The effect of ultraviolet radiation on cellular ultrastructure and photosystem II quantum yield of Alaria esculenta (L.) Greville from Spitsbergen (Norway)

Ecosystem Kongsfjorden: new views after more than a decade of research

“…Effects of both physical and biological factors have been considered the papers below. Lütz et al (2015) investigated the effect of UV radiation (UVR) on cell ultrastructure and photosynthetic activity in the kelp Alaria esculenta. UVR leads primarily to disruptions and dilations of chloroplast thylakoid membranes.…”

Structural stress responses and degradation of dictyosomes in algae analysed by TEM and FIB‐SEM tomography

“…Stress-induced physiological deficiencies of these organelles are reflected in structural alterations mostly determined by two-dimensional (2-D) transmission electron microscopic (TEM) analyses. Dilations of thylakoid membranes, decrease of grana stacks, increase or decrease of starch accumulation and formation of vacuolar structures are the most frequently reported structural stress reactions in the chloroplast (Hollosy, 2002;Holzinger & Lütz, 2006;Andosch et al, 2012;Lütz et al, 2015). Bloating of mitochondria and coinciding reduction of the number of abnormally elongated cristae is a typical structural hallmark of stress and/or programmed cell death (PCD) that can be found commonly both in plant (Gunawardena et al, 2001;Kolb et al, 2004;Scott & Logan, 2008) and animal cells (Muriel et al, 2000;Klein et al, 2011).…”

Kelps and Environmental Changes in Kongsfjorden: Stress Perception and Responses

“…Already 50 years ago electron microscopy was used to describe cellular features of brown algae, firstly from temperate regions (Bouck 1965). However, to our knowledge, detailed analyses of cellular structures of kelp thalli from Kongsfjorden have been made only for S. latissima (Hanelt et al 1997;Holzinger et al 2011) and A. esculenta (Lütz et al 2016). In case of Laminaria hyperborea from Helgoland (Steinhoff et al 2008) and S. latissima from Kongsfjorden (Steinhoff et al 2011a), the ultrastructural features of zoospores and developing gametophytes have been characterized.…”

“…proteins and other constituents. A light microscopic overview for A. esculenta is given in Lütz et al (2016) showing the typical anatomical structure of leathery thalli of brown algae. A similar tissue organization can be found in S. latissima from Kongsfjorden (Holzinger et al 2011), but also in Ecklonia radiata from Australia (Lüder and Clayton 2004) or Sargassum cymosum from Brazil (Polo et al 2014).…”

“…Under exposure to elevated UVA plus UVB radiation only chloroplasts show a response in ultrastructure, while all other cell organelles remain unchanged at least in membrane appearance (Holzinger and Lütz 2006;Holzinger et al 2011;Lütz et al 2016). An example of disturbed thylakoid structure under PAR+UVA/B is given in Fig.…”