biology and demonstrates CLF as a key modulator of leaf liquid water status via epigenetic regulation of the ABA pathway and stomatal movement.
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Affiliation(s)
- Jingni Wu
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Xiao Mei
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
- University of the Chinese Academy of Sciences, Beijing 101408, China
| | - Jinyu Zhang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
- University of the Chinese Academy of Sciences, Beijing 101408, China
| | - Luhuan Ye
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Yezhou Hu
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Tao Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hebei 430070, China
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
| | - Yiping Wang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Menghui Liu
- Key Laboratory of Plant Stress Biology, State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, Henan 475004, China
| | - Yijing Zhang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
- University of the Chinese Academy of Sciences, Beijing 101408, China
| | - Xiu-Fang Xin
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
- University of the Chinese Academy of Sciences, Beijing 101408, China
- CAS-JIC Center of Excellence for Plant and Microbial Sciences (CEPAMS), Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
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4
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Hong X, Qi F, Wang R, Jia Z, Lin F, Yuan M, Xin XF, Liang Y. Ascorbate peroxidase 1 allows monitoring of cytosolic accumulation of effector-triggered reactive oxygen species using a luminol-based assay. Plant Physiol 2023; 191:1416-1434. [PMID: 36461917 PMCID: PMC9922408 DOI: 10.1093/plphys/kiac551] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 11/04/2022] [Accepted: 12/02/2022] [Indexed: 05/06/2023]
Abstract
Biphasic production of reactive oxygen species (ROS) has been observed in plants treated with avirulent bacterial strains. The first transient peak corresponds to pattern-triggered immunity (PTI)-ROS, whereas the second long-lasting peak corresponds to effector-triggered immunity (ETI)-ROS. PTI-ROS are produced in the apoplast by plasma membrane-localized NADPH oxidases, and the recognition of an avirulent effector increases the PTI-ROS regulatory module, leading to ETI-ROS accumulation in the apoplast. However, how apoplastic ETI-ROS signaling is relayed to the cytosol is still unknown. Here, we found that in the absence of cytosolic ascorbate peroxidase 1 (APX1), the second phase of ETI-ROS accumulation was undetectable in Arabidopsis (Arabidopsis thaliana) using luminol-based assays. In addition to being a scavenger of cytosolic H2O2, we discovered that APX1 served as a catalyst in this chemiluminescence ROS assay by employing luminol as an electron donor. A horseradish peroxidase (HRP)-mimicking APX1 mutation (APX1W41F) further enhanced its catalytic activity toward luminol, whereas an HRP-dead APX1 mutation (APX1R38H) reduced its luminol oxidation activity. The cytosolic localization of APX1 implies that ETI-ROS might accumulate in the cytosol. When ROS were detected using a fluorescent dye, green fluorescence was observed in the cytosol 6 h after infiltration with an avirulent bacterial strain. Collectively, these results indicate that ETI-ROS eventually accumulate in the cytosol, and cytosolic APX1 catalyzes luminol oxidation and allows monitoring of the kinetics of ETI-ROS in the cytosol. Our study provides important insights into the spatial dynamics of ROS accumulation in plant immunity.
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Affiliation(s)
- Xiufang Hong
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Fan Qi
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Ran Wang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Zhiyi Jia
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Fucheng Lin
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Minhang Yuan
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Xiu-Fang Xin
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Yan Liang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
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5
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Affiliation(s)
- Minhang Yuan
- National key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Boying Cai
- National key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of the Chinese Academy of Sciences, Beijing, China
| | - Xiu-Fang Xin
- National key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of the Chinese Academy of Sciences, Beijing, China
- CAS-JIC Center of Excellence for Plant and Microbial Sciences (CEPAMS), Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- * E-mail:
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6
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Luo F, Tang G, Hong S, Gong T, Xin XF, Wang C. Promotion of Arabidopsis immune responses by a rhizosphere fungus via supply of pipecolic acid to plants and selective augment of phytoalexins. Sci China Life Sci 2022; 66:1119-1133. [PMID: 36449213 DOI: 10.1007/s11427-022-2238-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 11/01/2022] [Indexed: 12/03/2022]
Abstract
The ascomycete insect pathogenic fungi such as Metarhizium species have been demonstrated with the abilities to form the rhizosphere or endophytic relationships with different plants for nutrient exchanges. In this study, after the evident infeasibility of bacterial disease development in the boxed sterile soils, we established a hydroponic system for the gnotobiotic growth of Arabidopsis thaliana with the wild-type and transgenic strain of Metarhizium robertsii. The transgenic fungus could produce a high amount of pipecolic acid (PIP), a pivotal plant-immune-stimulating metabolite. Fungal inoculation experiments showed that M. robertsii could form a non-selective rhizosphere relationship with Arabidopsis. Similar to the PIP uptake by plants after exogenous application, PIP level increased in Col-0 and could be detected in the PIP-non-producing Arabidopsis mutant (ald1) after fungal inoculations, indicating that plants can absorb the PIP produced by fungi. The transgenic fungal strain had a better efficacy than the wild type to defend plants against the bacterial pathogen and aphid attacks. Contrary to ald1, fmo1 plants could not be boosted to resist bacterial infection after treatments. After fungal inoculations, the phytoalexins camalexin and aliphatic glucosinolate were selectively increased in Arabidopsis via both PIP-dependent and -independent ways. This study unveils the potential mechanism of the fungus-mediated beneficial promotion of plant immunity against biological stresses. The data also highlight the added values of M. robertsii to plants beyond the direct suppression of insect pest populations.
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Affiliation(s)
- Feifei Luo
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Guirong Tang
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Song Hong
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Tianyu Gong
- National key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Xiu-Fang Xin
- National key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Chengshu Wang
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China.
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, 100049, China.
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
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7
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Wan S, Xin XF. Regulation and integration of plant jasmonate signaling: a comparative view of monocot and dicot. J Genet Genomics 2022; 49:704-714. [PMID: 35452856 DOI: 10.1016/j.jgg.2022.04.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 04/01/2022] [Accepted: 04/02/2022] [Indexed: 10/18/2022]
Abstract
The phytohormone jasmonate plays a pivotal role in various aspects of plant life, including developmental programs and defense against pests and pathogens. A large body of knowledge on jasmonate biosynthesis, signal transduction as well as its functions in diverse plant processes has been gained in the past two decades. In addition, there exists extensive crosstalk between jasmonate pathway and other phytohormone pathways, such as salicylic acid (SA) and gibberellin (GA), in co-regulation of plant immune status, fine-tuning the balance of plant growth and defense, and so on, which were mostly learned from studies in the dicotyledonous model plants Arabidopsis thaliana and tomato but much less in monocot. Interestingly, existing evidence suggests both conservation and functional divergence in terms of core components of jasmonate pathway, its biological functions and signal integration with other phytohormones, between monocot and dicot. In this review, we summarize the current understanding on JA signal initiation, perception and regulation, and highlight the distinctive characteristics in different lineages of plants.
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Affiliation(s)
- Shiwei Wan
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Xiu-Fang Xin
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; University of Chinese Academy of Sciences, Beijing 100049, China; CAS-JIC Center of Excellence for Plant and Microbial Sciences (CEPAMS), Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.
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8
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Hu Y, Ding Y, Cai B, Qin X, Wu J, Yuan M, Wan S, Zhao Y, Xin XF. Bacterial effectors manipulate plant abscisic acid signaling for creation of an aqueous apoplast. Cell Host Microbe 2022; 30:518-529.e6. [PMID: 35247331 DOI: 10.1016/j.chom.2022.02.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 12/05/2021] [Accepted: 02/02/2022] [Indexed: 01/23/2023]
Abstract
Phytopathogens like Pseudomonas syringae induce "water soaking" in the apoplastic space of plant leaf tissue as a key virulence mechanism. Water soaking is commonly observed in diverse pathosystems, yet the underlying physiological basis remains largely elusive. Here, we show that one of the strong P. syringae water-soaking inducers, AvrE, alters the regulation of abscisic acid (ABA) to induce ABA signaling, stomatal closure, and, thus, water soaking. AvrE binds and inhibits the function of Arabidopsis type one protein phosphatases (TOPPs), which negatively regulate ABA by suppressing SnRK2s, a key node of the ABA signaling pathway. The topp12537 quintuple mutants display significantly enhanced water soaking after P. syringae inoculation, whereas the loss of the ABA pathway dampens P. syringae-induced water soaking and disease. Our study uncovers the hijacking of ABA signaling and stomatal closure by P. syringae effectors as key mechanisms of disease susceptibility.
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Affiliation(s)
- Yezhou Hu
- National key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Yanxia Ding
- National key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Boying Cai
- National key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaohui Qin
- Shanghai Center for Plant Stress Biology and CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Jingni Wu
- National key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Minhang Yuan
- National key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Shiwei Wan
- National key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Yang Zhao
- Shanghai Center for Plant Stress Biology and CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Xiu-Fang Xin
- National key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; University of the Chinese Academy of Sciences, Beijing 100049, China; Chinese Academy of Sciences (CAS) and John Innes Centre, Centre of Excellence for Plant and Microbial Sciences, Shanghai 200032, China.
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9
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Yuan M, Xin XF. Bacterial Infection and Hypersensitive Response Assays in Arabidopsis-Pseudomonas syringae Pathosystem. Bio Protoc 2021; 11:e4268. [PMID: 35087927 DOI: 10.21769/bioprotoc.4268] [Citation(s) in RCA: 3] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 10/07/2021] [Accepted: 10/08/2021] [Indexed: 11/02/2022] Open
Abstract
Arabidopsis thaliana-Pseudomonas syringae pathosystem has been used as an important model system for studying plant-microbe interactions, leading to many milestones and breakthroughs in the understanding of plant immune system and pathogenesis mechanisms. Bacterial infection and plant disease assessment are key experiments in the studies of plant-pathogen interactions. The hypersensitive response (HR), which is characterized by rapid cell death and tissue collapse after inoculation with a high dose of bacteria, is a hallmark response of plant effector-triggered immunity (ETI), one layer of plant immunity triggered by recognition of pathogen-derived effector proteins. Here, we present a detailed protocol for bacterial disease and hypersensitive response assays applicable to studies of Pseudomonas syringae interaction with various plant species such as Arabidopsis, Nicotiana benthamiana, and tomato.
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Affiliation(s)
- Minhang Yuan
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Xiu-Fang Xin
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China.,CAS-JIC Center of Excellence for Plant and Microbial Sciences (CEPAMS), Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
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10
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Wang S, Li S, Wang J, Li Q, Xin XF, Zhou S, Wang Y, Li D, Xu J, Luo ZQ, He SY, Sun W. A bacterial kinase phosphorylates OSK1 to suppress stomatal immunity in rice. Nat Commun 2021; 12:5479. [PMID: 34531388 PMCID: PMC8445998 DOI: 10.1038/s41467-021-25748-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 08/30/2021] [Indexed: 02/08/2023] Open
Abstract
The Xanthomonas outer protein C2 (XopC2) family of bacterial effectors is widely found in plant pathogens and Legionella species. However, the biochemical activity and host targets of these effectors remain enigmatic. Here we show that ectopic expression of XopC2 promotes jasmonate signaling and stomatal opening in transgenic rice plants, which are more susceptible to Xanthomonas oryzae pv. oryzicola infection. Guided by these phenotypes, we discover that XopC2 represents a family of atypical kinases that specifically phosphorylate OSK1, a universal adaptor protein of the Skp1-Cullin-F-box ubiquitin ligase complexes. Intriguingly, OSK1 phosphorylation at Ser53 by XopC2 exclusively increases the binding affinity of OSK1 to the jasmonate receptor OsCOI1b, and specifically enhances the ubiquitination and degradation of JAZ transcription repressors and plant disease susceptibility through inhibiting stomatal immunity. These results define XopC2 as a prototypic member of a family of pathogenic effector kinases and highlight a smart molecular mechanism to activate jasmonate signaling.
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Affiliation(s)
- Shanzhi Wang
- grid.22935.3f0000 0004 0530 8290Department of Plant Pathology, the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, China Agricultural University, Beijing, China
| | - Shuai Li
- grid.22935.3f0000 0004 0530 8290Department of Plant Pathology, the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, China Agricultural University, Beijing, China
| | - Jiyang Wang
- grid.22935.3f0000 0004 0530 8290Department of Plant Pathology, the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, China Agricultural University, Beijing, China
| | - Qian Li
- grid.22935.3f0000 0004 0530 8290Department of Plant Pathology, the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, China Agricultural University, Beijing, China
| | - Xiu-Fang Xin
- grid.17088.360000 0001 2150 1785DOE Plant Research Laboratory, Michigan State University, East Lansing, MI USA ,grid.9227.e0000000119573309National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences (CAS), CAS John Innes Centre of Excellence for Plant and Microbial Sciences (CEPAMS), Shanghai, China
| | - Shuang Zhou
- grid.22935.3f0000 0004 0530 8290Department of Plant Pathology, the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, China Agricultural University, Beijing, China
| | - Yanping Wang
- grid.22935.3f0000 0004 0530 8290Department of Plant Pathology, the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, China Agricultural University, Beijing, China
| | - Dayong Li
- grid.464353.30000 0000 9888 756XCollege of Plant Protection, Jilin Agricultural University, Changchun, Jilin China
| | - Jiaqing Xu
- grid.22935.3f0000 0004 0530 8290Department of Plant Pathology, the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, China Agricultural University, Beijing, China
| | - Zhao-Qing Luo
- grid.169077.e0000 0004 1937 2197Purdue Institute for Inflammation, Immunology and Infectious Disease and Department of Biological Sciences, Purdue University, West Lafayette, IN USA
| | - Sheng Yang He
- grid.17088.360000 0001 2150 1785DOE Plant Research Laboratory, Michigan State University, East Lansing, MI USA ,grid.17088.360000 0001 2150 1785Howard Hughes Medical Institute, Michigan State University, East Lansing, MI USA
| | - Wenxian Sun
- grid.22935.3f0000 0004 0530 8290Department of Plant Pathology, the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, China Agricultural University, Beijing, China ,grid.464353.30000 0000 9888 756XCollege of Plant Protection, Jilin Agricultural University, Changchun, Jilin China
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11
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Yuan M, Ngou BPM, Ding P, Xin XF. PTI-ETI crosstalk: an integrative view of plant immunity. Curr Opin Plant Biol 2021; 62:102030. [PMID: 33684883 DOI: 10.1016/j.pbi.2021.102030] [Citation(s) in RCA: 291] [Impact Index Per Article: 97.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/07/2021] [Accepted: 02/08/2021] [Indexed: 05/02/2023]
Abstract
Plants resist attacks by pathogens via innate immune responses, which are initiated by cell surface-localized pattern-recognition receptors (PRRs) and intracellular nucleotide-binding domain leucine-rich repeat containing receptors (NLRs) leading to pattern-triggered immunity (PTI) and effector-triggered immunity (ETI), respectively. Although the two classes of immune receptors involve different activation mechanisms and appear to require different early signalling components, PTI and ETI eventually converge into many similar downstream responses, albeit with distinct amplitudes and dynamics. Increasing evidence suggests the existence of intricate interactions between PRR-mediated and NLR-mediated signalling cascades as well as common signalling components shared by both. Future investigation of the mechanisms underlying signal collaboration between PRR-initiated and NLR-initiated immunity will enable a more complete understanding of the plant immune system. This review discusses recent advances in our understanding of the relationship between the two layers of plant innate immunity.
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Affiliation(s)
- Minhang Yuan
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China; University of Chinese Academy of Sciences, Beijing, China
| | - Bruno Pok Man Ngou
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Pingtao Ding
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK; Institute of Biology Leiden, Leiden University, Sylviusweg 72, Leiden 2333 BE, The Netherlands.
| | - Xiu-Fang Xin
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China; University of Chinese Academy of Sciences, Beijing, China; CAS-JIC Center of Excellence for Plant and Microbial Sciences (CEPAMS), Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China.
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12
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Yuan M, Jiang Z, Bi G, Nomura K, Liu M, Wang Y, Cai B, Zhou JM, He SY, Xin XF. Pattern-recognition receptors are required for NLR-mediated plant immunity. Nature 2021; 592:105-109. [PMID: 33692546 DOI: 10.1101/2020.04.10.031294] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 02/01/2021] [Indexed: 05/25/2023]
Abstract
The plant immune system is fundamental for plant survival in natural ecosystems and for productivity in crop fields. Substantial evidence supports the prevailing notion that plants possess a two-tiered innate immune system, called pattern-triggered immunity (PTI) and effector-triggered immunity (ETI). PTI is triggered by microbial patterns via cell surface-localized pattern-recognition receptors (PRRs), whereas ETI is activated by pathogen effector proteins via predominantly intracellularly localized receptors called nucleotide-binding, leucine-rich repeat receptors (NLRs)1-4. PTI and ETI are initiated by distinct activation mechanisms and involve different early signalling cascades5,6. Here we show that Arabidopsis PRR and PRR co-receptor mutants-fls2 efr cerk1 and bak1 bkk1 cerk1 triple mutants-are markedly impaired in ETI responses when challenged with incompatible Pseudomonas syrinage bacteria. We further show that the production of reactive oxygen species by the NADPH oxidase RBOHD is a critical early signalling event connecting PRR- and NLR-mediated immunity, and that the receptor-like cytoplasmic kinase BIK1 is necessary for full activation of RBOHD, gene expression and bacterial resistance during ETI. Moreover, NLR signalling rapidly augments the transcript and/or protein levels of key PTI components. Our study supports a revised model in which potentiation of PTI is an indispensable component of ETI during bacterial infection. This revised model conceptually unites two major immune signalling cascades in plants and mechanistically explains some of the long-observed similarities in downstream defence outputs between PTI and ETI.
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Affiliation(s)
- Minhang Yuan
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Zeyu Jiang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Guozhi Bi
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Kinya Nomura
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Menghui Liu
- Key Laboratory of Plant Stress Biology, State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, China
| | - Yiping Wang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Boying Cai
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jian-Min Zhou
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Sheng Yang He
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
- Howard Hughes Medical Institute, Duke University, Durham, NC, USA
- Department of Biology, Duke University, Durham, NC, USA
| | - Xiu-Fang Xin
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China.
- University of Chinese Academy of Sciences, Beijing, China.
- CAS-JIC Center of Excellence for Plant and Microbial Sciences (CEPAMS), Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China.
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13
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Gong T, Xin XF. Phyllosphere microbiota: Community dynamics and its interaction with plant hosts. J Integr Plant Biol 2021; 63:297-304. [PMID: 33369158 DOI: 10.1111/jipb.13060] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 12/17/2020] [Indexed: 05/22/2023]
Abstract
Plants are colonized by various microorganisms in natural environments. While many studies have demonstrated key roles of the rhizosphere microbiota in regulating biological processes such as nutrient acquisition and resistance against abiotic and biotic challenges, less is known about the role of the phyllosphere microbiota and how it is established and maintained. This review provides an update on current understanding of phyllosphere community assembly and the mechanisms by which plants and microbes establish the phyllosphere microbiota for plant health.
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Affiliation(s)
- Tianyu Gong
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
- University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiu-Fang Xin
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
- University of the Chinese Academy of Sciences, Beijing, 100049, China
- The Chinese Academy of Sciences (CAS) and CAS John Innes Centre of Excellence for Plant and Microbial Sciences, Shanghai, 200032, China
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14
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Chen T, Nomura K, Wang X, Sohrabi R, Xu J, Yao L, Paasch BC, Ma L, Kremer J, Cheng Y, Zhang L, Wang N, Wang E, Xin XF, He SY. A plant genetic network for preventing dysbiosis in the phyllosphere. Nature 2020; 580:653-657. [PMID: 32350464 PMCID: PMC7197412 DOI: 10.1038/s41586-020-2185-0] [Citation(s) in RCA: 207] [Impact Index Per Article: 51.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Accepted: 02/19/2020] [Indexed: 12/31/2022]
Abstract
The aboveground parts of terrestrial plants, collectively called the phyllosphere, have a key role in the global balance of atmospheric carbon dioxide and oxygen. The phyllosphere represents one of the most abundant habitats for microbiota colonization. Whether and how plants control phyllosphere microbiota to ensure plant health is not well understood. Here we show that the Arabidopsis quadruple mutant (min7 fls2 efr cerk1; hereafter, mfec)1, simultaneously defective in pattern-triggered immunity and the MIN7 vesicle-trafficking pathway, or a constitutively activated cell death1 (cad1) mutant, carrying a S205F mutation in a membrane-attack-complex/perforin (MACPF)-domain protein, harbour altered endophytic phyllosphere microbiota and display leaf-tissue damage associated with dysbiosis. The Shannon diversity index and the relative abundance of Firmicutes were markedly reduced, whereas Proteobacteria were enriched in the mfec and cad1S205F mutants, bearing cross-kingdom resemblance to some aspects of the dysbiosis that occurs in human inflammatory bowel disease. Bacterial community transplantation experiments demonstrated a causal role of a properly assembled leaf bacterial community in phyllosphere health. Pattern-triggered immune signalling, MIN7 and CAD1 are found in major land plant lineages and are probably key components of a genetic network through which terrestrial plants control the level and nurture the diversity of endophytic phyllosphere microbiota for survival and health in a microorganism-rich environment.
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Affiliation(s)
- Tao Chen
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, USA.,State Key Laboratory of Agriculture Microbiology, Huazhong Agricultural University, Wuhan, Hubei Province, China.,Howard Hughes Medical Institute, Michigan State University, East Lansing, MI, USA
| | - Kinya Nomura
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Xiaolin Wang
- National key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Reza Sohrabi
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Jin Xu
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, Florida, USA
| | - Lingya Yao
- National key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Bradley C. Paasch
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Li Ma
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - James Kremer
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Yuti Cheng
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, USA.,Howard Hughes Medical Institute, Michigan State University, East Lansing, MI, USA
| | - Li Zhang
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, USA.,Howard Hughes Medical Institute, Michigan State University, East Lansing, MI, USA
| | - Nian Wang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, Florida, USA
| | - Ertao Wang
- National key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Xiu-Fang Xin
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China. .,CAS-JIC Center of Excellence for Plant and Microbial Sciences (CEPAMS), Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China.
| | - Sheng Yang He
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, USA. .,Howard Hughes Medical Institute, Michigan State University, East Lansing, MI, USA. .,Plant Resilience Institute, Michigan State University, East Lansing, MI, USA.
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15
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Xin XF, Nomura K, Aung K, Velásquez AC, Yao J, Boutrot F, Chang JH, Zipfel C, He SY. Bacteria establish an aqueous living space in plants crucial for virulence. Nature 2016; 539:524-529. [PMID: 27882964 DOI: 10.1038/nature20166] [Citation(s) in RCA: 246] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 10/17/2016] [Indexed: 12/26/2022]
Abstract
High humidity has a strong influence on the development of numerous diseases affecting the above-ground parts of plants (the phyllosphere) in crop fields and natural ecosystems, but the molecular basis of this humidity effect is not understood. Previous studies have emphasized immune suppression as a key step in bacterial pathogenesis. Here we show that humidity-dependent, pathogen-driven establishment of an aqueous intercellular space (apoplast) is another important step in bacterial infection of the phyllosphere. Bacterial effectors, such as Pseudomonas syringae HopM1, induce establishment of the aqueous apoplast and are sufficient to transform non-pathogenic P. syringae strains into virulent pathogens in immunodeficient Arabidopsis thaliana under high humidity. Arabidopsis quadruple mutants simultaneously defective in a host target (AtMIN7) of HopM1 and in pattern-triggered immunity could not only be used to reconstitute the basic features of bacterial infection, but also exhibited humidity-dependent dyshomeostasis of the endophytic commensal bacterial community in the phyllosphere. These results highlight a new conceptual framework for understanding diverse phyllosphere-bacterial interactions.
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Affiliation(s)
- Xiu-Fang Xin
- Department of Energy, Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - Kinya Nomura
- Department of Energy, Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - Kyaw Aung
- Department of Energy, Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, USA.,Howard Hughes Medical Institute-Gordon and Betty Moore Foundation, Michigan State University, East Lansing, Michigan 48824, USA
| | - André C Velásquez
- Department of Energy, Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - Jian Yao
- Department of Energy, Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - Freddy Boutrot
- The Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, UK
| | - Jeff H Chang
- Department of Botany and Plant Pathology and Center for Genome Research and Biocomputing, Oregon State University, Corvallis, Oregon 97331, USA
| | - Cyril Zipfel
- The Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, UK
| | - Sheng Yang He
- Department of Energy, Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, USA.,Howard Hughes Medical Institute-Gordon and Betty Moore Foundation, Michigan State University, East Lansing, Michigan 48824, USA.,Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824, USA.,Plant Resilience Institute, Michigan State University, East Lansing, Michigan 48824, USA
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16
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Xin XF, Nomura K, Ding X, Chen X, Wang K, Aung K, Uribe F, Rosa B, Yao J, Chen J, He SY. Pseudomonas syringae Effector Avirulence Protein E Localizes to the Host Plasma Membrane and Down-Regulates the Expression of the NONRACE-SPECIFIC DISEASE RESISTANCE1/HARPIN-INDUCED1-LIKE13 Gene Required for Antibacterial Immunity in Arabidopsis. Plant Physiol 2015; 169. [PMID: 26206852 PMCID: PMC4577396 DOI: 10.1104/pp.15.00547] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Many bacterial pathogens of plants and animals deliver effector proteins into host cells to promote infection. Elucidation of how pathogen effector proteins function not only is critical for understanding bacterial pathogenesis but also provides a useful tool in discovering the functions of host genes. In this study, we characterized the Pseudomonas syringae pv tomato DC3000 effector protein Avirulence Protein E (AvrE), the founding member of a widely distributed, yet functionally enigmatic, bacterial effector family. We show that AvrE is localized in the plasma membrane (PM) and PM-associated vesicle-like structures in the plant cell. AvrE contains two physically interacting domains, and the amino-terminal portion contains a PM-localization signal. Genome-wide microarray analysis indicates that AvrE, as well as the functionally redundant effector Hypersensitive response and pathogenicity-dependent Outer Protein M1, down-regulates the expression of the NONRACE-SPECIFIC DISEASE RESISTANCE1/HARPIN-INDUCED1-LIKE13 (NHL13) gene in Arabidopsis (Arabidopsis thaliana). Mutational analysis shows that NHL13 is required for plant immunity, as the nhl13 mutant plant displayed enhanced disease susceptibility. Our results defined the action site of one of the most important bacterial virulence proteins in plants and the antibacterial immunity function of the NHL13 gene.
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Affiliation(s)
- Xiu-Fang Xin
- Department of Energy Plant Research Laboratory (X.-F.X., K.N., X.D., X.C., K.A., F.U., B.R., J.Y., J.C., S.Y.H.), Department of Plant Biology (X.-F.X.), Department of Biochemistry and Molecular Biology (K.W.), and Howard Hughes Medical Institute (S.Y.H.), Michigan State University, East Lansing, Michigan 48824;State Key Laboratory of Crop Biology, Shandong Provincial Key Laboratory of Agricultural Microbiology, Shandong Agricultural University, Tai'an, 271018 Shandong, China (X.D.);Key Laboratory of Plant Pathology, Department of Plant Pathology, China Agricultural University, Beijing 100193, China (X.C.);Genome Institute, Washington University, St. Louis, Missouri 63108 (B.R.); andDepartment of Biological Sciences, Western Michigan University, Kalamazoo, Michigan 49008 (J.Y.)
| | - Kinya Nomura
- Department of Energy Plant Research Laboratory (X.-F.X., K.N., X.D., X.C., K.A., F.U., B.R., J.Y., J.C., S.Y.H.), Department of Plant Biology (X.-F.X.), Department of Biochemistry and Molecular Biology (K.W.), and Howard Hughes Medical Institute (S.Y.H.), Michigan State University, East Lansing, Michigan 48824;State Key Laboratory of Crop Biology, Shandong Provincial Key Laboratory of Agricultural Microbiology, Shandong Agricultural University, Tai'an, 271018 Shandong, China (X.D.);Key Laboratory of Plant Pathology, Department of Plant Pathology, China Agricultural University, Beijing 100193, China (X.C.);Genome Institute, Washington University, St. Louis, Missouri 63108 (B.R.); andDepartment of Biological Sciences, Western Michigan University, Kalamazoo, Michigan 49008 (J.Y.)
| | - Xinhua Ding
- Department of Energy Plant Research Laboratory (X.-F.X., K.N., X.D., X.C., K.A., F.U., B.R., J.Y., J.C., S.Y.H.), Department of Plant Biology (X.-F.X.), Department of Biochemistry and Molecular Biology (K.W.), and Howard Hughes Medical Institute (S.Y.H.), Michigan State University, East Lansing, Michigan 48824;State Key Laboratory of Crop Biology, Shandong Provincial Key Laboratory of Agricultural Microbiology, Shandong Agricultural University, Tai'an, 271018 Shandong, China (X.D.);Key Laboratory of Plant Pathology, Department of Plant Pathology, China Agricultural University, Beijing 100193, China (X.C.);Genome Institute, Washington University, St. Louis, Missouri 63108 (B.R.); andDepartment of Biological Sciences, Western Michigan University, Kalamazoo, Michigan 49008 (J.Y.)
| | - Xujun Chen
- Department of Energy Plant Research Laboratory (X.-F.X., K.N., X.D., X.C., K.A., F.U., B.R., J.Y., J.C., S.Y.H.), Department of Plant Biology (X.-F.X.), Department of Biochemistry and Molecular Biology (K.W.), and Howard Hughes Medical Institute (S.Y.H.), Michigan State University, East Lansing, Michigan 48824;State Key Laboratory of Crop Biology, Shandong Provincial Key Laboratory of Agricultural Microbiology, Shandong Agricultural University, Tai'an, 271018 Shandong, China (X.D.);Key Laboratory of Plant Pathology, Department of Plant Pathology, China Agricultural University, Beijing 100193, China (X.C.);Genome Institute, Washington University, St. Louis, Missouri 63108 (B.R.); andDepartment of Biological Sciences, Western Michigan University, Kalamazoo, Michigan 49008 (J.Y.)
| | - Kun Wang
- Department of Energy Plant Research Laboratory (X.-F.X., K.N., X.D., X.C., K.A., F.U., B.R., J.Y., J.C., S.Y.H.), Department of Plant Biology (X.-F.X.), Department of Biochemistry and Molecular Biology (K.W.), and Howard Hughes Medical Institute (S.Y.H.), Michigan State University, East Lansing, Michigan 48824;State Key Laboratory of Crop Biology, Shandong Provincial Key Laboratory of Agricultural Microbiology, Shandong Agricultural University, Tai'an, 271018 Shandong, China (X.D.);Key Laboratory of Plant Pathology, Department of Plant Pathology, China Agricultural University, Beijing 100193, China (X.C.);Genome Institute, Washington University, St. Louis, Missouri 63108 (B.R.); andDepartment of Biological Sciences, Western Michigan University, Kalamazoo, Michigan 49008 (J.Y.)
| | - Kyaw Aung
- Department of Energy Plant Research Laboratory (X.-F.X., K.N., X.D., X.C., K.A., F.U., B.R., J.Y., J.C., S.Y.H.), Department of Plant Biology (X.-F.X.), Department of Biochemistry and Molecular Biology (K.W.), and Howard Hughes Medical Institute (S.Y.H.), Michigan State University, East Lansing, Michigan 48824;State Key Laboratory of Crop Biology, Shandong Provincial Key Laboratory of Agricultural Microbiology, Shandong Agricultural University, Tai'an, 271018 Shandong, China (X.D.);Key Laboratory of Plant Pathology, Department of Plant Pathology, China Agricultural University, Beijing 100193, China (X.C.);Genome Institute, Washington University, St. Louis, Missouri 63108 (B.R.); andDepartment of Biological Sciences, Western Michigan University, Kalamazoo, Michigan 49008 (J.Y.)
| | - Francisco Uribe
- Department of Energy Plant Research Laboratory (X.-F.X., K.N., X.D., X.C., K.A., F.U., B.R., J.Y., J.C., S.Y.H.), Department of Plant Biology (X.-F.X.), Department of Biochemistry and Molecular Biology (K.W.), and Howard Hughes Medical Institute (S.Y.H.), Michigan State University, East Lansing, Michigan 48824;State Key Laboratory of Crop Biology, Shandong Provincial Key Laboratory of Agricultural Microbiology, Shandong Agricultural University, Tai'an, 271018 Shandong, China (X.D.);Key Laboratory of Plant Pathology, Department of Plant Pathology, China Agricultural University, Beijing 100193, China (X.C.);Genome Institute, Washington University, St. Louis, Missouri 63108 (B.R.); andDepartment of Biological Sciences, Western Michigan University, Kalamazoo, Michigan 49008 (J.Y.)
| | - Bruce Rosa
- Department of Energy Plant Research Laboratory (X.-F.X., K.N., X.D., X.C., K.A., F.U., B.R., J.Y., J.C., S.Y.H.), Department of Plant Biology (X.-F.X.), Department of Biochemistry and Molecular Biology (K.W.), and Howard Hughes Medical Institute (S.Y.H.), Michigan State University, East Lansing, Michigan 48824;State Key Laboratory of Crop Biology, Shandong Provincial Key Laboratory of Agricultural Microbiology, Shandong Agricultural University, Tai'an, 271018 Shandong, China (X.D.);Key Laboratory of Plant Pathology, Department of Plant Pathology, China Agricultural University, Beijing 100193, China (X.C.);Genome Institute, Washington University, St. Louis, Missouri 63108 (B.R.); andDepartment of Biological Sciences, Western Michigan University, Kalamazoo, Michigan 49008 (J.Y.)
| | - Jian Yao
- Department of Energy Plant Research Laboratory (X.-F.X., K.N., X.D., X.C., K.A., F.U., B.R., J.Y., J.C., S.Y.H.), Department of Plant Biology (X.-F.X.), Department of Biochemistry and Molecular Biology (K.W.), and Howard Hughes Medical Institute (S.Y.H.), Michigan State University, East Lansing, Michigan 48824;State Key Laboratory of Crop Biology, Shandong Provincial Key Laboratory of Agricultural Microbiology, Shandong Agricultural University, Tai'an, 271018 Shandong, China (X.D.);Key Laboratory of Plant Pathology, Department of Plant Pathology, China Agricultural University, Beijing 100193, China (X.C.);Genome Institute, Washington University, St. Louis, Missouri 63108 (B.R.); andDepartment of Biological Sciences, Western Michigan University, Kalamazoo, Michigan 49008 (J.Y.)
| | - Jin Chen
- Department of Energy Plant Research Laboratory (X.-F.X., K.N., X.D., X.C., K.A., F.U., B.R., J.Y., J.C., S.Y.H.), Department of Plant Biology (X.-F.X.), Department of Biochemistry and Molecular Biology (K.W.), and Howard Hughes Medical Institute (S.Y.H.), Michigan State University, East Lansing, Michigan 48824;State Key Laboratory of Crop Biology, Shandong Provincial Key Laboratory of Agricultural Microbiology, Shandong Agricultural University, Tai'an, 271018 Shandong, China (X.D.);Key Laboratory of Plant Pathology, Department of Plant Pathology, China Agricultural University, Beijing 100193, China (X.C.);Genome Institute, Washington University, St. Louis, Missouri 63108 (B.R.); andDepartment of Biological Sciences, Western Michigan University, Kalamazoo, Michigan 49008 (J.Y.)
| | - Sheng Yang He
- Department of Energy Plant Research Laboratory (X.-F.X., K.N., X.D., X.C., K.A., F.U., B.R., J.Y., J.C., S.Y.H.), Department of Plant Biology (X.-F.X.), Department of Biochemistry and Molecular Biology (K.W.), and Howard Hughes Medical Institute (S.Y.H.), Michigan State University, East Lansing, Michigan 48824;State Key Laboratory of Crop Biology, Shandong Provincial Key Laboratory of Agricultural Microbiology, Shandong Agricultural University, Tai'an, 271018 Shandong, China (X.D.);Key Laboratory of Plant Pathology, Department of Plant Pathology, China Agricultural University, Beijing 100193, China (X.C.);Genome Institute, Washington University, St. Louis, Missouri 63108 (B.R.); andDepartment of Biological Sciences, Western Michigan University, Kalamazoo, Michigan 49008 (J.Y.)
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17
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Xin XF, Nomura K, Underwood W, He SY. Induction and suppression of PEN3 focal accumulation during Pseudomonas syringae pv. tomato DC3000 infection of Arabidopsis. Mol Plant Microbe Interact 2013; 26:861-7. [PMID: 23815470 DOI: 10.1094/mpmi-11-12-0262-r] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The pleiotropic drug resistance (PDR) proteins belong to the super-family of ATP-binding cassette (ABC) transporters. AtPDR8, also called PEN3, is required for penetration resistance of Arabidopsis to nonadapted powdery mildew fungi. During fungal infection, plasma-membrane-localized PEN3 is concentrated at fungal entry sites, as part of the plant's focal immune response. Here, we show that the pen3 mutant is compromised in resistance to the bacterial pathogen Pseudomonas syringae pv. tomato DC3000. P. syringae pv. tomato DC3000 infection or treatment with a flagellin-derived peptide, flg22, induced strong focal accumulation of PEN3-green fluorescent protein. Interestingly, after an initial induction of PEN3 accumulation, P. syringae pv. tomato DC3000 but not the type-III-secretion-deficient mutant hrcC could suppress PEN3 accumulation. Moreover, transgenic overexpression of the P. syringae pv. tomato DC3000 effector AvrPto was sufficient to suppress PEN3 focal accumulation in response to flg22. Analyses of P. syringae pv. tomato DC3000 effector deletion mutants showed that individual effectors, including AvrPto, appear to be insufficient to suppress PEN3 accumulation when delivered by bacteria, suggesting a requirement for a combined action of multiple effectors. Collectively, our results indicate that PEN3 plays a positive role in plant resistance to a bacterial pathogen and show that focal accumulation of PEN3 protein may be a useful cellular response marker for the Arabidopsis-P. syringae interaction.
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Affiliation(s)
- Xiu-Fang Xin
- Department of Plant Biology, Michigan State University, East Lansing, MI, USA
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18
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Abstract
Since the early 1980s, various strains of the gram-negative bacterial pathogen Pseudomonas syringae have been used as models for understanding plant-bacterial interactions. In 1991, a P. syringae pathovar tomato (Pst) strain, DC3000, was reported to infect not only its natural host tomato but also Arabidopsis in the laboratory, a finding that spurred intensive efforts in the subsequent two decades to characterize the molecular mechanisms by which this strain causes disease in plants. Genomic analysis shows that Pst DC3000 carries a large repertoire of potential virulence factors, including proteinaceous effectors that are secreted through the type III secretion system and a polyketide phytotoxin called coronatine, which structurally mimics the plant hormone jasmonate (JA). Study of Pst DC3000 pathogenesis has not only provided several conceptual advances in understanding how a bacterial pathogen employs type III effectors to suppress plant immune responses and promote disease susceptibility but has also facilitated the discovery of the immune function of stomata and key components of JA signaling in plants. The concepts derived from the study of Pst DC3000 pathogenesis may prove useful in understanding pathogenesis mechanisms of other plant pathogens.
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Affiliation(s)
- Xiu-Fang Xin
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, USA.
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Ji RQ, Song Q, Xin XF, Zhou X, Feng H. Isolation of fertility-related genes of multiple-allele-inherited male sterility in Brassica rapa ssp pekinensis by cDNA-AFLP. Genet Mol Res 2011; 10:4073-83. [PMID: 22180076 DOI: 10.4238/2011.december.5.8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
To better understand the molecular mechanisms of multiple-allele-inherited male sterility in Chinese cabbage (Brassica rapa ssp pekinensis), differentially expressed genes in fertile and sterile plants must be isolated. We used cDNA-AFLP analysis to isolate differentially expressed genes in fertile and sterile buds of the two-type line, AB01. Sixteen high-quality sequences were generated, 11 of which were up-regulated in fertile buds, and five of which were up-regulated in sterile buds. Based on BLAST screening and functional annotation, these genes have homology with genes encoding known flower- or bud-specific proteins, metabolism-related proteins and cell-structure proteins. In addition, the full-length cDNA sequences of the actin gene were cloned from the cabbage plants by RACE and used as an internal standard for semi-quantitative reverse transcription-PCR. Expression of three flower- or bud-specific differentially expressed transcript-derived fragments in fertile and sterile buds was examined using RT-PCR; the expression patterns of these genes were similar to the patterns observed in the cDNA-AFLP analysis.
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Affiliation(s)
- R Q Ji
- Department of Horticulture, Shenyang Agricultural University, Shenyang, China.
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Yang Q, Chen ZZ, Zhou XF, Yin HB, Li X, Xin XF, Hong XH, Zhu JK, Gong Z. Overexpression of SOS (Salt Overly Sensitive) genes increases salt tolerance in transgenic Arabidopsis. Mol Plant 2009; 2:22-31. [PMID: 19529826 PMCID: PMC2639737 DOI: 10.1093/mp/ssn058] [Citation(s) in RCA: 229] [Impact Index Per Article: 15.3] [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: 03/13/2008] [Accepted: 08/18/2008] [Indexed: 05/05/2023]
Abstract
Soil salinity is a major abiotic stress that decreases plant growth and productivity. Recently, it was reported that plants overexpressing AtNHX1 or SOS1 have significantly increased salt tolerance. To test whether overexpression of multiple genes can improve plant salt tolerance even more, we produced six different transgenic Arabidopsis plants that overexpress AtNHX1, SOS3, AtNHX1+SOS3, SOS1, SOS2+SOS3, or SOS1+SOS2+SOS3. Northern blot analyses confirmed the presence of high levels of the relevant gene transcripts in transgenic plants. Transgenic Arabidopsis plants overexpressing AtNHX1 alone did not present any significant increase in salt tolerance, contrary to earlier reports. We found that transgenic plants overexpressing SOS3 exhibit increased salt tolerance similar to plants overexpressing SOS1. Moreover, salt tolerance of transgenic plants overexpressing AtNHX1+SOS3, SOS2+SOS3, or SOS1+SOS2+SOS3, respectively, appeared similar to the tolerance of transgenic plants overexpressing either SOS1 or SOS3 alone.
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Affiliation(s)
- Qing Yang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
- The National Center for Plant Gene Research, Beijing, China
- University of California-Riverside-China Agricultural University Joint Center for Plant Cell and Molecular Biology, Beijing 100193, China
| | - Zhi-Zhong Chen
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
- The National Center for Plant Gene Research, Beijing, China
- University of California-Riverside-China Agricultural University Joint Center for Plant Cell and Molecular Biology, Beijing 100193, China
| | - Xiao-Feng Zhou
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
- The National Center for Plant Gene Research, Beijing, China
- University of California-Riverside-China Agricultural University Joint Center for Plant Cell and Molecular Biology, Beijing 100193, China
| | - Hai-Bo Yin
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
- The National Center for Plant Gene Research, Beijing, China
- University of California-Riverside-China Agricultural University Joint Center for Plant Cell and Molecular Biology, Beijing 100193, China
| | - Xia Li
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
- The National Center for Plant Gene Research, Beijing, China
- University of California-Riverside-China Agricultural University Joint Center for Plant Cell and Molecular Biology, Beijing 100193, China
| | - Xiu-Fang Xin
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
- The National Center for Plant Gene Research, Beijing, China
- University of California-Riverside-China Agricultural University Joint Center for Plant Cell and Molecular Biology, Beijing 100193, China
| | - Xu-Hui Hong
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
- The National Center for Plant Gene Research, Beijing, China
- University of California-Riverside-China Agricultural University Joint Center for Plant Cell and Molecular Biology, Beijing 100193, China
| | - Jian-Kang Zhu
- University of California-Riverside-China Agricultural University Joint Center for Plant Cell and Molecular Biology, Beijing 100193, China
- Department of Botany and Plant Sciences, Institute for Integrative Genome Biology, 2150 Batchelor Hall, University of California, Riverside, CA 92521, USA
| | - Zhizhong Gong
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
- The National Center for Plant Gene Research, Beijing, China
- University of California-Riverside-China Agricultural University Joint Center for Plant Cell and Molecular Biology, Beijing 100193, China
- To whom correspondence should be addressed. E-mail , fax 86-10-62733733
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21
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Abstract
In 1991, blood samples were obtained from 150 adult Jinan citizens (74 men and 76 women at the ages of 20 to 57 years) who had no known occupational exposure to heavy metals. Age, sex, two social habits of smoking and drinking (in terms of daily consumption) and negative occupational history were examined in a medical interview. The samples were analyzed for lead (Pb-B) and cadmium (Cd-B) with a flame atomic absorption spectrometer. The geometric mean (GM) Pb-B and Cd-B were 92.3 and 0.94 micrograms/l, respectively, among 39 nonsmoking men, whereas the counterpart values were 123.4 micrograms/l and 2.61 micrograms/l among 35 smoking men (mean consumption; > 15 cigarettes/day); the difference was significant both for Pb-B and Cd-B. Comparison between 39 male and 76 female nonsmokers showed that Pb-B was significantly higher in men (92.3 micrograms/l) than in women (71.6 micrograms/l, whereas the difference in Cd-B (0.94 micrograms/l) for men versus 0.83 micrograms/l for women) was insignificant. When the women were classified by decade of age and Cd-B were compared, there was a trend of age-dependent increase in Cd-B from 0.60 micrograms/l in 20s to 1.24 micrograms/l in 40s, followed by no further increase at higher ages. Age-dependent changes were not remarkable in Pb-B in women, or Cd-B and Pb-B in men. No significant time-dependent changes were observed when the present results were compared with the results from two similar studies conducted in 1983 and 1985, respectively.
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Affiliation(s)
- J B Qu
- Department of Public Health, Shandong Medical University, Jinan, China
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