action spectrum for phototropism

“Action spectra” of this type were determined for staphylococci and phages active on this organism, as well as for vaccinia virus (Rivers and Gates, 1928; Sturm et al., 1932; Gates, 1930, 1934). These measurements provide an important piece of evidence supporting the manganese mechanism of photoinhibition as the action spectrum of photoinhibition of manganese-less PSII closely resembles the absorption spectrum of thylakoids (Hakala et al., 2005; Ohnishi et al., 2005). These spectral features correspond to the action spectrum for phototropism in higher plants. As shown for alfalfa, there are no qualitative differences between the two plots (Fig. Most conventional wide-field microscopes can be modified to incorporate a field stop/diaphragm or pinhole in a conjugate image plane. (1995) also reported a two-phase stimulus-response curve. The action spectrum for phototropism typically shows maximal activity between 400 and 500 nm and shows a substantial degree of fine structure with a major band at 450 nm, a subsidiary shoulder at 430 nm, and a sharp peak at 470 nm ( 32 ). Stanley (1945), in studies of the UV inactivation of purified PR8 influenza virus, noted that the loss of virus infectivity greatly preceded that of red cell agglutinating activity and that a fully potent non-infectious vaccine could be produced by using an amount of irradiation sufficient to cause loss of infectivity, but insufficient to cause a marked decrease in red cell agglutinating activity. In both figures, spectra show maximum response in blue (∼ 450 nm) and strong shoulders at ∼ 475 and ∼ 425 nm. For example, the enhancement of CPD repair in human and melanocytes and mouse S91 melanoma cells by the addition of the DNA repair enzyme, T4 endonuclease V (T4N5), is associated with increased melanogenesis. In photobiology, the classical use of action spectra is to identify the photochemical compound that causes the observed biological response. Course Hero is not sponsored or endorsed by any college or university. Any barrier that prevents the transmission of solar UVB radiation to the earth’s surface or anything that interferes with the penetration of UVB radiation into the skin may significantly reduce vitamin D3 production. Some action spectra simply show the magnitude of a response as a function of wavelength, under conditions where a standard photon fluence (or fluence rate) is applied in all … The action spectrum of phototropism was recorded between 280 and 500 nm light, revealing the main contributions of UV-A and blue light (Baskin and Iino, 1987; Christie and Murphy, 2013). Bawden and Kleczkowski (1955) have remarked that the rule of McLaren (1949), that the quantum yields for proteins are approximately inversely proportional to the molecular weight, does not apply to TMV, which is too sensitive according to this rule. Although the focus will be on higher plant phototropism, several other blue light responses will contribute to the discussion. As pointed out by Kleczkowski, this suggests that the “sensitization to heat inactivation” is a multi-hit phenomenon. Interference between plant viruses after UV treatment was demonstrated by Bawden and Kleczkowski (1953) and heat inactivation of preirradiated TMV was studied by Kleczkowski (1954). Blue light excitation of the LOV2 domain generates, in less than 30 ns, a transient approximately 660 nm-absorbing species that spectroscopically resembles a flavin triplet state. Action spectra for these responses coincide with the absorption spectrum of the Pr form of phytochrome. The nucleic acid protein framework of the virus apparently serves to hold together the radicals formed by quanta and thus allows for a high probability of recombination without net chemical change and with an over-all low quantum efficiency.”. Abstract— Action spectra for phototropic balance of Phycomyces blakesleeanus sporangiophores were measured for various reference wavelengths and intensity ranges. Walter Shropshire , Robert B. Withrow Plant Physiology Sep 1958, 33 (5) 360-365; DOI: 10.1104/pp.33.5.360 Orange light is expected to be particularly photoinhibitory in cyanobacteria also because the cyanobacterial NPQ mechanism is induced by blue–green but not by orange light (Wilson et al., 2006). Since the. By modulating illumination intensity, low intensity can be used to target the protein uncaging light, followed by high intensity radiation to activate protein. Before reaching the ground, 25%–30% of UVB is attenuated by clouds in the global and attenuation may be as high as 99% under extremely thick clouds (Calbó and González, 2005). Schrott suggested that the photoreceptor and/or elements of the signal transduction chain become depleted during the first phase. (1957) for polio vaccine. Alternatively, various scan modes on laser scanning confocal microscopes can be used. The action spectrum of photoinhibition was first measured in vitro in 1966 (Jones and Kok, 1966). Thus, Wells and Brown (1936), demonstrated the effects of UV on air-borne influenza virus and extensive studies of a similar kind are reported by Edwards et al. The scale on the left is for the ascending arm and the one on the right is for the descending arm. The spectrum for destruction of interference was found to have a broad maximum, extending to about 2800 Å, as compared with the usual, well-defined maximum at 2600 Å in the action spectrum for inactivation. 26-3). From these curves, photon fluences required to produce a defined magnitude of response, a “standard” response, is determined for each wave band (i.e., the number of photons required to produce say 50% germination, or 50% inhibition of growth). Spatial control is perhaps the most valuable feature of light-mediated protein activation. FIGURE 27-2. We can qualitatively state that we found no difficulties in activating PA-Rac through global cell irradiation using a 100 W mercury source filtered through a ND 2.0 (1.0% transmission) filter and a CFP excitation filter (ET430/24 nm). Phototropism is the response of the interaction of photoreceptors to external stimuli which is the light. Under these conditions the chance of that cell producing normal phage is much higher than one would expect on the basis of the viability of the individual infecting particles. In addition, melanogenesis can be stimulated by thymidine dinucleotides (pTpT), that may be considered to mimic T=T, in vitro and in vivo [20]. Quantitative experiments have shown that a well-defined fraction of the UV damage can be reversed by light, and that a single quantum suffices to return the damaged site to a functional condition (Bowen, 1953). Consequently, such a period of restoration may be necessary before the sensitivity toward light is recovered. Price (1950) and Kleczkowski and Kleczkowski (1953), working with staphylococcus and Rhizobium phages, respectively, observed photo-reactivation but failed to elicit multiplicity reactivation. (1944). For example, an action spectrum of a chloroplast suspension cannot be used to calculate leaf responses. The first step in the determination of an action spectrum is the construction of fluence rate-response curves for different wavelengths (usually a 10-nm wave band) of irradiation (Fig. Also, as most biological responses are nonlinear, the action spectrum must be determined over the full range of natural irradiances and not only at the low end of the range. Overall, these data suggest that the putative lesion for melanogenesis is the CPD. In the visible range, the action spectrum has a small peak in red light. This preview shows page 22 - 33 out of 42 pages.. Wavelength (nm) (a) Action spectrum for blue-light phototropism Light Time = 0 min Time = 90 min (b) Coleoptile response to light colors Action spectrum for phototropism in coleoptiles (a) Action spectrum for blue-light phototropism Light Time = 0 min Time = 90 min (b) Coleoptile response to light colors Action Later in vitro measurements (Jung and Kim, 1990; Hakala et al., 2005; Ohnishi et al., 2005) have confirmed that the main feature of the spectrum is an increase in the photoinhibitory efficiency with decreasing wavelength starting in the blue–green range. It is difficult to say what this means; published inactivation curves for T2 irradiated at higher intensities do not deviate nearly as much from exponentiality. Therefore, a posttranscriptional event may be responsible for the observed biphasic response on the level of enzyme activity. Such spectra, referred to as the “three-finger” pattern, are typical for photoresponses with maximal activity in blue region of the spectrum. Inactivation by UV has also been considered in connection with vaccine production; e.g., by Levinson et al. Sicheng Zhang, ... Wei Li, in Essential and Toxic Trace Elements and Vitamins in Human Health, 2020. His estimate of the quantum yield was 3 × 10–4, but his action spectrum (Fluke and Pollard, 1949) differs from that of Zelle and Hollaender for the shortest wavelengths and, in that region, the quantum yield therefore does not remain constant. The action spectrum for the positive, directional photo-orientation of growth was determined by the null-point method in which the effectiveness of each selected wavelength was compared to a 665-nm standard in simultaneous, bilateral irra diation. Bawden and Kleczkowski (1953, 1955) demonstrated photo-reactivation in bushy stunt, tobacco necrosis, and, particularly strongly, in potato X virus. One of the main peaks of emission from the mercury light source falls at these wavelengths, and these observations were made with cells expressing low levels of PA-Rac (empirically optimized for optimal light response without induction of a Rac phenotype in the dark). Several other phages and a number of plant viruses have been tested for reactivation after UV inactivation. Different in vitro measurements have slight differences in the height and form of the peak in red light; this peak is substantial in the data of Jones and Kok (1966) but relatively low in the later spectra. Oster and McLaren summarized their discussion as follows: “… these approximate calculations simply serve to show that the quantum efficiency for destruction of nucleic acids as well as for protein linkages is much higher than for inactivation of viruses. Fluke (1956) carried out similar experiments with dried T1. The strong peak in UV-region of the spectrum (360-380 nm) suggests riboflavin as the photoreceptor pigment, while three peaks in blue regions (400 – 500 nm) of the spectrum favours carotene. This includes blue light-induced responses mediated by cryptochromes and stomatal opening mediated by a yet unidentified receptor. blue-light photoreceptor. 27-2A). At low survival values the rate of inactivation is sometimes observed to decrease; this may be due to the presence in the virus population of a few relatively resistant particles. The active wavelengths (about 400 to 650 mmicro) corresponded in general with those absorbed by extracts containing a pigment with an absorption spectrum … Duggar and Hollaender (1934a,b) and Hollaender and Duggar (1936) showed that TMV was most efficiently killed by the shortest wavelengths used (2200 Å) and that the efficiency decreased sharply with increasing wavelength, except for a possible minor peak between 2500 and 2600 Å. Rous’ sarcoma virus was found later to exhibit the same unusual pattern (Hollaender and Oliphant, 1944). Classically the goal of making an action spectrum was to help identify the process's photoreceptor pigment, which is often the first step in understanding the whole chain of events from absorption to signal transduction and amplification to one or more responses. 2A). The resulting action spectrum paralleled the in-vivo absorption spectrum of a single filament in the red region, showing a major peak at 680 nm. a Action spectrum for blue light phototropism Light Time 0 min Time 90 min b, (a) Action spectrum for blue-light phototropism, Phytochromes detect shading from neighbors, Light passing through another plant has a, determined the action spectrum for light-, This textbook can be purchased at R.E. Kendrick, J.L. Zelle and Hollaender (1954) suggest that nonspecific absorption by protein contained in the dry film perhaps accounts for this discrepancy. An action spectrum is constructed because it allows a comparison with absorption spectra of known pigments and thus an insight into the nature of the photoreceptor involved. Action spectrum The efficiency with which electromagnetic radiation produces a photochemical reaction plotted as a function of the wavelength of the radiation.The action Spectrum is an indicator of which wavelength of light can be used by a plant to allow photosynthesis. PCC6803 (Tyystjärvi et al., 2002). The minimum light energy inducing the phototropic bending was 30 J.m−2at 467 nm and 32°C. ScienceDirect ® is a registered trademark of Elsevier B.V. ScienceDirect ® is a registered trademark of Elsevier B.V. URL:, URL:, URL:, URL:, URL:, URL:, URL:, URL:, URL:, URL:, Encyclopedia of Applied Plant Sciences, 2003, Tropic and Nontropic Responses to Environmental Signals, Plant Growth and Development: Hormones and Environment, REGULATORS OF GROWTH | Phytochromes and Other Photoreceptors, International Review of Cell and Molecular Biology, Seeing the Light: News in Neurospora Blue Light Signal Transduction, blue light responses have been published. The wavelengths 405, 458, 473, and 488 nm all proved to be effective. An action spectrum for the phototropic curvature for an etiolated oat coleoptile is shown in Fig. Data from DeFabo et al. The action spectrum of photoinhibition has also been measured from thylakoid membranes lacking a functional oxygen-evolving manganese cluster. They arose from studies of response kinetics, action spectroscopy, interactions between blue and red regions of the visible spectrum, and discrepancies between in vivo and in vitro results. The fluence and fluence-rate dependence of densensitization and recovery from desensitization have been measured for etiolated and red light (669-nm) preirradiated Arabidopsis thaliana … This spectrum matched closely an action spectrum for blue light-stimulated stomatal opening. This chapter describes practical applications of action spectra. After transformation of Neurospora and photoinduction of the mycelia, the β-galactosidase activity was determined. This process is accompanied by the action of multiple enzymes and hormones undergoing a number of the signaling pathway. All speculations about the mechanism of UV inactivation are based on analysis of the relative efficiency of different wavelengths. This spectrum suggested a wide peak in yellow light (600 nm) while a wide peak in red light (650–660 nm) was obtained in an earlier in vivo measurement from Arabidopsis (Sarvikas et al., 2006). For broad‐blue light and 450 nm light as references, typical flavin‐like action … Fluence‐response relationships have been measured at wavelengths from 350 to 760 nm for the enhancement of phototropism in Arabidopsis thulium L. (Heynh) strain “Estland” by an irradiation at each of these wavelengths, given 2 h prior to a 450 nm inductive unilateral irradiation. One of the in vivo action spectra was obtained by deconvoluting the decrease in FV/FM, measured in a lincomycin-treated Arabidopsis leaf illuminated in sunlight through a prism (Takahashi et al., 2010). [21]. S. GARD, O. MAALØE, in General Virology, 1959. Five strains of TMV gave consistently negative results. This preview shows page 22 - 33 out of 42 pages. Schrott (1980, 1981) reported fluence response curves for light-induced carotenoid biosynthesis in N. crassa. An additional broad less-effective peak is typically observed at 380 nm. (A) Action spectra for an etiolated alfalfa (Medicago) hypocotyl were plotted for the entire fluence range of the first positive phototropism and thus include both ascending and descending arms. (2010) used mature leaves, whereas young leaves were used by Sarvikas et al. No response occurs above ∼ 500 nm. These spots can also be mobilized to scan across different shapes either manually or using galvanometer-driven mirrors. Fluke (1951) tested phage T1 inactivated by UV of different wavelengths, and found that a constant fraction (about 70%) of the inactivated phage could be reactivated by light. Very similar action spectra have later been established for influenza virus (Hollaender and Oliphant, 1944), for the coliphages T1 and T2 (Fluke and Pollard, 1949; Zelle and Hollaender, 1954), and for a megatherium phage (Franklin et al., 1953). The ionic yield for simple reactions, such as rupture of peptide, disulfide, or pyrimidine bonds is of the order of 10–2, and it was suggested that, perhaps, the TMV particles contained about 50 critical bonds, the rupture of one of which by absorption of a quantum of UV causes inactivation. The power dosage of the PA-Rac to 458 nm line was measured in stable MEF cell lines, where expression levels could be well controlled and the areas of induced protrusions readily measured. Examples of processes showing this kind of response are the stimulation of seed germination and regulation of gene expression. McCree, in Light and Plant Development, 1976. Light of wavelengths longer than 502 nm was ineffective. Since the action spectrum did not correspond to the absorption spectrum of the pigmented zone as measured in vivo, and since colorless sporangiophores formed on media containing diphenylamine were capable of phototropic response, it is unlikely that the conspicuous orange‐yellow pigment in young sporangiophores is the … The Do dose determined by irradiation with monochromatic UV is a convenient expression of the efficiency at the wavelength (λ) chosen. (1940) claimed that influenza virus harvested from the lungs of infected mice was more susceptible to UV than virus from tissue cultures, and the sensitivity of certain actinophages was found to depend on the strain on which the phage was propagated (Welsch and Minon, 1955b). It has been calculated that only one in a million molecules of Pr have to be excited. They prepared a translational fusion of the light inducible con-10 promoter and the Escherichia coli lacZ gene. The action spectrum of phototropism was recorded between 280 and 500 nm light, revealing the main contributions of UV-A and blue light (Baskin and Iino, 1987; Christie and Murphy, 2013). This means that these responses can be elicited by the green light often used as safelight for photomorphogenic studies and even by the low level of conversion of Pr to Pfr occurring in response to far-red light. (2006). Furthermore, photoreactivated phage-bacterium complexes were found to be sensitive to a second dose of UV to the same extent as nonreactivated complexes (at identical survival levels); this suggests that, once reactivated, a complex is as good as new (Lennox et al., 1954). For example, the action spectrum for photosynthesis using light shows a peak in the region 670–700 nm. The rate of adsorption and the bacteria-killing ability of phage T6 remain unchanged after extensive UV inactivation (Frédéricq, 1952); the enzymatic activity of certain phages on the Vi substance is also very resistant to UV (Kozinski and Opara, 1955). They are incredibly sensitive and can be saturated by very low fluences of red light. Antony R. Young, John M. Sheehan, in Comprehensive Series in Photosciences, 2001. ACTION SPECTRUM FOR ENHANCEMENT OF PHOTOTROPISM BY Arabidopsis thaliana SEEDLINGS ACTION SPECTRUM FOR ENHANCEMENT OF PHOTOTROPISM BY Arabidopsis thaliana SEEDLINGS Janoudi, Abdul‐Kader; Poff, Kfnneth L. 1992-11-01 00:00:00 Abstract— Fluence‐response relationships have been measured at wavelengths from 350 to 760 nm for the enhancement of phototropism … Positive phototropism is growth towards a light source; negative phototropism is growth away from light. The properties examined were affected in this order: (1) infectivity; (2) toxicity to mice; (3) interfering property and inhibition of the development of the chick embryo; (4) hemagglutinating capacity (including the adsorption-elution mechanism, the ability to block red cell agglutination, and the adsorption onto allantoic cells); and (5) complement-fixing capacity. Studies in skin type V have shown similar melanogenesis and erythema action spectra to those of ‘fair’ skin types [17]. It has been mentioned that, in contrast to X-rays, UV inactivates by direct effects only. A plot of 1/Do against λ gives a curve somewhat resembling an absorption spectrum; i.e., the curve has maxima corresponding to the most effective λ values and vice versa. The action spectra for phototropism and the phosphorylation of p120 were very similar and the phosphorylation occurred very rapidly after the onset of blue light. An action spectrum for the blue light-induced enhancement of the red light-stimulated quenching showed a major peak at 450 nm and two minor peaks at 420 and 470 nm. The coliphages T1 and T2 were thoroughly studied by Zelle and Hollaender (1954). Since the action spectrum of TMV does not particularly point to the nucleic acid as the principal photosensitive element, it is difficult to guess what type of bond might be involved. Actually, the action spectrum of photoinhibition resembles absorption spectra of manganese model compounds that mimic the oxygen-evolving manganese cluster (Hakala et al., 2005). All the blue-light-regulated genes isolated today show a one-phase response curve only. In the ultraviolet (UV) range (Jones and Kok, 1966; Bornman et al., 1984; Renger et al., 1989), a peak or shoulder at ∼270 nm can be distinguished in addition to the highest peak at approximately 250 nm (Fig. Several action spectra for different Neurospora blue light responses have been published. The action spectrum for phototropism of Conidiobolus conidiophores was determined crudely with glass filters and by projecting a spectrum on cultures of the fungus. The rate constant for heat inactivation was found to increase with preirradiation, but the process was first order also for suboptimal doses of UV. In this connection it is perhaps significant that infective RNA prepared from TMV is about six times as sensitive to UV as the RNA protein complex of the intact virus particle (McLaren and Takahashi, 1957). Therefore, it is usually impossible to obtain an exact match between in vitro absorption and in vivo action. There are differences in the details of the spectral form in visible light. Since any simple photoresponse is a function of fluence rate and duration of irradiation, the most effective wavelengths are those that require the fewest number of photons to elicit a certain level of response. Interestingly, this biphasic response has never been observed on the level of transcription. The immunizing capacity could not be definitely placed according to sensitivity to UV; certain differences between A and B strains were noticed, but, generally, antigenicity was at least as stable as the hemagglutinating capacity. A saturation of light-induced carotenogenesis was observed when the mycelia were exposed to fluence rates beyond 0.3 W m- 2 for up to 16 min. The absorption spectra of photoreceptor pigments suggest that the flavins and the carotenoids might be involved in phototropism. The action spectrum is then prepared by plotting the reciprocals of these photon fluences against the wavelength. Analysis of mutants has revealed that phyA is active in this mode of phytochrome action. They ascribe the relatively high sensitivity to the presence of nucleic acid in the virus. In T2, it is reasonably certain that it is the nucleic acid that determines the sensitivity to UV. In the latter case, safe and highly antigenic preparations are said to have been obtained by UV treatment and subsequent storage for a week at 37–40°C. A departure from this rule was observed by Eckart (1954), who found that the Do dose for inactivation of phage T1 by monochromatic UV increased slightly with increasing dose rate (i.e., low dose rates were most efficient). Action spectrum of DNA damage caused by ultraviolet light (dashed line, redrawn from Setlow, 1974) and that of photoinhibition of PSII (solid line). As we will see for phytochrome, action spectra did concentrate attention on the appropriate regions of the spectrum, but it was the light-reversible changes in absorption properties that led to the identification of the photoreceptor. These processes will be treated in detail in another chapter, but should be discussed briefly here because they reveal something about the state of UV-inactivated particles: Multiplicity reactivation (Luria, 1947; Luria and Dulbecco, 1949; Dulbecco, 1952) occurs when two or more UV-damaged phage particles infect the same cell. It is possible that in prism illumination, light scattering may affect the results because the angle of incidence in a prism illumination depends on wavelength. The theory of the action spectrum and the assumptions involved in interpreting data of this kind have been detailed in a review by Loofbourow (1948). were determined at selected wavelengths. The action spectra for single exposure UVR-induced melanogenesis and erythema in ‘fair’ untanned human skin are very similar [16] and are undistinguishable between 300 nm and 435 nm with UVB (at 300 nm) being more than 1000 times more effective per unit physical dose (J/cm2) than UVA (at 365 nm). Along with theoretical studies a considerable amount of work has been done to test the usefulness of UV as a bactericidal and virus inactivating agent, e.g., in barracks and laboratories. Hence, red or far-red irradiations and phytochromes that absorb those radiations are excluded as primary receptors for phototropism. Another abnormality connected with dose rate was noticed by Latarjet and Morenne (1951): in experiments with phage T2 irradiated with UV of very low intensity, a deviation from exponential inactivation was observed which suggested a “3-hit” process. The overall mechanisms of melanogenesis are reviewed by Gilchrest et al. Over this whole range reasonably constant values of about 6 and 3 × 10–4 were obtained for T1 and T2, respectively. 380 nm been measured from thylakoid membranes lacking a functional oxygen-evolving manganese cluster and ∼ 425 nm for cutaneous D3... 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In Photosciences, 2001 spectra is to identify the photochemical compound that causes the observed biological response licensors... Studied by growing plants in absolute darkness and they are obviously not reversible by far-red light the relatively sensitivity... Has been calculated that only one in a conjugate image plane independent of dose rate far-red ( 730 )! Leaves, whereas Young leaves were used by Sarvikas et al ( 1980, 1981 ) reported fluence response for... Uvb range ( 360–500 nm ) at different wavelengths John M. Sheehan, Essential. Gilchrest et al of Pr have to be excited be necessary for restoring maximum competence for a second response doubled...

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