Article

# Seasonal Patterns of Acid Metabolism and Gas Exchange in Opuntia basilaris

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## Abstract

Acid metabolism and gas exchange studies were conducted in situ on the cactus Opuntia basilaris Engelm. and Bigel. A pattern of significant seasonal variation was evident. The pattern was controlled by rainfall, which significantly influenced plant water potentials, total gas transfer resistances, and nocturnal organic acid synthesis. In winter and early spring, when plant water stress was mild, stomatal and mesophyll resistances remained low, permitting enhanced nocturnal assimilation of (14)CO(2). The day/night accumulation of acidity was large during these seasons. In summer and fall, plant water stress was moderate, although soil water stress was severe. The nocturnal assimilation of (14)CO(2) was very low during these seasons, even in stems with open stomata, indicating large mesophyll resistances restricting exogenous gas incorporation. The day/night accumulation of acidity was reduced, and a low level of acid metabolism persisted throughout this period. The rapid response to a midsummer rainfall emphasizes the importance of plant water potential as a parameter controlling over-all metabolic activity. The seasonal variations of acid metabolism and gas exchange significantly influenced the efficiency of water use and carbon dioxide assimilation. Periods of maximal efficiency followed rainfall throughout the course of the year.

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... Oken cy D Sutton and Osmond 1972, δ Bender 1973, Lüttge 1991, M Holtum 2007 Cotyledon ausana Dinter d Nishida 1963, Schutte 1967, Mooney 1977 1977, Ziegler 1996 Crassula pyramidalis Thunb. d Bonner and Bonner 1948, Thomas and Ranson 1954, Schutte 1967, Milburn 1968, Holdsworth 1971, Bender 1973, Mooney 1977, Kluge and Ting 1978, Rustin 1988, Brulfert 1991, von Willert 1992, Robinson 1993, Keeley 1996, 1998, Pilon-Smits 1996, Ziegler 1996, Herppich and Peckman 2000 Echeveria gibbiflora DC. d D Holdsworth 1971, δ Griffiths 1988 Hylotelephium cauticola Praeger H.Ohba d Kluge and Ting 1978, Muller and Kluge 1983, Lee and Griffiths 1987, Brulfert 1988, Smirnoff 1996 Gregory 1954, Nuernbergk 1961, Ac Nishida 1963, E Dittrich 1973, δ Osmond 1973 Kalanchoe marmorata Baker d Ac Nishida 1963Kalanchoe spathulata DC. d Gregory 1954, Nuernbergk 1961, Lyndon 1962, Nishida 1963, Oeschager and Lerman 1970, Holdworth 1971, Bender 1973, Jones 1975, Osmond 1975, Black and Williams 1976, Winter 1979, Schafer and Lüttge 1988, Robinson 1993, Kluge and Brulfert 1996, Winter and Holtum 2002 Sedum bulbiferum Makino d Thomas and Ranson 1954, Holdsworth 1971, Smith and Epstein 1971, Kluge and Osmond 1972, Bender 1973, Osmond 1975, Woodward 1975, Kluge 1977, Kluge and Ting 1978, Schuber and Kluge 1981, Teeri 1981, Smith and Eickmeier 1983, Lee and Griffiths 1987, Martin 1988, Pilon-Smits 1990, Gravatt and Martin 1992, Sayed 1994, Smirnoff 1996, Ziegler 1996 Ac Reddy and Das 1978, δ Bender 1971, Bender 1973, Eder 1981, Batanouny 1991 Bender 1971, Koch and Kennedy 1980, 1982, Ku 1981, Kraybill and Martin 1996, Guralnick and Jackson 2001, Guralnick 2002, Winter and Holtum 2014 Portulaca oleracea L. C 4 / cy δ Bender 1971, H Koch and Kennedy 1980, 1982, Ku 1981, D Koch and Kennedy 1980, Kraybill and Martin 1996, Winter and Holtum 2014, M Ku 1981, Kraybill and Martin 1996 Thomas and Ranson 1954, Kausch 1965, Ting and Dugger 1968, Pattern and Dinger 1969, Bender 1973, Osmond 1973, Szarek 1973,Mooney 1974, Szarek and Ting 1974, Samish and Ellern 1975, Osmond 1975, Black and Williams 1976, Eickmeier and Bender 1976, Syvertsen 1976, Ting 1976, Eickmeier 1978, Kluge and Ting 1978, Reddy and Das 1978, Szarek and Ting 1979, Whiting 1979, Koch and Kennedy 1980, Acevedo 1983, Nobel and Hartsock 1986, Robinson 1993 D Nuernbergk 1961, Rayder and Ting 1983, δ Bender 1971, Griffiths1988 , H Rayder and Ting1983 Hoya kerrii Craib Nuernbergk 1961, Bender 1971, Winter 1983, 1986a, Griffiths 1988 Aster tripolium L. ...
... Kleinia haworthii DC. Thoday and Evans 1931, Bennet-Clark 1933, Thomas and Richards 1944, Thomas and Ranson 1954, Schutte 1967 and Dugger 1968Despain 1970Bender 1973Dinger and Pattern 1974Mooney 1974Samish and Ellern 1975Syvertsen 1976Rayder and Ting 1981Acevedo 1983Nobel and Hartsock 1986Winter 1986aRobinson 1993 Thomas and Ranson 1954Nuernbergk 1961Kausch 1965Ting and Dugger 1968Patten and Dinger 1969Holdsworth 1971Bender 1973Osmond 1973Szarek 1973 Dinger and Pattern 1974Mooney 1974Szarek and Ting 1974Samish and Ellern 1975Osmond 1975Black and Williams 1976Eickmeier and Bender 1976Syvertsen 1976Ting 1976Eickmeier 1978Kluge and Ting 1978Reddy and Das 1978Szarek and Ting 1979Whiting 1979Koch and Kennedy 1980Rayder and Ting 1981Acevedo 1983 Nuernbergk 1961Milburn 1968Bender 1973Lange 1975Lange and Zuber 1977Mooney 1977Reddy and Das 1978Winter 19831986bEarnshaw 1987Griffiths 1988 5 2 Thomas and Ranson 1954Nuernbergk 1961Schutte 1967Milburn 1968 Ganzman and von Willert 1972Bender 1973Mooney 1977Klug and Ting 1978Earnshaw 1987Griffiths 1988 ...
Article
Crassulacean acid metabolism (CAM), the photosynthetic pathway that minimize water loss and the plants with CAM occupy hot and semi-arid regions. Recently, there has been increased attention to CAM plants that may serve as stable production under climate change and are cultivated for experiments. CAM plants live in variable environments on the earth as tropical epiphytes, halophytes, and aquatic macrophytes. Therefore, we would find them in variable environments in Japan. However, we have little information on the species and their habitats. In this study, CAM plants occurring in Japan are listed, especially the habitats, as a first step to understand the ecology of CAM plants by using domestic and foreign literature. There are 23 families, 83 genera, 237 CAM species in total in Japan. They are comprised of five submerged aquatic species of lycopodiophyte, Isotaceae, four epiphytic ferns of Pteridophyte, only one gymnosperm, Welwitschia mirabilis and in Magnoliophyta, one species of Piperaceae, 7 families 25 genera 86 monocots and 11 families 53 genera 140 eudicots. There are 185 cultivated species, which occupied about 80% of CAM species in Japan. There are also 56 native species in Japan, and almost of them live under water-limit condition such as on the rock or by the seaside. Although there are 33 naturalized species, CAM belonging to Rubiaceae and etc have not been found in Japan.
... Further studies with T. usneoides have supported this conclusion. In situ measurements of nocturnal C0 2 uptake in plants in North Carolina indicated that lower tissue water contents during rainless periods were not correlated with decreased CAM activity (MAR- TIN et al. 1981), as is usually the case (SZAREK and TING 1975;HANSCOM and TING 1978;KLUGE and TING 1978). Finally, plants monitored in the laboratory exhibited higher rates of nocturnal C0 2 uptake following wetting, relative to rates with the same plants before wetting (MARTIN and SIEDOW 1981). ...
... gested in the past(KLUGE et al. 1973;MARTIN and SIEDOW 1981). Although tissue water content and, hence, nocturnal C0 2 uptake declined very slowly, this atmospheric epiphyte responded to increasing tissue desiccation as do terrestrial CAM plants, i.e., by reducing C0 2 uptake(SZAREK and TING 1975;KLUGE and TING 1978). The lack of a positive correlation between nocturnal C0 2 uptake and tissue water content re-ported by MARTIN et al. (1981) is difficult to interpret since too many environmental conditions as well as plant water content varied between sampling dates in the field. ...
Article
A 10-d drought did not stimulate nocturnal CO2 uptake in this species, but reports of nocturnal water vapor absorption were confirmed in situ throughout a year, although tissue hydration from this source was insufficient to offset daytime water loss. The unusual nature of the water relations of T. usneoides is probably attributable to the interactions between 2 "pools' of water and the external atmosphere. The dense indumentum of trichomes obscuring the surface of this epiphyte comprises one pool and is most likely responsible for rapid hydration early in the night and dehydration early in the day. In addition, stomata control water loss from the living mesophyll cells, the 2nd pool, for the remainder of the night. The high rates of water loss observed throughout the day when stomata are closed probably result from leakage through the trichomes. -from Authors
... Beavertail cactus, Opuntia Basilaris, is a species of Cactaceae family, which is widespread in the arid areas of southwestern United States. 15 Production of high-performance cellulose nanofibers from this plant would provide a novel and abundant resource for bio-based, strong, and light weight composites. As a result, this study has been devoted to the isolation of cellulose nanofibers from the skin of beavertail cactus plant using a chemo-mechanical technique. ...
... Titratable acidity was measured by the method of Szarek and Ting (1974) and chlorophyll by the method of Arnon (1949). ...
Article
Adult leaves, protocorms and seedlings of succulent tropical orchids exhibit diurnal fluctuations in acidity. The titratable acidity varied at different stages of growth. The fluctuation in acidity was barely detectable in protocorms but as they grew older, their capacity for acid accumulation increased.The O2 exchange in orchid protocorms and seedlings was similar to that of adult leaves in their responses to temperature, bicarbonate and light intensity. It is concluded that protocorms and seedlings resemble adult organs in having the characteristics of crassulacean acid metabolism (CAM).
... Such a relatively high value after a 2-mo drought treatment agrees well with several other previous investigations of the water relations of atmospheric epiphytes (see Martin 1994). These findings are not unique to epiphytic bromeliads; they also characterize the response of many terrestrial succulents to drought (Szarek and Ting 1974;Nobel 1988;Goldstein et al. 19916). ...
Article
Although physiological responses to drought have been examined in several species of epiphytic bromeliads, few have included a comprehensive methodological approach to the study of the carbon and water relations of a single species undergoing drought: stress. Thus, physiological and anatomical responses to an imposed drought treatment were examined in the atmospheric Crassulacean acid metabolism (CA-M) epiphyte Tillandsia ionantha. From 0 through 20 d without water, nocturnal malic acid accumulation and CO(2) uptake rates did not change despite a 17% reduction in relative water content. In addition, water potentials averaged -0.40 MPa and, unlike leaf water content, did not decline. The avoidance of further declines In leaf water content was attributed to thr restriction of stomatal opening to the night (a characteristic feature of CAM), to low stomatal densities and small stomatal pores, and to a thick boundary layer resulting from a dense foliar trichome cover. The maintenance of high physiological activity during the first 20 d of the drought treatment was most likely a result of the high water potentials in the chlorenchyma, which were attributed, in part, to water movement from the water-storage parenchyma (= "hydrenchyma") to the chlorenchyma. Nocturnal malic acid accumulation and the rate of net CO(2) exchange declined in a linear fashion from 30 to 60 d without water, as did leaf water potential and osmotic potential. During this time, CO(2) recycling increased from ca. 20% to nearly 75%. Though declining throughout this later stage of the drought treatment, metabolic activity remained relatively high, possibly as a result of the observed osmotic adjustment as well as a potentially high cell wall elasticity.
... Similar results were obtained in the current study of Spanish moss. These results are opposite to the findings of most studies with CAM plants, where CO2 exchange is inhibited by increasing water stress (17,20,25). However, it is possible that the strands of Spanish moss were never actually water-stressed in these studies. ...
Article
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... El clorénquima de cada lado de la muestra es separado y molido en arena esterilizada agregando 30 ml de H2O destilada y enseguida titulada a pH 6,4 con NaOH 0,01 N con la ayuda de un pH metro portátil (WTW pH90). Los resultados experimentales indican que el 95% de los ácidos orgánicos que contribuyen a la variación de acidez son neutralizados a pH 6,4 (Szarek & Ting 1974, Nobel 1983, Acevedo et al. 1983). Los datos son expresados en moles de co2 por m 2 de tejido fotosintético por día (Kluge y Ting 1978, Nobel & Hartsock 1983, suponiendo una estequiometría aceptada por diversos autores de 2 H+ por un CO2 fijado (Luttge & Ball 1980, Nobel & Hartsock 1983, Nobel & Valenzuela 1987. ...
... The classic example of plants that are able to prevent dehydration are succulents, e.g., pineapple. Szarek and Ting (1974) showed that the internal \$ of the cactus Opunfia basilaris did not fall below -16 bars even after 4 months without rain. Although mesophytic crops do not possess such well-developed dehydrationresistant mechanisms, it is clear from the observations of Turner (1974b), Blum (1974), and Peake ef al. (1975) that species and varieties develop different degrees of leaf water stress under similar conditions of soil water and evaporative demand. ...
Chapter
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This chapter emphasizes the measurement of plant water potential following the realization of the importance of atmospheric demand in determining plant water deficits. The total water potential concept determines the movement of water through the soil-plant-atmosphere continuum in response to gradients in water potential and of the soil, plant, and atmospheric factors that influence the development of water deficits in plants. A water deficit occurs whenever water loss exceeds absorption. The use of total water potential as the best single indicator of plant water status has its limitations while attempting to understand the effect of water deficits on the various physiological processes involved in plant growth. The chapter discusses the effects of water deficits on crop growth, crop development, and crop yield. The differences in response of plants grown under controlled conditions and in the field are discussed. Some difficulties in extrapolating from controlled environments to the field are presented in the chapter.
... Beavertail cactus, Opuntia Basilaris, is a species of Cactaceae family, which is widespread in the arid areas of southwestern United States. 15 Production of high-performance cellulose nanofibers from this plant would provide a novel and abundant resource for bio-based, strong, and light weight composites. As a result, this study has been devoted to the isolation of cellulose nanofibers from the skin of beavertail cactus plant using a chemo-mechanical technique. ...
Article
In this study, the skin of the beavertail cactus, Opuntia Basilaris, was utilized for the isolation of cellulose nanofibers using a chemo-mechanical technique. It was shown that the skins had a relatively high cellulose content while their lignin content was low. Fourier transform infrared spectroscopy and X-ray diffraction proved that the isolation of cellulose nanofibers from the amorphous components of the skins was performed successfully. The cactus skins were also shown to have a very high content of calcium oxalate crystals. Morphological observations proved that the isolated cellulose fibers had diameters in the range of 10-50 nm. It was shown that the addition of nanofibers increased the modulus and strength of the polyvinyl alcohol matrix significantly while the elongation at break decreased. Thermogravimetric analysis proved that: (i) isolated nanofibers had higher thermal stabilities than the cactus skins, and (ii) inclusion of nanofibers increased the stability of polyvinyl alcohol noticeably.
... FW). 30 The difference in acidity may be explained by the reduced exposure to daylight during winter, which promotes greater CO 2 fixation for CAM metabolism. 31 Based on the above, it is recommended to harvest cladodes a couple of hours after dawn because that provides the best acidic characteristics for consuming them as vegetable; moreover, they are turgid, rich in sugars, pro-vitamin A and vitamin C. ...
Article
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The cover image, by Rosa Isela Ventura‐Aguilar et al., is based on the Review Cactus stem (Opuntia ficus‐indica Mill): anatomy, physiology and chemical composition with emphasis on its biofunctional properties, DOI: 10.1002/jsfa.8493.
... FW). 30 The difference in acidity may be explained by the reduced exposure to daylight during winter, which promotes greater CO 2 fixation for CAM metabolism. 31 Based on the above, it is recommended to harvest cladodes a couple of hours after dawn because that provides the best acidic characteristics for consuming them as vegetable; moreover, they are turgid, rich in sugars, pro-vitamin A and vitamin C. ...
Article
Cactus stem (Opuntia ficus-indica Mill) is native to Mesoamerica and marketed in different forms such as fresh, frozen or pre-cooked. Worldwide, this vegetable is recognized for its pharmaceutical actions, including its antioxidant, diuretic, anti-carcinogenic, anti-inflammatory, antidiabetic, and anti-hypercholesterolemic properties, as well as their anti-viral and antispermatogenic effects. However, not all of these properties have been associated to its chemical composition; therefore, this review aims to present and integrate information available on the physiology and anatomy of cactus stem and its chemical composition, focusing on some of the many factors that determine its biofunctionality.
... Ye et al. (2014) found that environmental stress blocked photosynthetic primary reaction and reduced the efficiency of the original light energy conversion for Broussonetia papyrifera young plants. It was reported that the reduction of qL and YII usually led to a decrease of open fraction of PSII reaction centers and efficiency of electron transport which blocked synthesis of ATP and NADPH and caused a reduction of plant carbon fixation and assimilation efficiency (Szarek and Ting 1974). In addition, the function of the D1 protein was easily impaired under stress conditions (Bricker and Frankel 2002, Khatoon et al. 2009, Cheng et al. 2016, Xue et al. 2017, which led to inhibition of PSII electron transport rate what corresponded to the reduction of YII and qL of the tested plants under different Pb treatments. ...
Article
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Chapter
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The objective of this study was to evaluate the effect of seasonal variation in temperature and irradiation on photosynthesis rates, proportion of nocturnal CO2uptake, and water-use efficiency (WUE) inHesperaloe funifera(Agavaceae), and to discuss what these seasonal patterns reveal about the nature of the interactions among environmental factors as they affect CO2uptake.CO2uptake showed the highest 24 h integrated values in fall and spring and the lowest in winter and summer. Temperature and light do not appear to interact in a simple multiplicative manner in their relationship to photosynthesis. A conceptual model describing the seasonal pattern of photosynthetic capacity inHesperaloeis presented.Moderately high daily integrated CO2uptake rates, a long growing season, and high WUE throughout the year have agronomic significance forHesperaloeas a potential new crop for arid lands.
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Three species of cacti survived an average stem water loss of 81%. Fractional water loss was greater from water-storage tissue than from the chlorenchyma. For Carnegiea gigantea and Ferocactus acanthodes, this differential loss of water resulted from a decrease in the moles of solute per cell for storage tissue; hence, less water was retained at a given osmotic pressure than for the chlorenchyma. Opuntia basilaris lost less water from the chlorenchyma during drought because of a greater initial osmotic pressure in the chlorenchyma than in the storage tissue. Greater retention of water in the chlorenchyma would result in less disruption of photosynthetic activity in these cacti during drought.-from Authors
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Natural stands of Opuntia basilaris Engelm. & Bigel, growing under irrigated and nonirrigated (control) conditions, were used to test the hypothesis that this CAM plant was capable of a "shift" in its method of gas exchange from a typical CAM mode to a C3 mode of carbon uptake. Gas exchange data were accumulated in the field with a dual-isotope (3H2O and 14CO2) porometer, which allowed simultaneous estimates of carbon uptake and transpiration on the same plant sample. Water availability (through irrigation) increased the response of the cacti to nighttime uptake of 14CO2 (9-10 mg dm-2 h-1 in irrigated plants vs 6-7 mg dm-2 h-1 in control plants) and did not result in appreciable daytime opening of stomata as reported for other succulents. Young stems responded to irrigation to a greater extent and with greater duration than mature stems. Increased rates of nocturnal 14CO2 were related to decreased stomatal (3-4 s cm-1 for irrigated plants, 7-8 s cm-1 for control plants) resistance to gas exchange. The nocturnal efficiency of water use and CO2 uptake, as measured by the transpiration ratio, was higher than the diurnal gas exchange efficiency. Opuntia basilaris, a stem succulent, did not show a shift in metabolism in response to irrigation as commonly observed in leaf succulents.
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Imposition of water stress in young and adult thick-leaved orchids (Arachnis hookeriana var. luteola X Vanda 'Hilo Blue') and Dendrobium taurinum caused a reduction in the titratable acidity (TA) of the leaves. The reduction in TA of orchids under water stress was correlated with a decrease in nocturnal CO2 uptake. Under severe water stress, CO2 assimilation was greatly reduced and exclusively nocturnal. -from Authors
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d13C values were determined in 20 succulents from Madagascar. The values were indicative of Crassulacean Acid Metabolism in 10 species of the Didiereaceae, 4 species of the Euphorbiaceae, 2 species of the Crassulaceae and 1 species of the Cucurbitaceae. The Didiereaceae and Euphorbiaceae studied are major components of a high biomass xerophytic flora in the semi-arid southwest and south of Madagascar. Three species of the Euphorbiaceae with succulent stems and non-succulent leaves, which were cultivated outdoors in the Tananarive Botanic Garden, showed C3 like d13C values for both leaves and stems. d13C values of leaf and stem material from a similar species, collected in the south of Madagascar, indicated Crassulacean Acid Metabolism.
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Crassulacean acid metabolism is widely distributed among Bromeliaceae. Gas chromatographic analyses of cell sap extracted at the beginning and the end of the light period showed that malate is responsible for above 70% of the acidity changes. Simultaneous concentration changes in other acids were detected but their significance is not clear.
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The paper describes the basic problems occurring in absorption and fluorescence spectroscopy and gives advices how to understand or correct the signal modifications appearing very often by measuring different biological samples. In the second part a short description is given about the connection between the electronic structure of chlorophyll type pigments and their absorption and fluorescence emission bands, then methods are described used for correction and analyses of the spectra.
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General interest in the different aspects of water relations in plants has recently increased greatly. For this review, treating the period of the last three years (1972–1974) 2,700 titles on this matter were checked. Supposing that this number covers not more than three fourths of the existing relevant literature, it is realistic to assume that at least three new publications on water relations of plants have been appearing every day (see STANHILL). It is impossible to summarize this immense bulk of information. An attempt is made, however, to point out the main trends of activity and to report on major findings and their implications.
Chapter
In the Macaronesian archipelagoes speciation in the course of an adaptive radiation has occurred since Tertiary times within the genus Sempervivum s. l. (Lems, i960). As a result, nowadays about 70 endemic species can be found in the Canary Islands, Madeira, and the Cape Verde Islands, classified into the genera Aeonium, Aichryson, Greenovia, Monanthes (Praeger, 1932/67). These can be found in various habitats ranging from Mediterranean-type environments of the lowland zones through crevices of rocks within laurel forests up to rocky places of the subalpine Pinus canariensis forests and reaching an altitudinal distribution border at about 2400 m. Many species are restricted to only one island.
Chapter
Plants with crassulacean acid metabolism (CAM) are rarely the most abundant in plant communities, and rarely attain high biomass, but they are capable of an extraordinary array of physiological activities in a wide range of environments. The peculiar morphology and nocturnal physiology of CAM plants have attracted the curiosity of plant biologists for many years. The most comprehensive syntheses of the environmental biology of desert CAM plants are those of Gibson and Nobel (1986) and Nobel (1988). Epiphytic CAM plants are dealt with by Smith et al. (1986a) and aquatic CAM plants by Boston and Adams (1986). Recent reviews of the metabolic activities of CAM plants have delineated phases of the complex nocturnal-diurnal metabolic cycle and component biochemical and physiological events (Kluge and Ting, 1978; Osmond, 1978; Osmond and Holtum, 1981). However, a decade or so of investigation of these plants in many habitats has uncovered a bewildering array of exceptions and variations. In response to this we now have a new set of terminologies (Cockburn, 1985), pleas that ‘more representative studies are needed from diverse taxa before a generalized theory of CAM will be forthcoming’ (Ting, 1985) and for the need to integrate ecological, physiological and biochemical studies (Lüttge, 1987). Obviously, further studies of the physiological ecology of CAM plants are likely to be most rewarding and this chapter seeks to outline appropriate methodologies for this research. For the most part we will be concerned with modifications of techniques to meet the special problems posed by CAM plant morphology and physiology.
Chapter
An investigation of CAM with the use of the gas transfer equations, $${\rm{T = D\Delta /}}{{\rm{R}}_{\rm{a}}}{\rm{ + }}{{\rm{R}}_{\rm{s}}}$$ and $${\rm{P = D'\Delta '/}}{{\rm{R}}_{\rm{a}}}{\rm{ + }}{{\rm{R}}_{\rm{s}}}{\rm{ + }}{{\rm{R}}_{\rm{m}}}$$ suggests that CAM is adaptive to xeric conditions and similar to the C4 pathway. Transpiration ratios (TR) are low and on the order of 150 whereas for C4-piants and C3-plants they average 300 and 600 respectively. Carbon assimilation efficiency (CAE) estimates, the ratio of P to Pmax where Pmax = $$D'\Delta \sim '({{R}_{a}} + {{R}_{s}})$$ or the estimated CO2 assimilation rate at Rm = O, in the dark are about 0.7–0.9 similarly to C4 plants but unlike C3 estimates of 0.2 to 0.3. We have concluded that the CAM pathway for plants in an arid, desert environment has a two-fold interpretation: primarily, immediately after periods of rainfall and consequent high plant water potentials, nocturnal acidification rates are highest. Minimum TR of 25–70 and maximum CAE values of 0.75–0.82 occur. The level of acid metabolism decreases with decreasing water potential. Secondly, during periods of drought and water potentials of −15 to −20 bars a reduced, but steady level of acidification occurs by the reassimilation of endogenous CO2. Perhaps, further, these plants can shift from the CAM option to the C3 option under extended, favorable conditions.
Chapter
In this concluding chapter, we review some of the major findings discussed in this book and their implications for our understanding of the CAM pathway. In particular, we highlight areas of uncertainty as well as consensus and refer to a number of recent findings not covered in the individual chapters. We shall focus on the biochemistry and energetics of the CAM pathway, the developmental and environmental control of its expression in different species, factors determining the growth and productivity of CAM plants in the field, and finally its possible evolutionary origins.
Chapter
The fate of respiratory CO2 released simultaneously with the absorption of atmospheric CO2 at night during crassulacean acid metabolism (CAM) is inevitable; both sources of CO2 will contribute to the nocturnal accumulation of malate. As a result, determinations of stoichiometric relationships between the amount of malate accumulated overnight and the net amount of CO2 absorbed from the external atmosphere should yield values greater than unity. Surprisingly, this is seldom the case. Studies of numerous CAM species under optimal conditions report ratios of the amount of malate accumulated overnight to the net amount of atmospheric CO2 absorbed (hereafter referred to as “malate/CO2”) consistently near one (Medina and Delgado 1976; Nobel and Hartsock 1978, 1983; Eickmeier 1979; Nobel et al. 1984; Winter et al. 1986; Virzo De Santo et al. 1987). Apparently, either the rate of respiration is too low to contribute substantially to the nocturnal pool of malate, or experimental variability in measurements of CO2 assimilation and malate accumulation during the night might obscure small differences between these measures of CAM.
Article
Studies of the effects of the environment on the photosynthesis of young plants of Agave tequilana are scarce, although these plants occupy one third of the cultivated surface in the State of Jalisco, México. The effect of the seasonal variation on irradiance, air temperature and relative humidity and plant water status in the photosynthesis of young plants of A. tequilana was studied during 2001 and 2002. The experimental design was randomized complete blocks and the different dates of measurements of photosynthesis, from January 2001 to November 2002, were considered as the treatments. Net CO2 uptake occurred during both dry (January to May) and wet months (July to October) of the year, and the higher values of daily net CO2 uptake coincided with cool daytime/nighttime air temperature and the highest values of irradiance. Night uptake of CO2 was accompanied by positive CO2 assimilation during the day. Both showed a greater relationship with temperature than with relative humidity. The succulence of the photosynthetic tissue, and both the night and the day net CO2 uptake were determinant to maintain carbon gain in A. tequilana throughout the year, particularly during the dry season.
Article
The thermal relations of the cactus Copiapoa haseltoniana were studied in the Atacama desert. These plants are oriented in such a manner as to minimize the absorption of midday solar radiation. Additional features, such as an epidermal surface that is highly wettable by fog and dew, and that is reflective when dry, apparently also operate to reduce the temperature differential between the plant and the air and hence increase water-use efficiency. In contrast, the meristematic and reproductive tissues are located so that they have high temperatures in relation to that of the air. This could be interpreted as a mechanism to increase growth and reproduction without affecting water-use efficiency.
Article
In Agave angustifolia Haw., a leaf-succulent constitutive crassulacean acid metabolism (CAM) plant of tropical Panama, we tested whether nocturnal CO2 uptake and growth were reduced at night temperatures above 20 degrees C. Unlike some CAM model species from habitats with pronounced day-night temperature variations, in A. angustifolia temperature affected little the relative contributions of CAM and C-3 photosynthesis to growth. In plants grown under 12h light/dark regimes of 25/17, 30/22 and 35/27 degrees C, biomass increased with temperature. Maintaining day temperature at 35 degrees C and reducing night temperature from 27 to 17 degrees C markedly lowered growth, a reduction partially reversed when roots were heated to 27 degrees C. Across all treatments, whole-shoot C-13 values ranged between -14.6 and -13.2 parts per thousand, indicating a stable proportion of CO2 was fixed at night, between 75 and 83%. Nocturnal acidification reflected growth, varying between 339 and 393mol H+ g(-1) fresh mass and 63-87mol H+ cm(-2). In outdoor open-top chambers, warming the air 3 degrees C above ambient at night did not reduce biomass accumulation. The persistence of a high capacity for nocturnal CO2 fixation at the expense of a limited capacity for switching between C-3 and CAM probably makes this Agave, and others like it, potential species for biomass production in seasonally-dry landscapes.
Article
The term Crassulacean acid metabolism characterizes a type of carbon metabolism occurring almost exclusively in succulent plants, and originally only observed in species of the Crassulaceae. Plant species exhibiting CAM1 feature essentially the following activity: 1. Diurnal fluctuation of the malic acid (not malate) content of the photosynthesizing tissue, with malic acid accumulation during the night and malic acid consumption during the day. 2. Diurnal fluctuation of the starch content inverse to the oscillation of malic acid, that is, the starch content decreases during the night and increases during the day. 3. Net consumption of atmospheric CO2 by the plant during the night and depression of net CO2 uptake during the day.
Chapter
Photosynthetic metabolism in plants capable of Crassulacean acid metabolism (CAM) may involve the net fixation of CO2 in the preceeding dark period or the net fixation of CO2 in the light. The properties of these two carboxylation reactions have been examined and evidence suggesting that dark fixation is essentially a C4-like process and light fixation is essentially a C3-like photosynthetic process is presented. A number of environmental conditions directly influence the contribution of C3-like and C4-like photosynthetic options to the net carbon gain of these plants. These responses, the indicator significance of the δ13C value in CAM plants, and the relationship to growth and persistence of these species are discussed.
Article
There are some explanations for the fact that circadian endogenous rhythmicity, which is a basic general property of the physiology of eukaryotes, appears as a rather disturbing phenomenon for the physiologist, both from conceptual and experimental points of view: a) The existence of circadian rhythms discloses the annoying situation that very little is known about the inner processes which, in eukaryotic organisms, confer an adaptive ability for identifying local time and measuring the progress of a season. Nevertheless, substantial advances have been achieved in recent years on understanding the chemical and genetic mechanisms of this biological clock. b) The ubiquity of circadian rhythms results in metabolic networks shifting continuously between repeated periodic patterns (even in the absence of external periodisms). Hence iterative measurements over 24 h are necessary if one intends to obtain a realistic description of a complex physiological function, particularly when two or more pathways are likely to be involved. In CAM, the “double carboxylation” mechanism for malate synthesis, the source of phosphoenolpyruvate (PEP), the fate of pyruvate, and the variability of δ13C are probably good examples of the mixing of different pathways in different ratios according to the time of day. Attempting to integrate the effects of endogenous rhythmicity obviously makes interpretation of data and elaboration of comprehensive models more difficult.
Article
CO2 exchange and diurnal rhythms of organic acids were measured in situ in some species of Sempervivum growing at the Botanical Garden of Technische Hochschule Darmstadt. The plants showed δ¹³ C values in the range of -15‰ indicative of CAM. This finding was reconfirmed by the gas exchange pattern and the diurnal rhythm of malic acid. In all species investigated dark CO2 fixation contributed substantially to the overall carbon gain of the plants. The gas exchange patterns were clearly temperature dependent. With high temperatures during the day, even in full sunlight net CO2 output may occur.
Article
The relationship between photosynthetic pathway and climatic regime has been investigated, for parts of Israel and the Sinai. These regions are characterized by hot, long, dry summer seasons with winter rainfall. The annual rainfall is high in the northern, Mediterranean parts of Israel, and extremely low in the Negev desert and the Sinai.
Article
Pricklypear ( Opuntia spp.) is a major constraint to rangeland livestock production in several resource areas of Texas. The phenological and physiological stages of pricklypear have heretofore been ignored in relation to timing of herbicide applications. The phenology, percent total nonstructural carbohydrates (TNC), and water content in Lindheimer pricklypear ( Opuntia lindheimeri Engelm. # OPULI) were monitored biweekly for 2 yr in the southern Rolling Plains of Texas. TNC in cladophylls, crowns, and roots declined sharply from bud break (late March to late April) through the period of rapid development of new cladophylls and fruits, with minimum levels occurring during mid-July to early August. This depletion period coincides with the period when control has traditionally been attempted with broadcast applications of translocated herbicides with erratic results. Replenishment of TNC in cladophylls and basal crowns occurred during August through March or mid-April; major increases in root TNC occurred from early autumn through midwinter. Application of herbicide in late summer, autumn, or winter when TNC is being replenished in organs bearing meristematic tissue may be more effective for pricklypear control if the herbicide is translocated with photosynthates.
Article
Le métabolisme crassulacéen (CAM), voie de fixation nocturne du CO2, confère aux plantes qui en ont la potentialité génétique, une possibilité d'adaptation à la sécheresse. Au stade actuel des recherches, deux types différents d'acquisition du fonctionnement CAM ont été mis en évidence: 1) le CAM se développe sous l'effet de la contrainte elle-même et cesse en même temps qu'elle; 2) le CAM se développe préalablement à la contrainte, constituant un système de préparation adaptative de la plante; dans ce dernier cas, le photopériodisme (qui fournit à la plante qui y est sensible une lecture des saisons) peut jouer un rôle d'inducteur ou de modulateur de la voie métabolique considérée. Il avait été montré précédemment pour diverses espèces de Kalanchoe, que le photopériodisme contrôlait le CAM par un remaniement des potentiels enzymatiques de la plante, en particulier par la mise en place d'une forme isofonctionnelle de l'enzyme-clé, la phosphoenolpyruvate carboxylase. Une recherche identique a été effectuée sur des Opuntia ficus-indica soumis à une contrainte hydrique extrême succédant à divers traitements photopériodiques. Les bilans d'échange de CO2, les capacités enzymatiques de la voie CAM, et les caractéristiques hydriques des plantes ont été mesurés. Il est conclu que l'application de jours courts assure une préparation des plantes à des conditions extrêmes de sécheresse et leur permet d'y résister. Mais le mécanisme de cette préparation ne se situe pas au niveau enzymatique, et reste encore à découvrir.
Article
The patterns of gas exchange exhibited by Opuntia aurantiaca under controlled conditions (photoperiod 12 h; day/night temperature regime 30/15°C) were investigated for plants subjected to various levels of moisture stress. Unstressed plants exhibited a typical full-CAM pattern of gas exchange in which all four phases of CAM-linked CO2 exchange were evident. Net CO2 uptake during phase 1 contributed up to 82% of total carbon fixed per 24 h. The transpiration: photosynthesis ratio was low (night 31; day 135), within the range exhibited by many CAM plants and indicative of a high water use efficiency. Under all conditions of water stress net carbon gain was reduced with phase IV showing the greatest reduction and phase 1 the least. On watering, stressed plants recovered rapidly. Within 48 h of receiving water total CO2 uptake per 24 h had risen from 5,8% to 76,5% of the unstressed value.
Article
THREE different photosynthetic options have been identified in plants1,2: (1) most plants have the reductive pentose phosphate or C3 pathway, where CO2 is incorporated into ribulose-1,5-diphosphate (RuDP) to yield two molecules of 3-phosphoglyceric acid, a three-carbon compound; (2) the C4 mode, where the first photosynthetic products are four-carbon dicarboxylic acids like oxaloacetate and malate formed following CO2 incorporation into phosphoenolpyruvate (PEP); and (3) crassulacean acid metabolism (CAM), found in many succulent plants growing in arid regions. In the last, stomatal opening and net CO2 uptake occur at night, CO2 being incorporated by way of PEP carboxylase into organic acids. The tissue acidity decreases as the organic acids are decarboxylated during the day, when the internally released CO2 is prevented from leaving by the closed stomata. The water vapour concentration difference between the tissue and ambient air is less at night, and thus the night-time stomatal opening of CAM plants leads to overall water conservation. For example, the water lost per CO2 fixed averages about sixfold higher for C4 plants and tenfold higher for C3 ones than for CAM plants in natural conditions2. The net daily CO2 uptake by CAM plants is less than for C3 or C4 plants, so CAM plants tend to be relatively slow growing.
Article
Full-text available
The influence of plant water status and leaf temperature on the mesophyll resistance to C02 transfer for Deltapine cotton leaves was determined under condi-tions when the C02 supply was limiting photosynthesis. The mesophyll resistance was calculated from C02 response curves in normal air and oxygen-free air, under conditions when air was forced from the abaxial to adaxial side of the leaf to obtain a direct estimate of the CO2 concentration at the mesophyll cell wall.
Article
tltudies on the transpiration of cotton leaves were made under a range of light intensities (3' 8, 7· 5, 15· 0, and 22·5 X 10'" erg cm-ll sec-I), temperatures (30, 35, and 40°C), and humidities (relative vapour pressures ranged from c. 0·4 to c. O· 8) at several low windspeeds, v, ranging from 0·6 to 3·1 em sec-I
Article
Detached shoots of Bryophyllum fedtschenkoi maintained in a closed system in the light exhibited an endogenous circadian rhythm in CO2 compensation. The rhythm was sensitive to changes in light intensity and temperature. At 15° C it damped rapidly in light of 78 J m-2 s-1, but at 10° C a rhythm of considerable amplitude was evident at this same light intensity. During the transient (i.e. the temporary state of the rhythm before it acquired its steady state) low compensation values between 0 and 5 ppm CO2 were achieved. When the plants were maintained at a higher light intensity prior to the measurements, the period of low compensation during the transient was extended, and zero values were obtained under some conditions. Studies of gas exchange at opposite phases of the rhythm revealed: (i) that the rate of uptake of 14CO2 differed, both in light and darkness (the epidermis was removed during these observations to avoid interference from stomatal rhythms); (ii) ‘photorespiration’, estimated by extrapolation of the graph relating photosynthetic rate and CO2 concentration, was highest during the peaks of the rhythm in CO2 compensation; (iii) estimates of the capacity for ‘photorespiration’ by the glycine-1-14C assay indicated highest values during the troughs of the rhythm. These findings are discussed in relation to the C4-acid metabolism of this species. Low CO2 compensation is probably due to the activity of phosphoenolpyruvate carboxylase and not to the absence of processes involving CO2 evolution.
Article
Modifications are described in a technique for the rapid quantitative ; measurement of CÂ¹â´ and HÂ³ in biological materials by liquid ; scintillation counting of the products of oxygen flask combustion. Good results ; are reported in applications of the method in pharmacological studies in animals ; in which CÂ¹â´- and HÂ³-labeled compounds were used. (C.H.);
Article
1. The transpiration in leaves of Bryophyllum daigremontianum exactly follows the changes in consumption of atmospheric carbon dioxide (caused by the Crassulaceen acid metabolism) during the light and dark periods. After removal of the epidermis no distinct rhythm in the course of transpiration can be observed any more, whereas the characteristic CO2 exchange continues in an unchanged matter. For this reason we assume that the changing rate of CO2 uptake from the atmosphere determines the concentration of carbon dioxide in the intercellular spaces of the leaves and in this way controls the opening of stomata. 2. CO2 uptake from the atmosphere in the light phase decreases faster than CO2 consumption in the dark when the plants are held under water stress conditions. At the endpoint CO2 is fixed only in the dark period. On the basis of the connection between CO2 uptake and movement of stomata we assume a closure of the stomata during the light period (since no extracellular CO2 is fixed). Since evaporation values in the light phase are high under natural conditions, this manner of gas exchange minimizes the loss of water during water stress conditions, and nevertheless guarantees a positive balance of carbon.
Article
An attempt was made to determine the relative importance of the stomata in restricting CO2 uptake under conditions of water stress. The air-phase and liquid-phase resistances to uptake of CO2 were determined from measurements of the rates of assimilation and transpiration and the corresponding concentration gradients of CO2 and H2O vapour. The results showed that the air-phase resistances (stomata) could account for only half the reduction in the rate of photosynthesis accompanying water stress. Experiments in which air was passed through the leaf confirmed that water stress restricted CO2 fixation within the leaf itself. The results and their possible explanation are discussed in relation to other work.
Article
A portable field apparatus for the measurement of photosynthesis is described. Short pulses (20 s) of air containing 14CO2 are applied to circular leaf areas of 1 cm2, enclosed in a transparent miniature chamber; the radioactivity of the leaf areas is measured by liquid scintillation, using a new in-vial wet combustion technique. Typical daily courses of photosynthesis in maize and cotton are presented.
Article
Measurements of growth, carbon dioxide exchange, transpiration, and transpiration ratio were made for pineapple (Ananas comosus [L.] Merr.) plants. During the experimental period, their growth rate was 0.015-0.018 g increase in dry weight per day per 100 cm2 of average leaf area. Carbon dioxide exchange was recorded for 24 hr. During the first part of the light period, CO2 was given off, but uptake began in mid-afternoon and continued through the dark period. This pattern of uptake is common in plants exhibiting a crassulacean type of acid metabolism. From the same measurements, the calculated theoretical rate of net photosynthesis for pineapple was 0.5-0.7 mg/hr per 100 cm2 of leaf area. Transpiration proceeded at a rate of 0.02-0.05 g/hr per 100 cm2. Both these values are lower than those for several crop plants. The transpiration ratio for pineapple, 50, was determined from values for gain in dry weight and water loss during the experimental period of 80 days. This also is considerably less than the values for other crop plants and for trees. Since its transpiration ratio and rate of water loss are low, pineapple probably can maintain high levels of productivity in regions where water is limited.
Article
Non-autotrophic ("dark") 14CO2 metabolism and associated acid accumulation were studied in the Cactaceae. Carbon dioxide assimilation and oxygen uptake were generally lower than in crassulacean succulents. The primary products were organic acids (malic acid) and amino acids. Little or no 14C activity was detected in lipoidal or neutral components. After a 2-hr dark CO2 fixation period, the first-order rate constant for steady-state decarboxylation in the dark was 1.7 x 10-3 min-1 and in the light was 0.2 x 10-3 min-1. The greater rate in the dark was reflected in the decay of the primary product, malic acid. The slower rate in the light was accounted for by photosynthetic reassimilation of 14CO2. In part, the observed diurnal fluctuation of organic acids may be explained in terms of steady-state decarboxylation. In the dark carboxylation evidently exceeds decarboxylation, and organic acids accumulate. In the light much of the available CO2 would be assimilated by photosynthetic carboxylation reactions so ...
Article
Assimilation of carbon dioxide in the dark and on inverted stomatal rhythm are important adaptations of xerophytes.
Article
1. Wiederbefeuchtung des Wurzelraumes monatelang trockengehaltener Kakteen ruft nach Ablauf weniger Stunden Saugwurzelbildung hervor. 2. Die Transpiration steigt nach der Wiederbefeuchtung im Laufe eines Tages stark an. Sie kann als ein Zeichen dafür angesehen werden, daß im Moment des Erscheinens der Wurzeln die Wasseraufnahme sofort stark in Gang kommt, und daß damit eine sofortige Verbesserung des Wasserzustandes der Pflanze eintritt. 3. Der CO2-Gaswechsel der Opuntie erhöht sich nach der Wiederbefeuchtung des Bodens schnell. Dabei zeigt sich nicht nur die Atmung von Boden-Wurzel und Sproß gefördert, sondern auch die CO2-Dunkelfixierung und die apparente Assimilation im Licht. Die Steigerung der CO2-Abgabe des durchwurzelten Bodens tritt jeweils innerhalb von wenigen Minuten in Erscheinung, während der CO2-Verbrauch bei Assimilation und Dunkelfixierung, der offenbar einer gewissen Rhythmik unterliegt, etwas verzögert beeinflußt wird. Der Beginn des apparenten CO2-Verbrauchs wird durch die Durchfeuchtung vorverlegt, und die Verbrauchsrate steigt an. 4. Das Zusammenspiel zwischen Wasserhaushalt und Stoffproduktion zeigt sich damit für die Kakteen sehr deutlich. Dabei ist die erste Voraussetzung für die äußerste Ausnützung der Umweltbedingungen, nämlich für die Ausnützung einer kurzfristig verfügbaren Bodenfeuchte, die sehr rasche Wurzelneubildung bei Einsetzen der Durchfeuchtung.
Article
Tillandsia usneoides, in the common sense a non-succulent plant, exhibits CO2 exchange characterized by net CO2 dark fixation during the night and depression of CO2 exchange during the day. Malate has been demonstrated to accumulate during CO2 dark fixation and to be converted to carbohydrates in light. Thus, T. usneoides exhibits CAM like typical succulents. Net CO2 uptake during the day is increased with net CO2 output being suppressed in duration of time and extent when light intensity increases. Furthermore, a slight increase in CO2 fixation during the following night can be observed if the plants were treated with high light intensity during the previous day. Curves of CO2 exchange typical for CAM are obtained if T. usneoides is kept at 15°C and 20°C. Lower temperature tend to increase CO2 uptake during the day and to inhibit CO2 dark fixation. Temperatures higher than 20°C favour loss of CO2 by respiration, which becomes apparent during the whole day and night at 30°C and higher temperatures. Thus, T. usneoides gains carbon only at temperatures well below 25°C. Net CO2 uptake during the day occurs only in moist plant material and is inhibited in plants cept under water stress conditions. However, CO2 uptake during the night is clearly favoured if the plants dry out. Therefore dry plants gain more carbon than moist ones. Curves of CO2 exchange typical for CAM were also obtained with 13 other species of the genus Tillandsia. The exhibition of CAM by the non-succulent T. usneoides calls for a new definition of the term “succulence” if it is to remain useful in characterizing this metabolic pathway. Because CO2-fixing cells of T. usneoides possess relatively large vacuoles and are relatively poor in chloroplasts, they resembles the assimilatory cells of typical CAM-exhibiting succulents. Therefore, if “succulence” only means the capacity of big vacuoles to store malate, the assimilatory cells in T. usneoides are succulent. It seems to be useful to investigate parameters which would allow a definition of the term “succulence” on the level of the cell rather than on the level of the whole plant or plant organs.
Article
Contrasting metabolic regimes operate in Opuntia basilaris Engelm. and Bigelov, before and after precipitation. During periods of drought, atmospheric CO(2) exchange and transpiration are greatly reduced throughout the day/night cycle by stomatal closure and a highly impervious cuticle. The hypothesis is that endogenously produced CO(2) is retained and recycled through dark CO(2) fixation, organic acid transformations, photosynthesis, and respiration. Immediately following precipitation, nighttime stomatal opening is initiated, permitting increased atmospheric CO(2) assimilation and organic acid synthesis.
Article
The photosynthesis of Tidestromia oblongifolia (Amranthaceae) is remarkably well adapted to operate at the very high summer temperatures of the native habitat on the floor of Death Valley. The photosynthetic rate was very high and reached its daily maximum when the light intensity reached its noon maximum at the high leaf temperatures of 460 degrees to 50 degrees C which occurred at this time. At the intensity of noon sunlight the rate decreased markedly when the leaf temperature was experimentally reduced to below 44 degrees C. The optimum rate occurred at 47 degrees C. At this temperature the photosynthetic rate was essentially directly proportional to light intensity up to full sunlight.
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