Cold stress effects on organelle ultrastructure in polar Caryophyllaceae species

Abstract

This study investigated leaf mesophyll cells of Caryophyllaceae plants growing in polar regions -Cerastium alpinum and Silene involucrata from the Hornsund region of Spitsbergen island (Svalbard Archipelago, Arctic), and Colobanthus quitensis from the Ad− miralty Bay region on King George Island (South Shetland Islands, West Antarctic). Ultra− structural changes were analyzed in mesophyll protoplasts of plants growing in natural Arctic and Antarctic habitats and plants grown in a greenhouse, including plants exposed to short−term cold stress under semi−controlled conditions. Cell organelles of plants growing in natural polar habitats and greenhouse−grown plants were characterized by significant mor− phological plasticity. Chloroplasts of plants studied in this work formed variously shaped pro− trusions and invaginations that visibly increased the contact area between adjacent cell com− partments and reduced the distance between organelles. S. involucrata plants grown under greenhouse conditions, tested by us in this work, were characterized by highly dynamic cell nuclei with single or multiple invaginations of the nuclear membrane and the presence of channels and cisternae filled with cytoplasm and organelles. Crystalline inclusion proteins were observed in the cell nuclei of C. quitensis between nuclear membranes and in the direct proximity of heterochromatin. Our study revealed significant conformational dynamics of organelles, manifested by variations in the optical density of matrices, membranes and enve− lopes, in particular in C. quitensis, which could suggest that the analyzed Caryophyllaceae taxa are well adapted to severe climate and changing conditions in polar regions.

How do vascular plants perform photosynthesis in extreme environments? An integrative ecophysiological and biochemical story

“…Although the chloroplast ultrastructure has been characterized in several high‐elevation and polar plants, few studies on warm and continental desert plants have been reported to date. Among plastidic ultrastructures, the presence of ‘chloroplast protrusions’ (broad thylakoid‐free stromal prolongations of chloroplasts, occurring mostly on the latitudinal ends of chloroplasts; Figure ; Holzinger et al , ) have been reported in a broad range of taxa, including polar and alpine species (Giełwanowska et al , , , ; Holzinger et al , ; Lütz et al , ). Cold stress has been widely related to the induction of chloroplast protrusions (Lütz, ; Lütz et al , ), although other stressors such as salinity and nutrient deficiency can also trigger the appearance of protrusions in model plants (Vismans et al , ).…”

The complete chloroplast genome ofColobanthus apetalus(Labill.) Druce: genome organization and comparison with related species

“…Colobanthus quitensis is a species of special concern as the only representative of Dicotyledoneae in the maritime Antarctic ( Skottsberg, 1954 ). Colobanthus quitensis has been extensively studied to explore the morphological, physiological and biochemical features that constitute the basis of adaptation to extreme Antarctic conditions ( Bravo et al, 2007 ; Giełwanowska et al, 2011 ; Giełwanowska et al, 2014 ; Bascunan-Godoy et al, 2012 ; Navarrete-Gallegos et al, 2012 ; Pastorczyk, Giełwanowska & Lahuta, 2014 ; Cuba-Díaz et al, 2017 ). In contrast, very little is known about the genetic diversity of this species and the genus Colobanthus ( Androsiuk et al, 2015 ; Koc et al., in press ).…”

Development of generative structures of polar Caryophyllaceae plants: the Arctic Cerastium alpinum and Silene involucrata, and the Antarctic Colobanthus quitensis

“…The key factors that inhibit the growth and development of flowering plants in polar regions are low temperature, low water availability and nutrient-poor soil (Billings 1987;Alberdi et al 2002;Block et al 2009). Other environmental hazards include high and largely unpredictable variability in temperature and moisture levels in local habitats (Bliss and Gold 1999;Jónsdóttir 2005;Convey 2012;Chwedorzewska et al 2014;Giełwanowska et al 2014.…”