1
|
Wang L, Zou Y, Kaw HY, Wang G, Sun H, Cai L, Li C, Meng LY, Li D. Recent developments and emerging trends of mass spectrometric methods in plant hormone analysis: a review. PLANT METHODS 2020; 16:54. [PMID: 32322293 PMCID: PMC7161177 DOI: 10.1186/s13007-020-00595-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Accepted: 04/04/2020] [Indexed: 05/18/2023]
Abstract
Plant hormones are naturally occurring small molecule compounds which are present at trace amounts in plant. They play a pivotal role in the regulation of plant growth. The biological activity of plant hormones depends on their concentrations in the plant, thus, accurate determination of plant hormone is paramount. However, the complex plant matrix, wide polarity range and low concentration of plant hormones are the main hindrances to effective analyses of plant hormone even when state-of-the-art analytical techniques are employed. These factors substantially influence the accuracy of analytical results. So far, significant progress has been realized in the analysis of plant hormones, particularly in sample pretreatment techniques and mass spectrometric methods. This review describes the classic extraction and modern microextraction techniques used to analyze plant hormone. Advancements in solid phase microextraction (SPME) methods have been driven by the ever-increasing requirement for dynamic and in vivo identification of the spatial distribution of plant hormones in real-life plant samples, which would contribute greatly to the burgeoning field of plant hormone investigation. In this review, we describe advances in various aspects of mass spectrometry methods. Many fragmentation patterns are analyzed to provide the theoretical basis for the establishment of a mass spectral database for the analysis of plant hormones. We hope to provide a technical guide for further discovery of new plant hormones. More than 140 research studies on plant hormone published in the past decade are reviewed, with a particular emphasis on the recent advances in mass spectrometry and sample pretreatment techniques in the analysis of plant hormone. The potential progress for further research in plant hormones analysis is also highlighted.
Collapse
Affiliation(s)
- Liyuan Wang
- Department of Chemistry, MOE Key Laboratory of Biological Resources of the Changbai Mountain and Functional Molecules, Yanbian University, Park Road 977, Yanji, 133002 China
| | - Yilin Zou
- Department of Chemistry, MOE Key Laboratory of Biological Resources of the Changbai Mountain and Functional Molecules, Yanbian University, Park Road 977, Yanji, 133002 China
| | - Han Yeong Kaw
- Department of Chemistry, MOE Key Laboratory of Biological Resources of the Changbai Mountain and Functional Molecules, Yanbian University, Park Road 977, Yanji, 133002 China
| | - Gang Wang
- Department of Chemistry, MOE Key Laboratory of Biological Resources of the Changbai Mountain and Functional Molecules, Yanbian University, Park Road 977, Yanji, 133002 China
| | - Huaze Sun
- Department of Chemistry, MOE Key Laboratory of Biological Resources of the Changbai Mountain and Functional Molecules, Yanbian University, Park Road 977, Yanji, 133002 China
| | - Long Cai
- Department of Chemistry, MOE Key Laboratory of Biological Resources of the Changbai Mountain and Functional Molecules, Yanbian University, Park Road 977, Yanji, 133002 China
| | - Chengyu Li
- State Key Laboratory of Application of Rare Earth Resources, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022 China
| | - Long-Yue Meng
- Department of Chemistry, MOE Key Laboratory of Biological Resources of the Changbai Mountain and Functional Molecules, Yanbian University, Park Road 977, Yanji, 133002 China
- Department of Environmental Science, Yanbian University, Yanji, 133002 China
| | - Donghao Li
- Department of Chemistry, MOE Key Laboratory of Biological Resources of the Changbai Mountain and Functional Molecules, Yanbian University, Park Road 977, Yanji, 133002 China
| |
Collapse
|
2
|
Bushey DF, Bannon GA, Delaney BF, Graser G, Hefford M, Jiang X, Lee TC, Madduri KM, Pariza M, Privalle LS, Ranjan R, Saab-Rincon G, Schafer BW, Thelen JJ, Zhang JX, Harper MS. Characteristics and safety assessment of intractable proteins in genetically modified crops. Regul Toxicol Pharmacol 2014; 69:154-70. [DOI: 10.1016/j.yrtph.2014.03.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 03/07/2014] [Accepted: 03/15/2014] [Indexed: 10/25/2022]
|
3
|
Ryazantsev DY, Rogozhin EA, Dimitrieva TV, Drobyazina PE, Khadeeva NV, Egorov TA, Grishin EV, Zavriev SK. A novel hairpin-like antimicrobial peptide from barnyard grass (Echinochloa crusgalli L.) seeds: Structure-functional and molecular-genetics characterization. Biochimie 2013; 99:63-70. [PMID: 24275143 DOI: 10.1016/j.biochi.2013.11.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Accepted: 11/08/2013] [Indexed: 11/26/2022]
Abstract
A novel plant hairpin-like defense polypeptide named EcAMP3 was isolated from latent barnyard grass (Echinochloa crusgalli L.) seeds. The native peptide and its recombinant analogue were characterized. EcAMP3 displays antifungal and antibacterial activity in vitro. The gene family encoding EcAMPs precursor protein was also characterized; the genes and pseudogenes of this family show 97-100% homology. Every member of EcAMPs precursor family contains seven identical cysteine motifs: C1XXXC2(11-13)C3XXXC4. One of those motifs corresponds to the isolated peptide. EcAMP3 is the first member of the plant hairpin-like peptide family that inhibits the growth of phytopathogenic bacteria. Obtained results can explain the nature of the complex resistance of barnyard grass to a variety of pathogenic microorganisms.
Collapse
Affiliation(s)
- Dmitry Yu Ryazantsev
- Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russian Federation.
| | - Eugene A Rogozhin
- Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russian Federation.
| | - Tatiana V Dimitrieva
- Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russian Federation.
| | - Polina E Drobyazina
- Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russian Federation; All-Russian Research Institute of Biotechnology, Russian Academy of Agricultural Sciences, ul. Timiryazevskaya 42, 127550 Moscow, Russian Federation.
| | - Natalia V Khadeeva
- Vavilov Institute of General Genetics, Russian Academy of Sciences, ul. Gubkina 3, 117809 Moscow, Russian Federation.
| | - Tsezi A Egorov
- Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russian Federation
| | - Eugene V Grishin
- Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russian Federation.
| | - Sergey K Zavriev
- Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russian Federation.
| |
Collapse
|
4
|
Hahn A, Kilian J, Mohrholz A, Ladwig F, Peschke F, Dautel R, Harter K, Berendzen KW, Wanke D. Plant core environmental stress response genes are systemically coordinated during abiotic stresses. Int J Mol Sci 2013; 14:7617-41. [PMID: 23567274 PMCID: PMC3645707 DOI: 10.3390/ijms14047617] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 03/28/2013] [Accepted: 03/29/2013] [Indexed: 11/16/2022] Open
Abstract
Studying plant stress responses is an important issue in a world threatened by global warming. Unfortunately, comparative analyses are hampered by varying experimental setups. In contrast, the AtGenExpress abiotic stress experiment displays intercomparability. Importantly, six of the nine stresses (wounding, genotoxic, oxidative, UV-B light, osmotic and salt) can be examined for their capacity to generate systemic signals between the shoot and root, which might be essential to regain homeostasis in Arabidopsis thaliana. We classified the systemic responses into two groups: genes that are regulated in the non-treated tissue only are defined as type I responsive and, accordingly, genes that react in both tissues are termed type II responsive. Analysis of type I and II systemic responses suggest distinct functionalities, but also significant overlap between different stresses. Comparison with salicylic acid (SA) and methyl-jasmonate (MeJA) responsive genes implies that MeJA is involved in the systemic stress response. Certain genes are predominantly responding in only one of the categories, e.g., WRKY genes respond mainly non-systemically. Instead, genes of the plant core environmental stress response (PCESR), e.g., ZAT10, ZAT12, ERD9 or MES9, are part of different response types. Moreover, several PCESR genes switch between the categories in a stress-specific manner.
Collapse
Affiliation(s)
| | | | - Anne Mohrholz
- Center for Plant Molecular Biology (ZMBP), Plant Physiology, University of Tübingen, Auf der Morgenstelle 1, Tübingen 72076, Germany; E-Mails: (A.H.); (J.K.); (A.M.); (F.L.); (F.P.); (R.D.); (K.H.); (K.W.B.)
| | - Friederike Ladwig
- Center for Plant Molecular Biology (ZMBP), Plant Physiology, University of Tübingen, Auf der Morgenstelle 1, Tübingen 72076, Germany; E-Mails: (A.H.); (J.K.); (A.M.); (F.L.); (F.P.); (R.D.); (K.H.); (K.W.B.)
| | - Florian Peschke
- Center for Plant Molecular Biology (ZMBP), Plant Physiology, University of Tübingen, Auf der Morgenstelle 1, Tübingen 72076, Germany; E-Mails: (A.H.); (J.K.); (A.M.); (F.L.); (F.P.); (R.D.); (K.H.); (K.W.B.)
| | - Rebecca Dautel
- Center for Plant Molecular Biology (ZMBP), Plant Physiology, University of Tübingen, Auf der Morgenstelle 1, Tübingen 72076, Germany; E-Mails: (A.H.); (J.K.); (A.M.); (F.L.); (F.P.); (R.D.); (K.H.); (K.W.B.)
| | - Klaus Harter
- Center for Plant Molecular Biology (ZMBP), Plant Physiology, University of Tübingen, Auf der Morgenstelle 1, Tübingen 72076, Germany; E-Mails: (A.H.); (J.K.); (A.M.); (F.L.); (F.P.); (R.D.); (K.H.); (K.W.B.)
| | - Kenneth W. Berendzen
- Center for Plant Molecular Biology (ZMBP), Plant Physiology, University of Tübingen, Auf der Morgenstelle 1, Tübingen 72076, Germany; E-Mails: (A.H.); (J.K.); (A.M.); (F.L.); (F.P.); (R.D.); (K.H.); (K.W.B.)
| | - Dierk Wanke
- Center for Plant Molecular Biology (ZMBP), Plant Physiology, University of Tübingen, Auf der Morgenstelle 1, Tübingen 72076, Germany; E-Mails: (A.H.); (J.K.); (A.M.); (F.L.); (F.P.); (R.D.); (K.H.); (K.W.B.)
| |
Collapse
|
5
|
Rogozhin EA, Ryazantsev DY, Grishin EV, Egorov TA, Zavriev SK. Defense peptides from barnyard grass (Echinochloa crusgalli L.) seeds. Peptides 2012; 38:33-40. [PMID: 22940285 DOI: 10.1016/j.peptides.2012.08.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Revised: 08/11/2012] [Accepted: 08/13/2012] [Indexed: 11/29/2022]
Abstract
A number of defense polypeptides from latent seeds of weed cereal barnyard grass (Echinochloa crusgalli L.) has been isolated and characterized using an acidic extraction and high performance liquid chromatography methods in combination with MALDI-TOF mass spectrometry and Edman sequencing. Members of three antimicrobial peptide families and two protease inhibitor families were found to be localized in barnyard grass seeds. Their biological activity concerning to Gram-Positive and Gram-Negative phytopathogenic bacteria, as well as oomycete Phytophthora infestans, has been investigated. Diversity of barnyard grass defense peptides is a significant factor that provides a resistance of E. crusgalli seeds to germination and latent phases.
Collapse
Affiliation(s)
- E A Rogozhin
- Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russian Federation.
| | | | | | | | | |
Collapse
|
6
|
Gao X, Guo Y. CLE peptides in plants: proteolytic processing, structure-activity relationship, and ligand-receptor interaction. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2012; 54:738-45. [PMID: 22925455 DOI: 10.1111/j.1744-7909.2012.01154.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Ligand-receptor signaling initiated by the CLAVATA3/ ENDOSPERM SURROUNDING REGION (CLE) family peptides is critical in regulating cell division and differentiation in meristematic tissues in plants. Biologically active CLE peptides are released from precursor proteins via proteolytic processing. The mature form of CLE ligands consists of 12-13 amino acids with several post-translational modifications. This review summarizes recent progress toward understanding the proteolytic activities that cleave precursor proteins to release CLE peptides, the molecular structure and function of mature CLE ligands, and interactions between CLE ligands and corresponding leucine-rich repeat (LRR) receptor-like kinases (RLKs).
Collapse
Affiliation(s)
- Xiaoming Gao
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences/Key Laboratory of Tobacco Biology and Processing, Ministry of Agriculture, Qingdao 266101, China
| | | |
Collapse
|
7
|
Analytical methods for tracing plant hormones. Anal Bioanal Chem 2012; 403:55-74. [PMID: 22215246 DOI: 10.1007/s00216-011-5623-x] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2011] [Revised: 11/27/2011] [Accepted: 11/28/2011] [Indexed: 12/22/2022]
Abstract
Plant hormones play important roles in regulating numerous aspects of plant growth, development, and response to stress. In the past decade, more analytical methods for the accurate identification and quantitative determination of trace plant hormones have been developed to better our understanding of the molecular mechanisms of plant hormones. As sample preparation is often the bottleneck in analysis of plant hormones in biological samples, this review firstly discusses sample preparation techniques after a brief introduction to the classes, roles, and methods used in the analysis of plant hormones. The analytical methods, especially chromatographic techniques and immuno-based methods, are reviewed in detail, and their corresponding advantages, limitations, applications, and prospects are also discussed. This review mainly covers reports published from 2000 to the present on methods for the analysis of plant hormones.
Collapse
|
8
|
Bai Y, Du F, Yang Y, Bai Y, Liu H. In-capillary non-covalent labeling and determination of tomato systemin with quantum dots in capillary electrophoresis with laser-induced fluorescence detection. J Sep Sci 2011; 34:2893-900. [DOI: 10.1002/jssc.201100551] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2011] [Revised: 07/23/2011] [Accepted: 07/23/2011] [Indexed: 11/06/2022]
|
9
|
DU FY, BAI Y, BAI Y, LIU HW. Mass Spectrometric Fragmentation Mechanism and Chromatographic Retention for Polypeptide Hormones-Systemin and Its Analogues. CHINESE JOURNAL OF ANALYTICAL CHEMISTRY 2011. [DOI: 10.1016/s1872-2040(10)60461-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
|
10
|
Bing T, Chang T, Yang X, Mei H, Liu X, Shangguan D. G-quadruplex DNA aptamers generated for systemin. Bioorg Med Chem 2011; 19:4211-9. [PMID: 21715176 DOI: 10.1016/j.bmc.2011.05.061] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2011] [Revised: 05/28/2011] [Accepted: 05/29/2011] [Indexed: 01/06/2023]
Abstract
Ligands specific to bioactive molecules play important roles in biomedical researches and applications, such as biological assay, diagnosis and therapy. Systemin is a peptide hormone firstly identified in plant. In this paper we report the selection of a group of DNA aptamers that can specifically bind to systemin. Through comparing the predicted secondary structures of all the aptamers, a hairpin structure with G-rich loop was determined to be the binding motif of these aptamers. The G-rich loop region of this binding motif was further characterized to fold into an antiparallel G-quadruplex by truncation-mutation assay and CD spectrum. The apparent equilibrium dissociation constant (K(d)) of one strong binding sequence (S-5-1) was measured to be 0.5 μM. The specificity assay shows that S-5-1 strongly bind to whole systemin, weakly bind to truncated or mutated systemin and does not bind to the scrambled peptide with the same amino acid composition as systemin. The high affinity and specificity make S-5-1 hold potentials to serve as a molecular ligand applied in detection, separation and functional investigation of systemin in plants.
Collapse
Affiliation(s)
- Tao Bing
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | | | | | | | | | | |
Collapse
|
11
|
Wang YH, Irving HR. Developing a model of plant hormone interactions. PLANT SIGNALING & BEHAVIOR 2011; 6:494-500. [PMID: 21406974 PMCID: PMC3142376 DOI: 10.4161/psb.6.4.14558] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Accepted: 12/21/2010] [Indexed: 05/18/2023]
Abstract
Plant growth and development is influenced by mutual interactions among plant hormones. The five classical plant hormones are auxins, cytokinins, gibberellins, abscisic acid and ethylene. They are small diffusible molecules that easily penetrate between cells. In addition, newer classes of plant hormones have been identified such as brassinosteroids, jasmonic acid, salicylic acid and various small proteins or peptides. These hormones also play important roles in the regulation of plant growth and development. This review begins with a brief summary of the current findings on plant hormones. Based on this knowledge, a conceptual model about interactions among plant hormones is built so as to link and develop an understanding of the diverse functions of different plant hormones as a whole in plants.
Collapse
Affiliation(s)
- Yu Hua Wang
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville Victoria, Australia
| | | |
Collapse
|
12
|
Batut J, Mergaert P, Masson-Boivin C. Peptide signalling in the rhizobium-legume symbiosis. Curr Opin Microbiol 2011; 14:181-7. [PMID: 21236724 DOI: 10.1016/j.mib.2010.12.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Revised: 12/14/2010] [Accepted: 12/15/2010] [Indexed: 01/06/2023]
Abstract
For two decades, signalling research in the rhizobium-legume symbiosis field has been dominated by oligosaccharide signals (mainly Nod factors and, to a lesser extent, surface polysaccharides made by the microsymbionts) and phytohormones. Recently, plant peptides have emerged as another major class of signalling molecules in the rhizobium-legume symbioses contributing to the control of nodulation, infection and bacteroid differentiation. Here we focus on three examples of symbiotically relevant peptides, namely Enod40, CLE and NCR peptides. The number of genes encoding these peptides, as well as the recent discovery of additional peptide players in the context of symbiosis, suggests that we might be seeing only the tip of the peptide iceberg in the sea of symbiotic regulations.
Collapse
Affiliation(s)
- Jacques Batut
- Laboratoire des Interactions Plantes Micro-organismes, UMR INRA-CNRS 441/2594, BP 52627, 31326 Castanet-Tolosan Cedex, France.
| | | | | |
Collapse
|
13
|
Du F, Bai Y, Bai Y, Liu H. Quantitative Detection of Trace Systemins in Solanaceous Plants by Immunoaffinity Purification Combined with Liquid Chromatography/Electrospray Quadrupole Time-of-Flight Mass Spectrometry. Anal Chem 2010; 82:9374-83. [DOI: 10.1021/ac101983b] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Fuyou Du
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Yu Bai
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Yu Bai
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Huwei Liu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| |
Collapse
|
14
|
Wang Q, Chen B, Liu P, Zheng M, Wang Y, Cui S, Sun D, Fang X, Liu CM, Lucas WJ, Lin J. Calmodulin binds to extracellular sites on the plasma membrane of plant cells and elicits a rise in intracellular calcium concentration. J Biol Chem 2009; 284:12000-7. [PMID: 19254956 PMCID: PMC2673269 DOI: 10.1074/jbc.m808028200] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2008] [Revised: 12/31/2008] [Indexed: 11/06/2022] Open
Abstract
Calmodulin (CaM) is a highly conserved intracellular calcium sensor. In plants, CaM also appears to be present in the apoplasm, and application of exogenous CaM has been shown to influence a number of physiological functions as a polypeptide signal; however, the existence and localization of its corresponding apoplasmic binding sites remain controversial. To identify the site(s) of action, a CaM-conjugated quantum dot (QD) system was employed for single molecule level detection at the surface of plant cells. Using this approach, we show that QD-CaM binds selectively to sites on the outer surface of the plasma membrane, which was further confirmed by high resolution transmission electron microscopy. Measurements of Ca(2+) fluxes across the plasma membrane, using ion-selective microelectrodes, demonstrated that exogenous CaM induces a net influx into protoplasts. Consistent with these flux studies, calcium-green-dextran and FRET experiments confirmed that applied CaM/QD-CaM elicited an increase in cytoplasmic Ca(2+) levels. These results support the hypothesis that apoplasmic CaM can act as a signaling agent. These findings are discussed in terms of CaM acting as an apoplasmic peptide ligand to mediate transmembrane signaling in the plant kingdom.
Collapse
Affiliation(s)
- Qinli Wang
- Key Laboratory of Photosynthesis and Molecular Environment Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Frommer WB, Schulz B, Murphy AS. Evaluating the function of putative hormone transporters. PLANT SIGNALING & BEHAVIOR 2009; 4:147-8. [PMID: 19649195 PMCID: PMC2637505 DOI: 10.4161/psb.4.2.7681] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2008] [Accepted: 12/23/2008] [Indexed: 05/10/2023]
Abstract
Hormones typically serve as long distance signaling molecules. To reach their site of action, hormones need to be transported from the sites of synthesis. Many plant hormones are mobile, thus requiring specific transport systems for the export from their source cells as well as subsequent import into target cells. Hormone transport in general is still poorly understood. Auxin is probably the most intensively studied plant hormone concerning transport in the moment. To advance our understanding of hormone transport we need two principal data sets: information on the properties of the transport systems including substrate specificity and kinetics, and we need to identify candidate genes for the respective transporters. Physiological transport data can provide an important basis for identifying and characterizing candidate transporters and to define their in vivo role. A recent publication in Plant Physiology highlights how kinetic and specificity studies may help to identify cytokinin transporters.
Collapse
Affiliation(s)
- Wolf B Frommer
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305, USA.
| | | | | |
Collapse
|