RESUMO
The evolution of land flora transformed the terrestrial environment. Land plants evolved from an ancestral charophycean alga from which they inherited developmental, biochemical, and cell biological attributes. Additional biochemical and physiological adaptations to land, and a life cycle with an alternation between multicellular haploid and diploid generations that facilitated efficient dispersal of desiccation tolerant spores, evolved in the ancestral land plant. We analyzed the genome of the liverwort Marchantia polymorpha, a member of a basal land plant lineage. Relative to charophycean algae, land plant genomes are characterized by genes encoding novel biochemical pathways, new phytohormone signaling pathways (notably auxin), expanded repertoires of signaling pathways, and increased diversity in some transcription factor families. Compared with other sequenced land plants, M. polymorpha exhibits low genetic redundancy in most regulatory pathways, with this portion of its genome resembling that predicted for the ancestral land plant. PAPERCLIP.
Assuntos
Evolução Biológica , Embriófitas/genética , Genoma de Planta , Marchantia/genética , Adaptação Biológica , Embriófitas/fisiologia , Regulação da Expressão Gênica de Plantas , Marchantia/fisiologia , Anotação de Sequência Molecular , Transdução de Sinais , Transcrição GênicaRESUMO
Plasma membrane (PM) H+-ATPase in guard cells is activated by phosphorylation of the penultimate residue, threonine (Thr), in response to blue and red light, promoting stomatal opening. Previous in vitro biochemical investigation suggested that Mg2+- and Mn2+-dependent membrane-localized type 2C protein phosphatase (PP2C)-like activity mediates the dephosphorylation of PM H+-ATPase in guard cells. PP2C clade D (PP2C.D) was later demonstrated to be involved in PM H+-ATPase dephosphorylation during auxin-induced cell expansion in Arabidopsis (Arabidopsis thaliana). However, it is unclear whether PP2C.D phosphatases are involved in PM H+-ATPase dephosphorylation in guard cells. Transient expression experiments using Arabidopsis mesophyll cell protoplasts revealed that all PP2C.D isoforms dephosphorylate the endogenous PM H+-ATPase. We further analyzed PP2C.D6/8/9, which display higher expression levels than other isoforms in guard cells, observing that pp2c.d6, pp2c.d8, and pp2c.d9 single mutants showed similar light-induced stomatal opening and phosphorylation status of PM H+-ATPase in guard cells as Col-0. In contrast, the pp2c.d6/9 double mutant displayed wider stomatal apertures and greater PM H+-ATPase phosphorylation in response to blue light, but delayed dephosphorylation of PM H+-ATPase in guard cells; the pp2c.d6/8/9 triple mutant showed similar phenotypes to those of the pp2c.d6/9 double mutant. Taken together, these results indicate that PP2C.D6 and PP2C.D9 redundantly mediate PM H+-ATPase dephosphorylation in guard cells. Curiously, unlike auxin-induced cell expansion in seedlings, auxin had no effect on the phosphorylation status of PM H+-ATPase in guard cells.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Membrana Celular/metabolismo , Luz , Fosfoproteínas Fosfatases/genética , Fosfoproteínas Fosfatases/metabolismo , Fosforilação , Proteína Fosfatase 2C/metabolismo , ATPases Translocadoras de Prótons/genética , ATPases Translocadoras de Prótons/metabolismoRESUMO
OBJECTIVES: To reduce cancer care disparities in people with mental illness, this study aimed to quantify psychiatric care providers' perceptions regarding issues that are insufficiently addressed or difficult to address. METHODS: Psychiatric care providers at 23 psychiatric hospitals in Japan were surveyed using mail questionnaires. Respondents were asked to rate 15 items with four categories related to insufficiencies/difficulties in cancer care for patients with mental illness on a five-point Likert scale. We analyzed the proportion of respondents who answered "insufficient/difficult" for each item. RESULTS: A total of 255 (76.3%) psychiatric care providers responded. For questions related to the skills and attitudes of psychiatric professionals, 48.3%-58.4% of respondents perceived that efforts for supporting cancer screening and treatment were insufficient. For the questions related to collaborations between cancer and psychiatric care providers, 75.3% of respondents perceived that inpatient visits between psychiatric and cancer hospitals were insufficient. For the questions related to in-psychiatric-hospital medical systems, 50.2%-87.2% of respondents perceived that support for screening, diagnosis/treatment, and palliative care for psychiatric inpatients were insufficient/difficult. 41.9%-57.4% of respondents perceived that social services in the community were insufficient. CONCLUSIONS: This study clarified the level of insufficiency/difficulty perceived by psychiatric care providers regarding issues related to cancer care for people with mental illness. Psychiatric care providers are required to have knowledge and skills in cancer screening and treatment. To improve access to cancer prevention, treatment, and palliative care, it may be helpful to establish systems to promote coordination between cancer hospitals and psychiatric hospitals.
Assuntos
Transtornos Mentais , Neoplasias , Humanos , Transtornos Mentais/terapia , Inquéritos e Questionários , Cuidados Paliativos , Psicoterapia , Atitude do Pessoal de Saúde , Neoplasias/terapiaRESUMO
OBJECTIVE: The Japanese Psycho-Oncology Society and the Japanese Association of Supportive Care in Cancer have recently revised the clinical practice guidelines for delirium in adult cancer patients. This article reports the process of developing the revised guidelines and summarizes the recommendations made. METHODS: The guidelines were developed in accordance with the Medical Information Network Distribution Service creation procedures. The guideline development group, consisting of multi-disciplinary members, created three new clinical questions: non-pharmacological intervention and antipsychotics for the prevention of delirium and trazodone for the management of delirium. In addition, systematic reviews of nine existing clinical questions have been updated. Two independent reviewers reviewed the proposed articles. The certainty of evidence and the strength of the recommendations were graded using the grading system developed by the Medical Information Network Distribution Service, following the concept of The Grading of Recommendations Assessment, Development, and Evaluation system. The modified Delphi method was used to validate the recommended statements. RESULTS: This article provides a compendium of the recommendations along with their rationales, as well as a short summary. CONCLUSIONS: These revised guidelines will be useful for the prevention, assessment and management of delirium in adult cancer patients in Japan.
Assuntos
Antipsicóticos , Delírio , Neoplasias , Humanos , Adulto , Delírio/etiologia , Delírio/prevenção & controle , Neoplasias/complicações , JapãoRESUMO
Plant stomata play an important role in CO2 uptake for photosynthesis and transpiration, but the mechanisms underlying stomatal opening and closing under changing environmental conditions are still not completely understood. Through large-scale genetic screening, we isolated an Arabidopsis mutant (closed stomata2 (cst2)) that is defective in stomatal opening. We cloned the causal gene (MGR1/CST2) and functionally characterized this gene. The mutant phenotype was caused by a mutation in a gene encoding an unknown protein with similarities to the human magnesium (Mg2+ ) efflux transporter ACDP/CNNM. MGR1/CST2 was localized to the tonoplast and showed transport activity for Mg2+ . This protein was constitutively and highly expressed in guard cells. Knockout of this gene resulted in stomatal closing, decreased photosynthesis and growth retardation, especially under high Mg2+ conditions, while overexpression of this gene increased stomatal opening and tolerance to high Mg2+ concentrations. Furthermore, guard cell-specific expression of MGR1/CST2 in the mutant partially restored its stomatal opening. Our results indicate that MGR1/CST2 expression in the leaf guard cells plays an important role in maintaining cytosolic Mg2+ concentrations through sequestering Mg2+ into vacuoles, which is required for stomatal opening, especially under high Mg2+ conditions.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Dióxido de Carbono/metabolismo , Dióxido de Carbono/farmacologia , Humanos , Luz , Magnésio/metabolismo , Magnésio/farmacologia , Mutação/genética , Estômatos de Plantas/genética , Vacúolos/metabolismoRESUMO
OBJECTIVES: To reduce cancer care disparities, this study aimed to clarify the difficulties in cancer care for people with mental disorders as perceived by cancer care providers. METHODS: Cancer care providers at 17 designated cancer hospitals in Japan were surveyed using mail questionnaires. Respondents were asked to rate 29 items related to difficulties or insufficiencies in cancer care for patients with mental disorders on a five-point Likert scale. We analyzed the proportion of respondents who answered "difficult/insufficient" in each item. We also calculated the proportions of responders stratified according to the presence of psychiatric support systems within their hospitals. RESULTS: A total of 388 (58.4%) cancer care providers responded. Among the issues related to "difficulties in diagnosing and treating cancer," support for decision-making, assessment of treatment adherence, and assessment of physical symptoms were perceived as most difficult (73.5%-81.5% of respondents). Among the issues related to 'difficulties or insufficiencies in collaboration among multidisciplinary health care providers,' the issue of advance consultation and sharing information with the patient's primary psychiatric care provider was perceived as most difficult (52.2%). Among the issues related to "insufficiencies of in-hospital and community medical systems," education to provide reasonable accommodation was perceived as most insufficient (47.4%). The perceived difficulties of over half of the issues varied significantly between hospitals depending on the level of psychiatric support systems. CONCLUSIONS: This study clarified the difficulties of cancer care in patients with mental disorders as perceived by cancer care providers. Some issues may be resolved by psychiatric liaison teams.
Assuntos
Transtornos Mentais , Neoplasias , Atitude do Pessoal de Saúde , Pessoal de Saúde , Humanos , Transtornos Mentais/diagnóstico , Transtornos Mentais/terapia , Neoplasias/terapia , Encaminhamento e Consulta , Inquéritos e QuestionáriosRESUMO
The clinical benefit of perospirone for treatment of delirium in patients with advanced cancer is not sufficiently clear. The objective of this study was to compare the safety and effectiveness of perospirone to those of risperidone for the treatment of delirium in patients with advanced cancer. This is a secondary analysis of a multicenter prospective observational study in nine psycho-oncology consultation services in Japan. The study used the Delirium Rating Scale (DRS) Revised-98 to measure effectiveness and the CTCAE (Common Terminology Criteria for Adverse Events) version 4 to assess safety. Data from 16 patients who received perospirone and 53 patients who received risperidone were analyzed. The mean age was 70 years in the perospirone group and 73 years in the risperidone group. Both groups showed a significant decrease in the total score of DRS-R-98 after three days of treatment (perospirone: 11.7 (7.9-15.4) to 7.0 (3.3-10.7), difference -4.7, effect size=0.72, p=0.003; risperidone: 15.5 (13.6-17.4) to 12.2 (10.1-14.2), difference -3.3, effect size=0.55, p=0.00). The risperidone group showed significant improvements in sleep-wake cycle disturbance, orientation, attention, and visuospatial ability. In the perospirone group, there was a significant improvement of sleep-wake cycle disturbance. The median daily dose of perospirone was 4 mg/day. There were fewer episodes of somnolence as an adverse event in the perospirone group. Low-dose perospirone was thus found to be effective for the treatment of delirium in patients with advanced cancer and may be associated with fewer episodes of over-sedation as an adverse event.
Assuntos
Antipsicóticos , Delírio , Neoplasias , Idoso , Antipsicóticos/efeitos adversos , Delírio/induzido quimicamente , Delírio/etiologia , Humanos , Isoindóis , Neoplasias/complicações , Neoplasias/tratamento farmacológico , Psico-Oncologia , Risperidona/efeitos adversos , TiazóisRESUMO
Phototropins (phot1 and phot2) are plant blue light receptor kinases that function to mediate phototropism, chloroplast movement, leaf flattening, and stomatal opening in Arabidopsis. Considerable progress has been made in understanding the mechanisms associated with phototropin receptor activation by light. However, the identities of phototropin signaling components are less well understood by comparison. In this study, we specifically searched for protein kinases that interact with phototropins by using an in vitro screening method (AlphaScreen) to profile interactions against an Arabidopsis protein kinase library. We found that CBL-interacting protein kinase 23 (CIPK23) interacts with both phot1 and phot2. Although these interactions were verified by in vitro pull-down and in vivo bimolecular fluorescence complementation assays, CIPK23 was not phosphorylated by phot1, as least in vitro. Mutants lacking CIPK23 were found to exhibit impaired stomatal opening in response to blue light but no deficits in other phototropin-mediated responses. We further found that blue light activation of inward-rectifying K+ (K+ in ) channels was impaired in the guard cells of cipk23 mutants, whereas activation of the plasma membrane H+ -ATPase was not. The blue light activation of K+ in channels was also impaired in the mutant of BLUS1, which is one of the phototropin substrates in guard cells. We therefore conclude that CIPK23 promotes stomatal opening through activation of K+ in channels most likely in concert with BLUS1, but through a mechanism other than activation of the H+ -ATPase. The role of CIPK23 as a newly identified component of phototropin signaling in stomatal guard cells is discussed.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Estômatos de Plantas/fisiologia , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas de Arabidopsis/genética , Cloroplastos/metabolismo , Luz , Mutação , Fosforilação , Fototropismo , Canais de Potássio/metabolismo , Mapas de Interação de Proteínas , Proteínas Serina-Treonina Quinases/genéticaRESUMO
Blue-light-induced chloroplast movements play an important role in maximizing light utilization for photosynthesis in plants. Under a weak light condition, chloroplasts accumulate to the cell surface to capture light efficiently (chloroplast accumulation response). Conversely, chloroplasts escape from strong light and move to the side wall to reduce photodamage (chloroplast avoidance response). The blue light receptor phototropin (phot) regulates these chloroplast movements and optimizes leaf photosynthesis by controlling other responses in addition to chloroplast movements. Seed plants such as Arabidopsis (Arabidopsis thaliana) have phot1 and phot2. They redundantly mediate phototropism, stomatal opening, leaf flattening, and the chloroplast accumulation response. However, the chloroplast avoidance response is induced by strong blue light and regulated primarily by phot2. Phots are localized mainly on the plasma membrane. However, a substantial amount of phot2 resides on the chloroplast outer envelope. Therefore, differentially localized phot2 might have different functions. To determine the functions of plasma membrane- and chloroplast envelope-localized phot2, we tethered it to these structures with their respective targeting signals. Plasma membrane-localized phot2 regulated phototropism, leaf flattening, stomatal opening, and chloroplast movements. Chloroplast envelope-localized phot2 failed to mediate phototropism, leaf flattening, and the chloroplast accumulation response but partially regulated the chloroplast avoidance response and stomatal opening. Based on the present and previous findings, we propose that phot2 localized at the interface between the plasma membrane and the chloroplasts is required for the chloroplast avoidance response and possibly for stomatal opening as well.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Cloroplastos/metabolismo , Arabidopsis/genética , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Membrana Celular/metabolismo , Fotossíntese/genética , Fotossíntese/fisiologia , Fototropinas/metabolismo , Fototropismo/genética , Fototropismo/fisiologia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Plantas Geneticamente Modificadas/fisiologiaRESUMO
OBJECTIVE: It is widely assumed that there are multiple levels (from individual to policy level) of problems involving disparities in cancer care for people with mental disorders. However, few studies have comprehensively investigated issues as perceived by medical professionals. The purpose of the present study was to identify a wide range of issues in cancer care for people with mental disorders and offer corresponding solutions for both cancer care professionals and psychiatric care professionals. METHODS: We distributed open-ended questionnaires to 754 healthcare professionals in various medical facilities, including designated cancer hospitals, psychiatric hospitals, and other local healthcare/welfare facilities. Participants were asked to describe issues in cancer care for people with mental disorders. RESULTS: Of the 754 recruited professionals, 439 (58.2%) responded to the questionnaire. Sixty-one issues were extracted and categorized into 10 categories: patient factors; isolation and lack of support; obstacles to transport; socioeconomic factors; attitudes of psychiatric professionals; medical system of psychiatric hospitals; attitudes of cancer care professionals; medical system of designated cancer hospitals; regional cancer medical systems; and lack of coordination among multidisciplinary healthcare professionals. Forty-eight specific solutions were summarized into 12 goals. CONCLUSIONS: The present study widely identified issues causing disparities in cancer care for patients with mental disorders. We found that the issues extended from the patient level to the public-policy level. Our findings suggest the need for a multidisciplinary approach that includes both cancer and psychiatric care professionals to address the gap in cancer care for people with mental disorders.
Assuntos
Transtornos Mentais , Neoplasias , Humanos , Japão , Transtornos Mentais/terapia , Neoplasias/terapia , Psicoterapia , Inquéritos e QuestionáriosRESUMO
This study shows that high-performance metasurface polarizers are possible in the deep ultraviolet (DUV) region. A metasurface consisting of a trilayer of an Al (Aluminum) grating, an Al2O3 (Alumina) thin film, and an Al thin film serves as a mirror with high reflectance for light with polarization parallel to the grooves. The reflectance for polarization perpendicular to the grooves vanishes owing to destructive interference between the propagating and gap surface plasmon polaritons. As a result, the metasurface plays the role of a polarizer with a high extinction ratio exceeding 6.2 × 106. This study also shows that the bandwidth is improved by adjusting the incident angle, period, and the Al2O3 layer of the metasurface. The performance of the metasurface polarizer is discussed experimentally. Our finding paves the way for realizing high-performance polarizers in the DUV region.
RESUMO
Stomatal pores, which are surrounded by pairs of guard cells in the plant epidermis, regulate gas exchange between plants and the atmosphere, thereby controlling photosynthesis and transpiration. Blue light works as a signal to guard cells, to induce intracellular signaling and open stomata. Blue light receptor phototropins (phots) are activated by blue light; phot-mediated signals promote plasma membrane (PM) H+-ATPase activity via C-terminal Thr phosphorylation, serving as the driving force for stomatal opening in guard cells. However, the details of this signaling process are not fully understood. In this study, through an in vitro screening of phot-interacting protein kinases, we obtained the CBC1 and CBC2 that had been reported as signal transducers in stomatal opening. Promoter activities of CBC1 and CBC2 indicated that both genes were expressed in guard cells. Single and double knockout mutants of CBC1 and CBC2 showed no lesions in the context of phot-mediated phototropism, chloroplast movement, or leaf flattening. In contrast, the cbc1cbc2 double mutant showed larger stomatal opening under both dark and blue light conditions. Interestingly, the level of phosphorylation of C-terminal Thr of PM H+-ATPase was higher in double mutant guard cells. The larger stomatal openings of the double mutant were effectively suppressed by the phytohormone abscisic acid (ABA). CBC1 and CBC2 interacted with BLUS1 and PM H+-ATPase in vitro. From these results, we conclude that CBC1 and CBC2 act as negative regulators of stomatal opening, probably via inhibition of PM H+-ATPase activity.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Membrana Celular/enzimologia , Estômatos de Plantas/metabolismo , ATPases Translocadoras de Prótons/metabolismo , FosforilaçãoRESUMO
BACKGROUND: The Japanese Psycho-Oncology Society and Japanese Association of Supportive Care in Cancer recently launched the clinical practice guidelines for delirium in adult cancer patients. The aim of the guidelines was to provide evidence-based recommendations for the clinical assessment and management of delirium in cancer patients. This article reports the process of developing the guideline and summarizes the recommendations made. METHODS: The guidelines were developed in accordance with the Medical Information Network Distribution Service creation procedures. The guideline development group, consisting of multidisciplinary members, formulated nine clinical questions. A systematic literature search was conducted to identify relevant articles published prior to through 31 May 2016. Each article was reviewed by two independent reviewers. The level of evidence and the strength of the recommendations were graded using the grading system developed by the Medical Information Network Distribution Service, following the concept of The Grading of Recommendations Assessment, Development and Evaluation system. The modified Delphi method was used to validate the recommendation statements. RESULTS: This article provides a summary of the recommendations with rationales for each, as well as a short summary. CONCLUSIONS: These guidelines will support the clinical assessment and management of delirium in cancer patients. However, additional clinical studies are warranted to further improve the management of delirium.
Assuntos
Delírio/etiologia , Delírio/terapia , Diretrizes para o Planejamento em Saúde , Neoplasias/complicações , Guias de Prática Clínica como Assunto , Sociedades Médicas , Adulto , Antipsicóticos/uso terapêutico , Humanos , Japão , Apoio Social , Doente TerminalRESUMO
Brassinosteroids (BRs) are steroid phytohormones that regulate plant growth and development, and promote cell elongation at least in part via the acid-growth process. BRs have been suggested to induce cell elongation by the activating plasma membrane (PM) H+-ATPase. However, the mechanism by which BRs activate PM H+-ATPase has not been clarified. In this study, we investigated the effects of BR on hypocotyl elongation and the phosphorylation status of a penultimate residue, threonine, of PM H+-ATPase, which affects the activation, in the etiolated seedlings of Arabidopsis thaliana. Brassinolide (BL), an active endogenous BR, induced hypocotyl elongation, phosphorylation of the penultimate, threonine residue of PM H+-ATPase, and binding of the 14-3-3 protein to PM H+-ATPase in the endogenous BR-depleted seedlings. Changes in both BL-induced elongation and phosphorylation of PM H+-ATPase showed similar concentration dependency. BL did not induce phosphorylation of PM H+-ATPase in the BR receptor mutant bri1-6. In contrast, bikinin, a specific inhibitor of BIN2 that acts as a negative regulator of BR signaling, induced its phosphorylation. Furthermore, BL accumulated the transcripts of SMALL AUXIN UP RNA 9 (SAUR9) and SAUR19, which suppress dephosphorylation of the PM H+-ATPase penultimate residue by inhibiting D-clade type 2C protein phosphatase in the hypocotyls of etiolated seedlings. From these results, we conclude that BL-induced phosphorylation of PM H+-ATPase penultimate residue is mediated via the BRI1-BIN2 signaling pathway, together with the accumulation of SAURs during hypocotyl elongation.
Assuntos
Brassinosteroides/farmacologia , Membrana Celular/enzimologia , Hipocótilo/metabolismo , ATPases Translocadoras de Prótons/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Brassinosteroides/metabolismo , Regulação da Expressão Gênica de Plantas , Hipocótilo/efeitos dos fármacos , Fosforilação/efeitos dos fármacosRESUMO
A variety of cellular metabolic reactions generate inorganic pyrophosphate (PPi) as an ATP hydrolysis byproduct. The vacuolar H+-translocating pyrophosphatase (H+-PPase) loss-of-function fugu5 mutant is susceptible to drought and displays pleotropic postgerminative growth defects due to excess PPi. It was recently reported that stomatal closure after abscisic acid (ABA) treatment is delayed in vhp1-1, a fugu5 allele. In contrast, we found that specific removal of PPi rescued all of the above fugu5 developmental and growth defects. Hence, we speculated that excess PPi itself, rather than vacuolar acidification, might delay stomatal closure. To test this hypothesis, we constructed transgenic plants expressing the yeast IPP1 gene (encoding a cytosolic pyrophosphatase) driven by a guard cell-specific promoter (pGC1::IPP1) in the fugu5 background. Our measurements confirmed stomatal closure defects in fugu5, further supporting a role for H+-PPase in stomatal functioning. Importantly, while pGC1::IPP1 transgenics morphologically mimicked fugu5, stomatal closure was restored in response to ABA and darkness. Quantification of water loss revealed that fugu5 stomata were almost completely insensitive to ABA. In addition, growth of pGC1::IPP1 plants was promoted compared to fugu5 throughout their life; however, it did not reach the wild type level. fugu5 also displayed an increased stomatal index, in violation of the one-cell-spacing rule, and phenotypes recovered upon removal of PPi by pAVP1::IPP1 (FUGU5, VHP1 and AVP1 are the same gene encoding H+-PPase), but not in the pGC1::IPP1 line. Taken together, these results clearly support our hypothesis that dysfunction in stomata is triggered by excess PPi within guard cells, probably via perturbed guard cell metabolism.
Assuntos
Difosfatos/metabolismo , Estômatos de Plantas/metabolismo , Ácido Abscísico/farmacologia , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Arabidopsis/metabolismo , Pirofosfatase Inorgânica/genética , Pirofosfatase Inorgânica/metabolismo , Mutação/genética , Estômatos de Plantas/efeitos dos fármacos , Estômatos de Plantas/fisiologiaRESUMO
Blue light (BL) is a fundamental cue for stomatal opening in both C3 and C4 plants. However, it is unknown whether crassulacean acid metabolism (CAM) plants open their stomata in response to BL. We investigated stomatal BL responses in the obligate CAM plants Kalanchoe pinnata and Kalanchoe daigremontiana that characteristically open their stomata at night and close them for part of the day, as contrasted with C3 and C4 plants. Stomata opened in response to weak BL superimposed on background red light in both intact leaves and detached epidermal peels of K. pinnata and K. daigremontiana. BL-dependent stomatal opening was completely inhibited by tautomycin and vanadate, which repress type 1 protein phosphatase and plasma membrane H+-ATPase, respectively. The plasma membrane H+-ATPase activator fusicoccin induced stomatal opening in the dark. Both BL and fusicoccin induced phosphorylation of the guard cell plasma membrane H+-ATPase in K. pinnata. These results indicate that BL-dependent stomatal opening occurs in the obligate CAM plants K. pinnata and K. daigremontiana independently of photosynthetic CO2 assimilation mode.
Assuntos
Ciclo do Carbono/efeitos da radiação , Kalanchoe/metabolismo , Luz , Estômatos de Plantas/efeitos da radiação , Kalanchoe/enzimologia , Kalanchoe/efeitos da radiação , Fotossíntese , Folhas de Planta/metabolismo , Folhas de Planta/efeitos da radiação , Estômatos de Plantas/metabolismo , Especificidade da EspécieRESUMO
Stomatal movements regulate gas exchange, thus directly affecting the efficiency of photosynthesis and the sensitivity of plants to air pollutants such as ozone. The GARP family transcription factors GOLDEN 2-LIKE1 (GLK1) and GLK2 have known functions in chloroplast development. Here, we show that Arabidopsis thaliana (A. thaliana) plants expressing the chimeric repressors for GLK1 and -2 (GLK1/2-SRDX) exhibited a closed-stomata phenotype and strong tolerance to ozone. By contrast, plants that overexpress GLK1/2 exhibited an open-stomata phenotype and higher sensitivity to ozone. The plants expressing GLK1-SRDX had reduced expression of the genes for inwardly rectifying K(+) (K(+) in) channels and reduced K(+) in channel activity. Abscisic acid treatment did not affect the stomatal phenotype of 35S:GLK1/2-SRDX plants or the transcriptional activity for K(+) in channel gene, indicating that GLK1/2 act independently of abscisic acid signaling. Our results indicate that GLK1/2 positively regulate the expression of genes for K(+) in channels and promote stomatal opening. Because the chimeric GLK1-SRDX repressor driven by a guard cell-specific promoter induced a closed-stomata phenotype without affecting chloroplast development in mesophyll cells, modulating GLK1/2 activity may provide an effective tool to control stomatal movements and thus to confer resistance to air pollutants.
Assuntos
Proteínas de Arabidopsis/fisiologia , Arabidopsis/efeitos dos fármacos , Ozônio/toxicidade , Estômatos de Plantas/fisiologia , Plantas Geneticamente Modificadas/efeitos dos fármacos , Fatores de Transcrição/fisiologia , Poluentes Atmosféricos/toxicidade , Arabidopsis/genética , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Cloroplastos/fisiologia , Regulação da Expressão Gênica de Plantas , Herbicidas/toxicidade , Oxidantes/toxicidade , Paraquat/toxicidade , Estômatos de Plantas/efeitos dos fármacos , Transpiração Vegetal , Plantas Geneticamente Modificadas/fisiologia , Canais de Potássio/fisiologia , Dióxido de Enxofre/toxicidade , Fatores de Transcrição/genéticaRESUMO
Phototropins (phots) are plasma membrane-associated serine/threonine kinases that coordinate a range of processes linked to optimizing photosynthetic efficiency in plants. These photoreceptors contain two light-, oxygen-, or voltage-sensing (LOV) domains within their N terminus, with each binding one molecule of flavin mononucleotide as a UV/blue light-absorbing chromophore. Although phots contain two LOV domains, light-induced activation of the C-terminal kinase domain and subsequent receptor autophosphorylation is controlled primarily by the A'α-LOV2-Jα photosensory module. Mutations that disrupt interactions between the LOV2 core and its flanking helical segments can uncouple this mode of light regulation. However, the impact of these mutations on phot function in Arabidopsis has not been explored. Here we report that histidine substitution of Arg-472 located within the A'α-helix of Arabidopsis phot1 constitutively activates phot1 kinase activity in vitro without affecting LOV2 photochemistry. Expression analysis of phot1 R472H in the phot-deficient mutant confirmed that it is autophosphorylated in darkness in vivo but unable to initiate phot1 signaling in the absence of light. Instead, we found that phot1 R472H is poorly functional under low-light conditions but can restore phototropism, chloroplast accumulation, stomatal opening, and leaf positioning and expansion at higher light intensities. Our findings suggest that Arabidopsis can adapt to the elevated phosphorylation status of the phot1 R472H mutant in part by reducing its stability, whereas the activity of the mutant under high-light conditions can be attributed to additional increases in LOV2-mediated photoreceptor autophosphorylation.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Proteínas de Ligação a DNA/metabolismo , Fosfoproteínas/metabolismo , Plantas Geneticamente Modificadas/enzimologia , Processamento de Proteína Pós-Traducional , Substituição de Aminoácidos , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/efeitos da radiação , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Dicroísmo Circular , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Ativação Enzimática/efeitos da radiação , Estabilidade Enzimática/efeitos da radiação , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Isoenzimas/genética , Isoenzimas/metabolismo , Luz , Fosfoproteínas/química , Fosfoproteínas/genética , Fosforilação/efeitos da radiação , Processos Fotoquímicos , Fototropismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Plantas Geneticamente Modificadas/efeitos da radiação , Mutação Puntual , Conformação Proteica em alfa-Hélice , Domínios e Motivos de Interação entre Proteínas , Processamento de Proteína Pós-Traducional/efeitos da radiação , Proteínas Serina-Treonina Quinases , Estabilidade Proteica/efeitos da radiação , Proteínas Recombinantes de Fusão/metabolismoRESUMO
We conducted this study to determine the short-term treatment outcomes of multidisciplinary approaches to chronic pain management for outpatients in Japan. We evaluated pain reduction and improvement in quality of life (QOL) after treatment. We analyzed 32 patients who had experienced intractable chronic pain for > 3 months. The patients received multidisciplinary therapeutic self-managed exercise instructions and then underwent evaluations 1 and 3 months after the treatment. We used the Pain Disability Short Form-36 (SF-36), Pain Catastrophizing Scale (PCS), and Pain Disability Assessment Scale (PDAS) to evaluate QOL. Although the pain levels were the same before and after the physical exercise program, the patients showed significant improvements in physical function on the SF-36 (48.5 vs. 54.5, 3 months vs. 1 month; p=0.0124), the magnification subscale on the PCS (6.8 vs. 5.9, 1 month vs. before; p=0.0164) and the PDAS (29.2 vs. 23.4, 3 months vs. before; p=0.0055). Chronic pain should be treated with a biopsychosocial approach, but time constraints and costs have limited the implementation of multidisciplinary and behavioral approaches to chronic pain management. Our findings demonstrate that clinical improvements are possible for patients with chronic pain, using multidisciplinary team resources widely available in Japanese clinical practice.
Assuntos
Dor Crônica/terapia , Terapia por Exercício , Manejo da Dor/métodos , Equipe de Assistência ao Paciente , Autogestão , Dor Crônica/psicologia , Humanos , Medição da Dor , Projetos Piloto , Qualidade de VidaRESUMO
Stomata within the plant epidermis regulate CO2 uptake for photosynthesis and water loss through transpiration. Stomatal opening in Arabidopsis thaliana is determined by various factors, including blue light as a signal and multiple phytohormones. Plasma membrane transporters, including H+-ATPase, K+ channels and anion channels in guard cells, mediate these processes, and the activities and expression levels of these components determine stomatal aperture. However, the regulatory mechanisms involved in these processes are not fully understood. In this study, we used infrared thermography to isolate a mutant defective in stomatal opening in response to light. The causative mutation was identified as an allele of the brassinosteroid (BR) biosynthetic mutant dwarf5. Guard cells from this mutant exhibited normal H+-ATPase activity in response to blue light, but showed reduced K+ accumulation and inward-rectifying K+ (K+in) channel activity as a consequence of decreased expression of major K+in channel genes. Consistent with these results, another BR biosynthetic mutant, det2-1, and a BR receptor mutant, bri1-6, exhibited reduced blue light-dependent stomatal opening. Furthermore, application of BR to the hydroponic culture medium completely restored stomatal opening in dwarf5 and det2-1 but not in bri1-6. However, application of BR to the epidermis of dwarf5 did not restore stomatal response. From these results, we conclude that endogenous BR acts in a long-term manner and is required in guard cells with the ability to open stomata in response to light, probably through regulation of K+in channel activity.