Ultraviolet-B Activates Components of the Systemin Signaling Pathway in Lycopersicon peruvianum Suspension-cultured Cells

Yalamanchili, Roopa; Stratmann, Johannes W.

doi:10.1074/jbc.m203844200

Cited by 36 publications

(38 citation statements)

References 54 publications

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“…Bioluminescence was measured for each seedling (approximately 20 seedlings/ treatment) 6 h after the second treatment using a CCD camera and the average light units per seedling with SEs are presented. to determine whether different plant signaling pathways share components, for example, UVB, oligosaccharide elicitors, and systemin (Yalamanchili and Stratmann, 2002;Holley et al, 2003). Our results suggest that different inducers of the GSTF8 promoter share one or more components in their respective signal transduction pathways and are consistent with the fact that many inducers of plant GSTs cause oxidative stress (Marrs, 1996).…”

Section: Discussionsupporting

confidence: 74%

Desensitization of GSTF8 Induction by a Prior Chemical Treatment Is Long Lasting and Operates in a Tissue-Dependent Manner

et al. 2006

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The Arabidopsis (Arabidopsis thaliana) GSTF8 gene is a member of the glutathione S-transferase (GST) family whose expression is induced by defense signals, certain chemical stresses, and some pathogens. Here, we have used transgenic plants and an in vivo imaging system to demonstrate that GSTF8 expression is subject to a distinct desensitization phenomenon because prior chemical treatment significantly reduces reactivation of the GSTF8 promoter by hydrogen peroxide, auxin, and salicylic acid. A GSTF8 null line had similar desensitization properties to wild type, demonstrating that GSTF8 protein levels are not responsible for desensitization. The resulting refractory period is unusually long lasting, with full recovery taking 4 d. Expression of the GSTF8 promoter following a second treatment occurred predominantly in newly formed tissue at the root tip, suggesting that desensitization is lost upon cell division. Expression of the endogenous GSTF8 gene and another GST gene, GSTF6, is also desensitized following treatment with hydrogen peroxide. The desensitization phenomenon can be activated by a very low concentration of inducer that is not sufficient to activate the GSTF8 promoter. These results demonstrate that activation of the GSTF8 promoter is not essential for eliciting desensitization. A key promoter sequence within the GSTF8 gene, the ocs element, is also affected by desensitization. Treatment with a phosphatase inhibitor prevents desensitization of GSTF8 expression and ocs element activity, suggesting that dephosphorylation of one or more proteins is required for desensitization to occur.

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Section: Discussionsupporting

confidence: 74%

Desensitization of GSTF8 Induction by a Prior Chemical Treatment Is Long Lasting and Operates in a Tissue-Dependent Manner

et al. 2006

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“…Further pharmacological experiments indicated that the UV-B effect on these responses could be abrogated by treatment of the cells with suramin, an inhibitor of the systemin receptor, and Ala-17-systemin, a systemin analog that competitively inhibits the binding of systemin to its receptor. This evidence, coupled with reciprocal desensitization experiments that involved UV-B and systemin, led Yalamanchili and Stratmann (2002) to suggest that the systemin receptor and/or other systeminresponsive signaling elements are the initial phototargets in the response to pulses of UV-B in L. peruvianum cells. In principle, this model may be compatible with our gene expression results in Nicotiana spp., which revealed a consistent effect of physiological levels of UV-B up-regulating genes that are known to be up-regulated in response to wounding (and systemin in the tomato model), such as those that encode enzymes involved in oxylipin synthesis (Ryan, 2000).…”

Section: Signaling Interactions Between Solar Uv-b-and Herbivore-indumentioning

confidence: 99%

Convergent Responses to Stress. Solar Ultraviolet-B Radiation and Manduca sexta Herbivory Elicit Overlapping Transcriptional Responses in Field-Grown Plants of Nicotiana longiflora

et al. 2003

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The effects of solar ultraviolet (UV)-B (280-315 nm) on plants have been studied intensively over the last 2 decades in connection with research on the biological impacts of stratospheric ozone depletion. However, the molecular mechanisms that mediate plant responses to solar (ambient) UV-B and their interactions with response mechanisms activated by other stressors remain for the most part unclear. Using a microarray enriched in wound-and insect-responsive sequences, we examined expression responses of 241 genes to ambient UV-B in field-grown plants of Nicotiana longiflora Cav. Approximately 20% of the sequences represented on the array showed differential expression in response to solar UV-B. The expression responses to UV-B had parallels with those elicited by simulated Manduca sexta herbivory. The most obvious similarities were: (a) down-regulation of several photosynthesis-related genes, and (b) up-regulation of genes involved in fatty acid metabolism and oxylipin biosynthesis such as HPL (hydroperoxide lyase), ␣-DIOX (alpha-dioxygenase), LOX (13-lipoxygenase), and AOS (allene oxide synthase). Genes encoding a WRKY transcription factor, a ferredoxin-dependent glutamate-synthase, and several other insect-responsive genes of unknown function were also similarly regulated by UV-B and insect herbivory treatments. Our results suggest that UV-B and caterpillar herbivory activate common regulatory elements and provide a platform for understanding the mechanisms of UV-B impacts on insect herbivory that have been documented in recent field studies.UV-B induces multiple responses in terrestrial plants. These responses have been studied using a variety of experimental approaches, from controlledenvironment experiments to large-scale field trials, and covering a broad spectrum of scales, from molecular to ecosystem level processes. Controlledenvironment experiments have contributed most of the information presently available on responses at the molecular level. However, this type of experiment, particularly those that are based on the use of heavily unbalanced light sources (i.e. with unnaturally high ratios of UV-B to photosynthetically active radiation [PAR] or UV-B to UV-A [315-400 nm]), are frequently criticized on the grounds that they lack functional and ecological realism (Fiscus and Booker, 1995;Caldwell and Flint, 1997). It has been shown clearly that treatments with high UV-B to PAR ratios, which are the norm in controlled-environment exposures, tend to result in greatly exaggerated effects of UV-B on photosynthesis and growth inhibition. Because these effects have been hard to duplicate under field conditions, it is unclear to what extent the molecular and mechanistic data that have been produced under spectrally unbalanced conditions (which commonly involve PAR levels lower than 1:10 of full sunlight) contribute to our understanding of the normal physiological responses of plants to ambient UV-B stress. In fact, it has been clearly demonstrated that the level of PAR strongly modulates the effect of UV-B on...

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“…However, parallel mechanisms may apply to other plant kinases. Receptor activation by UV was suggested for the systemin receptor in wild tomato (Lycopersicon peruvianum; Yalamanchili and Stratmann, 2002). Signaling cascades elicited by the initial products of DNA damage or by UV-B activation of receptors most likely govern the diverse physiological and developmental responses caused by exposure to this radiation.…”

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confidence: 99%

Gene Expression Profiling in Response to Ultraviolet Radiation in Maize Genotypes with Varying Flavonoid Content

2003

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Microarray hybridization was used to assess acclimation responses to four UV regimes by near isogenic maize (Zea mays) lines varying in flavonoid content. We found that 355 of the 2,500 cDNAs tested were regulated by UV radiation in at least one genotype. Among these, 232 transcripts are assigned putative functions, whereas 123 encode unknown proteins. UV-B increased expression of stress response and ribosomal protein genes, whereas photosynthesis-associated genes were down-regulated; lines lacking UV-absorbing pigments had more dramatic responses than did lines with these pigments, confirming the shielding role of these compounds. Sunlight filtered to remove UV-B or UV-B plus UV-A resulted in significant expression changes in many genes not previously associated with UV responses. Some pathways regulated by UV radiation are shared with defense, salt, and oxidative stresses; however, UV-B radiation can activate additional pathways not shared with other stresses.UV radiation is divided into three classes: UV-C, UV-B, and UV-A. Highly energetic UV-C (wavelengths Յ280 nm) is strongly absorbed by oxygen and ozone in the stratosphere such that none of this sterilizing radiation is present in terrestrial sunlight. Potentially harmful UV-B (280-315 nm) is strongly absorbed by atmospheric ozone, but approximately 4% of terrestrial radiation is UV-B from 290 to 315 nm. UV-A (315-400 nm) is not attenuated by atmospheric ozone, and this less damaging radiation is an important photomorphogenic signal in plant development (Bjorn, 1994). Chlorofluorocarbons and other pollutants have catalyzed depletion of the stratospheric ozone layer; consequently, terrestrial levels of UV-B are increasing with potentially deleterious consequences for all living organisms, particularly for plant development and physiology Searles et al., 2001;Paul and Gwynn-Jones, 2003).UV-B radiation induces diverse morphological and physiological responses in plants (for reviews, see Ballaré et al., 2001;Searles et al., 2001;Paul and Gwynn-Jones, 2003), but the underlying mechanisms governing these integrated responses are unknown. Concurrent with exposure, UV-B photons cause cellular damage by generating photoproducts in DNA (Britt, 1996) and direct damage to proteins (Gerhardt et al., 1999). In response to the inevitable exposure to damaging UV-B radiation, plants have evolved UVinduced mechanisms of protection and repair, such as accumulation of UV-absorbing pigments (Stapleton and Walbot, 1994;Mazza et al., 2000;Bieza and Lois, 2001) and use of UV-A photons to repair most UV-B-induced DNA damage (Britt, 1996). Because of its absorption spectrum, DNA is a major target of UV-B damage; even low doses of radiation can kill mutants lacking specific DNA repair pathways (Britt et al., 1993;Britt, 1996;Landry et al., 1997). In flowering plants, flavonoids, including anthocyanins, accumulate in the vacuoles of epidermal cells where they attenuate the UV component of sunlight with minimal absorption of photosynthetically active radiation (Stapleton and Walbot, 1...

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Ultraviolet-B Activates Components of the Systemin Signaling Pathway in Lycopersicon peruvianum Suspension-cultured Cells

Cited by 36 publications

References 54 publications

Desensitization of GSTF8 Induction by a Prior Chemical Treatment Is Long Lasting and Operates in a Tissue-Dependent Manner

Desensitization of GSTF8 Induction by a Prior Chemical Treatment Is Long Lasting and Operates in a Tissue-Dependent Manner

Convergent Responses to Stress. Solar Ultraviolet-B Radiation and Manduca sexta Herbivory Elicit Overlapping Transcriptional Responses in Field-Grown Plants of Nicotiana longiflora

Gene Expression Profiling in Response to Ultraviolet Radiation in Maize Genotypes with Varying Flavonoid Content

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