1061. Salicylic acid is an indispensable component of the Ny-1 resistance-gene-mediated response against Potato virus Y infection in potatoŠpela Baebler, Kamil Witek, Marko Petek, Katja Stare, Magda Tušek-Žnidarič, Maruša Pompe Novak, Jenny Renaut, K. Szajko, D. Strzelczyk-Żyta, W. Marczewski, Karolina Morgiewicz, Kristina Gruden, Jacek Hennig, 2014, izvirni znanstveni članek Povzetek: The purpose of the study was to investigate the role of salicylic acid (SA) signalling in Ny-1-mediated hypersensitive resistance (HR) of potato (Solanum tuberosum L.) to Potato virus Y (PVY). The responses of the Ny-1 allele in the Rywal potato cultivar and transgenic NahG-Rywal potato plants that do not accumulate SA were characterized at the cytological, biochemical, transcriptome, and proteome levels. Analysis of noninoculated and inoculated leaves revealed that HR lesions started to develop from 3 d post inoculation and completely restricted the virus spread. At the cytological level, features of programmed cell death in combination with reactive oxygen species burst were observed. In response to PVY infection, SA was synthesized de novo. The lack of SA accumulation in the NahG plants led to the disease phenotype due to unrestricted viral spreading. Grafting experiments show that SA has a critical role in the inhibition of PVY spreading in parenchymal tissue, but not in vascular veins. The whole transcriptome analysis confirmed the central role of SA in orchestrating Ny-1-mediated responses and showed that the absence of SA leads to significant changes at the transcriptome level, including a delay in activation of expression of genes known to participate in defence responses. Moreover, perturbations in the expression of hormonal signalling genes were detected, shown as a switch from SA to jasmonic acid/ethylene signalling. Viral multiplication in the NahG plants was accompanied by downregulation of photosynthesis genes and activation of multiple energy-producing pathways. Ključne besede: plant-pathogen interactions, Potato virus Y, salicylic acid, whole transcriptome analysis Objavljeno v DiRROS: 01.08.2024; Ogledov: 347; Prenosov: 249 Celotno besedilo (4,98 MB) Gradivo ima več datotek! Več... |
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1063. Turbulence observations in the Gulf of Trieste under moderate wind forcing and different water column stratificationFrancesco Marcello Falcieri, Lakshmi Kantha, Alvise Benetazzo, Andrea Bergamasco, Davide Bonaldo, Francesco Barbariol, Vlado Malačič, Mauro Sclavo, Sandro Carniel, 2016, izvirni znanstveni članek Povzetek: The oceanographic campaign CARPET2014 (Characterizing Adriatic Region Preconditionig EvenTs), (30 January–4 February 2014) collected the very first turbulence data in the Gulf of Trieste (northern Adriatic Sea) under moderate wind (average wind speed 10 m s−1) and heat flux (net negative heat flux ranging from 150 to 400 W m−2). Observations consisted of 38 CTD (Conductivity, Temperature, Depth) casts and 478 microstructure profiles (grouped into 145 ensembles) with three sets of yoyo casts, each lasting for about 12 consecutive hours. Averaging closely repeated casts, such as the ensembles, can lead to a smearing effect when in the presence of a vertical density structure with strong interfaces that can move up or down between subsequent casts under the influence of tides and internal waves. In order to minimize the smearing effect of such displacements on mean quantities, we developed an algorithm to realign successive microstructure profiles to produce sharper and more meaningful mean profiles of measured turbulence parameters.
During the campaign, the water column in the gulf evolved from well-mixed to stratified conditions due to Adriatic waters intruding at the bottom along the gulf's south-eastern coast. We show that during the warm and relatively dry winter, the water column in the Gulf of Trieste, even under moderate wind forcing, was not completely mixed due to the influence of bottom waters intruding from the open sea. Inside the gulf, two types of water intrusions were found during yoyo casts: one coming from the northern coast of the Adriatic Sea (i.e. cooler, fresher and more turbid) and one coming from the open sea in front of the Po Delta (i.e. warmer, saltier and less turbid). The two intrusions had different impacts on turbulence kinetic energy dissipation rate profiles. The former, with high turbidity, acted as a barrier to wind-driven turbulence, while the latter, with low sediment concentrations and a smaller vertical density gradient, was not able to suppress downward penetration of turbulence from the surface. Ključne besede: hydrology, oceanographic data, numerical modelling, wind forcing, turbulence Objavljeno v DiRROS: 01.08.2024; Ogledov: 386; Prenosov: 334 Celotno besedilo (2,99 MB) Gradivo ima več datotek! Več... |
1064. Protein gas vesicles of bacillus megaterium as enhancers of ultrasound-induced transcriptional regulationVid Jazbec, Nina Varda, Ernest Šprager, Maja Meško, Sara Vidmar, Rok Romih, Marjetka Podobnik, Andreja Kežar, Roman Jerala, Mojca Benčina, 2024, izvirni znanstveni članek Objavljeno v DiRROS: 01.08.2024; Ogledov: 435; Prenosov: 336 Celotno besedilo (1,47 MB) Gradivo ima več datotek! Več... |
1065. Evaluation of cyanobacteria biomass derived from upgrade of phycocyanin fluorescence estimationTinkara Rozina, Bojan Sedmak, Maja Zupančič Justin, Andrej Meglič, 2017, izvirni znanstveni članek Povzetek: The number of harmful cyanobacterial blooms has increased significantly at the global level in recent years. One of the characteristics of cyanobacteria that gives them advantage over other phytoplankton organisms are auxiliary photosynthetic pigments, such as phycocyanin. This fluorescent pigment emits light at a different wavelength as chlorophyll and can therefore be used for detection of cyanobacteria in situ. In this study we used submersible phycocyanin fluorescence sensors and compare their voltage output to concentration of extracted phycocyanin, cell counts and biovolume. The relation was linear in all three cases; however, the variability of regression line slopes between different cyanobacteria strains was high in the case of PC extract concentration and cell count. The highest uniformity in the linear fits was between fluorescence signal and biovolume therefore making it the best candidate for fluorescence sensor voltage output conversion. In the context of this work we also compared different methods for PC extraction. Modifying the equations by subtracting the absorption at 750 nm almost entirely reduces the false PC concentration estimation due to sample turbidity.
Ključne besede: fluorescence measurements, phycocyanin, cyanobacteria Objavljeno v DiRROS: 01.08.2024; Ogledov: 387; Prenosov: 160 Celotno besedilo (571,80 KB) Gradivo ima več datotek! Več... |
1066. Coralline algae on biogenic formations in marine waters off Slovenia (northern Adriatic Sea)Martina Orlando-Bonaca, Borut Mavrič, Lovrenc Lipej, Sara Kaleb, Annalisa Falace, 2017, izvirni znanstveni članek Povzetek: Two major biogenic formations, composed mainly by dead corallites of the Mediterranean stony coral (Cladocora caespitosa), have been recently studied in Slovenian marine waters. The paper presents new data about the presence of coralline algae on the biogenic formation situated off Cape Ronek and off Cape Debeli rtič. Coralline algae are very important for the creation, development and maintenance of calcareous bio-concretions that offer new niches for many invertebrates and other algae. They are listed as important builders of the coralligenous biocoenosis in the "Draft Lists of coralligenous/maërl populations and of main species to be considered by the inventory and monitoring" of the RAC-SPA, and should be further deeply studied and appropriately protected. Ključne besede: coralline algae, biogenic formations, circalittoral, northern Adriatic, Slovenia Objavljeno v DiRROS: 01.08.2024; Ogledov: 339; Prenosov: 306 Celotno besedilo (1,51 MB) Gradivo ima več datotek! Več... |
1067. Unusual bloom of tetrasporophytes of the non-indigenous red alga Asparagopsis armata in the northern Adriatic SeaMartina Orlando-Bonaca, Borut Mavrič, Domen Trkov, Lovrenc Lipej, 2017, izvirni znanstveni članek Povzetek: The tetrasporophyte of the non-indigenous red alga Asparagopsis armata (the Falkenbergia stage) is considered to be established in Slovenian coastal waters. However, until 2016, it was found only in low coverage and in few localities with hard substrata. The paper reports a recent bloom of these tetrasporophytes in the mediolittoral belt of the Bay of Piran, where thalli of this red alga overgrew the articularted coralline alga Corallina officinalis. The sites affected by this large expansion of tetrasporophytes of A. armata should be regularly monitored in the future, in order to point out which environmental factors are responsible for such phenomenon, and to formulate proper conclusions on the status of this non-indigenous alga in the coastal area concerned. Ključne besede: non-indigenous species, coastal waters, autburst, northern Adriatic Sea Objavljeno v DiRROS: 01.08.2024; Ogledov: 356; Prenosov: 220 Celotno besedilo (745,11 KB) Gradivo ima več datotek! Več... |
1068. Combined use of chlorophyll a and phycocyanin fluorescence sensors for quantification and differentiation of phytoplankton : a useful approach for small surface water bodiesTinkara Rozina, Tina Eleršek, Maja Zupančič Justin, Andrej Meglič, 2018, izvirni znanstveni članek Povzetek: Sensors based on in vivo measurements of photosynthetic pigments fluorescence enable real-time phytoplankton monitoring with high spatial and temporal resolution. A combination of chlorophyll a (CHL) and phycocyanin (PC) fluorescence sensors was used for phytoplankton quantification and differentiation in two small water bodies, Koseze Pond and pond in Hotinja vas. The high correlation of CHL and PC fluorescence signals with biovolume was confirmed during the two-year monitoring in anatural pond environment in spite of a seasonal succession of the phytoplankton. Additionally, disturbances of the sensors were investigated. Water bodies containing predominantly algae yielded false positive signals of the PC sensor, which reached up to 1% of the intensity of the CHL signal. Similarly, underestimated counts of cyanobacteria measured with CHL fluorescence sensor can be adjusted using PC fluorescence sensor. Ključne besede: small water bodies, algae, cyanobacteria, fluorescence sensors, biovolume Objavljeno v DiRROS: 01.08.2024; Ogledov: 327; Prenosov: 214 Celotno besedilo (699,64 KB) Gradivo ima več datotek! Več... |
1069. Stress tolerance of three opportunistic black yeastsJanja Zajc, Cene Gostinčar, Metka Lenassi, Nina Gunde-Cimerman, 2018, izvirni znanstveni članek Povzetek: Many species of black yeasts can survive extremely harsh conditions and can quickly adapt to novel environments. These traits were proposed to have a role in the ability of some fungal species tocolonise indoor habitats inhospitable for majority of microorganisms, and to cause (opportunistic)infections in humans. In order to better understand the stress tolerance of black yeasts and thereby their opportunism, we focused our research on the three model black yeasts: the polyextremotolerant Au-reobasidium melanogenum and Exophiala dermatitidis, and the extremely halotolerant Hortaeawerneckii. These black yeasts are shown to thrive at temperatures, salinities, pH values and, H2O2 concentrations that inhibit growth of mesophilic species. Most importantly, unlike their close relatives they can not only grow, but also synthesize siderophores (E. dermatitidis) or degradeproteins (A. melanogenum) at 37 °C - traits that are crucial for pathogenesis in humans. These results support the hypothesis that the ability to cope with various environmental stresses is linked to the opportunistic behaviour of fungi. Therefore, better understanding of the connections between the stress-tolerant biology of black fungi and their ability to cause disease is needed, in particular due to their changing interactions with humans and their emerging pathogenicity.
Ključne besede: melanised fungi, temperature, NaCl, pH tolerance, ROS, oligotrophism, proteolytic activity, capsule Objavljeno v DiRROS: 01.08.2024; Ogledov: 366; Prenosov: 203 Celotno besedilo (1,00 MB) Gradivo ima več datotek! Več... |
1070. "Only introduced" or "invasive" : spread of the alga Aulacoseira ambigua f. japonica from Asia to Africa and EuropeTina Eleršek, 2018, izvirni znanstveni članek Povzetek: Many non-native algal species are found in waters all over the world. Many terms are used to describe such organisms that have expanded their distribution. However, a unified model or concept remains to be defined, as how biological ‘invasions’ are seen depends on the perspective. Understanding invasive organisms is important for biodiversity, science policy and water management. During monitoring sampling at Slivniško Lake (Slovenia) in 2016, the curved diatom Aulacoseira ambigua f. japonica Tuji & D.M. Williams was identified. This species originates from Japan, from where it was described more than 100 years ago. The chronology of the published distributions of A. ambigua f. japonica defines its spread from Japan to Asia, then to western Russia and South Africa, and now to central Europe. This study provides further evidence that A. ambigua f. japonica has become established in Europe (Slovenia), as supported by light microscopy and scanning electron microscopy. To the best of our knowledge, this is the first qualitative and quantitative description of A. ambigua f. japonica in Europe. It has been suggested that the shape of these algal colonies is significant for the interpretation of ecological information, and indeed, also in the present case, spiral colonies were found in this eutrophic water body. Although curved cells and colonies can also be interpreted as (sub)populations or morphological variants, only detailed molecular studies can reveal if these also have taxonomic significance. Ključne besede: algae, introduced species, invasive species, scanning electron microscopy Objavljeno v DiRROS: 01.08.2024; Ogledov: 429; Prenosov: 265 Celotno besedilo (2,56 MB) Gradivo ima več datotek! Več... |