Analysis of the molecular response of the moss Pseudocrossidium replicatum to the accumulation of reactive oxygen species caused by abiotic stress
Resumen
Abiotic stress in plants leads to the buildup of reactive oxygen species (ROS) such as superoxide (O2.-), hydrogen peroxide (H2O2), hydroxyl radicals (HO.), and singlet oxygen (1O2). This accumulation causes oxidative damage to lipids, proteins, and nucleic acids, ultimately resulting in cell death. Plants have created antioxidant defence systems to combat this challenge, employing ROS-detoxifying enzymes. Pseudocrossidium replicatum, a moss classified as Fully Desiccation Tolerant (FDT), can endure swift dehydration and, after just one hour, restore its optimal photosystem II efficiency when rehydrated (Ríos-Meléndez et al., 2021). Our group has also noticed that this species exhibits significant tolerance to various stressors, such as high salinity levels (up to 800 mM NaCl) and extreme freezing temperatures (down to -80 °C). Consequently, we undertook a transcriptome analysis of this species' response to six distinct abiotic stress factors. With our 3h transcriptome data, we pinpointed important genes responsible for ROS detoxification, including catalases (CAT), peroxidases (PER), superoxide dismutase (SOD), and glutathione peroxidase (GPX), among others. We showcase experimental validation of the transcriptomes for our genes of interest through RT-qPCR, analysing their expression over various time points (15 min, 30 min, 1h, and 24h) and under conditions such as dehydration, rehydration, salinity, sorbitol, and ABA treatment. Furthermore, we conduct phylogenetic analysis by examining the genes that encode CAT, PER, and SOD across various bryophytes and plants. We introduce two distinct staining techniques to illustrate the accumulation of reactive oxygen species (especially O2.- and H2O2) in P. replicatum during the processes of dehydration and rehydration.