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Abstract
Ethylene is a gaseous phytohormone and the first of this hormone class to be discovered. It is the simplest olefin gas and is biosynthesized by plants to regulate plant development, growth, and stress responses via a well-studied signaling pathway. One of the earliest reported responses to ethylene is the triple response. This response is common in eudicot seedlings grown in the dark and is characterized by reduced growth of the root and hypocotyl, an exaggerated apical hook, and a thickening of the hypocotyl. This proved a useful assay for genetic screens and enabled the identification of many components of the ethylene-signaling pathway. These components include a family of ethylene receptors in the membrane of the endoplasmic reticulum (ER); a protein kinase, called constitutive triple response 1 (CTR1); an ER-localized transmembrane protein of unknown biochemical activity, called ethylene-insensitive 2 (EIN2); and transcription factors such as EIN3, EIN3-like (EIL), and ethylene response factors (ERFs). These studies led to a linear model, according to which in the absence of ethylene, its cognate receptors signal to CTR1, which inhibits EIN2 and prevents downstream signaling. Ethylene acts as an inverse agonist by inhibiting its receptors, resulting in lower CTR1 activity, which releases EIN2 inhibition. EIN2 alters transcription and translation, leading to most ethylene responses. Although this canonical pathway is the predominant signaling cascade, alternative pathways also affect ethylene responses. This review summarizes our current understanding of ethylene signaling, including these alternative pathways, and discusses how ethylene signaling has been manipulated for agricultural and horticultural applications.
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Affiliation(s)
- Brad M Binder
- Department of Biochemistry and Cellular & Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
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Sami A, Riaz MW, Zhou X, Zhu Z, Zhou K. Alleviating dormancy in Brassica oleracea seeds using NO and KAR1 with ethylene biosynthetic pathway, ROS and antioxidant enzymes modifications. BMC PLANT BIOLOGY 2019; 19:577. [PMID: 31870301 PMCID: PMC6929364 DOI: 10.1186/s12870-019-2118-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 11/05/2019] [Indexed: 05/20/2023]
Abstract
BACKGROUND Seed dormancy is a prevailing condition in which seeds are unable to germinate, even under favorable environmental conditions. Harvested Brassica oleracea (Chinese cabbage) seeds are dormant and normally germinate (poorly) at 21 °C. This study investigated the connections between ethylene, nitric oxide (NO), and karrikin 1 (KAR1) in the dormancy release of secondary dormant Brassica oleracea seeds. RESULTS NO and KAR1 were found to induce seed germination, and stimulated the production of ethylene and 1-aminocyclopropane-1-carboxylic acid (ACC), and both ethylene biosynthesis enzyme ACC oxidase (ACO) [1] and ACC synthase (ACS) [2]. In the presence of NO and KAR1, ACS and ACO activity reached maximum levels after 36 and 48 h, respectively. The inhibitor of ethylene 2,5-norbornadiene (NBD) had an adverse effect on Brassica oleracea seed germination (inhibiting nearly 50% of germination) in the presence of NO and KAR1. The benefits from NO and KAR1 in the germination of secondary dormant Brassica oleracea seeds were also associated with a marked increase in reactive oxygen species (ROS) (H2O2 and O2˙-) and antioxidant enzyme activity at early germination stages. Catalase (CAT) and glutathione reductase (GR) activity increased 2 d and 4 d, respectively, after treatment, while no significant changes were observed in superoxide dismutase (SOD) activity under NO and KAR1 applications. An increase in H2O2 and O2˙- levels were observed during the entire incubation period, which increasing ethylene production in the presence of NO and KAR1. Abscisic acid (ABA) contents decreased and glutathione reductase (GA) contents increased in the presence of NO and KAR1. Gene expression studies were carried out with seven ethylene biosynthesis ACC synthases (ACS) genes, two ethylene receptors (ETR) genes and one ACO gene. Our results provide more evidence for the involvement of ethylene in inducing seed germination in the presence of NO and KAR1. Three out of seven ethylene biosynthesis genes (BOACS7, BOACS9 and BOACS11), two ethylene receptors (BOETR1 and BOETR2) and one ACO gene (BOACO1) were up-regulated in the presence of NO and KAR1. CONCLUSION Consequently, ACS activity, ACO activity and the expression of different ethylene related genes increased, modified the ROS level, antioxidant enzyme activity, and ethylene biosynthesis pathway and successfully removed (nearly 98%) of the seed dormancy of secondary dormant Brassica olereace seeds after 7 days of NO and KAR1 application.
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Affiliation(s)
- Abdul Sami
- College of Agronomy, Anhui Agricultural University, Hefei, 230036, China
| | | | - Xiangyu Zhou
- College of Agronomy, Anhui Agricultural University, Hefei, 230036, China
| | - Zonghe Zhu
- College of Agronomy, Anhui Agricultural University, Hefei, 230036, China
| | - Kejin Zhou
- College of Agronomy, Anhui Agricultural University, Hefei, 230036, China.
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Ruduś I, Cembrowska-Lech D, Jaworska A, Kępczyński J. Involvement of ethylene biosynthesis and perception during germination of dormant Avena fatua L. caryopses induced by KAR 1 or GA 3. PLANTA 2019; 249:719-738. [PMID: 30370496 DOI: 10.1007/s00425-018-3032-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Accepted: 10/19/2018] [Indexed: 05/07/2023]
Abstract
Germination of primary dormant wild oat caused by KAR1 or GA3 is associated with ACC accumulation and increased ethylene production shortly before radicle protrusion as a result of the non-transcriptional and transcriptional activation of ACS and ACO enzymes, respectively. Response to both compounds involves the modulation of ethylene sensitivity through ethylene receptor genes. Harvested Avena fatua caryopses are primary dormant and, therefore, germinated poorly at 20 °C. Karrikin 1 (KAR1), which action probably requires endogenous gibberellins (GAs), and gibberellin A3 (GA3) was found to induce dormant caryopses to germinate. The stimulatory effects were accompanied by the activation of the ethylene biosynthesis pathway and depended on undisturbed ethylene perception. KAR1 and GA3 promoted 1-aminocyclopropane-1-carboxylic acid (ACC) accumulation during coleorhizae emergence and ethylene production shortly prior to the radicle protrusion, which resulted from the enhanced activity of two ethylene biosynthesis enzymes, ACC synthase (ACS) and ACC oxidase (ACO). The inhibitor of ACS adversely affected beneficial impacts of both KAR1 and GA3 on A. fatua caryopses germination, while the inhibitor of ACO more efficiently impeded the GA3 effect. The inhibitors of ethylene action markedly lowered germination in response to KAR1 and GA3. Gene expression studies preceded by the identification of several genes related to ethylene biosynthesis (AfACS6, AfACO1, and AfACO5) and perception (AfERS1b, AfERS1c, AfERS2, AfETR2, AfETR3, and AfETR4) provided further evidence for the engagement of ethylene in KAR1 and GA3 induced germination of A. fatua caryopses. Both AfACO1 and AfACO5 were upregulated, whereas AfACS6 remained unaffected by the treatment. This suggests the existence of different regulatory mechanisms of enzymatic activity, transcriptional for ACO and non-transcriptional for ACS. During imbibition in water, AfERS1b was stronger expressed than other receptor genes. In the presence of KAR1 or GA3, the expression of AfETR3 was substantially induced. Differential expression of ethylene receptor genes implies the modulation of caryopses sensitivity adjusted to ethylene availability and suggests the functional diversification of individual receptors.
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Affiliation(s)
- Izabela Ruduś
- Department of Plant Physiology and Genetic Engineering, Faculty of Biology, University of Szczecin, Wąska 13, 71-415, Szczecin, Poland
| | - Danuta Cembrowska-Lech
- Department of Plant Physiology and Genetic Engineering, Faculty of Biology, University of Szczecin, Wąska 13, 71-415, Szczecin, Poland
| | - Anna Jaworska
- Department of Plant Physiology and Genetic Engineering, Faculty of Biology, University of Szczecin, Wąska 13, 71-415, Szczecin, Poland
| | - Jan Kępczyński
- Department of Plant Physiology and Genetic Engineering, Faculty of Biology, University of Szczecin, Wąska 13, 71-415, Szczecin, Poland.
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Chen Y, Rofidal V, Hem S, Gil J, Nosarzewska J, Berger N, Demolombe V, Bouzayen M, Azhar BJ, Shakeel SN, Schaller GE, Binder BM, Santoni V, Chervin C. Targeted Proteomics Allows Quantification of Ethylene Receptors and Reveals SlETR3 Accumulation in Never-Ripe Tomatoes. FRONTIERS IN PLANT SCIENCE 2019; 10:1054. [PMID: 31555314 PMCID: PMC6727826 DOI: 10.3389/fpls.2019.01054] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 07/29/2019] [Indexed: 05/04/2023]
Abstract
Ethylene regulates fruit ripening and several plant functions (germination, plant growth, plant-microbe interactions). Protein quantification of ethylene receptors (ETRs) is essential to study their functions, but is impaired by low resolution tools such as antibodies that are mostly nonspecific, or the lack of sensitivity of shotgun proteomic approaches. We developed a targeted proteomic method, to quantify low-abundance proteins such as ETRs, and coupled this to mRNAs analyses, in two tomato lines: Wild Type (WT) and Never-Ripe (NR) which is insensitive to ethylene because of a gain-of-function mutation in ETR3. We obtained mRNA and protein abundance profiles for each ETR over the fruit development period. Despite a limiting number of replicates, we propose Pearson correlations between mRNA and protein profiles as interesting indicators to discriminate the two genotypes: such correlations are mostly positive in the WT and are affected by the NR mutation. The influence of putative post-transcriptional and post-translational changes are discussed. In NR fruits, the observed accumulation of the mutated ETR3 protein between ripening stages (Mature Green and Breaker + 8 days) may be a cause of NR tomatoes to stay orange. The label-free quantitative proteomics analysis of membrane proteins, concomitant to Parallel Reaction Monitoring analysis, may be a resource to study changes over tomato fruit development. These results could lead to studies about ETR subfunctions and interconnections over fruit development. Variations of RNA-protein correlations may open new fields of research in ETR regulation. Finally, similar approaches may be developed to study ETRs in whole plant development and plant-microorganism interactions.
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Affiliation(s)
- Yi Chen
- GBF, Université de Toulouse, INRA, Toulouse, France
| | - Valérie Rofidal
- BPMP, CNRS, INRA, Montpellier SupAgro, Université de Montpellier, Montpellier, France
| | - Sonia Hem
- BPMP, CNRS, INRA, Montpellier SupAgro, Université de Montpellier, Montpellier, France
| | - Julie Gil
- GBF, Université de Toulouse, INRA, Toulouse, France
- BPMP, CNRS, INRA, Montpellier SupAgro, Université de Montpellier, Montpellier, France
| | | | - Nathalie Berger
- BPMP, CNRS, INRA, Montpellier SupAgro, Université de Montpellier, Montpellier, France
| | - Vincent Demolombe
- BPMP, CNRS, INRA, Montpellier SupAgro, Université de Montpellier, Montpellier, France
| | | | - Beenish J. Azhar
- Department of Biochemistry, Quaid-i-azam University, Islamabad, Pakistan
- Department of Biological Sciences, Dartmouth College, Hanover, NH, United States
| | - Samina N. Shakeel
- Department of Biochemistry, Quaid-i-azam University, Islamabad, Pakistan
- Department of Biological Sciences, Dartmouth College, Hanover, NH, United States
| | - G. Eric Schaller
- Department of Biological Sciences, Dartmouth College, Hanover, NH, United States
| | - Brad M. Binder
- Department of Biochemistry, Cellular, and Molecular Biology, University of Tennessee, Knoxville, TN, United States
| | - Véronique Santoni
- BPMP, CNRS, INRA, Montpellier SupAgro, Université de Montpellier, Montpellier, France
- *Correspondence: Véronique Santoni, ; Christian Chervin,
| | - Christian Chervin
- GBF, Université de Toulouse, INRA, Toulouse, France
- *Correspondence: Véronique Santoni, ; Christian Chervin,
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Ciura J, Kruk J. Phytohormones as targets for improving plant productivity and stress tolerance. JOURNAL OF PLANT PHYSIOLOGY 2018; 229:32-40. [PMID: 30031159 DOI: 10.1016/j.jplph.2018.06.013] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 05/15/2018] [Accepted: 06/11/2018] [Indexed: 05/18/2023]
Abstract
In this review, we summarize the results of experiments that lead to altered levels of phytohormones in transgenic plants to improve plant productivity. The available data indicate that manipulating the level of phytohormones might also be a promising way to enhance the environmental stress tolerance of crop plants. In the regulation of the level of phytohormones, both biosynthesis and their catabolism pathways can be targeted for engineering purposes. Moreover, the signaling pathways of phytohormones should explored in this respect. In genetic modifications, conditional promoters must be developed to avoid undesired effects on growth. In order to find a practical application, the effects of genetic modifications should be further verified under field conditions and over a longer time scale.
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Affiliation(s)
- Joanna Ciura
- Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland.
| | - Jerzy Kruk
- Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland.
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Takahashi-Asami M, Shichijo C, Tsurumi S, Hashimoto T. Ethylene Is Not Responsible for Phytochrome-Mediated Apical Hook Exaggeration in Tomato. FRONTIERS IN PLANT SCIENCE 2016; 7:1756. [PMID: 27933077 PMCID: PMC5120132 DOI: 10.3389/fpls.2016.01756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 11/07/2016] [Indexed: 06/06/2023]
Abstract
The apical hook of tomato seedlings is exaggerated by phytochrome actions, while in other species such as bean, pea and Arabidopsis, the hook is exaggerated by ethylene and opens by phytochrome actions. The present study was aimed to clarify mainly whether ethylene is responsible for the phytochrome-mediated hook exaggeration of tomato seedlings. Dark-grown 5-day-old seedlings were subjected to various ways of ethylene application in the dark as well as under the actions of red (R) or far-red light (FR). The ethylene emitted by seedlings was also quantified relative to hook exaggeration. The results show: Ambient ethylene, up-to about 1.0 μL L-1, suppressed (opened) the hooks formed in the dark as well as the ones exaggerated by R or FR, while at 3.0-10 μL L-1 it enhanced (closed) the hook only slightly as compared with the most-suppressed level at about 1.0 μL L-1. Treatment with 1-aminocyclopropane-1-carboxylic acid (ACC), the immediate precursor of ethylene biosynthesis, did not enhance the hook, only mimicking the suppressive effects of ambient ethylene. The biosynthesis inhibitor, CoCl2 or aminoethoxyvinylglycine, enhanced hook curvature, and the enhancement was canceled by supplement of ethylene below 1.0 μL L-1. Auxin transport inhibitor, N-1-naphthylphthalamic acid, by contrast, suppressed curvature markedly without altering ethylene emission. The effects of the above-stated treatments did not differentiate qualitatively among the R-, FR-irradiated seedlings and dark control so as to explain phytochrome-mediated hook exaggeration. In addition, ethylene emission by seedlings was affected neither by R nor FR at such fluences as to cause hook exaggeration. In conclusion, (1) ethylene suppresses not only the light-exaggerated hook, but also the dark-formed one; (2) ethylene emission is not affected by R or FR, and also not correlated with the hook exaggerations; thus ethylene is not responsible for the hook exaggeration in tomato; and (3) auxin is essential for the maintenance and development of the hook in tomato as is the case in other species lacking phytochrome-mediated hook exaggeration. A possible mechanism of phytochrome action for hook exaggeration is discussed.
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Affiliation(s)
- Miki Takahashi-Asami
- Plant Physiology, Department of Biology, Graduate School of Science, Kobe UniversityKobe, Japan
| | - Chizuko Shichijo
- Plant Physiology, Department of Biology, Graduate School of Science, Kobe UniversityKobe, Japan
| | - Seiji Tsurumi
- Center for Supports to Research and Education Activities, Kobe UniversityKobe, Japan
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Abstract
Ethylene is a hormone involved in numerous aspects of growth, development, and responses to biotic and abiotic stresses in plants. Ethylene is perceived through its binding to endoplasmic reticulum-localized receptors that function as negative regulators of ethylene signaling in the absence of the hormone. In Arabidopsis thaliana, five structurally and functionally different ethylene receptors are present. These differ in their primary sequence, in the domains present, and in the type of kinase activity exhibited, which may suggest functional differences among the receptors. Whereas ethylene receptors functionally overlap to suppress ethylene signaling, certain other responses are controlled by specific receptors. In this review, I examine the nature of these receptor differences, how the evolution of the ethylene receptor gene family may provide insight into their differences, and how expression of receptors or their accessory proteins may underlie receptor-specific responses.
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Wang H, Stier G, Lin J, Liu G, Zhang Z, Chang Y, Reid MS, Jiang CZ. Transcriptome changes associated with delayed flower senescence on transgenic petunia by inducing expression of etr1-1, a mutant ethylene receptor. PLoS One 2013; 8:e65800. [PMID: 23874385 PMCID: PMC3706537 DOI: 10.1371/journal.pone.0065800] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2013] [Accepted: 04/26/2013] [Indexed: 11/18/2022] Open
Abstract
Flowers of ethylene-sensitive ornamental plants transformed with ethylene-insensitive 1-1(etr1-1), a mutant ethylene receptor first isolated from Arabidopsis, are known to have longer shelf lives. We have generated petunia plants in which the etr1-1 gene was over-expressed under the control of a chemically-inducible promoter, which would allow expression of etr1-1 to be initiated at the desired time and stage of development. Here, we showed that transgenic plants grew and developed normally without a chemical inducer. Semi-quantitative RT-PCR demonstrated that the abundance of transcripts of Arabidopsis etr1-1 gene was substantially induced in flowers with 30 μM dexamethasone (DEX). Consequently, t he life of the flowers was almost doubled and the peak of ethylene production was delayed. We compared gene expression changes of petals with DEX to those without DEX at 24 h and 48 h by microarray. Our results indicated that transcripts of many putative genes encoding transcription factors were down-regulated by etr1-1 induced expression at the early stage. In addition, putative genes involved in gibberellin biosynthesis, response to jasmonic acid/gibberellins stimulus, cell wall modification, ethylene biosynthesis, and cell death were down-regulated associating with etr1-1 induced expression. We investigated time-course gene expression profiles and found two profiles which displayed totally opposite expression patterns under these two treatments. In these profiles, 'the regulation of transcription' was predominant in GO categories. Taking all results together, we concluded those transcription factors down-regulated at early stage might exert a major role in regulating the senescence process which were consequently characterized by cell wall modification and cell death.
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Affiliation(s)
- Hong Wang
- Institute of Horticulture, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- Department of Plant Sciences, University of California Davis, Davis, California, United States of America
| | - Genevieve Stier
- Department of Plant Sciences, University of California Davis, Davis, California, United States of America
| | - Jing Lin
- Institute of Horticulture, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Gang Liu
- College of Horticulture, Nanjing Agricultural University, Nanjing, China
| | - Zhen Zhang
- College of Horticulture, Nanjing Agricultural University, Nanjing, China
| | - Youhong Chang
- Institute of Horticulture, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- * E-mail: (YHC); (MSR); (CZJ)
| | - Michael S. Reid
- Department of Plant Sciences, University of California Davis, Davis, California, United States of America
- * E-mail: (YHC); (MSR); (CZJ)
| | - Cai-Zhong Jiang
- Crops Pathology and Genetics Research Unit, United States Department of Agriculture, Agricultural Research Service, Davis, California, United States of America
- * E-mail: (YHC); (MSR); (CZJ)
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Wang H, Liu G, Li C, Powell ALT, Reid MS, Zhang Z, Jiang CZ. Defence responses regulated by jasmonate and delayed senescence caused by ethylene receptor mutation contribute to the tolerance of petunia to Botrytis cinerea. MOLECULAR PLANT PATHOLOGY 2013; 14:453-69. [PMID: 23437935 PMCID: PMC6638649 DOI: 10.1111/mpp.12017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Ethylene and jasmonate (JA) have powerful effects when plants are challenged by pathogens. The inducible promoter-regulated expression of the Arabidopsis ethylene receptor mutant ethylene-insensitive1-1 (etr1-1) causes ethylene insensitivity in petunia. To investigate the molecular mechanisms involved in transgenic petunia responses to Botrytis cinerea related to the ethylene and JA pathways, etr1-1-expressing petunia plants were inoculated with Botrytis cinerea. The induced expression of etr1-1 by a chemical inducer dexamethasone resulted in retarded senescence and reduced disease symptoms on detached leaves and flowers or intact plants. The extent of decreased disease symptoms correlated positively with etr1-1 expression. The JA pathway, independent of the ethylene pathway, activated petunia ethylene response factor (PhERF) expression and consequent defence-related gene expression. These results demonstrate that ethylene induced by biotic stress influences senescence, and that JA in combination with delayed senescence by etr1-1 expression alters tolerance to pathogens.
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Affiliation(s)
- Hong Wang
- College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
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Yi P, Dong L, Tan M, Wang W, Tang X, Yang F, Zhang G. Clinical application of a revised screw technique via the C1 posterior arch and lateral mass in the pediatric population. Pediatr Neurosurg 2013; 49:159-65. [PMID: 24603124 DOI: 10.1159/000358807] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Accepted: 01/16/2014] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Pediatric patients with insufficient height (≤4 mm) of the C1 posterior arch may restrict atlas screw placement via the posterior arch and lateral mass (PALM). For these patients, we modified this technique, called the 'pedicle exposure technique' (PET). We aimed to analyze the clinical feasibility and safety of the PET in the pediatric population. METHODS Twenty pediatric patients with atlantoaxial instability (AAI) were enrolled in this study. The average C1 posterior arch was 3.1 (2.5-3.9) mm on CT scan. All patients underwent the C1 PET and C2 pedicle screw fixation. The imaging was performed to evaluate the accuracy of screw placement and bony fusion. RESULTS Forty screws were inserted via C1 PALM using the PET. Venous plexus bleeding occurred in 1 patient and the internal wall of the C1 lateral mass was perforated in 1 patient. There were no perioperative neurological deficits or vertebral artery injury. Follow-up was performed in all 20 cases over a period ranging from 6 to 80 months. Bony union was seen within 3-6 months. At the final follow-up visit, 14 patients had experienced an improvement, while 6 had complete resolution of their neck pain. Myelopathy symptoms were improved in 9 patients with spinal compression. CONCLUSION The PET is an effective alternative for pediatric AAI when the height of the C1 posterior arch is <4 mm. Because of the higher screw entry point through the C1 posterior arch, there is effective biomechanical stability and less irritation of the venous plexus and C2 nerve root.
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Affiliation(s)
- Ping Yi
- Department of Orthopedic Surgery, China-Japan Friendship Hospital, Beijing, People's Republic of China
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Agarwal G, Choudhary D, Singh VP, Arora A. Role of ethylene receptors during senescence and ripening in horticultural crops. PLANT SIGNALING & BEHAVIOR 2012; 7:827-46. [PMID: 22751331 PMCID: PMC3583974 DOI: 10.4161/psb.20321] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The past two decades have been rewarding in terms of deciphering the ethylene signal transduction and functional validation of the ethylene receptor and downstream genes involved in the cascade. Our knowledge of ethylene receptors and its signal transduction pathway provides us a robust platform where we can think of manipulating and regulating ethylene sensitivity by the use of genetic engineering and making transgenic. This review focuses on ethylene perception, receptor mediated regulation of ethylene biosynthesis, role of ethylene receptors in flower senescence, fruit ripening and other effects induced by ethylene. The expression behavior of the receptor and downstream molecules in climacteric and non climacteric crops is also elaborated upon. Possible strategies and recent advances in altering the ethylene sensitivity of plants using ethylene receptor genes in an attempt to modulate the regulation and sensitivity to ethylene have also been discussed. Not only will these transgenic plants be a boon to post-harvest physiology and crop improvement but, it will also help us in discovering the mechanism of regulation of ethylene sensitivity.
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Affiliation(s)
| | | | - Virendra P. Singh
- Division of Plant Physiology; Indian Agricultural Research Institute; PUSA Campus; New Delhi, India
| | - Ajay Arora
- Division of Plant Physiology; Indian Agricultural Research Institute; PUSA Campus; New Delhi, India
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Okabe Y, Asamizu E, Ariizumi T, Shirasawa K, Tabata S, Ezura H. Availability of Micro-Tom mutant library combined with TILLING in molecular breeding of tomato fruit shelf-life. BREEDING SCIENCE 2012; 62:202-8. [PMID: 23136532 PMCID: PMC3405968 DOI: 10.1270/jsbbs.62.202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Accepted: 02/05/2012] [Indexed: 05/04/2023]
Abstract
Novel mutant alleles of an ethylene receptor Solanum lycopersicum ETHYLENE RESPONSE1 (SlETR1) gene, Sletr1-1 and Sletr1-2, were isolated from the Micro-Tom mutant library by TILLING in our previous study. They displayed different levels of impaired fruit ripening phenotype, suggesting that these alleles could be a valuable breeding material for improving shelf life of tomato fruit. To conduct practical use of the Sletr1 alleles in tomato breeding, genetic complementation analysis by transformation of genes carrying each allele is required. In this study, we generated and characterized transgenic lines over-expressing Sletr1-1 and Sletr1-2. All transgenic lines displayed ethylene insensitive phenotype and ripening inhibition, indicating that Sletr1-1 and Sletr1-2 associate with the ethylene insensitive phenotype. The level of ethylene sensitivity in the seedling was different between Sletr1-1 and Sletr1-2 transgenic lines, whereas no apparent difference was observed in fruit ripening phenotype. These results suggested that it is difficult to fine-tune the extent of ripening by transgenic approach even if the weaker allele (Sletr1-2) was used. Our present and previous studies indicate that the Micro-Tom mutant library combined with TILLING could be an efficient tool for exploring genetic variations of important agronomic traits in tomato breeding.
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Affiliation(s)
- Yoshihiro Okabe
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Erika Asamizu
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Tohru Ariizumi
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Kenta Shirasawa
- Kazusa DNA Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu, Chiba 292-0818, Japan
| | - Satoshi Tabata
- Kazusa DNA Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu, Chiba 292-0818, Japan
| | - Hiroshi Ezura
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
- Corresponding author (e-mail: )
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Wilkinson S, Kudoyarova GR, Veselov DS, Arkhipova TN, Davies WJ. Plant hormone interactions: innovative targets for crop breeding and management. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:3499-509. [PMID: 22641615 DOI: 10.1093/jxb/ers148] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Here we highlight how both the root and shoot environment impact on whole plant hormone balance, particularly under stresses such as soil drying, and relate hormone ratios and relative abundances to processes influencing plant performance and yield under both mild and more severe stress. We discuss evidence (i) that abscisic acid (ABA) and ethylene act antagonistically on grain-filling rate amongst other yield-impacting processes; (ii) that ABA's effectiveness as an agent of stomatal closure can be modulated by coincident ethylene or cytokinin accumulation; and (iii) that enhanced cytokinin production can increase growth and yield by improving foliar stay-green indices under stress, and by improving processes that impact grain-filling and number, and that this can be the result of altered relative abundances of cytokinin and ABA (and other hormones). We describe evidence and novel processes whereby these phenomena are/could be amenable to manipulation through genetic and management routes, such that plant performance and yield can be improved. We explore the possibility that a range of ABA-ethylene and ABA-cytokinin relative abundances could represent targets for breeding/managing for yield resilience under a spectrum of stress levels between severe and mild, and could circumvent some of the pitfalls so far encountered in the massive research effort towards breeding for increases in the complex trait of yield.
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Affiliation(s)
- Sally Wilkinson
- Lancaster Environment Centre, Lancaster University, Lancaster, UK.
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