Two Hymenophyllaceae species from contrasting natural environments exhibit a homoiochlorophyllous strategy in response to desiccation stress

First evidence of freezing tolerance in a resurrection plant: insights into molecular mobility and zeaxanthin synthesis in the dark

“…The observed decrease in F v / F m upon desiccation of R. myconi leaves was much more moderate than what has been reported for bryophytes or lichens, but is consistent with values reported for other resurrection plants; i.e. F v / F m values >0.3 were measured in dry leaves of R. serbica (Gashi et al ), R. nathaliae (Fernández‐Marín et al ), H. rhodopensis (Rapparini et al ) or Craterostigma pumilum (Charuvi et al ); and F v / F m values >0.4 were obtained in R. nathaliae (Gashi et al ) or in dry fronds of the desiccation tolerant‐fern Hymenoglossum cruentum (Flores‐Bavestrello et al ). The drop in F v / F m shown by R. myconi was accompanied by synthesis of Z, even in the dark (Fig.…”

“…The high chlorophyll content retained in the leaves of R. myconi after drying (i.e. decrease <15%) is in agreement with the homoiochlorophyllous strategy described so far for the rest of angiosperm resurrection plants, including other species of the genus Ramonda (Gashi et al 2013 (Rapparini et al 2015) or Craterostigma pumilum (Charuvi et al 2015); and F v /F m values >0.4 were obtained in R. nathaliae (Gashi et al 2013) or in dry fronds of the desiccation tolerant-fern Hymenoglossum cruentum (Flores-Bavestrello et al 2016). The drop in F v /F m shown by R. myconi was accompanied by synthesis of Z, even in the dark (Fig.…”

Changes in photosynthetic rate and stress volatile emissions through desiccation‐rehydration cycles in desiccation‐tolerant epiphytic filmy ferns (Hymenophyllaceae)

“…1–4 μmol m −2 s −1 (Parra et al, ; Parra et al, ) as was also observed in the current study in fully hydrated samples (Table , Figure ). Due to lack of stomata and water‐permeable cuticular layer, the RWC of filmy ferns rapidly decreases in dry atmospheres, resulting in concomitant reductions in foliage photosynthetic characteristics (Flores‐Bavestrello et al, ; Proctor, ; Saldaña et al, ) as observed in our study (Figure , Table ). Numerically, the rate of initial decrease in RWC and net assimilation rate ( A ) was similar in H. cruentum and H. dentatum , but RWC decreased somewhat faster than A in H. caudiculatum and H. plicatum (Figure A).…”

“…Representative images of the hydrated, desiccated, and rehydrated fronds of the four studied filmy fern species, (a) Hymenoglossum cruentum, (b) Hymenophyllum dentatum, (c) Hymenophyllum caudiculatum, and (d) Hymenophyllum plicatum. The experiment was conducted according to the protocol described in Figure 2 dentatum colonizes habitats with lower humidity and greater light intensity on tree stems between 1 and 9 m, and H. plicatum is a generalist with dispersal between 0 and 9 m (Flores-Bavestrello et al, 2016;Parra et al, 2015;Saldaña et al, 2014). We hypothesized that desiccation stress results in enhancement of stress volatile emissions and that these emissions are particularly enhanced upon rewatering.…”

“…The studied species differ in their vertical distribution in the stem of the host trees in Chilean temperate rainforest canopy. H. cruentum and H. caudiculatum colonize more humid and deeper shade habitats with their cover on tree stems extending from tree base to up to 3 m in the canopy, H. dentatum colonizes habitats with lower humidity and greater light intensity on tree stems between 1 and 9 m, and H. plicatum is a generalist with dispersal between 0 and 9 m (Flores‐Bavestrello et al, ; Parra et al, ; Saldaña et al, ). We hypothesized that desiccation stress results in enhancement of stress volatile emissions and that these emissions are particularly enhanced upon rewatering.…”