| 1. |
- Yoda, Hiroshi, et al.
(författare)
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Polyamines as a common source of hydrogen peroxide in host- and nonhost hypersensitive response during pathogen infection
- 2009
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Ingår i: Plant Molecular Biology. - : Springer Science and Business Media LLC. - 0167-4412 .- 1573-5028. ; 70:02-jan, s. 103-112
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Tidskriftsartikel (refereegranskat)abstract
- The hypersensitive response (HR) is a powerful resistance system that plants have developed against pathogen attack. There are two major pathways for HR induction; one is through recognition of the pathogen by a specific host protein, and is known as the host HR. The other is through common biochemical changes upon infection-the nonhost HR. We previously demonstrated that hydrogen peroxide derived from polyamine degradation by polyamine oxidase triggers the typical host HR in tobacco plants upon infection with tobacco mosaic virus. However, it remains to be determined whether or not polyamines are involved in the nonhost HR in tobacco, and in the host HR in other plant species. When tobacco plants were infected with Pseudomonas cichorii, a representative nonhost pathogen, transcripts for six genes encoding enzymes for polyamine metabolism were simultaneously induced, and polyamines were accumulated in apoplasts. Hydrogen peroxide was concomitantly produced and hypersensitive cell death occurred at infected sites. Silencing of polyamine oxidase by the virus-induced gene silencing method resulted in suppression of hydrogen peroxide production and in disappearance of visible hypersensitive cell death with an increase in bacterial growth. Our results indicated that polyamines served as the source of hydrogen peroxide during the nonhost HR in tobacco plants. Further analysis revealed that polyamines were accumulated in apoplasts of Arabidopsis thaliana infected with Pseudomonas syringae, and of rice infected with Magnaporthe grisea, both causing the typical host HR. As in tobacco, it is conceivable that the same mechanism operates for nonhost HR in these plants. Our present observations thus suggested that polyamines are commonly utilized as the source of hydrogen peroxide during host- and nonhost HRs in higher plants.
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| 2. |
- Kim, Yun-Soo, et al.
(författare)
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Resistance against beet armyworms and cotton aphids in caffeine-producing transgenic chrysanthemum
- 2011
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Ingår i: PLANT BIOTECHNOLOGY. - : Japanese Society for Plant Cell and Molecular Biology. - 1342-4580 .- 1347-6114. ; 28:4, s. 393-395
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Tidskriftsartikel (refereegranskat)abstract
- Transgenic chrysanthemum plants were constructed to simultaneously express three N-methyltransferases involved in caffeine biosynthetic pathways. Resulting plants produced caffeine at approximately 3 mu g g(-1) fresh tissue, and were tested for herbivore repellence. When starved second-instar caterpillars of beet armyworms (Spodoptera exigu) were allowed to feed, they ate up to 4.4 mm(2) of leaf discs from the wild type plants, while less than 1.5 mm(2) of those from the transgenic plants. When third-instars of cotton aphid (Aphis gossypii) were subjected to a choice-test, 27 gathered on wild type leaves, and 6 on transgenic leaves. These results indicate that caffeine-producing chrysanthemum is resistant against herbivores, lepidoptera caterpillars and aphids, both being one of the most serious pests in agriculture. We propose that the method can be practically applied to a variety of important plant species to confer resistance against biotic stresses.
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| 3. |
- Klionsky, Daniel J., et al.
(författare)
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Guidelines for the use and interpretation of assays for monitoring autophagy in higher eukaryotes
- 2008
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Ingår i: Autophagy. - : Landes Bioscience. - 1554-8627 .- 1554-8635. ; 4:2, s. 151-175
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Forskningsöversikt (refereegranskat)abstract
- Research in autophagy continues to accelerate,1 and as a result many new scientists are entering the field. Accordingly, it is important to establish a standard set of criteria for monitoring macroautophagy in different organisms. Recent reviews have described the range of assays that have been used for this purpose.2,3 There are many useful and convenient methods that can be used to monitor macroautophagy in yeast, but relatively few in other model systems, and there is much confusion regarding acceptable methods to measure macroautophagy in higher eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers of autophagosomes versus those that measure flux through the autophagy pathway; thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from fully functional autophagy that includes delivery to, and degradation within, lysosomes (in most higher eukaryotes) or the vacuole (in plants and fungi). Here, we present a set of guidelines for the selection and interpretation of the methods that can be used by investigators who are attempting to examine macroautophagy and related processes, as well as by reviewers who need to provide realistic and reasonable critiques of papers that investigate these processes. This set of guidelines is not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to verify an autophagic response.
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| 4. |
- Kodama, Yutaka, et al.
(författare)
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A novel protein phosphorylation pathway involved in osmotic-stress response in tobacco plants
- 2009
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Ingår i: Biochimie. - : Elsevier BV. - 0300-9084 .- 1638-6183. ; 91:4, s. 533-539
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Tidskriftsartikel (refereegranskat)abstract
- Osmotic stress is one of the severest environmental pressures for plants, commonly occurring under natural growing condition due to drought, salinity, cold and wounding. Plants sensitively respond to these stresses by activating a set of genes, which encode proteins necessary to overcome the crises. We screened such genes from tobacco plants, and identified a particular clone, which encoded a 45 kDa protein kinase belonging to the plant receptor-like cytoplasmic protein kinase class-VII, NAK (novel Arabidopsis protein kinase) group. The clone was consequently designated as NtNAK (Nicotiana tabacum AK, accession number: DQ447159). GFP-NtNAK fusion protein was localized in both cytoplasm and nucleus, and bacterially expressed NtNAK exhibited in vitro kinase activity. Its transcripts were clearly induced upon treatments of leaves with salt, mannitol, low temperature and also with abscisic and jasmonic acids and ethylene. These properties indicated NtNAK to be a typical osmo-stress-responsive protein kinase. Its target protein(s) were then screened by the yeast two-hybrid system, and one clone encoding a 32 kDa protein was identified. The protein resembled a potato stress-responsive protein CK251806, and designated as NtCK25 (accession number: DQ448851). Bacterially expressed NtCK25 was phosphorylated by NtNAK, and NtCK25-GFP fusion protein was exclusively localized in nucleus. The structure of NtCK25 was found to be similar to a human nuclear body protein, SP110, which is involved in DNA/protein binding regulation. This suggested that, perceiving osmo-stress signal, NtNAK phosphorylates and activates NtCK25, which might function in regulation of nucleus function. The present study thus suggests that NtNAK/NtCK25 constitutes a novel phosphorylation pathway for osmotic-stress response in plants.
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| 5. |
- Morokuma, Tomoki, et al.
(författare)
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Kiso Supernova Survey (KISS) : Survey strategy
- 2014
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Ingår i: Nippon Tenmon Gakkai obun kenkyu hokoku. - : Oxford University Press (OUP). - 0004-6264. ; 66:6
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Tidskriftsartikel (refereegranskat)abstract
- lThe Kiso Supernova Survey (KISS) is a high-cadence optical wide-field supernova (SN) survey. The primary goal of the survey is to catch the very early light of a SN, during the shock breakout phase. Detection of SN shock breakouts combined with multi-band photometry obtained with other facilities would provide detailed physical information on the progenitor stars of SNe. The survey is performed using a 2 degrees.2 x 2 degrees.2 field-of-view instrument on the 1.05-m Kiso Schmidt telescope, the Kiso Wide Field Camera (KWFC). We take a 3-min exposure in g-band once every hour in our survey, reaching magnitude g similar to 20-21. About 100 nights of telescope time per year have been spent on the survey since 2012 April. The number of the shock breakout detections is estimated to be of the order of 1 during our three-year project. This paper summarizes the KISS project including the KWFC observing setup, the survey strategy, the data reduction system, and CBET-reported SNe discovered so far by KISS.
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| 6. |
- Perkiö Kato, Naoko, et al.
(författare)
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How effective is an in-hospital heart failure self-care program in a Japanese setting? Lessons from a randomized controlled pilot study
- 2016
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Ingår i: Patient Preference and Adherence. - : DOVE MEDICAL PRESS LTD. - 1177-889X. ; 10, s. 171-181
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Tidskriftsartikel (refereegranskat)abstract
- Background: Although the effectiveness of heart failure (HF) disease management programs has been established in Western countries, to date there have been no such programs in Japan. These programs may have different effectiveness due to differences in health care organization and possible cultural differences with regard to self-care. Therefore, the purpose of this study was to evaluate the effectiveness of a pilot HF program in a Japanese setting. Methods: We developed an HF program focused on enhancing patient self-care before hospital discharge. Patients were randomized 1: 1 to receive the new HF program or usual care. The primary outcome was self-care behavior as assessed by the European Heart Failure Self-Care Behavior Scale (EHFScBS). Secondary outcomes included HF knowledge and the 2-year rate of HF hospitalization and/or cardiac death. Results: A total of 32 patients were enrolled (mean age, 63 years; 31% female). There was no difference in the total score of the EHFScBS between the two groups. One specific behavior score regarding a low-salt diet significantly improved compared with baseline in the intervention group. HF knowledge in the intervention group tended to improve more over 6 months than in the control group (a group-by-time effect, F=2.47, P=0.098). During a 2-year follow-up, the HF program was related to better outcomes regarding HF hospitalization and/or cardiac death (14% vs 48%, log-rank test P=0.04). In Cox regression analysis after adjustment for age, sex, and logarithmic of B-type natriuretic peptide, the program was associated with a reduction in HF hospitalization and/or cardiac death (hazard ratio, 0.17; 95% confidence interval, 0.03-0.90; P=0.04). Conclusion: The HF program was likely to increase patients HF knowledge, change their behavior regarding a low-salt diet, and reduce HF hospitalization and/or cardiac events. Further improvement focused on the transition of knowledge to self-care behavior is necessary.
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