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Guo H, Zhang Y, Li B, Li C, Shi Q, Zhu-Salzman K, Ge F, Sun Y. Salivary carbonic anhydrase II in winged aphid morph facilitates plant infection by viruses. Proc Natl Acad Sci U S A 2023; 120:e2222040120. [PMID: 36976769 PMCID: PMC10083582 DOI: 10.1073/pnas.2222040120] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 02/17/2023] [Indexed: 03/29/2023] Open
Abstract
Aphids are the most common insect vector transmitting hundreds of plant viruses. Aphid wing dimorphism (winged vs. wingless) not only showcases the phenotypic plasticity but also impacts virus transmission; however, the superiority of winged aphids in virus transmission over the wingless morph is not well understood. Here, we show that plant viruses were efficiently transmitted and highly infectious when associated with the winged morph of Myzus persicae and that a salivary protein contributed to this difference. The carbonic anhydrase II (CA-II) gene was identified by RNA-seq of salivary glands to have higher expression in the winged morph. Aphids secreted CA-II into the apoplastic region of plant cells, leading to elevated accumulation of H+. Apoplastic acidification further increased the activities of polygalacturonases, the cell wall homogalacturonan (HG)-modifying enzymes, promoting degradation of demethylesterified HGs. In response to apoplastic acidification, plants accelerated vesicle trafficking to enhance pectin transport and strengthen the cell wall, which also facilitated virus translocation from the endomembrane system to the apoplast. Secretion of a higher quantity of salivary CA-II by winged aphids promoted intercellular vesicle transport in the plant. The higher vesicle trafficking induced by winged aphids enhanced dispersal of virus particles from infected cells to neighboring cells, thus resulting in higher virus infection in plants relative to the wingless morph. These findings imply that the difference in the expression of salivary CA-II between winged and wingless morphs is correlated with the vector role of aphids during the posttransmission infection process, which influences the outcome of plant endurance of virus infection.
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Affiliation(s)
- Huijuan Guo
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing100101, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing100049, China
| | - Yanjing Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing100101, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing100049, China
| | - Bingyu Li
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing100101, China
| | - Chenwei Li
- School of Life Sciences, Hebei University, Baoding071002, China
| | - Qingyun Shi
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing100101, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing100049, China
| | - Keyan Zhu-Salzman
- Department of Entomology, Texas A&M University, College Station, TX77843
| | - Feng Ge
- Institute of Plant Protection, Shandong Academy of Agriculture Sciences, Jinan250100, China
| | - Yucheng Sun
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing100101, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing100049, China
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Ahmed MA, Ban N, Hussain S, Batool R, Zhang YJ, Liu TX, Cao HH. Preference and performance of the green peach aphid, Myzus persicae on three Brassicaceae vegetable plants and its association with amino acids and glucosinolates. PLoS One 2022; 17:e0269736. [PMID: 36454720 PMCID: PMC9714699 DOI: 10.1371/journal.pone.0269736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 10/27/2022] [Indexed: 12/03/2022] Open
Abstract
The green peach aphid, Myzus persicae (Sulzer) is a generalist pest of various host plants, whose feeding preference and growth performance mainly depends on the quantity and quality of nutrients and defensive metabolites in host plants. Here, we studied the preference and performance of M. persicae on three major Brassicaceae vegetables in China and measured nutrient (amino acids) and defensive metabolites (glucosinolates) in these plants. We found that M. persicae preferred and performed better on Chinese cabbage than cabbage and radish, which may be due to the relatively higher concentration of amino acids and lower levels of indole glucosinolates in their leaves. The glucosinolates level in cabbage leaves was ten times higher than the other two plants, while the amino acid concentration in radish was only half of the cabbage or Chinese cabbage. The higher concentration of indole glucosinolates in cabbage and lower levels of amino acids in radish may account for the poorer preference and growth of M. persicae on these two plants. These results suggest that both amino acids and glucosinolates in plants may play important roles in the preference and performance of M. persicae, which provide new knowledge for the cultivation and breeding of Brassicaceae vegetables.
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Affiliation(s)
- Muhammad Afaq Ahmed
- Key Laboratory of Insect Ecology and Molecular Biology, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, Shandong, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Ning Ban
- Key Laboratory of Insect Ecology and Molecular Biology, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, Shandong, China
| | - Sarfaraz Hussain
- Key Laboratory of Agro-products Quality and Safety Control, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Raufa Batool
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yong-Jun Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Tong-Xian Liu
- Key Laboratory of Insect Ecology and Molecular Biology, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, Shandong, China
- * E-mail: (T-XL); (H-HC)
| | - He-He Cao
- Key Laboratory of Insect Ecology and Molecular Biology, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, Shandong, China
- * E-mail: (T-XL); (H-HC)
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Nalam VJ, Han J, Pitt WJ, Acharya SR, Nachappa P. Location, location, location: Feeding site affects aphid performance by altering access and quality of nutrients. PLoS One 2021; 16:e0245380. [PMID: 33539358 PMCID: PMC7861455 DOI: 10.1371/journal.pone.0245380] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 12/29/2020] [Indexed: 01/30/2023] Open
Abstract
Aphid feeding behavior and performance on a given host plant are influenced by the plants' physical and chemical traits, including structural characters such as trichomes and nutritional composition. In this study, we determined the feeding behavior and performance of soybean aphids (Aphis glycines) on the stem, the adaxial (upper), and the abaxial (lower) leaf surfaces during early vegetative growth of soybean plants. Using the electrical penetration graph technique, we found that aphids feeding on the stem took the longest time to begin probing. Once aphids began probing, the sieve elements were more conducive to feeding, as evidenced by less salivation on the stem than either leaf surface. In whole-plant assays, stems harbored higher aphid populations, and aphids had shorter development time on stems than the adaxial and the abaxial leaf surfaces. We compared trichome density and length on the stem, the adaxial, and the abaxial leaf surfaces to investigate whether plant trichomes affected aphid feeding and performance. There were higher density and longer trichomes on stems, which likely resulted in aphids taking a longer time to probe. Still a negative impact on aphid population growth was not observed. Analysis of phloem sap composition revealed that vascular sap-enriched exudates from stems had higher sugars and amino acids than exudates from leaves. In artificial diet feeding assays, the population of aphids reared on a diet supplemented with stem exudates was higher than on a diet supplemented with leaf petiole exudates which is in agreement with results of the whole-plant assays. In summary, our findings suggest that the performance of soybean aphids on a specific plant location is primarily driven by accessibility and the quality of phloem composition rather than structural traits.
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Affiliation(s)
- Vamsi J. Nalam
- Department of Agricultural Biology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Jinlong Han
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, North Carolina, United States of America
| | - William Jacob Pitt
- Department of Agricultural Biology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Shailesh Raj Acharya
- Department of Agricultural Biology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Punya Nachappa
- Department of Agricultural Biology, Colorado State University, Fort Collins, Colorado, United States of America
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Gyan NM, Yaakov B, Weinblum N, Singh A, Cna’ani A, Ben-Zeev S, Saranga Y, Tzin V. Variation Between Three Eragrostis tef Accessions in Defense Responses to Rhopalosiphum padi Aphid Infestation. FRONTIERS IN PLANT SCIENCE 2020; 11:598483. [PMID: 33363559 PMCID: PMC7752923 DOI: 10.3389/fpls.2020.598483] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 11/09/2020] [Indexed: 05/12/2023]
Abstract
Tef (Eragrostis tef), a staple crop that originated in the Horn of Africa, has been introduced to multiple countries over the last several decades. Crop cultivation in new geographic regions raises questions regarding the molecular basis for biotic stress responses. In this study, we aimed to classify the insect abundance on tef crop in Israel, and to elucidate its chemical and physical defense mechanisms in response to insect feeding. To discover the main pests of tef in the Mediterranean climate, we conducted an insect field survey on three selected accessions named RTC-144, RTC-405, and RTC-406, and discovered that the most abundant insect order is Hemiptera. We compared the differences in Rhopalosiphum padi (Hemiptera; Aphididae) aphid performance, preference, and feeding behavior between the three accessions. While the number of aphid progeny was lower on RTC-406 than on the other two, the aphid olfactory assay indicated that the aphids tended to be repelled from the RTC-144 accession. To highlight the variation in defense responses, we investigated the physical and chemical mechanisms. As a physical barrier, the density of non-granular trichomes was evaluated, in which a higher number of trichomes on the RTC-406 than on the other accessions was observed. This was negatively correlated with aphid performance. To determine chemical responses, the volatile and central metabolite profiles were measured upon aphid attack for 4 days. The volatile analysis exposed a rich and dynamic metabolic profile, and the central metabolism profile indicated that tef plants adjust their sugars and organic and amino acid levels. Overall, we found that the tef plants possess similar defense responses as other Poaceae family species, while the non-volatile deterrent compounds are yet to be characterized. A transcriptomic time-series analysis of a selected accession RTC-144 infested with aphids revealed a massive alteration of genes related to specialized metabolism that potentially synthesize non-volatile toxic compounds. This is the first report to reveal the variation in the defense mechanisms of tef plants. These findings can facilitate the discovery of insect-resistance genes leading to enhanced yield in tef and other cereal crops.
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Affiliation(s)
- Nathan M. Gyan
- The Albert Katz International School for Desert Studies, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer, Israel
| | - Beery Yaakov
- French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer, Israel
| | - Nati Weinblum
- The Albert Katz International School for Desert Studies, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer, Israel
| | - Anuradha Singh
- Jacob Blaustein Center for Scientific Cooperation, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer, Israel
| | - Alon Cna’ani
- Jacob Blaustein Center for Scientific Cooperation, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer, Israel
| | - Shiran Ben-Zeev
- The Robert H. Smith Faculty of Agriculture, Food & Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Yehoshua Saranga
- The Robert H. Smith Faculty of Agriculture, Food & Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Vered Tzin
- French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer, Israel
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The Probing Behavior Component of Disease Transmission in Insect-Transmitted Bacterial Plant Pathogens. INSECTS 2019; 10:insects10070212. [PMID: 31331012 PMCID: PMC6681269 DOI: 10.3390/insects10070212] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 07/08/2019] [Accepted: 07/15/2019] [Indexed: 11/16/2022]
Abstract
Insects can be effective vectors of plant diseases and this may result in billions of dollars in lost agricultural productivity. New, emerging or introduced diseases will continue to cause extensive damage in afflicted areas. Understanding how the vector acquires the pathogen and inoculates new hosts is critical in developing effective management strategies. Management may be an insecticide applied to kill the vector or a host plant resistance mechanism to make the host plant less suitable for the vector. In either case, the tactic must act before the insect performs the key behavior(s) resulting in either acquisition or transmission. This requires knowledge of the timing of behaviors the insect uses to probe the plant and commence ingestion. These behaviors are visualized using electropenetrography (EPG), wherein the plant and insect become part of an electrical circuit. With the tools to define specific steps in the probing process, we can understand the timing of acquisition and inoculation. With that understanding comes the potential for more relevant testing of management strategies, through insecticides or host plant resistance. The primary example will be Candidatus Liberibacter asiaticus transmitted by Diaphorina citri Kuwayama in the citrus agroecosystem, with additional examples used as appropriate.
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Nalam V, Louis J, Patel M, Shah J. Arabidopsis-Green Peach Aphid Interaction: Rearing the Insect, No-choice and Fecundity Assays, and Electrical Penetration Graph Technique to Study Insect Feeding Behavior. Bio Protoc 2018; 8:e2950. [PMID: 34395762 DOI: 10.21769/bioprotoc.2950] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 07/13/2018] [Accepted: 07/16/2018] [Indexed: 01/11/2023] Open
Abstract
Aphids constitute a large group of Hemipterans that use their slender stylets to tap into the sieve elements of plants from which they consume copious amounts of phloem sap, thus depriving the plant of photoassimilates. Some aphids also transmit viral diseases of plants. Myzus persicae Sülzer, commonly known as the green peach aphid (GPA), which is a polyphagous insect with a host range that covers 50 plant families, is considered amongst the top 3 insect pest of plants. The interaction between Arabidopsis thaliana and the GPA is utilized as a model pathosystem to study plant-aphid interaction. Here we describe the protocol used in our laboratories for rearing the GPA, and no-choice and fecundity bioassays to study GPA performance on Arabidopsis. In addition, we describe the procedure for the electrical penetration graph (EPG) technique to monitor feeding behavior of the GPA on Arabidopsis.
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Affiliation(s)
- Vamsi Nalam
- Department of Biology, Indiana-Purdue University-Fort Wayne, Fort Wayne, IN, USA
| | - Joe Louis
- Department of Entomology and Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Monika Patel
- Department of Biological Sciences and the BioDiscovery Institute, University of North Texas, Denton, TX, USA
| | - Jyoti Shah
- Department of Biological Sciences and the BioDiscovery Institute, University of North Texas, Denton, TX, USA
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Stolarz M, Dziubinska H. Osmotic and Salt Stresses Modulate Spontaneous and Glutamate-Induced Action Potentials and Distinguish between Growth and Circumnutation in Helianthus annuus Seedlings. FRONTIERS IN PLANT SCIENCE 2017; 8:1766. [PMID: 29093722 PMCID: PMC5651625 DOI: 10.3389/fpls.2017.01766] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 09/27/2017] [Indexed: 05/04/2023]
Abstract
Action potentials (APs), i.e., long-distance electrical signals, and circumnutations (CN), i.e., endogenous plant organ movements, are shaped by ion fluxes and content in excitable and motor tissues. The appearance of APs and CN as well as growth parameters in seedlings and 3-week old plants of Helianthus annuus treated with osmotic and salt stress (0-500 mOsm) were studied. Time-lapse photography and extracellular measurements of electrical potential changes were performed. The hypocotyl length was strongly reduced by the osmotic and salt stress. CN intensity declined due to the osmotic but not salt stress. The period of CN in mild salt stress was similar to the control (~164 min) and increased to more than 200 min in osmotic stress. In sunflower seedlings growing in a hydroponic medium, spontaneous APs (SAPs) propagating basipetally and acropetally with a velocity of 12-20 cm min-1 were observed. The number of SAPs increased 2-3 times (7-10 SAPs 24 h-1plant-1) in the mild salt stress (160 mOsm NaCl and KCl), compared to the control and strong salt stress (3-4 SAPs 24 h-1 plant-1 in the control and 300 mOsm KCl and NaCl). Glutamate-induced series of APs were inhibited in the strong salt stress-treated seedlings but not at the mild salt stress and osmotic stress. Additionally, in 3-week old plants, the injection of the hypo- or hyperosmotic solution at the base of the sunflower stem evoked series of APs (3-24 APs) transmitted along the stem. It has been shown that osmotic and salt stresses modulate differently hypocotyl growth and CN and have an effect on spontaneous and evoked APs in sunflower seedlings. We suggested that potassium, sodium, and chloride ions at stress concentrations in the nutrient medium modulate sunflower excitability and CN.
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Affiliation(s)
- Maria Stolarz
- Department of Biophysics, Institute of Biology and Biochemistry, Maria Curie-Skłodowska University, Lublin, Poland
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Vincent TR, Avramova M, Canham J, Higgins P, Bilkey N, Mugford ST, Pitino M, Toyota M, Gilroy S, Miller AJ, Hogenhout SA, Sanders D. Interplay of Plasma Membrane and Vacuolar Ion Channels, Together with BAK1, Elicits Rapid Cytosolic Calcium Elevations in Arabidopsis during Aphid Feeding. THE PLANT CELL 2017; 29:1460-1479. [PMID: 28559475 PMCID: PMC5502460 DOI: 10.1105/tpc.17.00136] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 05/22/2017] [Accepted: 05/29/2017] [Indexed: 05/17/2023]
Abstract
A transient rise in cytosolic calcium ion concentration is one of the main signals used by plants in perception of their environment. The role of calcium in the detection of abiotic stress is well documented; however, its role during biotic interactions remains unclear. Here, we use a fluorescent calcium biosensor (GCaMP3) in combination with the green peach aphid (Myzus persicae) as a tool to study Arabidopsis thaliana calcium dynamics in vivo and in real time during a live biotic interaction. We demonstrate rapid and highly localized plant calcium elevations around the feeding sites of M. persicae, and by monitoring aphid feeding behavior electrophysiologically, we demonstrate that these elevations correlate with aphid probing of epidermal and mesophyll cells. Furthermore, we dissect the molecular mechanisms involved, showing that interplay between the plant defense coreceptor BRASSINOSTEROID INSENSITIVE-ASSOCIATED KINASE1 (BAK1), the plasma membrane ion channels GLUTAMATE RECEPTOR-LIKE 3.3 and 3.6 (GLR3.3 and GLR3.6), and the vacuolar ion channel TWO-PORE CHANNEL1 (TPC1) mediate these calcium elevations. Consequently, we identify a link between plant perception of biotic threats by BAK1, cellular calcium entry mediated by GLRs, and intracellular calcium release by TPC1 during a biologically relevant interaction.
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Affiliation(s)
- Thomas R Vincent
- Department of Metabolic Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom
| | - Marieta Avramova
- Department of Metabolic Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom
| | - James Canham
- Department of Metabolic Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom
| | - Peter Higgins
- Department of Crop Genetics, John Innes Centre, Norwich NR4 7UH, United Kingdom
| | - Natasha Bilkey
- Department of Crop Genetics, John Innes Centre, Norwich NR4 7UH, United Kingdom
- Department of Botany, University of Wisconsin, Madison, Wisconsin 53706
| | - Sam T Mugford
- Department of Crop Genetics, John Innes Centre, Norwich NR4 7UH, United Kingdom
| | - Marco Pitino
- Department of Crop Genetics, John Innes Centre, Norwich NR4 7UH, United Kingdom
| | - Masatsugu Toyota
- Department of Botany, University of Wisconsin, Madison, Wisconsin 53706
- Department of Biochemistry and Molecular Biology, Saitama University, Sakura-ku, Saitama 338-8570, Japan
- Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology (PRESTO), Kawaguchi, Saitama 332-0012, Japan
| | - Simon Gilroy
- Department of Botany, University of Wisconsin, Madison, Wisconsin 53706
| | - Anthony J Miller
- Department of Metabolic Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom
| | - Saskia A Hogenhout
- Department of Crop Genetics, John Innes Centre, Norwich NR4 7UH, United Kingdom
| | - Dale Sanders
- Department of Metabolic Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom
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Stolarz M, Dziubinska H. Osmotic and Salt Stresses Modulate Spontaneous and Glutamate-Induced Action Potentials and Distinguish between Growth and Circumnutation in Helianthus annuus Seedlings. FRONTIERS IN PLANT SCIENCE 2017; 8:1766. [PMID: 29093722 DOI: 10.1007/s11738-017-2528-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 09/27/2017] [Indexed: 05/21/2023]
Abstract
Action potentials (APs), i.e., long-distance electrical signals, and circumnutations (CN), i.e., endogenous plant organ movements, are shaped by ion fluxes and content in excitable and motor tissues. The appearance of APs and CN as well as growth parameters in seedlings and 3-week old plants of Helianthus annuus treated with osmotic and salt stress (0-500 mOsm) were studied. Time-lapse photography and extracellular measurements of electrical potential changes were performed. The hypocotyl length was strongly reduced by the osmotic and salt stress. CN intensity declined due to the osmotic but not salt stress. The period of CN in mild salt stress was similar to the control (~164 min) and increased to more than 200 min in osmotic stress. In sunflower seedlings growing in a hydroponic medium, spontaneous APs (SAPs) propagating basipetally and acropetally with a velocity of 12-20 cm min-1 were observed. The number of SAPs increased 2-3 times (7-10 SAPs 24 h-1plant-1) in the mild salt stress (160 mOsm NaCl and KCl), compared to the control and strong salt stress (3-4 SAPs 24 h-1 plant-1 in the control and 300 mOsm KCl and NaCl). Glutamate-induced series of APs were inhibited in the strong salt stress-treated seedlings but not at the mild salt stress and osmotic stress. Additionally, in 3-week old plants, the injection of the hypo- or hyperosmotic solution at the base of the sunflower stem evoked series of APs (3-24 APs) transmitted along the stem. It has been shown that osmotic and salt stresses modulate differently hypocotyl growth and CN and have an effect on spontaneous and evoked APs in sunflower seedlings. We suggested that potassium, sodium, and chloride ions at stress concentrations in the nutrient medium modulate sunflower excitability and CN.
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Affiliation(s)
- Maria Stolarz
- Department of Biophysics, Institute of Biology and Biochemistry, Maria Curie-Skłodowska University, Lublin, Poland
| | - Halina Dziubinska
- Department of Biophysics, Institute of Biology and Biochemistry, Maria Curie-Skłodowska University, Lublin, Poland
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10
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Salvador-Recatalà V. New roles for the GLUTAMATE RECEPTOR-LIKE 3.3, 3.5, and 3.6 genes as on/off switches of wound-induced systemic electrical signals. PLANT SIGNALING & BEHAVIOR 2016; 11:e1161879. [PMID: 26966923 PMCID: PMC4883974 DOI: 10.1080/15592324.2016.1161879] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 02/26/2016] [Accepted: 03/01/2016] [Indexed: 05/19/2023]
Abstract
Wounding induces systemic potentials in Arabidopsis thaliana that can be abolished by concomitant suppression of the GLUTAMATE RECEPTOR-LIKE GLR3.3 and GLR3.6 genes. However, the roles of specific GLR channels to these potentials remain unclear. Here I applied the Electrical Penetration Graph (EPG) to study the contribution of three GLR channels to wound-induced, systemically propagated electrical potentials in Arabidopsis thaliana. In contrast to recordings made with conventional rigs for whole-plant electrophysiology, the EPG allows for the unambiguous distinction of the phloem-propagated action potential (AP) from the electrical activity outside of the phloem. The data reported here suggest that: (a) the transmission of wound-induced, phloem-propagated AP to neighbor leaves, requires expression of GLR3.3 or GLR3.6, whereas GLR3.5 prevents its transmission to non-neighbor leaves; (b) the generation of wound-induced electrical signals outside the phloem network depends on GLR3.6 expression; and (c) wound-induced systemic potentials initiated in the shoot are transmitted to the root in the adult plant, which suggests a role for these electrical signals in coordinating the plant defenses in the shoot and in the root. Here, I propose a model for wound-induced systemic electrical signals at the molecular, cellular and anatomical level. In this model, GLR3.3 and GLR3.6 function as on switches for the propagation of wound-induced potentials beyond the wounded leaf, while GLR3.5 functions as an off switch that prevents the propagation of wound-induced electrical potentials to distal, non-neighbor leaves.
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