Tagged: desiccation

Thin-walled hydroids forming the central strand of Pleurozium schreberi.

Solute transport inside feather moss stems

Feather mosses serve as important regulatory organisms for many ecological processes in boreal forests. They are generally considered to be ectohydric species, transporting water on the surface of the plant. But is this really so? Sokołowska et al. investigate their stem tissue traits and ability to transport solutes via food-conducting cells internally under modified environmental conditions. They find that food-conducting cells that have a major role in determining internal conduction in the pleurocarpous mosses Pleurozium schreberi and Hylocomium splendens. Both P. schreberi and H. splendens are able to absorb solutes from the stem surface and transport them horizontally towards the...

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Quercus Ilex

Ecophysiology of recalcitrant seed persistence

Dominant tree species in northern temperate forests, for example oak and beech, produce desiccation-sensitive seeds. Despite the potentially major influence of this functional trait on the regeneration and distribution of species under climate change, little is currently known about the ecological determinants of the persistence of desiccation-sensitive seeds in transient soil seed banks. Knowing which key climatic and microsite factors favour seed survival will help define the regeneration niche for species whose seeds display extreme sensitivity to environmental stress. Joët et al. use the Mediterranean Holm oak (Quercus ilex) as a model system and monitor seed water status and viability...

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Dehydration rate and ROS production in an aquatic moss

Dehydration rate and ROS production in an aquatic moss

Desiccation induces an increase of reactive oxygen species (ROS) in chloroplasts, mitochondria and peroxisomes as cellular water content decreases. Cruz de Carvalho et al. examine how dehydration rate influences ROS production and cell damage in the aquatic bryophyte, Fontinalis antipyretica, through the use of confocal laser microscopy and a ROS-specific chemical probe. They find that rehydration of cells that have been dried slowly is associated with lower ROS production than in cells dried at a faster rate, thereby reducing the amount of cellular damage and increasing cell survival. They thus conclude that a slow dehydration rate may induce cell protection mechanisms...

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Is the moss calyptra covered by a cuticle?

Is the moss calyptra covered by a cuticle?

Over a century ago, the gametophytic calyptra was predicted to be covered by a cuticle that protects the sporophyte apex from desiccation. Budke et al. examine the moss Funaria hygrometrica using electron microscopy techniques and find that its calyptra is covered by a comparatively thick, multi-layered cuticle with cuticular pegs. The calyptra and its associated cuticle represent a unique form of maternal care that may have been essential for the evolution of the moss sporophyte.

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