Dehydration rate determines the degree of membrane damage and desiccation tolerance in bryophytes

Abstract

Desiccation tolerant (DT) organisms are able to withstand an extended loss of body water and rapidly resume metabolism upon rehydration. This ability, however, is strongly dependent on a slow dehydration rate. Fast dehydration affects membrane integrity leading to intracellular solute leakage upon rehydration and thereby impairs metabolism recovery. We test the hypothesis that the increased cell membrane damage and membrane permeability observed under fast dehydration, compared with slow dehydration, is related to an increase in lipid peroxidation. Our results reject this hypothesis because following rehydration lipid peroxidation remains unaltered, a fact that could be due to the high increase of NO upon rehydration. However, in fast-dried samples we found a strong signal of red autofluorescence upon rehydration, which correlates with an increase in ROS production and with membrane leakage, particularly the case of phenolics. This could be used as a bioindicator of oxidative stress and membrane damage.

Desiccation tolerance in the Antarctic moss Sanionia uncinata

“…Desiccation affects the fluidity and stability of organelle membranes, allowing the electron leak from the electron chain transport [1], that lead to the generation of reactive oxygen species, like singlet oxygen ( 1 O 2 ), superoxide ion (O 2 − ), hydroxyl radical (OH·) and peroxides, mainly the oxygen peroxide [7, 23]. Our results show that S. uncinata have an increase in ROS levels, but at the end of the experiment ROS return to basal levels, these are consistent with the grade of lipoperoxidation, the moss experiment a slight increase that was controlled at the 24 h of the desiccation, similar behavior was observed in the moss F. antipyretica under fast desiccation treatment [24], but they also show that a slow desiccation allows a better response by the moss, because enables the moss to engage the mechanisms against desiccation minimizing the damage.…”

A field portable method for the semi‐quantitative estimation of dehydration tolerance of photosynthetic tissues across distantly related land plants

“…B). As the desiccation treatments dried the bryophyte samples in ≤24 h, and given that recent literature indicates that slow desiccation in bryophytes occurs over several days or even weeks (Buda et al , Stark et al , Cruz de Carvalho et al , Xiao et al ), we used the nomenclature fast DT (FDT) and fast DS (FDS) to refer to the bryophyte species tested. The three RHs used successfully induced three different rates of dehydration and final water contents after 24 h (Fig.…”

“…Thus, even among DT species, rapid drying can be more damaging as it precludes sufficient time to furnish adequate protection. This general rule applies for most groups of photosynthetic DT organisms, including mosses (Cruz de Carvalho et al , Fernández‐Marín et al , Cruz de Carvalho et al ), green algae (Gasulla et al , Guéra ), lichens (Fernández‐Marín et al , Gauslaa et al ), angiosperms (Farrant et al , Fernández‐Marín et al , ) and even for DT animals, such as tardigrades (Boothby et al ). From this perspective, some differences can also be found within DT plants, with some species being able to withstand drying <30% RWC only when it is reached slowly and/or after acclimation processes (Farrant et al , Cruz de Carvalho et al , Cruz de Carvalho et al , Cruz de Cargalho et al ).…”

Dehydration survival of crop plants and its measurement

“…The corollary for a realistic phenotyping protocol of dehydration survival and its metabolic basis is sufficient time under dehydration strain, namely, slow drying. This is true for native desiccation-tolerant plants such as bryophytes ( Cruz de Carvalho et al , 2017 ) and crops such as sorghum ( Jones and Rawson, 1979 ). Although there is no set prescription, dehydration rate is related to the plant size, available soil volume, and the soil and atmospheric environment, all of which determine the rate of water loss from plants.…”