Decoding Gene Networks Modules That Explain the Recovery of Cav. After Extreme Desiccation.

(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 to better understand the genetic dynamics behind its desiccation tolerance mechanism. 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 ( / ) of 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 / (ca. 73% and 0.8, respectively). Based on clustering and network analysis, our results reveal key genes, such as , , and , orchestrating intracellular motility and photosynthetic metabolism; strong balance between avoiding cell death and defense (, ) when dehydrated, and detoxifying pathways and stabilization of photosystems (, , and ) during rehydration. Here we provide novel insights into the genetic dynamics behind the desiccation tolerance mechanism of .