201. Temperature dependence of planktonic metabolism in the subtropical North Atlantic OceanL.S. Garcia-Corral, E. Barber, A. Regaudie-de_Gioux, S. Sal, J.M. Holding, S. Agusti, N. Navarro, P. Serret, Patricija Mozetič, Carlos M. Duarte, 2014, izvirni znanstveni članek Povzetek: The temperature dependence of planktonic metabolism in the subtropical North Atlantic Ocean was assessed on the basis of measurements of gross primary production (GPP), community respiration (CR) and net community production (NCP), as well as experimental assessments of the response of CR to temperature manipulations. Metabolic rates were measured at 68 stations along three consecutive longitudinal transects completed during the Malaspina 2010 Expedition, in three different seasons. Temperature gradients were observed in depth and at basin and seasonal scale. The results showed seasonal variability in the metabolic rates, the highest rates being observed during the spring transect. The overall mean integrated GPP / CR ratio was 1.39 ± 0.27 decreasing from winter to summer, and the NCP for the subtropical North Atlantic Ocean during the cruises exhibits net autotrophy (NCP > 0) in about two-thirds (66%) of the total sampled communities. Also, we reported the activation energies describing the temperature dependence of planktonic community metabolism, which was generally higher for CR than for GPP in the subtropical North Atlantic Ocean, as the metabolic theory of ecology predicts. Furthermore, we made a comparison of activation energies describing the responses to in situ temperature in the field (EaCR = 1.64 ± 0.36 eV) and those derived experimentally by temperature manipulations (EaCR = 1.45 ± 0.6 eV), which showed great consistency. Ključne besede: morje, plankton, fitoplankton, klorofil, trofični status, anoksije Objavljeno v DiRROS: 01.08.2024; Ogledov: 99; Prenosov: 117
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202. Meiofauna winners and losers of coastal hypoxia: case study harpacticoid copepodsMateja Grego, Bettina Riedel, Michael Stachowitsch, Marleen De Troch, 2014, izvirni znanstveni članek Povzetek: The impact of anoxia on meiobenthic copepod species was assessed by means of a field experiment. Four plexiglass chambers were deployed in situ in 24 m depth to simulate an anoxic event of 9 days, 1 month, 2 months and 10 months. From normoxic to anoxic conditions, we recorded a drop in copepod density and species richness. With increasing duration of anoxia the relative abundance of the individuals of the family Cletodidae increased, and they survived the 1 month and 2 month anoxia, the latter with few specimens. They were the true "winners" of the experimentally induced anoxia. Dominance did not increase in the deployments because not one, but several species from this family were tolerant to anoxia. The overall rate of survival was the same for males and females, but no juvenile stages of copepods survived in anoxia. During a recovery phase of 7 days after a short-term anoxia of 9 days, harpacticoid copepod density did not increase significantly, and there was only a slight increase in species diversity. We concluded that no substantial colonisation from the surrounding sediment took place. The survivors, however, showed a high potential for recovery according to the number of gravid females, whose number increased significantly once the oxygen was available again. These findings imply that substantial energy is allocated to reproduction in the recovery phase. Objavljeno v DiRROS: 01.08.2024; Ogledov: 121; Prenosov: 74
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203. 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: 125; Prenosov: 118
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205. 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: 122; Prenosov: 138
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206. 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: 137; Prenosov: 176
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207. 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: 113; Prenosov: 57
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208. 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: 111; Prenosov: 151
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209. 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: 120; Prenosov: 73
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210. 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: 114; Prenosov: 76
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