A method for determining the concentration of ethylene in the gas phase of vegetative plant tissues.
About: This article is published in Plant Physiology.The article was published on 1970-08-01 and is currently open access. It has received 130 citations till now.
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TL;DR: The present findings do not authenticate the involvement of F. mangiferae in the disease, however hormonal imbalance, most probably ethylene, might be responsible for deformed functional morphology of panicle and a signal transduction mechanism of stress-stimulated ethylene imbalance causing physio-morphological changes in reproductive organs of mango flower and thereby failure of fertilization and fruit set needs to be investigated.
Abstract: Mango malformation is the most important and threatening disease of recent times, primarily because of persistent lacuna in complete understanding of its nature. Diverse Fusarium spp, including F. mangiferae, were found to be associated with the disease. Here, F. mangiferae from mango cv Dashehri was morphologically characterized. Typically, oval-shaped microconidia without septum and crescent-shaped macroconidia with 3-septate were more often observed, whereas not a single chlamydospore was detected. The length and width of micro- and macro-conidia were 7.5, 55, 3.2, and 3.5, respectively. The plant growth regulators such as NAA, GA3, BAP and ethrel were found to induce in vitro germination of conidia of F. mangiferae after 12 h. In contrast, antimalformin silver nitrate (AgNO3) inhibits conidial germination in vitro and none of conidia was germinated beyond 500 ppm, however antimalformin glutathione was highly effective in stimulating conidial germination of F. mangiferae in vitro at > 1000 ppm after 24 h. We observed that the response of F. mangiferae to germinate the conidia in vitro under influence of plant growth regulators and antimalformins is not coincided with earlier findings of reduced disease incidence by exogenous application of these compounds. The present findings do not authenticate the involvement of F. mangiferae in the disease, however hormonal imbalance, most probably ethylene, might be responsible for deformed functional morphology of panicle. Further, a signal transduction mechanism of stress-stimulated ethylene imbalance causing physio-morphological changes in reproductive organs of mango flower and thereby failure of fertilization and fruit set, which needs to be investigated.
2,202 citations
TL;DR: The results suggest that adventitious rooting and cortical air space formation in nodal roots in Zea mays may be stimulated by enhanced concentrations of endogenous ethylene arising either from entrapment of the gas by unstirred water layers around the roots and/or by increased biosynthesis, considered conducive to survival in waterlogged soil.
Abstract: The roots and stem base of intact, 10 day old maize (Zea mays L. cv. LG11) plants, grown in nutrient solution, were continuously aerated either with ethylene (5 μl l(-1)) in air or with air alone. Ethylene treatment hastened the emergence of adventitious (nodal) roots from the base of the shoot, but slowed their subsequent extension. Ethylene also promoted the collapse of cells in the cortex of these roots, with lysigenous development of prominent air spaces (aerenchyma). Non-aeration of the nutrient solution caused endogenously produced ethylene to accumulate in the roots, and stimulated both the emergence of adventitious roots and the formation of cortical air spaces in them. With non-aeration the concentration of oxygen did not fall below 1% in the equilibrium gas phase (air=20.8%). Complete deoxygenation of the nutrient solution, produced by passing oxygen-free nitrogen gas, prevented both air space formation and the evolution of ethylene by root segments.These results suggest that adventitious rooting and cortical air space formation in nodal roots in Zea mays may be stimulated by enhanced concentrations of endogenous ethylene arising either from entrapment of the gas by unstirred water layers around the roots and/or by increased biosynthesis. These responses are considered conducive to survival in waterlogged soil.
381 citations
TL;DR: Edible coatings can be used to help in the preservation of minimally processed fruits, providing a partial barrier to moisture, oxygen and carbon dioxide, improving mechanical handling properties, carrying additives, avoiding volatiles loss, and even contributing to the production of aroma volatile.
Abstract: The production of fresh-cut fruits is increasingly becoming an important task as consumers are more aware of the importance of healthy eating habits, and have less time for food preparation. A fresh-cut fruit is a fruit that has been physically altered from its original state (trimmed, peeled, washed and/or cut), but remains in a fresh state. Unfortunately since fruits have living tissue, they undergo enzymatic browning, texture decay, microbial contamination, and undesirable volatile production, highly reducing their shelf life if they are in any way wounded. Edible coatings can be used to help in the preservation of minimally processed fruits, providing a partial barrier to moisture, oxygen and carbon dioxide, improving mechanical handling properties, carrying additives, avoiding volatiles loss, and even contributing to the production of aroma volatiles.
365 citations
TL;DR: Results suggest that a gradual build-up of FRs leads to peroxidative damage of membrane lipids during aging of potato seed-tubers.
Abstract: Previous research has shown that cell membranes of potato (Solanum tuberosum L. cv Russet Burbank) seed-tubers lose integrity between 7 and 26 months of storage (4[deg]C, 95% relative humidity), and this loss coincides with a significant decrease in growth potential. The age-induced decline in membrane integrity is apparently due to increased peroxidative damage of membrane lipids. Malondialdehyde (MDA) and ethane concentrations (sensitive markers of lipid peroxidation and membrane damage) increased in seed-tuber tissues with advancing age. Moreover, in vivo ethane production from discs of cortex tissue from 13- and 25-month-old seed-tubers was 87% greater (on average) than that from discs from 1-month-old tubers. Calcium suppressed ethane production from all ages of tissue discs, and the effect was concentration dependent. Linoleic acid enhanced ethane production from 5- and 17-month-old tubers by 61 and 228%, respectively, suggesting that older tissue may contain a higher free-radical (FR) titer and/or lower free polyunsaturated fatty acid content. In addition, throughout plant establishment, the internal ethane concentration of older seed-tubers was 54% higher than that of younger seed-tubers. MDA concentration of tuber tissue declined by about 65% during the initial 7 months of storage and then increased 267% as tuber age advanced to 30 months. The age-induced trend in tuber reducing sugar concentration was similar to that of MDA, and the two were linearly correlated. The age-dependent increase in reducing sugars may thus reflect peroxidative degeneration of the amyloplast membrane, leading to increased starch hydrolysis. Compared with 5-month-old seed tubers, 17- and 29-month-old seed-tubers had significantly higher levels of lipofuscin-like fluorescent compounds (FCs), which are produced when MDA reacts with free amino acids. Age-dependent increases in MDA, ethane, and FCs were not associated with higher activities of phospholipase and lipoxygenase in tissue from older tubers. In fact, 8-month-old seed-tubers had significantly higher activities of these enzymes than 20-month-old seed-tubers. However, the activities of superoxide dismutase, peroxidase, and catalase in 20-month-old tubers were substantially higher out of storage, and increased at a faster rate during plant establishment, than in 8-month-old seed-tubers. Collectively, these results suggest that a gradual build-up of FRs leads to peroxidative damage of membrane lipids during aging of potato seed-tubers.
251 citations
TL;DR: The data suggest that the association of peroxidase with resistance was a consequence of, not a determinant in, resistance, and that this isozyme can account for the increased per oxidase activity observed in extracts from resistant plants.
Abstract: In common with other disease situations, rust-resistant wheat leaves show a large increase in peroxidase activity during infection. Peroxidase isozymes from healthy or infected lines of wheat (Triticum aestivum L.) near isogenic for resistance and susceptibility to race 56 of Puccinia graminis tritici were separated by gel electrophoresis and the activity of each was estimated by photometric scanning. In order to ensure that the activity of isozymes observed on gels reflected the changes found in peroxidase enzymes assayed spectrophotometrically in extracts, a study was made of extraction procedures, substrates, and reaction conditions for both types of enzyme measurements. Of the 14 isozymes detected in both healthy and infected leaves, increases in only 1 (isozyme 9) were associated consistently with the development of resistant disease reaction at 20 C. Additional evidence was obtained to show that this isozyme can account for the increased peroxidase activity observed in extracts from resistant plants. When plants with high induced peroxidase activity due to resistance at 20 C were treated with ethylene or transferred to 25 C, they reverted to complete susceptibility. However, the disease-induced activity of isozyme 9 did not fall. The data suggest that, in this case, the association of peroxidase with resistance was a consequence of, not a determinant in, resistance.
204 citations
References
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TL;DR: It is feasible to appraise critically those instances in which fruits have been reported to produce ethylene not at all or only after the climacteric has started, and also to determine the content of ethylene within a fruit at the onset of the rise in respiration.
Abstract: There have arisen two schools of thought concerning the role of ethylene in fruit maturation: the classic view of Kidd and West (26) and Hansen (22) that ethylene is a ripening hormone, and a recent interpretation by Biale et al (7, 3, 4) that it is a by-product of the ripening process The original presentation of the by-product theory in this journal (7) was tempered with the reminder that 01 ppm ethylene may stimulate ripening, so that "in the absence of any information correlating the internal ethylene content with the rate of ethylene production, one can advance the argument that small quantities sufficient to induce ripening are produced prior to the rise of respiration, but measurable amounts are detected only after the onset of the climacteric" The development of highly sensitive gas chromatographic instruments makes it feasible to appraise critically those instances in which fruits have been reported to produce ethylene not at all or only after the climacteric has started, and also to determine the content of ethylene within a fruit at the onset of the rise in respiration Results of such experiments are reported in this communication, and they have a direct bearing on the problem of whether or not ethylene is a natural ripening hormone
416 citations
TL;DR: Experiments indicate that ethylene is derived from acetate or acids of the Krebs cycle and acts by binding to a metal receptor site in the tissue, and reinforces the view that Ethylene is a ripening hormone.
Abstract: Recent studies employing gas chromatography show that an amount of ethylene large enough to stimulate ripening is always present within a fruit before the respiratory climacteric begins. This fact and data from experiments in which fruits were exposed to a partial vacuum or varying concentrations of O(2), CO(2), and ethylene oxide reinforces the view that ethylene is a ripening hormone. The respiratory climacteric begins soon after the fruit is harvested because the tissue no longer receives from the shoot system a substance which inhibits ripening; this substance may act by lowering the sensitivity of the fruit to ethylene. The threshold for ethylene action is also influenced by the composition of the atmosphere, for O(2) is a substrate in the reaction activated by ethylene and CO(2) inhibits the action of ethylene by competing with the olefin for the receptor site. Experiments indicate that ethylene is derived from acetate or acids of the Krebs cycle and acts by binding to a metal receptor site in the tissue.
335 citations
254 citations
Journal Article•
TL;DR: The data indicate that ethylene causes abscission in vivo by inhibiting auxin synthesis and transport or enhancing auxin destruction, thus lowering the diffusible auxin level.
Abstract: Evidence supporting the hypothesis that ethylene is involved in the control of senescence and abscission is reviewed. The data indicate that ethylene causes abscission in vivo by inhibiting auxin synthesis and transport or enhancing auxin destruction, thus lowering the diffusible auxin level. Studies with isolated leaves and explants suggest that the gas also may influence abscission by accelerating senescence and through an action on plant cell walls. Freshly prepared explants produce ethylene at a rate which must be high enough to maximally affect the tissue and this may explain why these explants (stage I) cannot respond to applied ethylene.
189 citations
178 citations