AUTHOR=Ostria-Gallardo Enrique , Larama Giovanni , Berríos Graciela , Fallard Ana , Gutiérrez-Moraga Ana , Ensminger Ingo , Manque Patricio , Bascuñán-Godoy Luisa , Bravo León A. 

TITLE=Decoding Gene Networks Modules That Explain the Recovery of Hymenoglossum cruentum Cav. After Extreme Desiccation

JOURNAL=Frontiers in Plant Science

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2020.00574

DOI=10.3389/fpls.2020.00574

ISSN=1664-462X

ABSTRACT=<p><italic>Hymenoglossum cruentum</italic> (Hymenophyllaceae) is a poikilohydric, homoiochlorophyllous desiccation-tolerant (DT) epiphyte fern. It can undergo fast and frequent dehydration-rehydration cycles. This fern is highly abundant at high-humidity/low-light microenvironments within the canopy, although rapid changes in humidity and light intensity are frequent. The objective of this research is to identify genes associated to desiccation-rehydration cycle in the transcriptome of <italic>H. cruentum</italic> to better understand the genetic dynamics behind its desiccation tolerance mechanism. <italic>H. cruentum</italic> plants were subjected to a 7 days long desiccation-rehydration process and then used to identify key expressed genes associated to its capacity to dehydrate and rehydrate. The relative water content (RWC) and maximum quantum efficiency (<italic>F</italic><sub>v</sub>/<italic>F</italic><sub>m</sub>) of <italic>H. cruentum</italic> fronds decayed to 6% and 0.04, respectively, at the end of the desiccation stage. After re-watering, the fern showed a rapid recovery of RWC and <italic>F</italic><sub>v</sub>/<italic>F</italic><sub>m</sub> (ca. 73% and 0.8, respectively). Based on clustering and network analysis, our results reveal key genes, such as <italic>UBA/TS-N</italic>, <italic>DYNLL</italic>, and <italic>LHC</italic>, orchestrating intracellular motility and photosynthetic metabolism; strong balance between avoiding cell death and defense (<italic>CAT3</italic>, <italic>AP2/ERF</italic>) when dehydrated, and detoxifying pathways and stabilization of photosystems (<italic>GST</italic>, <italic>CAB2</italic>, and <italic>ELIP9</italic>) during rehydration. Here we provide novel insights into the genetic dynamics behind the desiccation tolerance mechanism of <italic>H. cruentum</italic>.</p>