Molecular interactions of BBX24 and BBX25 with HYH, HY5 HOMOLOG, to modulate Arabidopsis seedling development

BBX24 and BBX25 are two important transcriptional regulators, which regulate seedling photomorphogenesis in Arabidopsis. Very recently, we have shown that BBX24 and BBX25 negatively regulate the expression of BBX22, reducing the function of HY5, by physically interacting with its bZIP domain.1 Furthermore, HY5 HOMOLOG, HYH, has been reported to heterodimerize with HY5 and enhances its photomorphogenic function in seedling de-etiolation by serving as coactivator.8 Here, we further report that BBX24 and BBX25 physically interact with HYH. The physical interactions of BBX24 and BBX25 with HYH could lead to depletion of HYH molecules from the active pool and, thus indirectly, reduce the function of HY5 in promoting photomorphogenesis. Hence, our results suggest another mode of regulation by which BBX24 and BBX25 exert their negative effects on HY5 indirectly through HYH for the fine-tuning of seedling photomorphogenesis.Fil: Gangappa, Sreeramaiah N.. Gothenburg University. Department of Biological and Environmental Sciences; SueciaFil: Holm, Magnus. Gothenburg University. Department of Biological and Environmental Sciences; SueciaFil: Botto, Javier Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentin

Parámetros biológicos del parasitoide Encarsia formosa (Gahan) (Hymenoptera: Aphelinidae) en condiciones de laboratorio

Encarsia formosa es el parasitoide más utilizado para el control biológico de la mosca blanca de los invernáculos, Trialeurodes vaporariorum. Dado que en la Argentina no existen antecedentes sobre estudios biológicos de este entomófago, el objetivo de este trabajo fue analizar los siguientes parámetros biológicos de E. formosa: supervivencia (1x) fecundidad específica (mx), tasa intrínseca de incremento poblacional (rm) tasa neta de reproducción (R0) y tiempo generacional (T). Para ello se obtuvieron las tablas de vida y de fecundidad utilizando a T. vaporariorum como huésped y al tomate como planta hospedera. Bajo las condiciones experimentales utilizadas se obtuvieron los siguientes resultados: mortalidad en el estado de pupa =4%; longevidad media del adulto =10.4 d; lx50 (adultos)=8-9 d; rm=0.283 pupas parasitadas / ♀ / d, R0=155.6 pupas parasitadas/hembra; T=17.9 d. Las curvas lx-mx y los parámetros poblacionales analizados indican que la población local de E. formosa estudiada posee un gran potencial para ser utilizada como agente de biocontrol de T. vaporariorum.The estimation of biological parameters of natural enemies is an important tool in applied biological control since it contributes to reduce the risk of selecting the wrong agents. Population parameters like the intrinsic rate of increase (rm) have been widely used as indices of the potencial performance of natural enemies. This paper deals with the development of life and fecundity tables to estimate rm and other biological parameters (i.e., the net reproductive rate R0, survival lx, specific fecundity mx, generational time T) in the parasitic wasp Encarsia formosa, a biological control agent to be used against the greenhouse whitefly Trialeurodes vaporariorum, in Argentina. Under the experimental conditions performed the estimated parameters were: rm=0.283 parazitized pupae / ♀ / d; lx, (immature stages) =96%; mean longevity of adults =10.4 days; survival (lx50%) of adults =8-9 days; R0= 155.6 parasitized pupae / ♀; T=17.9 days. This is the first time that E. formosa is evaluated regarding its potential as a biocontrol agent of the greenhouse whitefly in Argentina

Evaluación del parasitoide Trichogramma pretiosum (Hymenoptera: Trichogrammatidae) como agente de control biológico de Anticarsia gemmatalis (Lepidoptera: Noctuidae) en condiciones de laboratorio

Los parasitoides oófagos del género Trichogramma son utilizados a nivel mundial como agentes de control de lepidópteros plaga de numerosos cultivos. El estudio de parámetros biológicos poblacionales,entre ellos la tasa intrínseca de crecimiento poblacional(rm)ha sido de gran utilidad para evaluar la efictividad de numerosas especies de parasitoides. En el presente trabajo se evalúa el potencial de una población local de Trichogramma pretiosum como agente de control de Anticarsia gemmatalis. Para esto, se estimaron y analizaron algunos parámetros biológicos poblacionales de los parasitoides mediante técnicas de tabla de vida y fecundidad en condiciones controladas de temperatura (25 ± 1ºC), humedad relativa (50-70%) y fotoperíodo(14L:10O). Se obtuvieron los siguientes resultados: longevidad media de hembras adultas: 6.53 d; 1x50%: 6d; máximo mx; 20 ♀ / ♀ / d, rm: 0.41; R0: 41.48 ♀ / ♀; T: 8.99 d. Estos valores indican que T. pretiosum podría resultar de gran utilidad como agente de control de A. genunatalis en cultivos de soja de nuestro país.Egg parasitoids of the genus Trichogramma are used worldwide as biological control agents against lepidopterous pests of several crops. The intrinsic rate of natural increase (rm) and other biological parameters have been very useful in assessing parasitoids. We used life and fertility tables to estimate several population parameters of a local population of the parasitoid Trichogramma pretiosum and to explore its potential value as a biological control agent of the velvetbean caterpillar Anticarsia gemmatalis. All studies were performed at 25 ± 1ºC, 50-70% RH and a photoperiod of 14:10 (L:D). The following results were obtained: mean adult female longevity: 6.53 d; survivorship (1x50%) of adult females: 6 d; maximum mx: 20 ♀ / ♀ / d; rm: 0.41; R0: 41.48 ♀ / ♀; T: 8.99 d. These results suggest that T. pretiosum has a great potential to be used for supression of the velvetbean caterpillar in soybean crops in Argentina

Serum Amyloid P Aids Complement-Mediated Immunity to Streptococcus pneumoniae

The physiological functions of the acute phase protein serum amyloid P (SAP) component are not well defined, although they are likely to be important, as no natural state of SAP deficiency has been reported. We have investigated the role of SAP for innate immunity to the important human pathogen Streptococcus pneumoniae. Using flow cytometry assays, we show that SAP binds to S. pneumoniae, increases classical pathway–dependent deposition of complement on the bacteria, and improves the efficiency of phagocytosis. As a consequence, in mouse models of infection, mice genetically engineered to be SAP-deficient had an impaired early inflammatory response to S. pneumoniae pneumonia and were unable to control bacterial replication, leading to the rapid development of fatal infection. Complement deposition, phagocytosis, and control of S. pneumoniae pneumonia were all improved by complementation with human SAP. These results demonstrate a novel and physiologically significant role for SAP for complement-mediated immunity against an important bacterial pathogen, and provide further evidence for the importance of the classical complement pathway for innate immunity

Quantitative MRI Measurement of Binder Distributions in Green-State Ceramics

Development of reliable and improved structural ceramics for advanced heat engines and other applications requires process diagnostics and materials evaluation from powder preparation to green-body forming to final sintering. Injection molding is a promising processing method being developed for mass production of complex-shaped heat engine components such as turbochargers (rotors and stator vanes) and engine valves. Major processing steps in injection-molded ceramic manufacturing include preparation of ceramic powders and organic binders, mixing, molding, binder removal, sintering, and finishing [1]. While materials evaluation and diagnostics are needed throughout the process, it is particularly important to evaluate the distributions of binders/plasticizers in as-molded green bodies [2]. Poor distribution of these organics in a green body can lead to a final part that is defective or that has poor mechanical properties after it is sintered

The Arabidopsis B-BOX Protein BBX25 Interacts with HY5, Negatively Regulating BBX22 Expression to Suppress Seedling Photomorphogenesis

ELONGATED HYPOCOTYL5 (HY5) is a basic domain/leucine zipper (bZIP) transcription factor, central for the regulation of seedling photomorphogenesis. Here, we identified a B-BOX (BBX)–containing protein, BBX25/SALT TOLERANCE HOMOLOG, as an interacting partner of HY5, which has been previously found to physically interact with CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1). BBX25 physically interacts with HY5 both in vitro and in vivo. By physiological and genetic approaches, we showed that BBX25 is a negative regulator of seedling photomorphogenesis. BBX25 and its homolog BBX24 regulate deetiolation processes and hypocotyl shade avoidance response in an additive manner. Moreover, genetic relationships of bbx25 and bbx24 with hy5 and cop1 revealed that BBX25 and BBX24 additively enhance COP1 and suppress HY5 functions. BBX25 accumulates in a light-dependent manner and undergoes COP1-mediated degradation in dark and light conditions. Furthermore, a protoplast cotransfection assay showed that BBX24 and BBX25 repress BBX22 expression by interfering with HY5 transcriptional activity. As HY5 binds to the BBX22 promoter and promotes its expression, our results identify a direct mechanism through which the expression of BBX22 is regulated. We suggest that BBX25 and BBX24 function as transcriptional corepressors, probably by forming inactive heterodimers with HY5, downregulating BBX22 expression for the fine-tuning of light-mediated seedling development.Fil: Gangappa, Sreeramaiah N.. Gothenburg University. Department of Biological and Environmental Sciences; SueciaFil: Crocco, Carlos Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas A la Agricultura; ArgentinaFil: Johansson, Henrik. Gothenburg University. Department of Biological and Environmental Sciences; SueciaFil: Datta, Sourav. Gothenburg University. Department of Biological and Environmental Sciences; SueciaFil: Hettiarachchi, Chamari. Gothenburg University. Department of Biological and Environmental Sciences; SueciaFil: Holm, Magnus. Gothenburg University. Department of Biological and Environmental Sciences; SueciaFil: Botto, Javier Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas A la Agricultura; Argentin

Complement C3 exacerbates imiquimod-induced skin inflammation and psoriasiform dermatitis

The complement system is pivotal in protection against pathogens, but also plays important roles in bridging innate and adaptive imm une responses (Scott and Botto, 2015) and in modulating local and systemic inflammation (Markiewski and Lambris, 2007). Activation of complement occurs through three different path ways (classical, alte rnative and lectin), converges at C3 cleavage and culminates in the formation of the membrane attack complex. The anaphylotoxic fragments, C3a and C5a, gene rated during the proteolytic cascade, recruit immune cells that can promote the removal of debris and pat hogens, but can also cause tissue damage (Markiewski and Lambris, 2007)