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Wang R, Li C, Zeng L, Liu L, Xi J, Li J. Polyethylene Glycol Priming Enhances the Seed Germination and Seedling Growth of Scutellaria baicalensis Georgi under Salt Stress. PLANTS (BASEL, SWITZERLAND) 2024; 13:565. [PMID: 38475412 DOI: 10.3390/plants13050565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 01/28/2024] [Accepted: 02/17/2024] [Indexed: 03/14/2024]
Abstract
Seed priming has become a practical pre-sowing strategy to deal with abiotic stresses. This study aims to explore the effects of polyethylene glycol (PEG) priming on seed germination and seedling growth of Scutellaria baicalensis Georgi under salt stress. Regardless of seed priming, salt stress significantly inhibited the seed germination and seedling growth of S. baicalensis. PEG priming significantly alleviates the inhibitory effects of salt stress on seed germination and seedling growth when compared to non-priming and water priming. Among all treatments, PEG priming exhibited the highest germination rate, germination potential, seed vigor index, fresh weight, dry weight, and plant length; the highest contents of proline, soluble sugar, and soluble protein; the highest K+/Na+ ratio and relative water content; the highest antioxidant activities and contents; but the lowest H2O2, malondialdehyde (MDA) content, and relative electrical conductivity in response to salt stress. In addition, PEG priming had the highest transcript levels of antioxidant-related genes among all treatments under NaCl stress. Taken together, the results demonstrated that seed priming with PEG could be recommended as an effective practice to enhance the germination and early seedling growth of S. baicalensis under saline conditions.
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Affiliation(s)
- Renjie Wang
- College of Agronomy, Qingdao Agricultural University, Qingdao 266109, China
| | - Chenxuan Li
- School of Traditional Chinese Medicine, Capital Medical University, Beijing 100069, China
| | - Li Zeng
- College of Agronomy, Qingdao Agricultural University, Qingdao 266109, China
- National Engineering Research Center for Vegetables, Beijing Vegetable Research Center, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China
| | - Ligong Liu
- National Engineering Research Center for Vegetables, Beijing Vegetable Research Center, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China
| | - Jiayi Xi
- College of Agronomy, Qingdao Agricultural University, Qingdao 266109, China
| | - Jun Li
- College of Agronomy, Qingdao Agricultural University, Qingdao 266109, China
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Li J, Zhao M, Liu L, Guo X, Pei Y, Wang C, Song X. Exogenous Sorbitol Application Confers Drought Tolerance to Maize Seedlings through Up-Regulating Antioxidant System and Endogenous Sorbitol Biosynthesis. PLANTS (BASEL, SWITZERLAND) 2023; 12:2456. [PMID: 37447017 DOI: 10.3390/plants12132456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 06/20/2023] [Accepted: 06/21/2023] [Indexed: 07/15/2023]
Abstract
This study aims to explore the impacts of exogenous sorbitol on maize seedlings under polyethylene glycol (PEG)-simulated drought stress. Six treatments were set: normal condition (CK), PEG (P), 10 mM sorbitol (10S), PEG plus 10 mM sorbitol (10SP), 100 mM sorbitol (100S) and PEG plus 100 mM sorbitol (100SP). Maize seedlings' growth under PEG-simulated drought stress was significantly inhibited and exogenous sorbitol largely alleviated this growth inhibition. The seedlings under 10SP treatment grew much better than those under P, 100S and 100SP treatments and no significant difference in growth parameters was observed between the control and 10S treatment. The seedlings treated with 10SP had higher contents of soluble sugar, soluble protein, proline, ascorbic acid (AsA), reduced glutathione (GSH), sorbitol and relative water content, higher activities of antioxidant enzymes and aldose reductase, but lower contents of malondialdehyde (MDA), H2O2 and relative electrical conductivity than those treated with P, 100S and 100SP. qRT-PCR analysis showed that the transcript levels of genes encoding putative aldose reductase (AR) under P treatment were significantly up-regulated in sorbitol-applied treatments. Taken together, the results demonstrated that exogenous sorbitol application conferred drought tolerance to maize seedlings by up-regulating the expression levels of AR-related genes to enhance the accumulation of intracellular osmotic substances such as sorbitol and improve antioxidant systems to tone down the damage caused by drought stress.
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Affiliation(s)
- Jun Li
- College of Agronomy, Qingdao Agricultural University, Qingdao 266109, China
| | - Meiai Zhao
- College of Life Sciences, Qingdao Agricultural University, Qingdao 266109, China
| | - Ligong Liu
- Beijing Vegetable Research Center, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China
| | - Xinmei Guo
- College of Agronomy, Qingdao Agricultural University, Qingdao 266109, China
| | - Yuhe Pei
- College of Agronomy, Qingdao Agricultural University, Qingdao 266109, China
| | - Chunxiao Wang
- College of Agronomy, Qingdao Agricultural University, Qingdao 266109, China
| | - Xiyun Song
- College of Agronomy, Qingdao Agricultural University, Qingdao 266109, China
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Tang D, Quan C, Lin Y, Wei K, Qin S, Liang Y, Wei F, Miao J. Physio-Morphological, Biochemical and Transcriptomic Analyses Provide Insights Into Drought Stress Responses in Mesona chinensis Benth. FRONTIERS IN PLANT SCIENCE 2022; 13:809723. [PMID: 35222473 PMCID: PMC8866654 DOI: 10.3389/fpls.2022.809723] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 01/18/2022] [Indexed: 05/04/2023]
Abstract
Drought stress affects the normal growth and development of Mesona chinensis Benth (MCB), which is an important medicinal and edible plant in China. To investigate the physiological and molecular mechanisms of drought resistance in MCB, different concentrations of polyethylene glycol 6000 (PEG6000) (0, 5, 10, and 15%) were used to simulate drought conditions in this study. Results showed that the growth of MCB was significantly limited under drought stress conditions. Drought stress induced the increases in the contents of Chla, Chlb, Chla + b, soluble protein, soluble sugar, and soluble pectin and the activities of superoxide dismutase (SOD), catalase (CAT), total antioxidant capacity (TAC), hydrogen peroxide (H2O2), and malondialdehyde (MDA). Transcriptome analysis revealed 3,494 differentially expressed genes (DEGs) (1,961 up-regulated and 1,533 down-regulated) between the control and 15% PEG6000 treatments. These DEGs were identified to be involved in the 10 metabolic pathways, including "plant hormone signal transduction," "brassinosteroid biosynthesis," "plant-pathogen interaction," "MAPK signaling pathway-plant," "starch and sucrose metabolism," "pentose and glucuronate interconversions," "phenylpropanoid biosynthesis," "galactose metabolism," "monoterpenoid biosynthesis," and "ribosome." In addition, transcription factors (TFs) analysis showed 8 out of 204 TFs, TRINITY_DN3232_c0_g1 [ABA-responsive element (ABRE)-binding transcription factor1, AREB1], TRINITY_DN4161_c0_g1 (auxin response factor, ARF), TRINITY_DN3183_c0_g2 (abscisic acid-insensitive 5-like protein, ABI5), TRINITY_DN28414_c0_g2 (ethylene-responsive transcription factor ERF1b, ERF1b), TRINITY_DN9557_c0_g1 (phytochrome-interacting factor, PIF3), TRINITY_DN11435_c1_g1, TRINITY_DN2608_c0_g1, and TRINITY_DN6742_c0_g1, were closely related to the "plant hormone signal transduction" pathway. Taken together, it was inferred that these pathways and TFs might play important roles in response to drought stress in MCB. The current study provided important information for MCB drought resistance breeding in the future.
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Affiliation(s)
- Danfeng Tang
- Guangxi Key Laboratory of Medicinal Resources Protection and Genetic Improvement, Guangxi Botanical Garden of Medicinal Plants, Nanning, China
- Guangxi Engineering Research Center of TCM Resource Intelligent Creation, Guangxi Botanical Garden of Medicinal Plants, Nanning, China
| | - Changqian Quan
- Guangxi Key Laboratory of Medicinal Resources Protection and Genetic Improvement, Guangxi Botanical Garden of Medicinal Plants, Nanning, China
- Guangxi Engineering Research Center of TCM Resource Intelligent Creation, Guangxi Botanical Garden of Medicinal Plants, Nanning, China
| | - Yang Lin
- Guangxi Key Laboratory of Medicinal Resources Protection and Genetic Improvement, Guangxi Botanical Garden of Medicinal Plants, Nanning, China
- Guangxi Engineering Research Center of TCM Resource Intelligent Creation, Guangxi Botanical Garden of Medicinal Plants, Nanning, China
| | - Kunhua Wei
- Guangxi Key Laboratory of Medicinal Resources Protection and Genetic Improvement, Guangxi Botanical Garden of Medicinal Plants, Nanning, China
- Guangxi Engineering Research Center of TCM Resource Intelligent Creation, Guangxi Botanical Garden of Medicinal Plants, Nanning, China
| | - Shuangshuang Qin
- Guangxi Key Laboratory of Medicinal Resources Protection and Genetic Improvement, Guangxi Botanical Garden of Medicinal Plants, Nanning, China
- Guangxi Engineering Research Center of TCM Resource Intelligent Creation, Guangxi Botanical Garden of Medicinal Plants, Nanning, China
| | - Ying Liang
- Guangxi Key Laboratory of Medicinal Resources Protection and Genetic Improvement, Guangxi Botanical Garden of Medicinal Plants, Nanning, China
- Guangxi Engineering Research Center of TCM Resource Intelligent Creation, Guangxi Botanical Garden of Medicinal Plants, Nanning, China
| | - Fan Wei
- Guangxi Key Laboratory of Medicinal Resources Protection and Genetic Improvement, Guangxi Botanical Garden of Medicinal Plants, Nanning, China
- Guangxi Engineering Research Center of TCM Resource Intelligent Creation, Guangxi Botanical Garden of Medicinal Plants, Nanning, China
| | - Jianhua Miao
- Guangxi Key Laboratory of Medicinal Resources Protection and Genetic Improvement, Guangxi Botanical Garden of Medicinal Plants, Nanning, China
- Guangxi Engineering Research Center of TCM Resource Intelligent Creation, Guangxi Botanical Garden of Medicinal Plants, Nanning, China
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Shabala SN, Lew RR. Turgor regulation in osmotically stressed Arabidopsis epidermal root cells. Direct support for the role of inorganic ion uptake as revealed by concurrent flux and cell turgor measurements. PLANT PHYSIOLOGY 2002; 129:290-9. [PMID: 12011359 PMCID: PMC155892 DOI: 10.1104/pp.020005] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2002] [Accepted: 01/14/2002] [Indexed: 05/05/2023]
Abstract
Hyperosmotic stress is known to significantly enhance net uptake of inorganic ions into plant cells. Direct evidence for cell turgor recovery via such a mechanism, however, is still lacking. In the present study, we performed concurrent measurements of net ion fluxes (with the noninvasive microelectrode ion flux estimation technique) and cell turgor changes (with the pressure-probe technique) to provide direct evidence that inorganic ion uptake regulates turgor in osmotically stressed Arabidopsis epidermal root cells. Immediately after onset of hyperosmotic stress (100/100 mM mannitol/sorbitol treatment), the cell turgor dropped from 0.65 to about 0.25 MPa. Turgor recovery started within 2 to 10 min after the treatment and was accompanied by a significant (30-80 nmol m-2 s-1) increase in uptake of K+, Cl-, and Na+ by root cells. In most cells, almost complete (>90% of initial values) recovery of the cell turgor was observed within 40 to 50 min after stress onset. In another set of experiments, we combined the voltage-clamp and the microelectrode ion flux estimation techniques to show that this process is, in part, mediated by voltage-gated K+ transporters at the cell plasma membrane. The possible physiological significance of these findings is discussed.
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Affiliation(s)
- Sergey N Shabala
- School of Agricultural Science, University of Tasmania, Hobart, Australia
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Stahlberg R, Cosgrove DJ. Induction and ionic basis of slow wave potentials in seedlings of Pisum sativum L. PLANTA 1996; 200:416-25. [PMID: 11541124 DOI: 10.1007/bf00231397] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Slow wave potentials (SWPs) are transient depolarizations which propagate substantial distances from their point of origin. They were induced in the epidermal cells of pea epicotyls by injurious methods such as root excision and heat treatment, as well as by externally applied defined steps in xylem pressure (Px) in the absence of wounding. The common principle of induction was a rapid increase in Px. Such a stimulus appeared under natural conditions after (i) bending of the epicotyl, (ii) wounding of the epidermis, (iii) rewatering of dehydrated roots, and (iv) embolism. The induced depolarization was not associated with a change in cell input resistance. This result and the ineffectiveness of ion channel blockers point to H(+)-pumps rather than ion channels as the ionic basis of the SWP. Stimuli such as excision, heat treatment and pressure steps, which generate SWPs, caused a transient increase in the fluorescence intensity of epicotyls loaded with the pH-indicator DM-NERF, a 2',7'-dimethyl derivative of rhodol, but not of those loaded with the pH indicator 2',7'bis(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF). Matching kinetics of depolarization and pH response identify a transient inactivation of proton pumps in the plasma membrane as the causal mechanism of the SWP. Feeding pump inhibitors to the cut surface of excised epicotyls failed to chemically simulate a SWP; cyanide, azide and 2,4-dinitrophenol caused sustained, local depolarizations which did not propagate. Of all tested substances, only sodium cholate caused a transient and propagating depolarization whose arrival in the growing region of the epicotyl coincided with a transient growth rate reduction.
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Affiliation(s)
- R Stahlberg
- Department of Biology, Pennsylvania State University, University Park 16802, USA.
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Stahlberg R, Cosgrove DJ. Rapid alterations in growth rate and electrical potentials upon stem excision in pea seedlings. PLANTA 1992; 187:523-31. [PMID: 11538115 DOI: 10.1007/bf00199972] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Excision of the epicotyl base of pea (Pisum sativum L.) seedlings in air results in a fast drop in the growth rate and rapid transient membrane depolarization of the surface cells near the cut. Subsequent immersion of the cut end into solution leads to a rapid, transient rise in the epicotyl growth rate and an acropetally propagating depolarization with an amplitude of about 35 mV and a speed of approx. 1 mm s-1. The same result can be achieved directly by excision of the pea epicotyl under water. Shape, amplitude and velocity of the depolarization characterize it as a "slow-wave potential". These results indicate that the propagating depolarization is caused by a surge in water uptake. Neither a second surge in water uptake (measured as a rapid increase in growth rate when the cut end was placed in air and then back into solution) nor another cut can produce the depolarization a second time. Cyanide suppresses the electrical signal at the treated position without inhibiting its transmission through this area and its development in untreated parts of the epicotyl. The large depolarization and repolarization which occur in the epidermal and subepidermal cells are not associated with changes in cell input resistance. Both results indicate that it is a transient shut-down of the plasma-membrane proton pump rather than large ion fluxes which is causing the depolarization. We conclude that the slow wave potential is spread in the stem via a hydraulic surge occurring upon relief of the negative xylem pressure after the hydraulic resistance of the root has been removed by excision.
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Affiliation(s)
- R Stahlberg
- Department of Biology, Pennsylvania State University, University Park 16802, USA
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7
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Bouzayen M, Latché A, Pech JC. Subcellular localization of the sites of conversion of 1-aminocyclopropane-1-carboxylic acid into ethylene in plant cells. PLANTA 1990; 180:175-180. [PMID: 24201941 DOI: 10.1007/bf00193992] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/28/1989] [Indexed: 06/02/2023]
Abstract
The subcellular localization of the sites of 1-aminocyclopropane-1-carboxylic acid (ACC) conversion into ethylene was studied by comparing the specific radioactivity of ethylene evolved from the whole cells with that of intra- and extracellular pools of labelled ACC. We demonstrate that some cells cultured in vitro (Vitis vinifera L. cv. Muscat) or leaf tissues (Hordeum vulgare L. and Triticum aestivum L.) have two sites of ethylene production: (i) an external site, converting apoplastic ACC, located at the plasma membrane, and very sensitive to high osmotica and, (ii) an intracellular site, converting internal ACC and remaining unaffected even under severe plasmolysis. In other cells cultured in vitro (Vitis vinifera L. cv. Gamay) and pea leaves (Pisum sativum L.), only the intracellular site operates and ethylene production is almost unaffected by plasmolysis. Protoplasts obtained from plasmolysis-sensitive Muscat cells lose 97% of their capacity for ethylene production compared with the parent cell, while those from plasmolysisinsensitive Gamay cells retain up to 50%. Protoplasts from both Gamay and Muscat cells cultured for 8 d in vitro, recover the full capacity of ethylene production of the initial whole cells, whether or not they are allowed to reform their cell wall. Therefore, we exclude a cooperation between the cell wall and the plasma membrane in ethylene production.
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Affiliation(s)
- M Bouzayen
- Ecole Nationale Supérieure Agronomique, 145, avenue de Muret, F-31076, Toulouse Cédex, France
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Flores HE, Galston AW. Osmotic Stress-Induced Polyamine Accumulation in Cereal Leaves : II. Relation to Amino Acid Pools. PLANT PHYSIOLOGY 1984; 75:110-3. [PMID: 16663552 PMCID: PMC1066844 DOI: 10.1104/pp.75.1.110] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Arginine decarboxylase activity increases 2- to 3-fold in osmotically stressed oat leaves in both light and dark, but putrescine accumulation in the dark is only one-third to one-half of that in light-stressed leaves. If arginine or ornithine are supplied to dark-stressed leaves, putrescine rises to levels comparable to those obtained by incubation under light. Thus, precursor amino acid availability is limiting to the stress response. Amino acid levels change rapidly upon osmotic treatment; notably, glutamic acid decreases with a corresponding rise in glutamine. Difluoromethylarginine (0.01-0.1 millimolar), the enzyme-activated irreversible inhibitor of arginine decarboxylase, prevents the stress-induced putrescine rise, as well as the incorporation of label from [(14)C]arginine, with the expected accumulation of free arginine, but has no effect on the rest of the amino acid pool. The use of specific inhibitors such as alpha-difluoromethylarginine is suggested as probes for the physiological significance of stress responses by plant cells.
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Affiliation(s)
- H E Flores
- ARCO Plant Cell Research Institute, Dublin, California 94568
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Iglesias A, Satter RL. H fluxes in excised samanea motor tissue : I. Promotion by light. PLANT PHYSIOLOGY 1983; 72:564-9. [PMID: 16663043 PMCID: PMC1066274 DOI: 10.1104/pp.72.2.564] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Previous investigators revealed that white light-promoted leaflet opening in Samanea saman (Jacq) Merrill depends upon K(+) uptake by extensor cells and efflux from flexor cells of the pulvinus, while dark-promoted closure depends upon K(+) fluxes in the opposite directions. We now monitored H(+) fluxes during pulvinar movement to test a model proposing coupled H(+)/K(+) fluxes. H(+) fluxes were monitored by measuring changes in the pH of a weakly buffered solution (initial pH = 5.5) bathing excised strips of extensor or flexor tissue. White light at hour 3 of the usual dark period promoted pulvinar opening, H(+) efflux from extensor cells and uptake by flexor cells, while darkness at hours 2 to 4 of the usual light period promoted pulvinar closure, H(+) uptake by extensor cells and efflux from flexor cells. The following conditions altered H(+) fluxes during dark-promoted closure. (a) Light reversed the directions of the fluxes in both extensor and flexor cells. (b) Anoxia increased the rate of H(+) uptake by extensor cells and promoted H(+) uptake (rather than efflux) by flexor cells, consistent with an outwardly directed H(+) pump. KCN showed similar effects initially, but they were transient. (c) Increase in external pH from 5.5 to 6.7 promoted H(+) efflux (rather than uptake) by extensor cells and increased the rate of H(+) efflux from flexor cells, presumably by decreasing the rate of inward diffusion. (d) Change in external K(+) did not alter H(+) fluxes by extensor cells, but removal of external K(+) decreased the rate of H(+) efflux from flexor cells by 70%. These observations support a model for coupled H(+)/K(+) fluxes in pulvinar cells during light-and dark-promoted leaflet movements.
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Affiliation(s)
- A Iglesias
- Biological Sciences Group U-42, University of Connecticut, Storrs, Connecticut 06268
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Rubinstein B. Regulation of H Excretion : ROLE OF PROTEIN RELEASED BY OSMOTIC SHOCK. PLANT PHYSIOLOGY 1982; 69:945-9. [PMID: 16662324 PMCID: PMC426333 DOI: 10.1104/pp.69.4.945] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
When the protoplasts of peeled oat leaf segments (Avena sativa L.) expand after a brief plasmolysis (osmotic shock), fusicoccin-enhanced H(+) excretion is reduced and protein is released to the rehydration medium. This shock protein seems to arise from the cell surface, not from the interior of leaky cells or from broken cells, because (a) the protein differs quantitatively and qualitatively from protein of cell homogenates as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis; (b) peroxidase, phosphatase, and malate dehydrogenase activities, which are associated with the cell surface, are detected in the shock fluids; (c) the specific activities of enzymes in shock fluids are different than those of cell homogenates; (d) the amount of protein released is correlated with tissue mass, not number of cut surfaces and is not diminished by pre-washing the tissue.Some of the shock protein may arise from plasmodesmata; this suggestion is based on (a) the cell surface origin of the protein; (b) the presence in the shock fluid of NADPH-cytochrome c reductase activity, usually associated with the endoplasmic reticulum which traverses plasmodesmata; (c) on the release of smaller amounts of protein after plasmolysis with polyethylene glycol 4000, an osmoticum which may tend to preserve plasmodesmata.The amount of protein released by osmotic shock is correlated with the extent of inhibition of fusicoccin-enhanced H(+) excretion. A specific function for the shock protein is implied by the presence of a component which specifically binds fusicoccin.
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Affiliation(s)
- B Rubinstein
- Department of Botany, University of Massachusetts, Amherst, Massachusetts 01003
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