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Ethylene Modulates the Developmental Plasticity and the Growth Balance Between Shoot and Root Systems in the In Vitro Grown Epiphytic Orchid Catasetum fimbriatum

Rodrigues, Maria Aurineide; Freschi, Luciano; Purgatto, Eduardo; Lima, Vera Fátima Gomes Alves Pereira; Kerbauy, Gilberto Barbante
Fonte: Springer Science+Business Media New York; New York Publicador: Springer Science+Business Media New York; New York
Tipo: Artigo de Revista Científica
ENG
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36.93%
The epiphytic habitat is potentially one of the most stressful environments for plants, making the effective developmental control in response to external cues critical for epiphyte survival. Because ethylene mediates several abiotic stresses in plants, here, we have examined the ethylene influence in both shoot and root systems of the epiphytic orchid Catasetum fimbriatum. Under controlled conditions, ethylene production was quantified during an entire growth cycle of C. fimbriatum development in vitro, while treatments modulating either ethylene concentration or perception were carried out over the early growth phase of these plants. After treatments, growth measurements and histological features were studied in both shoot and root tissues. Ethylene production showed a decreasing trend over the period of organ elongation; however, it increased considerably when leaves were shed, and a new axillary bud was initiating. The early exposure of young plants to higher concentrations of ethylene triggered morphogenic responses that included root hair formation instead of velamen, and a combination of inhibitory effects (decreases in both stem enlargement and cellular/organ elongation) and inductive effects (increases in leaf and root formation...

Efeito da aplicação de 1-metilciclopropeno e etileno na fisiologia e no amadurecimento de mamões `Golden´; Effect of 1-methylcyclopropene and ethylene on the physiology and ripening of Golden papaya

Trevisan, Marcos José
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 03/07/2012 PT
Relevância na Pesquisa
37%
O mamão é um fruto climatérico, cujas transformações resultantes do amadurecimento ocorrem rapidamente após a colheita. O tratamento com 1- metilciclopropeno (1-MCP) tem sido testado para ampliar sua vida útil, entretanto, com resultados até então pouco consistentes. Pesquisas com peras, bananas e ameixas foram realizadas utilizando conjuntamente 1-MCP e etileno, com resultados relevantes. Portanto, o objetivo deste trabalho foi estudar a fisiologia e a conservação pós-colheita do mamão Golden, submetido a diferentes combinações de 1-MCP e etileno, aplicados simultaneamente. Os frutos foram colhidos em pomares comerciais no estádio 1 de maturação, tratados e armazenados em câmaras frias a 11 e a 22ºC. O projeto foi dividido em três etapas. Na primeira etapa, observou-se que doses de 100 e 200 nL.L-1 de etileno combinados com iguais concentrações de 1-MCP, apresentaram resultados semelhantes aos do 1-MCP aplicado isoladamente. Na segunda etapa, o etileno nas concentrações entre 0 e 10 SL.L-1 foi combinado com 100 nL.L-1 de 1-MCP. Esse aumento na concentração de etileno diminuiu ou até mesmo anulou a ação do 1-MCP, nas concentrações mais elevadas. A mudança de cor e a perda da firmeza foram mais lentas nos tratamentos com 1-MCP na dose de 100 nL.L-1...

Perfis de compostos voláteis de banana submetidos a diferentes tratamentos pós-colheita e suas correlações com a expressão diferencial dos receptores de etileno; Volatile compounds profile of bananas submitted to different post-harvest treatments and its correlations to differential expression of ethylene receptors.

Chiebáo, Helena Pontes
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 27/03/2013 PT
Relevância na Pesquisa
36.93%
O aroma de frutos é um atributo fortemente associado à qualidade, e quaisquer alterações ambientais ou tratamentos pós-colheita podem alterar a sua composição. Acredita-se que a biossíntese de voláteis seja um dos processos regulados pelo etileno. Estudos indicam que a expressão diferencial dos elementos que compõem os receptores de etileno desempenha importante papel na sinalização dos processos ligados ao amadurecimento, entre eles a formação do aroma. Os objetivos deste trabalho são: caracterizar as alterações decorrentes de tratamentos pós-colheita no aroma de banana durante o amadurecimento, e correlacionar com as variações nos padrões de expressão gênica diferencial dos receptores de etileno. Bananas pré-climatéricas variedade Nanicão foram divididas em quatro grupos: controle (não tratado), etileno (100ppm/12h), 1-MCP (100ppb/12h), armazenados a 20°C, e grupo frio (armazenado por 15 dias a 13°C). Foram analisados diariamente a produção de etileno e de CO2 por CG. Foram analisadas a cor da casca, açúcares solúveis e amido. Os compostos voláteis foram isolados por microextração em fase sólida (SPME) em frutos inteiros e polpas e analisados em CG-MS. Para confirmar os resultados e verificar se as alterações encontradas se repetem em outras variedades de bananas...

Tnt1 retrotransposon expression and ethylene phytohormone interplay mediates tobacco (Nicotiana tabacum) defense responses; A dinâmica entre a expressão do retrotransposon Tnt1 e o fitormônio etileno envolvida nas respostas de defesa em tabaco (Nicotiana tabacum)

Quintanilha, Danielle Maluf
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 10/10/2014 EN
Relevância na Pesquisa
36.92%
Tnt1 is a transcriptionally active LTR-retrotransposon, present in over 600 copies in the Nicotiana tabacum genome. Under normal growth conditions, Tnt1 expression is limited to basal levels, but its expression is further induced under biotic and abiotic stresses. Transgenic tobacco plants (HP plants) expressing a Tnt1 reverse transcriptase hairpin were generated. These showed pleiotropic phenotypes such as cell death spots on the leaves and callose deposition and other severe abnormal development in aerial and underground portions. RNA sequencing of leaves with cell death spots revealed a rewiring of transcriptional regulatory networks related to stress responses exclusive to HPs. Among the positively modulated genes were ethylene synthesis and response cascade genes. The objective of the present work was to unravel the relation observed between Tnt1 and ethylene, generating a model. The results obtained suggest that HP seedlings and plants have increased ethylene synthesis when compared to the wildtype. Folding prediction of Tnt1 messenger RNA allowed the identification of ethylene-responsive sequences in putative stem loop locations. Thus it is possible that Tnt1 expression can produce small RNAs targeted to sequences present in the Tnt1 retrotransposon itself as well as at the promoter region of other ethylene responsive genes. Quantification of the expression of Tnt1 and ethylene related genes revealed "phase opposition" expression kinetics in the HPs...

Vitrificação de embriões Mus domesticus domesticus contidos em volumes diferentes de 9,0 m de etileno glicol.; Vitrification of mus domesticus domesticus embryos exposed to differents volumes of 9.0 m ethylene glycol solution

Assaf, Sabrina Silveira
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
36.93%
Os experimentos tiveram como objetivo determinar a taxa de eclosão dos embriões vitrificados em volumes diferentes de 9,0 M de etileno glicol. Simultaneamente, testou-se dois procedimentos de estocagem dos fios de teflon, denominados caixa de aço inoxidável e globete/raque. No experimento I, os 881 embriões coletados foram distribuídos em 4 tratamentos: tratamento 1 (T1= controle): 307 embriões foram cultivados in vitro em meio PBSm, acrescido de 0,4% de BSA; tratamento 2 (T2): 292 embriões foram expostos à solução de glicerol 10% acrescida de 0,4% de BSA, envasados em palhetas de 0,25 mL e submetidos ao congelamento pelo método rápido em Biocool; tratamento 3 (T3): 138 embriões foram expostos durante 2 minutos à solução de desidratação (10% de EG + 6% BSA em PBSm) e então transferidos para a solução de vitrificação (50% de EG + 6% de BSA em PBSm), onde permaneceram por 30 segundos e foram colocados em volume de 1 μL no interior de um fio de teflon, medindo 0,4 mm de diâmetro, 2,0 cm de comprimento e 0,05 mm de espessura. Os fios foram acondicionados em uma caixa de aço inoxidável para serem armazenados em nitrogênio líquido; tratamento 4 (T4): 144 embriões foram expostos à solução de desidratação (10% de EG + 6% BSA em PBSm) e após 2 minutos...

The Central Role of PhEIN2 in Ethylene Responses throughout Plant Development in Petunia1

Shibuya, Kenichi; Barry, Kristin G.; Ciardi, Joseph A.; Loucas, Holly M.; Underwood, Beverly A.; Nourizadeh, Saeid; Ecker, Joseph R.; Klee, Harry J.; Clark, David G.
Fonte: American Society of Plant Biologists Publicador: American Society of Plant Biologists
Tipo: Artigo de Revista Científica
Publicado em /10/2004 EN
Relevância na Pesquisa
36.96%
The plant hormone ethylene regulates many aspects of growth and development. Loss-of-function mutations in ETHYLENE INSENSITIVE2 (EIN2) result in ethylene insensitivity in Arabidopsis, indicating an essential role of EIN2 in ethylene signaling. However, little is known about the role of EIN2 in species other than Arabidopsis. To gain a better understanding of EIN2, a petunia (Petunia × hybrida cv Mitchell Diploid [MD]) homolog of the Arabidopsis EIN2 gene (PhEIN2) was isolated, and the role of PhEIN2 was analyzed in a wide range of plant responses to ethylene, many that do not occur in Arabidopsis. PhEIN2 mRNA was present at varying levels in tissues examined, and the PhEIN2 expression decreased after ethylene treatment in petals. These results indicate that expression of PhEIN2 mRNA is spatially and temporally regulated in petunia during plant development. Transgenic petunia plants with reduced PhEIN2 expression were compared to wild-type MD and ethylene-insensitive petunia plants expressing the Arabidopsis etr1-1 gene for several physiological processes. Both PhEIN2 and etr1-1 transgenic plants exhibited significant delays in flower senescence and fruit ripening, inhibited adventitious root and seedling root hair formation, premature death...

Interactions between Ethylene and Gibberellins in Phytochrome-Mediated Shade Avoidance Responses in Tobacco1

Pierik, Ronald; Cuppens, Mieke L.C.; Voesenek, Laurentius A.C.J.; Visser, Eric J.W.
Fonte: American Society of Plant Biologists Publicador: American Society of Plant Biologists
Tipo: Artigo de Revista Científica
Publicado em /10/2004 EN
Relevância na Pesquisa
36.89%
Plants respond to proximate neighbors with a suite of responses that comprise the shade avoidance syndrome. These phytochrome-mediated responses include hyponasty (i.e. a more vertical orientation of leaves) and enhanced stem and petiole elongation. We showed recently that ethylene-insensitive tobacco (Nicotiana tabacum) plants (Tetr) have reduced responses to neighbors, showing an important role for this gaseous plant hormone in shade avoidance. Here, we investigate interactions between phytochrome signaling and ethylene action in shade avoidance responses. Furthermore, we investigate if ethylene acts in these responses through an interaction with the GA class of hormones. Low red to far-red light ratios (R:FR) enhanced ethylene production in wild-type tobacco, resulting in shade avoidance responses, whereas ethylene-insensitive plants showed reduced shade avoidance responses. Plants with inhibited GA production showed hardly any shade avoidance responses at all to either a low R:FR or increased ethylene concentrations. Furthermore, low R:FR enhanced the responsiveness of hyponasty and stem elongation in both wild-type and Tetr plants to applied GA3, with the stem elongation process being more responsive to GA3 in the wild type than in Tetr. We conclude that phytochrome-mediated shade avoidance responses involve ethylene action...

Airborne Ethylene May Alter Antioxidant Protection and Reduce Tolerance of Holm Oak to Heat and Drought Stress1

Munné-Bosch, Sergi; Peñuelas, Josep; Asensio, Dolores; Llusià, Joan
Fonte: American Society of Plant Biologists Publicador: American Society of Plant Biologists
Tipo: Artigo de Revista Científica
Publicado em /10/2004 EN
Relevância na Pesquisa
36.92%
Plant-emitted ethylene has received considerable attention as a stress hormone and is considered to play a major role at low concentrations in the tolerance of several species to biotic and abiotic stresses. However, airborne ethylene at high concentrations, such as those found in polluted areas (20–100 nL L−1) for several days, has received far less attention in studies of plant stress tolerance, though it has been shown to alter photosynthesis and reproductive stages (seed germination, flowering, and fruit ripening) in some species. To assess the potential effects of airborne ethylene on plant stress tolerance in polluted areas, the extent of oxidative stress, photo- and antioxidant protection, and visual leaf area damage were evaluated in ethylene-treated (approximately 100 nL L−1 in air) and control (without ethylene fumigation) holm oak (Quercus ilex) plants exposed to heat stress or to a combination of heat and drought stress. Control plants displayed tolerance to temperatures as high as 50°C, which might be attributed, at least in part, to enhanced xanthophyll de-epoxidation and 2-fold increases in α-tocopherol, and they suffered oxidative stress only when water deficit was superimposed on temperatures above 45°C. By contrast...

Requirement of the Histidine Kinase Domain for Signal Transduction by the Ethylene Receptor ETR11

Qu, Xiang; Schaller, G. Eric
Fonte: American Society of Plant Biologists Publicador: American Society of Plant Biologists
Tipo: Artigo de Revista Científica
Publicado em /10/2004 EN
Relevância na Pesquisa
36.89%
In Arabidopsis, ethylene is perceived by a receptor family consisting of five members, one of these being ETR1. The N-terminal half of ETR1 functions as a signal input domain. The C-terminal region of ETR1, consisting of a His kinase domain and a putative receiver domain, is likely to function in signal output. The role of the proposed signal output region in ethylene signaling was examined in planta. For this purpose, the ability of mutant versions of ETR1 to rescue the constitutive ethylene-response phenotype of the etr1-6;etr2-3;ein4-4 triple loss-of-function mutant line was examined. A truncated version of ETR1 that lacks both the His kinase domain and the receiver domain failed to rescue the triple mutant phenotype. A truncated ETR1 receptor that lacks only the receiver domain restored normal growth to the triple mutant in air, but the transgenic seedlings displayed hypersensitivity to low doses of ethylene. A mutation that eliminated His kinase activity had a modest effect upon the ability of the receptor to repress ethylene responses in air. These results demonstrate that the His kinase domain plays a role in the repression of ethylene responses. The potential roles of the receiver domain and His kinase activity in ethylene signaling are discussed.

Insights into how ethylene over production alters tree stature in the dwarfy mutant of Populus tremula x P. alba

Dubuc, Mathieu
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN
Relevância na Pesquisa
36.89%
Poplar trees have quickly become one of the key plants investigated for the development of second generation biofuels due to its rapid growth rate, broad growth range in North America and high quality wood properties for ethanol production. This thesis investigates the role of the hormone ethylene in regulating tree stature, an important trait when considering the establishment of tree plantations. An activation tagged poplar (Populus tremula x Populus alba) mutant called dwarfy was chosen due to its profoundly reduced stature that has been attributed to the over-expression of the ethylene synthesis gene 1-aminocyclopropane-1-carboxylic acid (ACC) 5, which lead to a 15x increase in ethylene production. In addition to the reduced stature, the dwarfy mutant also had low biomass production, shortened internodes and a suspected resistance to pathogens. To understand the dwarf phenotype of this mutant, anatomical and molecular approaches were used. Hand sections were prepared for leaf and stem tissues from internodes 1 to 14 to determine if there were cellular differences between the mutant and wildtype. It was found that dwarfy stems contained far fewer xylem vessel elements than wildtype. Since ethylene alone is not known to specifically cause dwarfism it was necessary to identify what pathways could interact with ethylene and then I chose two to study. The light receptor CRYPTOCHROME 1 was studied as increased expression had been linked to dwarfism as well as several cyanide related genes as cyanide is produced in the ethylene synthesis pathway. CRYPTOCHROME 1 levels were found to be significantly elevated as well as the cyanide removal gene BETA-CYANOALANINE SYNTHETASE. These results provide insight into the mechanisms of stem elongation and cyanide sequestration and how ethylene interacts with these processes.

Characterisation of ethylene pathway components in non-climacteric capsicum

Aizat, W.; Able, J.; Stangoulis, J.; Able, A.
Fonte: BioMed Central Ltd. Publicador: BioMed Central Ltd.
Tipo: Artigo de Revista Científica
Publicado em //2013 EN
Relevância na Pesquisa
37.03%
Background: Climacteric fruit exhibit high ethylene and respiration levels during ripening but these levels are limited in non-climacteric fruit. Even though capsicum is in the same family as the well-characterised climacteric tomato (Solanaceae), it is non-climacteric and does not ripen normally in response to ethylene or if harvested when mature green. However, ripening progresses normally in capsicum fruit when they are harvested during or after what is called the ‘Breaker stage’. Whether ethylene, and components of the ethylene pathway such as 1-aminocyclopropane 1-carboxylate (ACC) oxidase (ACO), ACC synthase (ACS) and the ethylene receptor (ETR), contribute to non-climacteric ripening in capsicum has not been studied in detail. To elucidate the behaviour of ethylene pathway components in capsicum during ripening, further analysis is therefore needed. The effects of ethylene or inhibitors of ethylene perception, such as 1-methylcyclopropene, on capsicum fruit ripening and the ethylene pathway components may also shed some light on the role of ethylene in non-climacteric ripening. Results: The expression of several isoforms of ACO, ACS and ETR were limited during capsicum ripening except one ACO isoform (CaACO4). ACS activity and ACC content were also low in capsicum despite the increase in ACO activity during the onset of ripening. Ethylene did not stimulate capsicum ripening but 1-methylcyclopropene treatment delayed the ripening of Breaker-harvested fruit. Some of the ACO...

Involvement of ethylene biosynthesis and signalling in fruit set and early fruit development in zucchini squash (Cucurbita pepo L.)

Mart??nez, Cecilia; Manzano, Susana; Meg??as, Zoraida; Garrido Garrido, Mar??a Dolores; Pic??, Bel??n; Jamilena, Manuel
Fonte: Biomed Central Publicador: Biomed Central
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37%
Background We have identified a kind of parthenocarpy in zucchini squash which is associated with an incomplete andromonoecy, i.e. a partial conversion of female into bisexual flowers. Given that andromonoecy in this and other cucurbit species is caused by a reduction of ethylene production in the female flower, the associated parthenocarpic development of the fruit suggested the involvement of ethylene in fruit set and early fruit development.; Results We have compared the production of ethylene as well as the expression of 13 ethylene biosynthesis and signalling genes in pollinated and unpollinated ovaries/fruits of two cultivars, one of which is parthenocarpic (Cavili), while the other is non-parthenocarpic (Tosca). In the latter, unpollinated ovaries show an induction of ethylene biosynthesis and ethylene signal transduction pathway genes three days after anthesis, which is concomitant with the initiation of fruit abortion and senescence. Fruit set and early fruit development in pollinated flowers of both cultivars and unpollinated flowers of Cavili is coupled with low ethylene biosynthesis and signalling, which would also explain the partial andromonoecy in the parthenocarpic genotype. The reduction of ethylene production in the ovary cosegregates with parthenocarpy and partial andromonoecy in the selfing progeny of Cavili. Moreover...

Individual Shrink Wrapping of Zucchini Fruit Improves Postharvest Chilling Tolerance Associated with a Reduction in Ethylene Production and Oxidative Stress Metabolites

Meg??as, Zoraida; Mart??nez, Cecilia; Manzano, Susana; Garc??a, Alicia; Rebolloso-Fuentes, Mar??a del Mar; Garrido Garrido, Dolores; Valenzuela Manj??n-Cabeza, Juan Luis; Jamilena, Manuel
Fonte: Public Library of Science (PLOS) Publicador: Public Library of Science (PLOS)
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.93%
We have studied the effect of individual shrink wrapping (ISW) on the postharvest performance of refrigerated fruit from two zucchini cultivars that differ in their sensitivity to cold storage: Sinatra (more sensitive) and Natura (more tolerant). The fruit was individually shrink wrapped before storing at 4??C for 0, 7 and 14 days. Quality parameters, ethylene and CO2 productions, ethylene gene expression, and oxidative stress metabolites were assessed in shrink wrapped and non-wrapped fruit after conditioning the fruit for 6 hours at 20??C. ISW decreased significantly the postharvest deterioration of chilled zucchini in both cultivars. Weight loss was reduced to less than 1%, pitting symptoms were completely absent in ISW fruit at 7 days, and were less than 25% those of control fruits at 14 days of cold storage, and firmness loss was significantly reduced in the cultivar Sinatra. These enhancements in quality of ISW fruit were associated with a significant reduction in cold-induced ethylene production, in the respiration rate, and in the level of oxidative stress metabolites such as hydrogen peroxide and malonyldialdehyde (MDA). A detailed expression analysis of ethylene biosynthesis, perception and signaling genes demonstrated a downregulation of CpACS1 and CpACO1 genes in response to ISW...

Ethylene negatively regulates aluminium-induced malate efflux from wheat roots and tobacco cells transformed with TaALMT1

Tian, Q.; Zhang, X.; Ramesh, S.; Gilliham, M.; Tyerman, S.D.; Zhang, W.H.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
Publicado em //2014 EN
Relevância na Pesquisa
36.92%
An important mechanism for Al(3+) tolerance in wheat is exudation of malate anions from the root apex through activation of malate-permeable TaALMT1 channels. Here, the effect of ethylene on Al(3+)-activated efflux of malate was investigated using Al(3+)-tolerant wheat genotype ET8, which has high expression of TaALMT1. Exposure of ET8 plants to Al(3+) enhanced ethylene evolution in root apices. Treatment with the ethylene synthesis precursor 1-aminocyclopropane-1-carboxylic acid (ACC) and ethylene gas suppressed Al(3+)-induced malate efflux from root apices, whereas the intracellular malate concentrations in roots were not affected. Malate efflux from root apices was enhanced in the presence of Al(3+) by two antagonists of ethylene biosynthesis, aminoethoxyvinylglycine (AVG) and 2-aminoisobutyric acid (AIB). An increase in Al accumulation in root apices was observed when treated with ACC, whereas AVG and AIB suppressed Al accumulation in root apices. Al(3+)-induced inhibition of root elongation was ameliorated by pretreatment with AIB. In addition, ethylene donor (Ethrel) also inhibited Al(3+)-induced malate efflux from tobacco cells transformed with TaALMT1. ACC and the anion-channel blocker niflumate had a similar and non-additive effect on Al-induced malate efflux from root apices. Treatment of ET8 plants with ACC enhanced expression of TaALMT1...

Meloidogne incognita (nematode) parasitism of Lycopersicon esculentum (tomato) plants : Ethylene action in susceptible and resistant host responses

Akitt, David Baxter.
Fonte: Brock University Publicador: Brock University
Tipo: Electronic Thesis or Dissertation
ENG
Relevância na Pesquisa
36.95%
Involvement of ethylene in the etiology of tomato plants (Lycopersicon esculentum) infected with the root-knot nematode (Meloidogyne incognita) was investigated. Endogenous root concentrations of ethylene were not significantly different in uninfected resistant var. Anahu and susceptible var. Vendor plants. Exposure of resistant plants to high doses of infectious nematode larvae did not affect root ethylene concentrations during the subsequent 30 day period. The possibility that ethylene may be involved in the mechanism of resistance is therefore not supported by these experiments. In no experiments did ethylene concentrations in roots of susceptible plants increase significantly subsequent to ~ incognita infestation. This result is not consistent with the hypothesis in the literature which suggests that increased ethylene production accompanies gall formation. Growth of susceptible tomato plants was affected by ~ incognita infestation such that root weights increased (due to galling), stem heights decreased and top weights increased. The possibility that alterations in stem growth resulted from increased production of 'stress' ethylene is discussed. Growth of resistant plants was unaffected by exposure to high doses of ~ incognita and galls were never detected on the roots of these plants. Root ethane concentrations generally varied in parallel with root ethylene concentrations although ethane concentrations were without exception greater. In 4 of 6 experiments conducted ethane/ethylene ratios increased significantly with time. These results are discussed in the light of published data on the relationship between ethane and ethylene synthesis. The term infested is used throughout this thesis in reference to plants whose root systems had been exposed to nematodes and does not distinguish between the susceptible and resistant response.

Use of ethylene production as a marker for the selection of gynoecy in melon (Cucumis melo L.)

Manzano, S.; Martínez, C.; Kraakman, P.; Jamilena, M.
Fonte: INRA. Centre de Recherche d'Avignon. Unité Génétique et Amélioration des Fruits et Légumes, Montfavet (France) Publicador: INRA. Centre de Recherche d'Avignon. Unité Génétique et Amélioration des Fruits et Légumes, Montfavet (France)
Tipo: Poster
EN; ENG
Relevância na Pesquisa
36.92%
Two different approaches have been used to analyze whether the measurements of ethylene produced by different plant organs may constitute a good tool for the selection of gynoecy in melon (Cucumis melo). Firstly, the effects of treatments with either ethylene or the ethylene inhibitor AVG on the sex expression of different gynoecious, monoecious and andromonoecious lines of melon were compared. Secondly, the level of ethylene was measured in leaves, as well as apical and lateral meristems of different gynoecious and monoecious lines of melon. The differences observed in the sensitivity of the analyzed gynoecious lines to ethylene treatments suggested the existence of variation in the internal level of ethylene. In fact, leaves and apical meristems from seedlings of gynoecious plants produced two to threefold higher ethylene than monoecious lines. Taken together, our results indicate that ethylene production may be used as an early selective tool for gynoecy in melon breeding programs.; Cucurbitaceae 2008. IX EUCARPIA Meeting. Avignon (France), May 21-24th, 2008

Arabidopsis Seedling Growth Response and Recovery to Ethylene. A Kinetic Analysis1

Binder, Brad M.; O'Malley, Ronan C.; Wang, Wuyi; Moore, Jeannette M.; Parks, Brian M.; Spalding, Edgar P.; Bleecker, Anthony B.
Fonte: American Society of Plant Biologists Publicador: American Society of Plant Biologists
Tipo: Artigo de Revista Científica
Publicado em /10/2004 EN
Relevância na Pesquisa
36.92%
Responses to the plant hormone ethylene are mediated by a family of five receptors in Arabidopsis that act in the absence of ethylene as negative regulators of response pathways. In this study, we examined the rapid kinetics of growth inhibition by ethylene and growth recovery after ethylene withdrawal in hypocotyls of etiolated seedlings of wild-type and ethylene receptor-deficient Arabidopsis lines. This analysis revealed that there are two phases to growth inhibition by ethylene in wild type: a rapid phase followed by a prolonged, slower phase. Full recovery of growth occurs approximately 90 min after ethylene removal. None of the receptor null mutations tested had a measurable effect on the two phases of growth inhibition. However, loss-of-function mutations in ETR1, ETR2, and EIN4 significantly prolonged the time for recovery of growth rate after ethylene was removed. Plants with an etr1-6;etr2-3;ein4-4 triple loss-of-function mutation took longer to recover than any of the single mutants, while the ers1;ers2 double mutant had no effect on recovery rate, suggesting that receiver domains play a role in recovery. Transformation of the ers1-2;etr1-7 double mutant with wild-type genomic ETR1 rescued the slow recovery phenotype, while a His kinase-inactivated ETR1 construct did not. To account for the rapid recovery from growth inhibition...

Ethylene regulation under different watering conditions and its possible involvement in coffee (Coffea arabica L.) flowering; Regulação do etileno sob diferentes condições hídricas e seu possível envolvimento no florescimento do café (Coffea arabica L.)

Lima, André Almeida
Fonte: Universidade Federal de Lavras; Programa de Pós-Graduação em Fisiologia Vegetal; UFLA; brasil; Departamento de Zootecnia; Science of Tropical Environments Postgraduate program, Lancaster University, United Kingdom Publicador: Universidade Federal de Lavras; Programa de Pós-Graduação em Fisiologia Vegetal; UFLA; brasil; Departamento de Zootecnia; Science of Tropical Environments Postgraduate program, Lancaster University, United Kingdom
Tipo: Tese de Doutorado
Publicado em 23/11/2015 ENG
Relevância na Pesquisa
36.95%
Coffee is one of the world's favourite beverage and the second most traded commodity after oil However, coffee quality can be greatly affected by fruit ripening stage at harvest time, which is often asynchronous due to the sequential flowering in this species. Coffee sequential flowering is a result of asynchronies in bud development and also environmental factors, since anthesis is triggered by precipitation after a period of water deficit. This series of events is commonly associated with an increase in ethylene production levels, suggesting that ethylene may be involved in the control of coffee anthesis promotion and its regulation might help to reduce the number of flowering events and thus promoting blossoming concentration. Thus, it was hypothesised that a droughtrewatering-induced ethylene burst might be the basis of the drought-rewateringinduced flowering in coffee trees. In order to test this hypothesis, this study aimed to access the effects of exogenous 1-MCP application on flowering of coffee trees under field conditions and, under greenhouse conditions, we aimed to study the ethylene regulation, through quantification of ethylene levels and expression levels of genes of the ethylene biosynthesis and signaling pathways...

Transient exposure to ethylene stimulates cell division and alters the fate and polarity of hypocotyl epidermal cells

Kazama, H; Dan, Haruka; Imaseki, Hidemasa; Wasteneys, Geoffrey
Fonte: American Society of Plant Biologists Publicador: American Society of Plant Biologists
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
36.96%
After transient exposure to the gaseous hormone ethylene, dark-grown cucumber (Cucumis sativus) hypocotyls developed unusual features. Upon ethylene's removal, the developing epidermis showed significant increases in cell division rates, producing an abundance of guard cells and trichomes. These responses to ethylene depended on the stage of development at the time of ethylene exposure. In the upper region of the hypocotyl, where cells were least differentiated at the onset of ethylene treatment, complex, multicellular protuberances formed. Further down the hypocotyl, where stomata and trichomes were beginning to develop at the onset of ethylene exposure, an increase in the number of stomata and trichomes was observed. Stomatal complexes developing after the ethylene treatment had a significant increase in the number of stomatal subsidiary cells and the number of cells per trichome increased. Analysis of division patterns in stomatal complexes indicated that exposure to ethylene either suspended or altered cell fate. Ethylene also altered cell division polarity, resulting in aberrant stomatal complexes and branched trichomes. To our knowledge, the results of this study demonstrate for the first time that transient treatment with physiological concentrations of ethylene can alter cell fate and increase the propensity of cells to divide.

Ethylene modulates root wave responses in Arabidopsis

Buer, Charles; Wasteneys, Geoffrey; Masle, Josette
Fonte: American Society of Plant Biologists Publicador: American Society of Plant Biologists
Tipo: Artigo de Revista Científica
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When stimulated to bend downward by being held at 45 degrees off vertical but unable to penetrate into agar-based media, Arabidopsis roots develop waving and looping growth patterns. Here, we demonstrate that ethylene modulates these responses. We determined that agar-containing plates sealed with low-porosity film generate abiotic ethylene concentrations of 0.1 to 0.3 μL L-1, whereas in plates wrapped with porous tape, ethylene remains at trace levels. We demonstrate that exogenous ethylene at concentrations as low as a few nanoliters per liter modulates root waving, root growth direction, and looping but through partly different mechanisms. Nutrients and Suc modify the effects of ethylene on root waving. Thus, ethylene had little effect on temporal wave frequency when nutrients were omitted but reduced it significantly on nutrient-supplemented agar. Suc masked the ethylene response. Ethylene consistently suppressed the normal tendency for roots of Landsberg erecta to skew to the right as they grow against hard-agar surfaces and also generated righthanded petiole twisting. Furthermore, ethylene suppressed root looping, a gravity-dependent growth response that was enhanced by high nutrient and Suc availability. Our work demonstrates that cell file twisting is not essential for root waving or skewing to occur. Differential flank growth accounted for both the extreme root waving on zero-nutrient plates and for root skewing. Root twisting was nutrient-dependent and was thus strongly associated with the looping response. The possible role of auxin transport in these responses and the involvement of circadian rhythms are discussed.