Annual cambial rhythm in Pinus halepensis and Pinus sylvestris as indicator for climate adaptationPeter Prislan
, Jožica Gričar
, Martin De Luis
, Klemen Novak
, Edurne Martinez Del Castillo
, Uwe Schmitt
, Gerald Koch
, Jasna Štrus
, Polona Mrak
, Magda Tušek-Žnidarič
, Katarina Čufar
Povzetek: To understand better the adaptation strategies of intra-annual radial growth in Pinus halepensis and Pinus sylvestris to local environmental conditions, we examined the seasonal rhythm of cambial activity and cell differentiation at tissue and cellular levels. Two contrasting sites differing in temperature and amount of precipitation were selected for each species, one typical for their growth and the other represented border climatic conditions, where the two species coexisted. Mature P. halepensis trees from Mediterranean (Spain) and sub-Mediterranean (Slovenia) sites, and P. sylvestris from sub-Mediterranean (Slovenia) and temperate (Slovenia) sites were selected. Repeated sampling was performed throughout the year and samples were prepared for examination with light and transmission electron microscopes. We hypothesized that cambial rhythm in trees growing at the sub-Mediterranean site where the two species co-exist will be similar as at typical sites for their growth. Cambium in P. halepensis at the Mediterranean site was active throughout the year and was never truly dormant, whereas at the sub-Mediterranean site it appeared to be dormant during the winter months. In contrast, cambium in P. sylvestris was clearly dormant at both sub-Mediterranean and temperate sites, although the dormant period seemed to be significantly longer at the temperate site. Thus, the hypothesis was only partly confirmed. Different cambial and cell differentiation rhythms of the two species at the site where both species co-exist and typical sites for their growth indicate their high but different adaptation strategies in terms of adjustment of radial growth to environmental heterogeneity, crucial for long-term tree performance and survival.
Ključne besede: Aleppo pine, Pinus halepensis, Scots pine, Pinus sylvestris, cambium, light microscopy, Mediterranean environment, temporate environment, transmission electron microscopy, xylem
DiRROS - Objavljeno: 12.07.2017; Ogledov: 1862; Prenosov: 736
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Post-fire effects on development of leaves and secondary vascular tissues in Quercus pubescensJožica Gričar
, Polona Hafner
, Martina Lavrič
, Mitja Ferlan
, Nives Ogrinc
, Bor Krajnc
, Klemen Eler
, Dominik Vodnik
Povzetek: An increased frequency of fire events on the Slovenian Karst is in line with future climate-change scenarios for drought-prone environments worldwide. It is therefore of the utmost importance to better understand tree-fire-climate interactions for predicting the impact of changing environment on tree functioning. To this purpose, we studied the post-fire effects on leaf development, leaf carbon isotope composition (%13C), radial growth patterns and the xylem and phloem anatomy in undamaged (H-trees) and fire-damaged trees (F-trees) of Q. pubescens with good re-sprouting ability in spring 2017, the growing season after a rangeland fire in August 2016. We found that the fully developed canopy of F-trees reached only half of the LAI values measured in H-trees. Throughout the season, F-trees were characterised by higher water potential and stomatal conductivity and achieved higher photosynthetic rates compared to unburnt H-trees. The foliage of F-trees had more negative %13C values than those of H-trees. This reflects that F-trees less frequently meet stomatal limitations due to reduced transpirational area and more favourable leaf-to-root ratio. In addition, the growth of leaves in F-trees relied more on the recent photosynthates than on reserves due to the fire disturbed starch accumulation in the previous season. Cambial production stopped 3 weeks later in F-trees, resulting in 60% and 22% wider xylem and phloem increments, respectively. A novel approach by including phloem anatomy in the analyses revealed that fire caused changes in conduit dimensions in the early phloem but not in the earlywood. However, premature formation of the tyloses in the earlywood vessels of the youngest two xylem increments in F-trees implies that xylem hydraulic integrity was also affected by heat. Analyses of secondary tissues showed that although xylem and phloem tissues are interlinked changes in their transport systems due to heat damage are not necessarily coordinated.
Ključne besede: pubescent oak, cambium, radial growth, xylem, phloem, anatomy, sub-Mediterranean
DiRROS - Objavljeno: 19.03.2020; Ogledov: 864; Prenosov: 399
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The efficacy, safety and tolerability of canakinumab in the treatment of familial Mediterranean fever : a systematic review of the literatureMark Kačar
, Sinisa Savic
, Jeroen CH van der Hilst
Povzetek: Familial Mediterranean Fever (FMF) is the most prevalent genetic autoinflammatory disorder. In most patients, treatment with colchicine can prevent attacks of fever and inflammation. However, 5%-10% of patients are resistant to colchicine treatment, while a similar percentage cannot tolerate colchicine in doses needed to prevent attacks. For these patients, Canakinumab, a full human antibody against IL-1[beta], has been approved recently by the FDA and EMA. In this article, we present a systematic review of the long-term efficacy, safety, and tolerability of Canakinumab in FMF patients who cannot tolerate colchicine or who are resistant to colchicine treatment.
Ključne besede: familial Mediterranean fever -- therapy -- review, amonoclonal antibodies, canakinumab, anti-IL1 therapy
DiRROS - Objavljeno: 08.04.2021; Ogledov: 28; Prenosov: 14
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